JPH0548587B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a closed lead-acid battery, and particularly to improvements in its structure. Conventional technology and its problems Sealed lead-acid batteries have recently been used for various purposes. This type of battery restricts the electrolyte and impregnates and retains an ultra-fine glass retainer with a diameter of several microns or less, and unlike lead-calcium alloys, it does not significantly reduce the hydrogen overvoltage of the negative electrode plate. A lead alloy is used for the grid. For this reason, paste-type positive electrode plates have the drawback of short charge-discharge cycle life due to corrosion and elongation of the lattice and accompanying softening and falling off of the active material. On the other hand, in the case of a clad type battery, the above-mentioned drawbacks are alleviated because the active material surrounds the mandrel and is firmly supported by the tube. However, in sealed batteries in which the electrode plates are impregnated with a limited amount of electrolyte, there is a problem in retaining the electrolyte in the tube, and the contact area between the flat separator and the cylindrical tube is small, making charging and discharging difficult. The drawback was that the reaction did not proceed smoothly. In addition, there have been proposals for using a corrugated separator that matches the shape of the positive electrode plate or using a flat cladding type positive electrode plate in liquid type clad type batteries. These attempts to increase capacity by making large amounts of positive and negative electrode active materials exist within the cell. However, in liquid batteries, the space formed between the cylindrical clad positive electrode plate and the flat separator is not only effective for gas release and liquid convection, but also sufficient as a path for discharge current. working in Therefore, compared to this commonly used configuration, the battery proposed in the previous period has almost no capacity, and is not put into practical use. Means for Solving the Problems The present invention provides a closed-type sealed lead-acid battery with limited flowable electrolyte, including a closed-type positive electrode plate using a lead alloy core and a circular tube that does not significantly reduce hydrogen overvoltage. A flat negative electrode plate is laminated with a flat mat separator made of fibers of hydrophilic material having a diameter of 10 microns or less interposed therebetween to form an electrode plate group, and by pressing the electrode plate group, a tube is formed. Its feature is that more than 1/2 of the outer circumference of the separator is in close contact with the separator. Function Since the sealed lead-acid battery of the present invention uses a pine-like separator made of fibers made of a hydrophilic material with a diameter of 10 microns or less, even with a limited amount of electrolyte, the separator has sufficient capacity for the charge/discharge reaction to proceed. The electrolyte is retained. Furthermore, the separator, the negative electrode plate, and the tube are in close contact with each other, and in particular, more than half of the outer circumference of the tube is in close contact with the separator, so that the electrolyte has good contact between the separator and the tube. Furthermore, when fibers of 10 microns or less made of hydrophilic material are used in the tube, the electrolyte retention of the tube itself is good. That is, since the negative electrode plate, the separator, the tube, and the positive electrode active material are in close contact with each other, charging and discharging reactions proceed smoothly. Embodiment FIG. 1 is a cross-sectional view of a main part showing an embodiment of a lead-acid battery according to the present invention. In the figure, 1 is a lead alloy core that does not significantly reduce hydrogen overvoltage, 2 is a positive electrode active material, and 3 is a tube with a circular cross section made of a hydrophilic material such as glass, polyester, polyacrylonitrile, etc. It is a cloth braided with threads using micron or less fibers or a nonwoven cloth bound with plastic, and 1, 2, and 3 form a clad positive electrode plate. 4 is a flat negative electrode plate;
Reference numeral 5 denotes a mat-like separator made of fibers of hydrophilic material, such as glass, polyester, polyacrylonitrile, polyethylene, etc., with a diameter of 10 microns or less, and deforms when pressed while impregnated with electrolyte. 6 is a battery case, and 7 is a rib of the battery case. As is well known, the positive electrode plate, the separator, and the negative electrode plate are sequentially stacked to form an electrode plate group, and the positive electrode plate and the negative electrode plate are pressed through the separator so that 1/2 of the outer circumference of the tube is in contact with the mat. and place the electrode plate group in the battery case. The electrolytic solution is impregnated and retained in the electrode plate group to limit the fluid electrolytic solution to prevent leakage and to smoothly proceed with the sealing reaction due to the oxygen cycle. We prototyped a battery with the above configuration, in which the contact area between the separator and the tube was changed depending on the degree of compression of the electrode plate group, and obtained the following results in terms of 5 and 0.1 hour rate (HR) discharge capacity and charge/discharge cycle life. Table 1 shows the results of a comparative test with a conventional paste-type sealed battery.

[Table] Batteries 3 and 4 according to the present invention have almost the same 5HR and 0.1HR capacities and extremely excellent cycle life compared to conventional paste-type sealed batteries. Clad-type batteries, which have a small contact area between the separator and the positive electrode plate, have excellent cycle life, but have poor rapid discharge performance. This is because fluid electrolyte is limited, so ensuring continuity of the electrolyte between the positive and negative electrode plates, that is, a path for ion movement, is an essential condition for smooth charging and discharging reactions. It is. In a normal battery having a structure in which a group of electrode plates is embedded in a fluid electrolyte, there is no problem in charging and discharging reactions even if the contact area between the separator and the tube is small. Effects of the Invention In the positive electrode plate of the battery according to the present invention, the core metal is surrounded by the active material, and the outer periphery is firmly held by the tube, so the active material is less likely to soften or fall off, and can be used for a long period of time. Can withstand charge/discharge cycles. In addition, since the tube is laminated with a mat-like separator made of fibers of hydrophilic material with a diameter of 10 microns or less in between, and more than half of the outer circumference of the tube is in close contact with the separator, even if the electrolyte is limited Sufficient electrolyte is retained for the charge/discharge reaction to proceed,
In addition, sufficient contact with the positive and negative electrode plates can be obtained, sufficient ionic conduction between the two electrode plates can be ensured, and good battery performance can be obtained. As described above, the battery according to the present invention can provide a clad-type sealed battery with good performance and a long charge/discharge cycle life.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of the main parts of a closed lead-acid battery according to the present invention. DESCRIPTION OF SYMBOLS 1... Core metal, 2... Positive electrode active material, 3... Tube, 4... Negative electrode plate, 5... Separator.

Claims (1)

[Claims] 1. A clad positive electrode plate using a lead alloy core and a circular tube that does not significantly reduce hydrogen overvoltage, and a flat negative electrode plate are combined into a flat plate made of fibers made of hydrophilic material with a diameter of 10 microns or less. The electrode plates are laminated with a pine-like separator interposed therebetween to form an electrode plate group, and by pressing the electrode plate group, more than 1/2 of the outer circumference of the tube is brought into close contact with the separator, and the fluid electrolyte is restricted. A closed-type sealed lead-acid battery.