JP5591141B2 - Control valve type lead storage battery manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a control valve type lead-acid battery, and more specifically, a positive electrode plate and a negative electrode plate containing carbon are alternately stacked via a retainer mat to form an electrode plate group, and the electrode plate The present invention relates to a method for manufacturing a control valve type lead-acid battery in which a group is housed in a battery case under high pressure, and then a dilute sulfuric acid electrolyte is injected to form a battery case.

Lead storage batteries can be broadly classified into two types: liquid lead storage batteries and control valve type lead storage batteries. Among them, the valve-regulated lead-acid battery is formed by alternately laminating a positive electrode plate and a negative electrode plate formed by filling a substrate mainly composed of lead with an active material paste through a mat-like separator mainly composed of fine glass fibers, Next, the electrode plate group is formed by welding the ears of the electrode plates of the same polarity to each other by welding, and the electrode plate group is stored in the battery case in a compressed state. The lid having the opening is welded or adhered with an adhesive, and the electrolytic solution is injected so that the liquid surface height is about 110% of the electrode plate group height excluding the electrode plate ear from this opening, Subsequently, the battery case is formed, and finally, a rubber valve (control valve) is covered with an opening for pouring and exhausting. The control valve type lead-acid battery manufactured in this way is a lead-acid battery that does not require rehydration by absorbing oxygen generated at the positive electrode at the time of overcharging and is sealed, and is variously maintenance-free. It is used in various fields.

In recent years, control valve type lead-acid batteries that do not require replenishment of replenishing liquid are becoming mainstream from the viewpoint of maintenance-free, and the diffusion rate is rapidly expanding. Improvements are also being made to withstand cycle use that repeats deep charging and discharging for power storage, electric vehicles, etc., rather than for float use such as backup of communication equipment, uninterruptible power supply systems, and the like. In such cycle use applications, the lead-acid battery often reaches the end of its life due to softening and mudification of the positive electrode active material. In order to suppress this and improve the adhesion between the lattice and the active material, the electrode plate group is inserted into the battery case in a compressed state of about 40 kPa.

In addition, in the case where electricity obtained from natural energy such as sunlight and wind power is stored in a storage battery, a partially charged state (PSOC; Partial)
Since the cycle is often repeated in the state of charge), the lead-acid battery may reach the end of its life due to sulfation of the negative electrode active material. For this reason, in order to improve the charge acceptance of the negative electrode, a conductive material such as carbon may be added to the negative electrode.

When carbon is added to the negative electrode plate of a lead-acid battery, depending on the amount added, carbon is discharged together with gas from the surface of the negative electrode plate, especially from the cracks on the surface when hydrogen gas is generated during charging by battery case formation, and comes into contact with this. It tends to flow out to the separator surface. Further, carbon that has flowed out to the separator surface may penetrate into the separator and cause an internal short circuit.

As a countermeasure, a separator mainly composed of glass fiber, which is a sealed lead-acid battery separator (Patent Document 1) obtained by mixing glass fiber, silica powder and silica sol, and granular silica-type sealed lead-acid battery In US Pat. No. 6,053,059, a carbon material in which 0.5 to 5.0 mass% of the amount of the negative electrode active material is added to the negative electrode active material is proposed (Patent Document 2).

However, when the separator described in Patent Document 1 is used, the separator becomes hard because a large amount of silica is present in the glass fiber, and when the electrode plate group is formed, the formed electrode plate group is placed in the battery case. There are problems such as difficulty in handling and storage of a small amount of electrolyte solution. On the other hand, it is conceivable to increase the thickness of the separator. However, if the thickness of the separator is significantly increased in a limited volume battery case, the number of electrode plates will be reduced, resulting in insufficient capacity. Is not realistic. Even if the thickness of the separator can be increased slightly, the effect is not sufficient. Further, when a relatively hard separator having excellent short circuit resistance is used, there is a problem that cycle performance is not good.

Although the method described in Patent Document 2 shows an improvement in charge acceptability, when the formation at the time of producing a lead-acid battery is performed in a battery case, the added carbon is removed from the negative electrode plate by the generated hydrogen gas. There was a problem that it flowed into the separated electrolyte and floated upward, and as a result, carbon entered the separator and eventually caused a short circuit.

Therefore, the applicant of the present invention is a positive electrode plate obtained by filling a lattice substrate made of lead or a lead alloy with a paste-like active material, and a lattice substrate made of lead or a lead alloy and filled with a paste-like active material containing carbon. An electrode plate group is formed by laminating a negative electrode plate with a retainer mat mainly made of glass fiber, and then the electrode plate group is stored in a battery case at a group pressure of 40 to 100 kPa. In the manufacturing method of a control valve type lead-acid battery in which dilute sulfuric acid electrolyte solution is injected into the battery case after sealing and then formed into a battery case, and then replenished and recharged. 1) Rare after cover closure The amount of sulfuric acid electrolyte injected is 95 to 105% of the plate group height excluding the electrode tabs. 2) After the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100% The charging current until the amount of charge with respect to the theoretical capacity of the positive electrode active material reaches 100% And the positive electrode plate total surface area relative to the 4.5 mA / cm ² or less, 3) then performs the charging, 4) replacement fluid, proposed a method for manufacturing valve-regulated lead-acid battery, characterized in that the auxiliary charge (Patent Document 3) . According to this method, the outflow of carbon could be reduced as much as possible, and therefore the short circuit could be greatly reduced.

However, in the case of battery case formation, an electrode group is composed of unformed electrode plates, a battery is assembled, a specific gravity and a predetermined amount of sulfuric acid are injected into the battery case, and formation is performed in a short time with a large current. It is common. At this time, since the conversion is carried out with a large current, the battery heat generation at the initial stage of formation and at the end of the conversion stage becomes intense, so further improvement such as suppressing the heat generation of the battery itself at the time of battery case formation and improving the formation efficiency. Is desired.

JP-A-7-29560 JP-A-6-283176 JP 2008-171709 A

The present invention provides a control valve type lead that has no carbon outflow and good conversion efficiency and has a remarkably long cycle life even when a battery is formed by laminating a group of electrode plates containing carbon on the negative electrode at high pressure. A method for manufacturing a storage battery is provided.

The present inventors tried various studies to further improve the invention described in Patent Document 3. As a result, in the invention described in Patent Document 3, the liquid injection amount of the dilute sulfuric acid electrolyte was determined based on the height of the electrode plate group. If the change is made so that it is determined based on the amount of dilute sulfuric acid electrolyte to be impregnated, the effect is more realistic and accurate because it is related to the amount of dilute sulfuric acid electrolyte actually present in the electrode group. I came up with the idea that it could be expressed. And when the injection amount of the dilute sulfuric acid electrolyte is set to the following predetermined 75 to 95% based on the liquid occupancy rate in the electrode plate group, a better result is obtained as compared with the invention described in Patent Document 3 above. I found out. Further, in the invention described in Patent Document 3, the current during battery formation is set such that the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100% and the charge amount with respect to the theoretical capacity of the positive electrode active material reaches 100%. It was specified by the maximum charging current until it reached. When the battery formation is performed under such conditions, the negative electrode potential starts to rise from around 90% of the charge amount with respect to the theoretical capacity of the negative electrode active material, and when the charge amount reaches 100%, hydrogen gas starts to be generated (sulfuric acid first When the dimercury electrode is used as a reference electrode, the hydrogen generation potential is about -1.5 V). When the charge amount reaches 100%, when charging with the current value according to the invention described in Patent Document 3 described above, the charge amount is more likely to change at a hydrogen gas generation potential or higher, and the charge amount with respect to the theoretical capacity of the positive electrode active material is small. From where it exceeds 100%, it becomes higher than the hydrogen gas generation potential. Therefore, considering the entire period of battery case formation, it was estimated that the amount of gas generated could not be sufficiently suppressed, and the carbon outflow was relatively large as a whole. Therefore, the present inventors conducted a preliminary experiment and extracted and disassembled the retainer mat at various charge amounts with respect to the theoretical capacity of the negative electrode active material. As a result, the charge amount with respect to the theoretical capacity of the negative electrode active material reached 100% . After that , the outflow of carbon was observed until the amount of charge with respect to the theoretical capacity of the positive electrode active material reached 200%. That is, the present inventors considered that it is necessary to further suppress the carbon outflow within the range of the charge amount in order to improve the invention described in Patent Document 3.

Therefore, the inventors of the present invention have conventionally used a current during battery formation until the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100% until the charge amount with respect to the theoretical capacity of the positive electrode active material reaches 100%. The maximum charge current during the period was limited, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reached 100%, the amount of charge with respect to the theoretical capacity of the positive electrode active material was 200%. When the value is defined as the maximum current of the charging current until reaching the value of 1.0 mA / cm ² or less as described below, the effect is also compared with the invention described in Patent Document 3 above. We have found that better results can be obtained. In addition, the present inventors thought that when the battery temperature during battery case formation rises, the current is consumed for the generation of hydrogen gas and the like, which eventually promotes the outflow of carbon. Therefore, a new requirement that is not found in the invention described in Patent Document 3, that is, the battery temperature at the time of battery case formation, is added to the above two requirements, and is significantly better than the invention described in Patent Document 3. The inventors have found that the results can be obtained and have completed the present invention.

That is, the present invention
(1) A positive electrode plate obtained by filling a lattice substrate made of lead or a lead alloy with a paste-like active material, and a negative electrode plate made by filling a lattice substrate made of lead or a lead alloy with a paste-like active material containing carbon. Then, the electrode plate group is formed by laminating through a retainer mat mainly composed of glass fiber, and then the electrode plate group is stored in a battery case with a group pressure of 40 to 100 kPa, and the lid is sealed. In the method for producing a control valve type lead-acid battery, a dilute sulfuric acid electrolyte solution is injected into the battery case to form a battery case, and then the replenishment solution and the auxiliary charge are performed.
1) The amount of the diluted sulfuric acid electrolyte injected is set to 75 to 95% of the liquid occupation ratio in the electrode plate group,
2) In the battery case formation, the charging current from when the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100% until the charge amount with respect to the theoretical capacity of the positive electrode active material reaches 200% 3. A method for producing a valve-regulated lead-acid battery, wherein the battery temperature is 1.0 mA / cm ² or less with respect to the surface area, and 3) the battery temperature during battery case formation is suppressed to 30 to 45 ° C. It is.

As a preferred embodiment,
(2) The manufacturing method of the control valve type lead acid battery according to (1), wherein the injection amount of 1) is 80 to 85% of the liquid occupancy in the electrode plate group,
(3) The method for producing a control valve type lead-acid battery according to (1) or (2), wherein the charging current of 2) is 0.1 to 1.0 mA / cm ² .
(4) The method for producing a valve-regulated lead-acid battery according to (1) or (2), wherein the charging current of 2) is 0.3 to 1.0 mA / cm ² .
(5) The method for producing a control valve-type lead-acid battery according to any one of (1) to (4), wherein the battery temperature in 3) is suppressed to 32 to 45 ° C.
(6) The method for producing a control valve type lead-acid battery according to any one of (1) to (4), wherein the battery temperature of 3) is suppressed to 36 to 43 ° C.
(7) The method for producing a control valve type lead storage battery according to any one of (1) to (6), wherein the group pressure of the electrode plate group is 40 to 70 kPa,
(8) Any of the above (1) to (7), wherein the amount of carbon contained in the pasty active material filled in the negative electrode plate is 0.1 to 5.0% by mass relative to the amount of the negative electrode active material A method for producing a control valve type lead-acid battery according to one of the above,
(9) Any of the above (1) to (7), wherein the amount of carbon contained in the pasty active material filled in the negative electrode plate is 0.2 to 2.0 mass% with respect to the amount of the negative electrode active material. A method for producing a control valve type lead-acid battery according to one of the above,
(10) Any of the above (1) to (7), wherein the amount of carbon contained in the pasty active material filled in the negative electrode plate is 0.5 to 2.0 mass% with respect to the amount of the negative electrode active material. The manufacturing method of the control valve type lead acid battery as described in one can be mentioned.

According to the control valve type lead-acid battery manufacturing method of the present invention, by controlling the injection amount of dilute sulfuric acid electrolyte to 75 to 95% of the liquid occupancy rate of the electrode plate group, carbon outflow due to generation of hydrogen gas can be suppressed. Is possible.

In addition, the charging current is set to a predetermined value during the latter half of the battery formation, that is, from when the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100% until the charge amount with respect to the theoretical capacity of the positive electrode active material reaches 200%. By controlling the value, the generation of hydrogen gas is suppressed, and the liquid occupancy in the electrode plate group is controlled to expose the negative electrode plate surface, thereby promoting the absorption of oxygen gas generated at the positive electrode at the negative electrode. Thus, the negative electrode potential can be lowered below the hydrogen generation potential, and in addition, the battery temperature is suppressed to 45 ° C. at the maximum. As a result, carbon outflow associated with the generation of hydrogen gas, and elution and floating of carbon in the electrolytic solution can be prevented, and formation at a high temperature can be achieved throughout the battery case formation.

Therefore, the control valve type lead acid battery manufactured by the method of the present invention has no internal short circuit, and according to the method of the present invention, the control valve type lead acid battery can be efficiently manufactured. Instead, it is possible to produce a control valve type lead-acid battery having a significantly long cycle life.

In the method for producing a control valve type lead storage battery of the present invention, during the formation of the battery case, 1) the injection amount of the dilute sulfuric acid electrolyte solution into the battery case is 75 to 95% of the liquid occupancy rate in the electrode plate group, preferably 80-85%. When the above upper limit is exceeded, most of the electrode plate group is immersed in the electrolyte until immediately before the end of the battery case formation, and the negative electrode absorption of oxygen gas generated from the positive electrode during charging is inhibited. Therefore, the negative electrode potential shifts to the hydrogen generation potential, and the hydrogen gas generation period during the formation of the battery case is lengthened, so that carbon may easily flow out. In addition, when most of the electrode plate group is immersed in the electrolytic solution, the formation is completed while the carbon is likely to be eluted and floated, so that there is a possibility that the carbon is likely to ooze out to the separator due to gas generation. On the other hand, if the amount is less than the above lower limit, the negative electrode absorption amount of oxygen gas generated from the positive electrode during charging increases, leading to an increase in battery temperature, which may adversely affect battery characteristics. Here, the liquid occupancy ratio in the electrode plate group is a ratio of the amount of electrolyte actually held in the electrode plate group when the total amount of electrolyte solution that can be held in the electrode plate group is 100%. It is a thing.

In the method for producing a control valve type lead storage battery of the present invention, 2) after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge amount with respect to the theoretical capacity of the positive electrode active material is 200%. Until the charging current reaches 1.0 mA / cm ^{2 with} respect to the total surface area of the positive electrode plate. When the above upper limit is exceeded, the current is more easily consumed for gas generation than chemical conversion, so that the outflow of carbon cannot be suppressed and the temperature rise cannot be suppressed. The lower limit of the charging current is better, but if the current is too low, the charging time becomes longer and the production efficiency becomes worse. Therefore, the lower limit is preferably 0.1 mA / cm ² , more preferably 0.3 mA / cm ² in consideration of the balance with production efficiency. Here, the total surface area of the positive electrode plate is the total area of the front and back surfaces of the positive electrode plate, excluding the areas of the ears and feet of the positive electrode plate, and the area of the peripheral side surface (up and down, left and right) in the thickness direction of the positive electrode plate. This is a product of the number of positive plates.

Moreover, in the manufacturing method of the control valve type lead acid battery of this invention, 3) The battery temperature at the time of battery case formation is restrained to 30-45 degreeC, Preferably it is 32-45 degreeC, More preferably, it is 36-43 degreeC. Thereby, battery case formation can be carried out efficiently, and the outflow of carbon can be suppressed by preventing gas generation from the negative electrode. Outside the above range, the chemical conversion efficiency decreases, which is not preferable. For example, when chemical conversion is performed at a conventional current value and the battery temperature is 60 ° C. or higher, chemical conversion efficiency is significantly reduced.

According to the method of the present invention, a positive electrode plate formed by filling a lattice substrate made of lead or a lead alloy with a paste-like active material, and a lattice plate made of lead or a lead alloy are filled with a paste-like active material containing carbon. After forming the electrode plate group by laminating the negative electrode plate and the retainer mat mainly made of glass fiber, the electrode plate group is then housed in the battery case under high pressure and the lid is sealed. Then, as described above, a dilute sulfuric acid electrolyte is injected into the battery case to form a battery case, and then a control valve type lead-acid battery is manufactured by replenishing and replenishing the solution. Here, the electrode plate group is stored in the battery case while the electrode plate group is held in a high pressure state, that is, 40 to 100 kPa, preferably 40 to 70 kPa. If it is less than the lower limit, the effect of suppressing the softening of the positive electrode active material is weakened.On the other hand, if the upper limit is exceeded, it becomes difficult to insert the electrode plate group into the battery case, and the distance between the positive electrode plate and the negative electrode plate is small. Shortened and easier to short circuit.

In the present invention, a positive electrode plate obtained by filling a lattice substrate made of lead or a lead alloy with a paste-like active material, a negative electrode plate made by filling a lattice substrate made of lead or a lead alloy with a paste-like active material containing carbon, and As the retainer mat mainly composed of glass fiber, a known mat manufactured by a known method can be used. Here, the amount of carbon contained in the paste-like active material filled in the negative electrode plate is preferably 0.1 to 5.0% by mass, more preferably 0.2 to 2.0% with respect to the amount of the negative electrode active material. It is 0.5 mass%, More preferably, it is 0.5-2.0 mass%. If the above upper limit is exceeded, the outflow of carbon during battery case formation may not be sufficiently suppressed, and the strength of the negative electrode active material may decrease, causing the active material to fall off the negative electrode and causing a short circuit. On the other hand, if it is less than the above lower limit, the charge acceptability of the negative electrode cannot be sufficiently improved. In addition, these positive and negative plates are alternately laminated via a retainer mat in accordance with a conventional method to form a plate group, and are incorporated into a battery case with the above group pressure, and the same polarity ear group is strapped by a conventional method. At the same time as welding, the positive electrode and the negative electrode terminal are formed, and the battery case and the lid are welded. Then, the dilute sulfuric acid electrolyte is injected as described above, and the battery case is formed with the predetermined charging current. A control valve type lead-acid battery is manufactured by supplementing the electrolytic solution so as to be a target liquid amount, for example, 110% of the height of the electrode plate group, and performing supplementary charging.

In the following examples, the present invention will be described in more detail, but the present invention is not limited to these examples.

In the examples and comparative examples, the degree of carbon outflow, the formation state of the end plate and the cycle life test were evaluated as follows.

<Degree of carbon spill>
Remove the retainer mat from each control valve type lead-acid battery manufactured, cut it in the thickness direction, visually observe the cross section, and how much carbon flows out from the negative electrode to the positive electrode in the thickness direction of the retainer mat It was evaluated depending on whether it was doing. Each symbol shown in Tables 1 to 3 represents the following contents.
A: No carbon outflow in the retainer mat.
○: Carbon outflow was observed within 20% of the retainer mat thickness.
Δ: Carbon outflow was observed within 50% exceeding 20% of the retainer mat thickness.
X: Carbon outflow was observed exceeding 50% of the retainer mat thickness.

<Formation of end plate>
The end plate in the present invention means a plate located at both ends of the plate group. Here, the negative plate is an end plate. The formation state of the end electrode plate, that is, the negative electrode plate was evaluated by the amount of PbSO ₄ . PbO and PbSO ₄ are quantified by chemical analysis, and the ratio of metallic lead (Pb), which is the active metal of the lead acid battery, is calculated from [100% − (PbO + PbSO ₄ )]. As a result, it is possible to know how much PbSO ₄ has been reduced to Pb by chemical conversion. Therefore, the chemical conversion state can be evaluated by the amount of PbSO _{4 in} the negative electrode plate.

PbSO ₄ chemical analysis methods: the negative electrode active material specified amount collected, dissolved in 5% acetic acid, then separated into filtrate and the filtrate subjected to gradient filtration. PbO is dissolved in this filtrate. Further, the filtrate is heated and dissolved using ammonium acetate, and separated into a filtrate and a filtrate by tilt filtration. Included in this filtrate is PbSO _4. For the determination of PbO and PbSO ₄ contained in the filtrate, EDTA (ethylenediaminetetraacetic acid: Ethylene) was used.
This was performed using a titration analysis by Diamin Tetraacetic Acid). Each symbol shown in Tables 1 to 3 represents the following contents.
[Formation state]
◎: PbSO ₄ content less than 5% ○: PbSO ₄ content 5% or more but less than 10% Δ: PbSO ₄ content 10% or more but less than 20% ×: PbSO ₄ content 20% or more

<Cycle life test>
The test condition of the valve-regulated lead-acid battery is DOD (Depth) at 0.25 CA from SOC 100% in an environment of 25 ° C.
Of Discharge (depth of discharge) 70% of discharge was performed, and then 104% of the discharge capacity was charged with 0.1 CA, which was defined as one cycle. Further, the capacity test of the control valve type lead-acid battery was performed every 50 cycles in the same manner as the above test conditions, and when the capacity was reduced to 70% with respect to the initial capacity, the life was defined. Each symbol shown in Tables 1 to 3 represents the following contents.
[Number of cycles]
◎: 2,500 cycles or more ◯: 2,000 cycles or more and less than 2,500 cycles Δ: 1,000 cycles or more and less than 2,000 cycles ×: Less than 1,000 cycles

Example 1
A positive electrode active material paste prepared in accordance with a conventional method was filled into a lattice substrate mainly composed of lead as a positive electrode plate. On the other hand, a negative electrode active material paste obtained by adding 1.0% by mass of carbon to the amount of the negative electrode active material is added to a negative electrode active material paste prepared according to a conventional method for a grid substrate mainly composed of lead for the negative electrode plate. Filled. Subsequently, these were aged and dried according to a conventional method to produce an unformed positive electrode plate and negative electrode plate, respectively. These 9 positive plates and 10 negative plates are laminated alternately via retainer mats made mainly of paper fibers, and the ears of the plates of the same polarity are connected by welding. Groups were formed. The theoretical capacity of the positive electrode active material at this time was 1.5 times the theoretical capacity of the negative electrode active material. Next, the electrode plate group was assembled in a battery case under a high pressure of 40 kPa. Next, after the battery case and the lid were welded, a predetermined amount of dilute sulfuric acid electrolyte was injected so that the liquid occupation ratio in the electrode plate group would be 75%. Then, until the charging amount with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charging current with respect to the total surface area of the positive electrode plate is set to 5.3 mA / cm ² , and then the charging amount with respect to the theoretical capacity of the negative electrode active material is 100 From reaching the%, until the amount of charge with respect to the theoretical capacity of the positive electrode active material reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was set to 1.0 mA / cm ² . During energization, the battery temperature was measured, and air cooling was performed as necessary so that the battery temperature was in the range of 30 ° C to 45 ° C. After the chemical conversion is completed, the electrolyte solution is replenished so that the amount of the electrolyte solution becomes 110% of the target solution amount, that is, the height of the electrode plate group, and the charge amount with respect to the theoretical capacity of the positive electrode active material becomes 1%. The auxiliary charge was carried out to produce a 2V-200 Ah control valve type lead acid battery. About the control valve type lead acid battery manufactured in this way, the extent of carbon outflow, the formation state of the end plate, and the cycle life were evaluated. Here, the measurement of the said battery temperature stuck the thermocouple in the center part of the battery case side surface, and performed the measurement at any time. In addition, the liquid occupancy rate, the electrode plate dimensions of the positive and negative electrode plates, the electrode plate volume (here, the electrode plate volume is an apparent volume and includes holes. The volume (volume) of the holes is Void volume = apparent volume (vertical × horizontal × thickness) −actual volume, and the actual volume can be determined by, for example, the amount of water that has risen when submerged in water). Calculate the pore volume contained in the plate, calculate the pore volume contained in the separator for each separator from the size and compression ratio of the separator, calculate the sum of the pore volumes of both, and calculate all When the amount of electrolyte solution that fills the pore volume was injected, the liquid occupation ratio was set to 100%. When injecting before forming the battery case, the amount of the electrolyte to be injected was determined so that the liquid occupation ratio would be 75%.

(Example 2)
The charging current with respect to the total surface area of the positive electrode plate is 0.5 mA / cm ² until the charging amount with respect to the theoretical capacity of the positive electrode active material reaches 200% after the charging amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. The same operation as in Example 1 was performed except that power was supplied.

(Example 3)
The charging current with respect to the total surface area of the positive electrode plate is set to 0.3 mA / cm ² until the charging amount with respect to the theoretical capacity of the positive electrode active material reaches 200% after the charging amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. The same operation as in Example 1 was performed except that power was supplied.

Example 4
From the time when the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100% until the charge amount with respect to the theoretical capacity of the positive electrode active material reaches 200%, the charge current with respect to the total surface area of the positive electrode plate is set to 0.1 mA / cm ^2. The same operation as in Example 1 was performed except that power was supplied.

(Example 5)
The charging current with respect to the total surface area of the positive electrode plate is 0.05 mA / cm ² until the charging amount with respect to the theoretical capacity of the positive electrode active material reaches 200% after the charging amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. The same operation as in Example 1 was performed except that power was supplied.

(Example 6)
The same operation as in Example 1 was carried out except that a predetermined amount of dilute sulfuric acid electrolyte was injected so as to be 80% of the liquid occupation ratio in the electrode plate group.

(Example 7)
A predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy rate in the electrode plate group is 80%, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.5 mA / cm ² .

(Example 8)
A predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy rate in the electrode plate group is 80%, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same procedure as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.3 mA / cm ² .

Example 9
A predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy rate in the electrode plate group is 80%, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set at 0.1 mA / cm ² .

(Example 10)
A predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy rate in the electrode plate group is 80%, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.05 mA / cm ² .

(Example 11)
The same operation as in Example 1 was performed except that a predetermined amount of dilute sulfuric acid electrolyte was injected so as to be 85% of the liquid occupation ratio in the electrode plate group.

(Example 12)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupancy ratio in the electrode plate group, and the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.5 mA / cm ² .

(Example 13)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupancy ratio in the electrode plate group, and the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. Until the amount reached 200%, the same procedure as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.3 mA / cm ² .

(Example 14)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupancy ratio in the electrode plate group, and the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set at 0.1 mA / cm ² .

(Example 15)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupancy ratio in the electrode plate group, and the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.05 mA / cm ² .

(Example 16)
The same operation as in Example 1 was carried out except that a predetermined amount of dilute sulfuric acid electrolyte was injected so as to be 90% of the liquid occupation ratio in the electrode plate group.

(Example 17)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 90% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.5 mA / cm ² .

(Example 18)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 90% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same procedure as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.3 mA / cm ² .

(Example 19)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 90% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set at 0.1 mA / cm ² .

(Example 20)
The same operation as in Example 1 was performed except that a predetermined amount of dilute sulfuric acid electrolyte was injected so as to be 95% of the liquid occupation ratio in the electrode plate group.

(Example 21)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 95% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.5 mA / cm ² .

(Example 22)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 95% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same procedure as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set to 0.3 mA / cm ² .

(Example 23)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 95% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same operation as in Example 1 was performed except that the charging current with respect to the total surface area of the positive electrode plate was set at 0.1 mA / cm ² .

(Example 24)
The electrode group is assembled in a battery case under a high pressure of 60 kPa, a predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy of the electrode group is 85%, and the charge amount relative to the theoretical capacity of the negative electrode active material is The same as Example 1 except that the charging current with respect to the total surface area of the positive electrode plate was set at 0.5 mA / cm ² until the charging amount with respect to the theoretical capacity of the positive electrode active material reached 200% after reaching 100%. Implemented.

(Example 25)
The electrode group is assembled in a battery case under a high pressure of 80 kPa, a predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupation ratio in the electrode group, and the charge amount with respect to the theoretical capacity of the negative electrode active material is The same as Example 1 except that the charging current with respect to the total surface area of the positive electrode plate was set at 0.5 mA / cm ² until the charging amount with respect to the theoretical capacity of the positive electrode active material reached 200% after reaching 100%. Implemented.

(Example 26)
The electrode plate group is assembled in a battery case under a high pressure of 100 kPa, a predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy of the electrode plate group is 85%, and the charge amount with respect to the theoretical capacity of the negative electrode active material is The same as Example 1 except that the charging current with respect to the total surface area of the positive electrode plate was set at 0.5 mA / cm ² until the charging amount with respect to the theoretical capacity of the positive electrode active material reached 200% after reaching 100%. Implemented.

(Comparative Example 1)
The same procedure as in Example 1 was performed except that a predetermined amount of dilute sulfuric acid electrolyte was injected so as to be 70% of the liquid occupancy ratio in the electrode plate group, and the battery temperature was heated to exceed 45 ° C. during energization. .

(Comparative Example 2)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 70% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same procedure as in Example 1 was performed, except that the charging current with respect to the total surface area of the positive electrode plate was 1.5 mA / cm ² .

(Comparative Example 3)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 70% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was energized as 1.5 mA / cm ^{2 and} during the energization, except for forced cooling by water cooling so that the battery temperature was less than 30 ° C. Performed identically to Example 1.

(Comparative Example 4)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 70% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was applied as 1.5 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during the application. Implemented.

(Comparative Example 5)
A predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy rate in the electrode plate group is 80%, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same procedure as in Example 1 was performed, except that the charging current with respect to the total surface area of the positive electrode plate was 1.5 mA / cm ² .

(Comparative Example 6)
A predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy rate in the electrode plate group is 80%, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was applied as 1.5 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during the application. Implemented.

(Comparative Example 7)
A predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy rate in the electrode plate group is 80%, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was set to 1.0 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during the energization. Implemented.

(Comparative Example 8)
A predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy rate in the electrode plate group is 80%, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was energized as 0.5 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during energization. Implemented.

(Comparative Example 9)
A predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy rate in the electrode plate group is 80%, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was set to 0.05 mA / cm ² , and during the energization, except for forced cooling by water cooling so that the battery temperature was less than 30 ° C., The same operation as in Example 1 was performed.

(Comparative Example 10)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupancy ratio in the electrode plate group, and the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was set at 0.1 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during the energization. Implemented.

(Comparative Example 11)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupancy ratio in the electrode plate group, and the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was set to 0.3 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during the energization. Implemented.

(Comparative Example 12)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupancy ratio in the electrode plate group, and the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was energized as 0.5 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during energization. Implemented.

(Comparative Example 13)
Example 1 Except for injecting a predetermined amount of dilute sulfuric acid electrolyte so as to be 85% of the liquid occupancy ratio in the electrode plate group, and forcibly cooling by water cooling so that the battery temperature is less than 30 ° C. during energization. It carried out identically.

(Comparative Example 14)
The same procedure as in Example 1 was performed, except that a predetermined amount of dilute sulfuric acid electrolyte was injected so as to be 85% of the liquid occupancy in the electrode plate group, and the battery temperature was heated to exceed 45 ° C. during energization. .

(Comparative Example 15)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupancy ratio in the electrode plate group, and the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was applied as 1.5 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during the application. Implemented.

(Comparative Example 16)
The same procedure as in Example 1 was performed except that a predetermined amount of dilute sulfuric acid electrolyte was injected so as to be 95% of the liquid occupancy in the electrode plate group, and the battery temperature was heated to exceed 45 ° C. during energization. .

(Comparative Example 17)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 95% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was applied as 1.5 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during the application. Implemented.

(Comparative Example 18)
Example 1 Except for injecting a predetermined amount of dilute sulfuric acid electrolyte so as to be 105% of the liquid occupancy in the electrode plate group, and forcibly cooling by water cooling so that the battery temperature is less than 30 ° C. during energization. It carried out identically.

(Comparative Example 19)
The same procedure as in Example 1 was performed except that a predetermined amount of dilute sulfuric acid electrolyte was injected so as to be 105% of the liquid occupancy ratio in the electrode plate group, and the battery temperature was heated to exceed 45 ° C. during energization. .

(Comparative Example 20)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 105% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was energized as 1.5 mA / cm ² , and during the energization, forcibly cooled by water cooling so that the battery temperature was less than 30 ° C., The same operation as in Example 1 was performed.

(Comparative Example 21)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 105% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reached 200%, the same procedure as in Example 1 was performed, except that the charging current with respect to the total surface area of the positive electrode plate was 1.5 mA / cm ² .

(Comparative Example 22)
A predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 105% of the liquid occupancy ratio in the electrode plate group, and after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100%, the charge with respect to the theoretical capacity of the positive electrode active material is charged. Until the amount reaches 200%, the charging current with respect to the total surface area of the positive electrode plate was applied as 1.5 mA / cm ² , and the same as Example 1 except that the battery temperature was heated to exceed 45 ° C. during the application. Implemented.

(Comparative Example 23)
The electrode group is assembled in a battery case under a high pressure of 20 kPa, a predetermined amount of dilute sulfuric acid electrolyte is injected so as to be 85% of the liquid occupancy in the electrode group, and the charge amount with respect to the theoretical capacity of the negative electrode active material is The same as Example 1 except that the charging current with respect to the total surface area of the positive electrode plate was set at 0.5 mA / cm ² until the charging amount with respect to the theoretical capacity of the positive electrode active material reached 200% after reaching 100%. Implemented.

(Comparative Example 24)
The electrode group is assembled in a battery case under a high pressure of 120 kPa, a predetermined amount of dilute sulfuric acid electrolyte is injected so that the liquid occupancy of the electrode group is 85%, and the charge amount with respect to the theoretical capacity of the negative electrode active material is The same as Example 1 except that the charging current with respect to the total surface area of the positive electrode plate was set at 0.5 mA / cm ² until the charging amount with respect to the theoretical capacity of the positive electrode active material reached 200% after reaching 100%. Implemented.

The results of these examples and comparative examples are shown in Tables 1 and 2 below, respectively.

In Examples 1 to 26, the liquid occupancy ratio in the electrode plate group is 75 to 95% within the range of the present invention, and the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100%. The charging current until the amount of charge reaches 200% is 0.1 to 1.0 mA / cm ² within the range of the present invention, and the battery temperature is in the range of 30 to 45 ° C. during the formation of the battery case. The temperature of the battery is within the range of the present invention by air cooling as necessary. In any of the examples, the outflow of carbon could be suppressed and the chemical conversion state was good. The cycle life was 2,500 cycles or more, and good results were obtained. This is considered to be because the generation of Joule heat could be prevented by setting the above requirements within the scope of the present invention, thereby minimizing the amount of gas generated. In Examples 24 to 26, the electrode plate group is incorporated in the battery case in a high pressure state of 60 kPa, 80 kPa, and 100 kPa, respectively. As in the other examples, carbon outflow could be suppressed and the chemical conversion state was good.

On the other hand, in Comparative Examples 1 to 4, the liquid occupancy in the electrode plate group is 70% outside the range of the present invention. In any case, it was difficult to perform sufficient chemical conversion due to the lack of the amount of the electrolytic solution, and as a result, the cycle life was reduced. In Comparative Examples 1 and 4, further heating was performed to bring the temperature of the battery during battery case formation to a temperature exceeding the range of the present invention. Many outflows of carbon were observed due to poor conversion efficiency and easy gassing. In Comparative Examples 2 and 3, the temperature of the battery during battery case formation is set to 45 ° C. or less, which is the upper limit of the range of the present invention, by performing air cooling or water cooling. Although the chemical conversion state and the cycle life were poor, it was confirmed that carbon outflow could be suppressed if the temperature was kept below the upper limit temperature of the present invention. However, it was found that when the temperature was lowered below the range of the present invention as in Comparative Example 3, the carbon outflow could be suppressed, but the reaction hardly proceeded.

In Comparative Examples 5 to 9, the liquid occupancy rate in the electrode plate group is 80% within the range of the present invention, and in Comparative Examples 10 to 15 the liquid occupancy rate in the electrode plate group is 85% within the range of the present invention. In both cases, the charging current and / or during the formation of the battery case after the amount of charge with respect to the theoretical capacity of the negative electrode active material reaches 100% until the amount of charge with respect to the theoretical capacity of the positive electrode active material reaches 200%. The battery temperature is outside the scope of the present invention. In Comparative Example 5, the charging current after the charge amount with respect to the theoretical capacity of the negative electrode active material reached 100% until the charge amount with respect to the theoretical capacity of the positive electrode active material reached 200% was 1.5 mA / cm ^2. It was quite large and carbon outflow due to gassing occurred. In Comparative Examples 6-8, 10-12, and 14-15, heating is performed to change the temperature of the battery during battery case formation to a temperature exceeding the range of the present invention at each current value. Although the chemical conversion state was good, many carbon outflows were observed regardless of the current value. In Comparative Examples 9 and 13, since forced cooling by water cooling was performed, the temperature of the battery during battery case formation was less than the range of the present invention, and no carbon outflow was observed, but the formation efficiency was low and the formation state was good. No, and the cycle life was low. In Comparative Examples 6 and 15, both the charging current and the battery temperature exceeded the scope of the present invention. Since the charging current was as large as 1.5 mA / cm ² , carbon outflow due to gassing occurred, and the battery temperature greatly exceeded the temperature range of the present invention. The cycle life was also poor.

In Comparative Examples 16 to 17, the liquid occupancy ratio in the electrode plate group was set to 95% which is the upper limit of the range of the present invention, and the charge amount with respect to the theoretical capacity of the negative electrode active material reached 100%. the charging current value until the charge amount reaches 200% of, respectively, a 1.0 mA / cm ² within the scope of the present invention and 1.5 mA / cm ² range of the present invention, and the heating Thus, the temperature of the battery during battery case formation exceeds the range of the present invention. Since the liquid occupancy was sufficient, the chemical conversion state was good, but since it was heated, gassing was likely to occur, and carbon outflow was considerably observed.

In Comparative Examples 18 to 22, the liquid occupancy in the electrode plate group was set to 105% outside the range of the present invention, and the charge amount with respect to the theoretical capacity of the negative electrode active material reached 100%. the charging current value until the amount reaches 200%, and 1.0 mA / cm ² within the scope of the present invention and 1.5 mA / cm ² range of the present invention, and is subjected to a cooling or heating The battery temperature during battery case formation is changed. In Comparative Examples 18 and 20, since forced cooling by water cooling was performed, the temperature of the battery during battery case formation was less than the range of the present invention, and no carbon outflow was observed, but the formation efficiency was low and the formation state was good. No, and the cycle life was extremely low. In Comparative Examples 19 and 22, the temperature of the battery during battery case formation was set to a temperature exceeding the range of the present invention by heating. Carbon outflow could not be suppressed due to the high temperature of the battery. In Comparative Example 21, although the temperature of the battery during battery case formation was within the range of the present invention, the liquid occupancy was excessive, and thus significant carbon outflow was observed.

In Comparative Examples 23 and 24, the compressed state of the electrode group assembled in the battery case is outside the scope of the present invention. In Comparative Example 23, since the compression state of the electrode plate group was low, the effect of suppressing the softening of the positive electrode active material was weak, and the cycle life was extremely low. In Comparative Example 24, since the compression state of the electrode plate group was high, the distance between the positive electrode plate and the negative electrode plate was shortened, causing a short circuit during the cycle life test, and the cycle life was extremely low.

From the results of the above examples and comparative examples, the amount of charge with respect to the theoretical capacity of the positive electrode active material reaches 200% after the liquid occupancy in the electrode plate group and the amount of charge with respect to the theoretical capacity of the negative electrode active material reach 100%. It was found that good results could not be obtained if any one of the charging current and the temperature of the battery during battery case formation was outside the scope of the present invention.

(Examples 27 to 34)
In these examples, the amount of carbon added to the negative electrode active material is changed. The amount of carbon was a negative electrode active material prepared by adding carbon in a range of 0.05 to 6.0% by mass as shown in Table 3 with respect to the amount of the negative electrode active material in a negative electrode active material paste prepared according to a conventional method. It was changed by filling the paste. Except that the amount of carbon added to the negative electrode active material was changed as described above, Example 12 (the liquid occupancy in the electrode plate group was 85%, and the charge amount with respect to the theoretical capacity of the negative electrode active material reached 100%. The charge current value until the amount of charge with respect to the theoretical capacity of the positive electrode active material reached 200% was set to be the same as 0.5 mA / cm ² ). About the control valve type lead acid battery manufactured in this way, the degree of carbon outflow, the formation state of the end plate and the cycle life were evaluated in the same manner as described above.

The results of these examples are shown in Table 3 below. Table 3 also shows the results of Example 12 for comparison.

As is apparent from Table 3, in Example 12 and Examples 27 to 34, the amount of carbon added to the negative electrode active material was 0.05 to 6.0% by mass, the carbon outflow, the chemical conversion state, and the cycle life were good. Met. Among them, Examples 12, 29, and 30 in which the amount of carbon added to the negative electrode active material is in the range of 0.5 to 2.0 mass% are free from carbon outflow, and the chemical conversion state and cycle life are remarkably good. Met. Here, in Example 27, since the amount of carbon added is as small as 0.05% by mass, the charge acceptability of the negative electrode is not so good, and it is considered that the cycle life is somewhat reduced. Further, in Example 34, since the amount of carbon added was as large as 6.0% by mass, it was considered that some carbon outflow was observed and the cycle life was somewhat reduced, but the chemical conversion state was good. Also in these examples, the effects of the present invention were not significantly impaired. In Example 12 and Examples 27 to 34, the liquid occupancy in the electrode plate group was 85%, and the charge amount with respect to the theoretical capacity of the negative electrode active material reached 100%, and then the charge with respect to the theoretical capacity of the positive electrode active material was performed. The charging current value until the amount reaches 200% is 0.5 mA / cm ² , the battery temperature at the time of battery case formation is 36-37 ° C., and the amount of carbon added to the negative electrode active material is 0.05 The amount of carbon added to the negative electrode active material was varied within the range of ˜6.0% by mass, but the liquid occupancy, charging current value and battery temperature were set to various values within the range of the present invention. When the content was changed in the range of 0.05 to 6.0% by mass, the same tendency as in the above example was obtained.

According to the method of the present invention, carbon outflow due to generation of hydrogen gas, and elution and floating of carbon in the electrolyte solution can be prevented, and formation at a high temperature can be achieved throughout the battery case formation. Become. Therefore, the manufactured control valve type lead-acid battery is not short-circuited inside and can not only enable the efficient production of such a control valve-type lead acid battery, but also the manufactured control valve-type lead acid battery. The cycle life is extremely long. Therefore, it is expected that the method of the present invention will be used greatly in the future for the production of a control valve type lead storage battery in which carbon is added to the negative electrode.

Claims (4)

A positive electrode plate obtained by filling a lattice substrate made of lead or a lead alloy with a paste-like active material, and a negative electrode plate made by filling a lattice substrate made of lead or a lead alloy with a paste-like active material containing carbon. Are stacked via a retainer mat mainly, and then the electrode plate group is housed in a battery case at a group pressure of 40 to 100 kPa and sealed with a lid, In the manufacturing method of the control valve type lead-acid battery, the dilute sulfuric acid electrolyte solution is injected into the battery case to form a battery, and then the replacement liquid and the auxiliary charge are performed.
1) The amount of the diluted sulfuric acid electrolyte injected is set to 75 to 95% of the liquid occupation ratio in the electrode plate group,
2) In the battery case formation, the charging current from when the charge amount with respect to the theoretical capacity of the negative electrode active material reaches 100% until the charge amount with respect to the theoretical capacity of the positive electrode active material reaches 200% 3. A method for producing a valve-regulated lead-acid battery, wherein the battery temperature is 1.0 mA / cm ² or less with respect to the surface area, and 3) the battery temperature during battery case formation is suppressed to 30 to 45 ° C. . The manufacturing method of the control valve type lead-acid battery of Claim 1 whose injection amount of said 1) is 80 to 85% of the liquid occupation rate in an electrode group. The manufacturing method of the control valve type lead acid battery of Claim 1 or 2 whose charging current of said 2) is 0.1-1.0mA / cm < ² >. The control according to any one of claims 1 to 3, wherein the amount of carbon contained in the pasty active material filled in the negative electrode plate is 0.1 to 5.0 mass% with respect to the amount of the negative electrode active material. Manufacturing method of valve-type lead acid battery.