JP4868852B2 - Control valve type lead acid battery - Google Patents

Description

  The present invention relates to a control valve type lead-acid battery in which an electrode plate group in which positive and negative electrode plates are laminated via a separator is housed in a battery case in a high-pressure state.

  Lead-acid batteries have a long history, and still occupy the mainstream of storage batteries because of their low cost and high reliability resulting from stable performance. Its application has been extended to SLI batteries for automobiles, mobile power supplies for small electronic devices and electric vehicles, and stationary power sources for backups that operate at the time of commercial power outages such as computers and communication devices.

  In recent years, this lead-acid battery has become a mainstream control valve type that does not require replenishment in place of the conventional vent type from the viewpoint of maintenance measures, and the control valve type is also used as a float use battery for backup applications such as communication equipment. In addition, the demand for cycle-use batteries that repeat deep charging and discharging of electric power storage, electric vehicles, etc. is widening, and the service life is being extended.

  In cycle applications, the positive electrode active material is often softened and mudified due to long-term use of the storage battery, resulting in a long life, and in order to improve the adhesion between the grid and the active material, the electrode plate group is placed in the battery case at a high pressure. Increasing insertion in the state.

  Cycle-use batteries have a higher degree of pressure on the electrode plate group than before, and as the use cycle progresses, separators such as glass fiber retainer mats that separate the positive electrode plate and negative electrode plate are crushed by repeated contraction and expansion. Therefore, it is known that the distance between the positive and negative electrode plates is reduced, causing an internal short circuit, resulting in a short battery life.

  As a countermeasure, it has been proposed that the crossing portion of the current collector grid body of either the positive or negative electrode plate and the crossing or crossing portion of the current collector grid body of the other electrode plate do not face each other. (See Patent Document 1).

  In addition, in a small control valve type lead-acid battery made by laminating positive / negative electrode plates and retainer mats, stack the vertical and horizontal lattices inside the lattice body constituting the bipolar plates so that they do not face each other across the retainer mat. It has been proposed (see Patent Document 2).

Furthermore, in a valve-regulated lead-acid battery in which a positive and negative electrode plate and a separator are laminated on a grid-like current collector made of a frame bone, vertical bone, and horizontal bone made of a lead alloy and a paste-like active material is held. In addition, it has been proposed that at least one of the longitudinal bone and the lateral bone of the positive and negative electrode plates does not face each other (see Patent Document 3).
JP-A-8-264202 JP 2001-332291 A JP 2005-116206 A

  However, in the lead storage battery described in Patent Document 1, since the frame frames of the positive and negative electrode plates face each other, if the electrode plate group is placed in a high-pressure state when inserted into the battery case, the cycle of the storage battery is increased. There is a case where the frame bone breaks through the separator and short-circuits in a short time.

  Moreover, in the small control valve type lead battery described in Patent Document 2, although the frame frames of the positive and negative electrode plates do not face each other, the positive and negative electrode plates are shifted and stacked, so that assembly of the electrode plate group becomes complicated. There is a problem. Furthermore, in the control valve-type lead storage battery described in Patent Document 3, the frame of the positive / negative electrode plate is completely or partially confronted in the same manner as the lead storage battery described in Patent Document 1, When a group is inserted into the battery case under high pressure, the frame bone may break through the separator and cause a short circuit.

  Therefore, an object of the present invention is to provide a long-life control valve type lead-acid battery with few short-circuits even if the electrode plate group is stacked and inserted under high pressure.

  In order to solve the above problems, in the present invention, attention is paid to the short-circuited portions of the positive and negative grid substrates, the grid substrate is divided into a frame grid and a middle grid formed in the frame grid, and each portion is prevented from short circuit. It is a measure taken. First, in the frame lattice, the width of the surface of the frame lattice of the positive / negative electrode lattice substrate is at least 3 mm or more and 3 to 6 times the surface width of the medium lattice.

  Further, in the middle lattice, the intersection of the middle lattice of the positive electrode lattice substrate and the intersection of the middle lattice of the negative electrode lattice substrate do not overlap.

Here, the reason why the width of the surface of the frame lattice of the lattice substrate is set to 3 mm or more is that if the width is smaller than this, a short circuit is likely to occur due to partial stress concentration when high pressure is applied. Also, the reason why the width is 3 to 6 times the surface width of the medium lattice is that the lattice of the lattice substrate is generally thinner than the frame lattice. This is because the short-circuit prevention effect is saturated, but the filling space is reduced, the weight of the substrate is increased, and the weight efficiency of the battery is lowered. Of course, it preferred to Gasara be so as not to overlap the frame grid portion.

Further, in order to facilitate handling when the electrode plates are laminated, it is preferable that the heights of the positive and negative grid substrates are equal. Positive electrode necessary for this, both of the negative electrode, or the one grating substrate lower, by adding a protruding portion serving as a foot, or adjust the height to such a height from the base of both electrodes become equal its It is preferable to do.

  Furthermore, in the present invention, the intersection of the intermediate lattice of the positive electrode lattice substrate and the intersection of the intermediate lattice of the negative electrode lattice substrate do not overlap each other, so that It is confronted, and the effect of preventing the softening of the positive electrode active material can be expected because the compression force and distance between the electrode plates can be stabilized when the electrode plate group is pressed against high pressure.

  ADVANTAGE OF THE INVENTION According to this invention, a control valve type lead acid battery with few internal short circuits and long life and high reliability can be provided.

  Examples of the present invention will be described together with comparative examples. First, the lead storage battery is prepared by first preparing positive / negative electrode lattice substrates having different sizes of the inner lattice and frame lattice, and the size of the mesh, and kneading a predetermined amount of lead powder and dilute sulfuric acid into the paste. A paste type positive / negative electrode plate was prepared by filling the active material in the form of a conventional method, performing aging and drying, and then immediately using chemical conversion.

These positive and negative plates are appropriately selected so as to be in the state shown in FIGS. 1 to 5 when they are overlapped, and are laminated as a separator via a retainer mat made of glass fiber, and three positive plates and four negative plates After being configured into a combination of electrode plates, it was inserted into a battery case so as to achieve each level of compression force shown in Table 1, and a control valve type lead acid battery having a voltage of 2 V and a rated capacity of 7 Ah was obtained by a conventional method. .
In the example shown in FIG. 1, the positive grid substrate 1 and the negative grid substrate 2 are made the same size so that both sides of the positive grid substrate 1 and the entire circumference of the upper and lower frame grids 3 overlap, and only the middle grid 4 does not overlap each other. The intersecting portions 5 are positioned within the cell 6 of the opposite substrate, the frame grid width magnification (frame grid surface width / medium grid surface width) is 2 to 8, the frame grid surface width is 1 to 8 mm, Yes No of opposed frame grid, was produced 0.5-1.0 medium grating surface width mm, none has the facing intersections species people varied (examples A1-A10, Comparative example A1-A10). In the figure, 7 is an ear.
Example shown in FIG. 2, the middle grating 4 frame grating 3 not only obtained by so no overlapping, formed by laminating a positive grid substrate 1 the frame grid width of less than the negative electrode grid substrate 2, A foot 8 is provided at the lower part (Example B).
In the example shown in FIG. 3, the positive grid substrate 1 and the negative grid substrate 2 have the same size, and the frame grid 3 and the middle grid 4 are all overlapped. (Medium lattice surface width) was 4 and 6, frame lattice surface widths were 2 mm and 3 mm, and medium lattice surface width was 0.5 mm (conventional examples 1 and 2).
Example shown in FIG. 4 is slightly shifted only frame grating 3 below and the leg portion 8 provided in the lower portion of the negative electrode grid substrate 2, other as frame grid overlap, in addition, the medium grating 4 subtly the interval it is obtained so that only the lattice overlaps in a portion shifted in the (Comparative example A11).
Example shown in FIG. 5, the positive grid substrate 1 and the negative electrode grid substrate 2 so as not to overlap only the frame grating 3, the middle grating 4 is obtained by the overlap of all, the width ratio of the frame lattice (frame grating surface width / Medium grid surface widths (2 and 3), frame grid surface widths of 2 mm and 3 mm, and medium grid surface widths of 1.0 mm were prepared (Comparative Examples B1 and B2) .

Each of the produced control valve type lead-acid batteries was prepared, and after confirming the initial capacity, the battery was left in a charged state at a temperature of 25 ° C. for 1 week, and then the open-circuit voltage was measured to check for the presence of a short circuit. None of them were short-circuited.
Next, these lead storage batteries conform to “7.6 Acceptance of Charge after Deep Discharge” described in JIS C8702-1: 1998 “Small Sealed Lead Storage Battery Part 1: General Requirements, Functional Characteristics and Test Methods”. A test was conducted to confirm the short circuit condition after being left overdischarged.

  Specifically, each level of valve-regulated lead-acid batteries is connected in series and connected to a constant resistor, and at a temperature of 25 ° C., a minute discharge current (0.05 C) at a rate of 20 hours flows for 360 hours. Then, the battery was charged for 24 hours at a constant voltage of 2.35 V / cell with an initial current of 3 A, left for 24 hours after charging, and discharged at a current of 10 hours to confirm the capacity. A short of less than 70% of the initial capacity was defined as a short circuit.

  The results are shown in Table 1.

  In Examples A1 to A10 and Example B according to the present invention, a short circuit check after the production of the control valve type lead-acid battery and a short circuit test after being left overdischarged were performed. Did not occur.

Comparative Example A1~A9 is the intersection of the middle gratings so as not to overlap each other, a short circuit in the width ratio or frame grid width dimension of the frame lattice is outside the predetermined range has occurred. When these lead storage batteries were disassembled, the frame grid was thin and the separator was cut at the part where the frame grid was opposed. Of the 10 lead storage batteries prepared at each level, one was short-circuited and was short-circuited.

  Even when the separator was not cut, traces of short-circuiting were observed, such as resinous lead grown from the negative electrode side at the place where the frame grid contacted after being left overdischarged. The reason for this is that in this specification, the electrode plate group is built in the battery case under high pressure to improve cycle characteristics, so stress concentrates on the opposite part of the frame grid and deformation or cutting tends to occur. Even if not, it is presumed that this part of the separator became extremely thin due to the compressive force, and the distance between the positive and negative electrodes was reduced, causing a short circuit.

  In Comparative Example A10, although a short circuit did not occur, the width of the frame grid was wide, and accordingly, the filling space (mesh area) decreased and the weight increased, the weight efficiency of the storage battery itself deteriorated. The limit of the width magnification is about 6 times.

  In addition, in the lead storage batteries of Conventional Examples 1 and 2, Comparative Example A11, and Comparative Examples B1 and B2 where the intersecting portions of the intermediate grids face each other, the frame grid width magnification or the frame grid width dimension is within a predetermined range. However, a short circuit at the intersection was observed.

Moreover, although the short circuit did not generate | occur | produce the lead storage battery of Example 10 integrated at 120 kPa regarding the group pressure, the retainer mat between the overlapping frame lattices was compressed considerably as a result of disassembly. Furthermore, although the short circuit is not found in the lead storage battery of Example A6 incorporated at a group pressure of 20 kPa, cycle characteristics cannot be expected under these conditions, a preferable group pressure is 40 kPa or more, and a particularly preferable group pressure is 40 to 100 kPa. .

6 and 7 show the stacked state of the positive electrode lattice substrate 1 and the negative electrode lattice substrate 2 of another embodiment. In the example shown in FIG. 6, the positive electrode lattice substrate 1 and the negative electrode lattice substrate 2 have the same width. Te formed by laminating together, as laminated together both side ends of the substrate, shifting so as not to overlap the lattice 4 together in each substrate, located squares 6 parts of the counterpart substrate intersection 5 are stacked Thus, the foot grid 8 is provided below the positive grid substrate 1 so that the frame grids 3 on both sides overlap and the upper and lower frame grids 3 do not overlap, and the negative grid substrate 2 is higher than the positive grid substrate 1 in the height direction. The dimensions are longer. Reference numeral 7 denotes an ear provided on the top of each lattice substrate. Example shown in FIG. 7 is obtained by non-overlapping same frame grid 3 and 2, and only the width dimension of the positive grid substrate 1 frame grid width of the negative electrode grid substrate 2 small, negative electrode grid Legs 8 are provided only on the substrate 2 so that the upper and lower frame lattices 3 do not overlap each other. Also in this case, the intermediate lattices 4 are made not to overlap each other.

The positive grid substrate according to one embodiment, is a diagram showing a heavy proof state over the negative electrode grid substrate is omitted separator. The positive grid substrate according to another embodiment, and shows the heavy proof state over the negative electrode grid substrate is omitted separator. The positive grid substrate according to a conventional example, shows a heavy proof state over the negative electrode grid substrate is omitted separator. The positive grid substrate in Comparative Example illustrates heavy proof state over the negative electrode grid substrate is omitted separator. The positive grid substrate according to another comparative example illustrates the heavy proof state over the negative electrode grid substrate is omitted separator. The positive grid substrate according to another embodiment, and shows the heavy proof state over the negative electrode grid substrate is omitted separator. The positive grid substrate according to another embodiment, and shows the heavy proof state over the negative electrode grid substrate is omitted separator.

DESCRIPTION OF SYMBOLS 1 Positive grid substrate 2 Negative grid substrate 3 Frame grid 4 Middle grid 5 Intersection 6 Grid

Claims (3)

  A control valve type lead-acid battery in which a positive electrode plate made by laminating a positive and negative electrode plate filled with a paste-like active material on a grid substrate made of lead or a lead alloy via a retainer mat is housed in a battery case. The width of the surface of the frame lattice of the positive and negative grid substrates is at least 3 mm or more and 3 to 6 times the surface width of the medium lattice, and when the layers are further laminated, A valve-regulated lead-acid battery, characterized in that the intersection of the intermediate grid and the negative grid substrate does not overlap. The control valve-type lead-acid battery according to claim 1, wherein when stacked, the frame grid of the positive grid substrate and the frame grid of the negative grid substrate do not overlap. The control valve-type lead-acid battery according to claim 1 or 2, wherein the positive and negative grid substrates have the same height.