JP2552353B2 - Sealed secondary battery - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to making a sealed secondary battery thinner.

Conventional technology Conventionally, rechargeable batteries such as lead storage batteries required uniform charging and maintenance such as water replenishment, but due to improvements in lattice alloys and electrolyte retention methods, oxygen gas generated at the positive electrode was absorbed by the negative electrode. It became possible to seal by the negative electrode absorption type of reducing. For this reason, maintenance of the battery is not necessary, and the liquid can be made leak-free regardless of the installation direction of the battery. Therefore, the applications thereof are expanded to OA equipments, audio equipments, etc., and accordingly, there is a demand for miniaturization and thinning of sealed lead acid batteries. However, the conventional method of alternately stacking the positive electrode plate, the electrolyte holder, and the negative electrode plate has a limit in thinning. Therefore, as shown in FIG. 5, the positive electrode plate 1 and the negative electrode plate are coplanar. 2 through the electrolyte holder 5, and
There is proposed a sealed lead-acid battery having a structure in which the whole is fixedly supported and closely adhered to the battery case substrate 4. (Conventional product) The problem to be solved by the invention However, in this type of battery, since the amount of the electrolytic solution is limited in order to absorb oxygen gas generated from the positive electrode in the negative electrode to achieve hermetic sealing, Although the contact between the electrolyte holder and the electrolyte holder is important, the structure proposed above does not apply pressure in the direction of contact with the electrode plate of the electrolyte holder.

Therefore, as shown in FIG. 5, a gap 6 is likely to occur between the positive electrode plate 1, the negative electrode plate 2 and the electrolyte holding body 5, resulting in poor adhesion. Further, the oxygen gas generated during charging does not reach the negative electrode plate 2 and becomes a gas pool 8 which remains between the positive electrode plate 1 and the electrolyte holding body 5, and the electrolytic solution in the electrolyte holding body 5 is transferred to the electrode plates 1 and 2. Since it does not come into contact, there is a drawback that it does not have sufficient discharge capacity,
Further, when the battery is subjected to rapid charging, gas generation becomes more intense and the contact with the electrolytic solution is interrupted early, which has a drawback of hindering the negative electrode absorption reaction.

An object of the present invention is to provide a sealed secondary battery that solves the above problems and enables improvement of capacity performance and charge / discharge cycle performance.

Means for Solving the Problems The present invention relates to a sealed secondary battery in which the plate surfaces of a positive electrode plate and a negative electrode plate are arranged on the same plane of a substrate, and the end faces of the positive electrode plate and the negative electrode plate are installed apart from each other. The thickness of the plate surface of the negative electrode plate is thinner than the thickness of the plate surface of the positive electrode plate, and in the space where the end faces of the positive electrode plate and the negative electrode plate are separated from each other, a non-woven fabric holding an electrolytic solution. And an electrolyte holder composed of a gel electrolyte, wherein the electrolyte holder is characterized in that the solid component of the gel electrolyte is distributed on the surface facing the positive electrode plate and the negative electrode plate. (Claim 1) Further, the electrolyte holder has an original shape larger than the volume of a space in which the end faces of the positive electrode plate and the negative electrode plate are separated from each other, and the positive electrode plate and It is characterized in that it is in close contact with the surface facing the negative electrode plate (claim (Item 2)
Further, the electrolyte holder has an original shape that is thicker than the thickness of the positive electrode plate and the negative electrode plate, and the end faces of the positive electrode plate and the negative electrode plate are in a space separated from each other with respect to the substrate. It is brought into close contact with the surfaces of the positive electrode plate and the negative electrode plate facing each other by being pressed in the vertical direction (claim 3).

Action The present invention is a sealed secondary battery in which the plate surfaces of the positive electrode plate and the negative electrode plate are arranged on the same plane of the substrate, and the end faces of the positive electrode plate and the negative electrode plate are installed apart from each other, and the present invention exists in a non-woven fabric. Since the gel electrolyte that is formed is gelled after pouring in the sol state during pouring, contact (adhesion) with the end face of the electrode plate is good without being affected by the shape of the electrode plate. And contribute to the reaction with the electrode plate.

Example One example of the present invention will be described below.

FIG. 1 shows a plan view of a sealed lead-acid battery as an embodiment of the sealed secondary battery of the present invention, in which 1 is a positive electrode plate, 2 is a negative electrode plate, 3 is an electrolyte holder, and 4 is It is a substrate for fixing the electrode plate group.

In FIG. 1, between a positive electrode plate 1 and a negative electrode plate 2 to be sealed, an electrolyte holding body 3 composed of a non-woven fabric mainly containing fine glass fibers holding an electrolytic solution and a gel electrolyte 7 is placed on a substrate 4. It shows the state installed in. For example, 0 for non-woven fabric.
It is a glass fiber non-woven fabric mainly having a fiber diameter of 7 m, and the gel electrolyte 7 is obtained by gelling an electrolytic solution such as dilute sulfuric acid with a gelling agent of silicic acid. Next, the electrolyte holder 3 and the electrode plate 1,
When the state between the two is enlarged, as shown in FIG. 2, when the positive electrode plate 1, the negative electrode plate 2 and the electrolyte holder 3 are installed on the substrate 4 on the same plane, the positive electrode plate 1, the negative electrode plate 2 and the electrolyte are Since the gel electrolyte 7 is formed in the gap 6 generated in the contact direction of the holding body 3 with the nonwoven fabric, the positive electrode plate 1, the negative electrode plate 2 (active material) and the electrolytic solution in the nonwoven fabric of the electrolyte holding body 3 are formed. The reaction is sufficiently performed even without pressure. Non-woven fabric is mainly gel electrolyte 7
The purpose of this is to reinforce the mechanical strength of the non-woven fabric by reducing the fiber diameter as in this example to make the gel permeation into the non-woven fabric superficially. The reaction with can be made more likely to occur. That is, in order to make gel permeation into the non-woven fabric superficially, if the non-woven fabric has a relatively large fiber diameter of 5 to 30 m, the gel permeation is easy, so that the solid content in the gel is 6 to 6. Applying a relatively large amount of gel electrolyte 7 such as 20 wt% suppresses gel permeation. On the other hand, when the fiber diameter of the non-woven fabric is relatively thin, such as 4 m or less, the permeation of gel into the nonwoven fabric is Since it is small, the gel electrolyte 7 having a relatively small solid content in the gel of 0.5 to 5 wt% can be applied.

Further, as the non-woven fabric, in addition to glass fibers, inorganic fibers such as alumina fibers and dicornia fibers and organic fibers such as polypropylene fibers, polyester fibers and acrylic fibers can be used.

Further, as shown in FIG. 2, when the thickness of the negative electrode plate 2 is made thinner than that of the positive electrode plate 1, the entire upper surface of the negative electrode plate 2 is exposed inside the sealed battery, and oxygen gas The absorption and reduction ability of is further improved. Also, FIG. 3 (a)
When the non-woven fabric of the electrolyte holder 3 has a shape slightly larger than the space between the positive electrode plate 1 and the negative electrode plate 2 as shown in Fig. 3, by pushing it into the space as shown in Fig. 3 (b). Further, the adhesiveness in the contact direction with the positive electrode plate 1 and the negative electrode plate 2 can be further improved, and the nonwoven fabric of the electrolyte holder 3 has a thickness greater than that of the positive electrode plate 1 and the negative electrode plate 2 as shown in FIG. 4 (a). Even in the case of a thick and slightly narrow shape, as shown in FIG. 4 (b), it is deformed to some extent by pressurization. Therefore, when used in combination with the gel electrolyte 7, the positive electrode plate 1 and the negative electrode plate 2 come into contact with each other. The adhesion in the direction can be easily improved.

FIG. 6 shows the results of a rapid charge / discharge cycle test performed on the product of the present invention and a conventional product manufactured as a sealed lead-acid battery. As test conditions, charge: 1h, discharge: 1CA, temperature: 25
As a result of carrying out at ± 2 ° C., it is found that the product of the present invention has good capacity performance and can withstand more than twice the number of times of charge and discharge as the conventional product.

Effects of the Invention As described above, according to the present invention, the adhesion between the electrode plate and the electrolyte holder is good in both the unpressurized state and the pressurized state, and the capacity property and the charge / discharge cycle performance are sufficiently obtained, Moreover, since the oxygen gas absorption capacity is good, rapid charging is possible.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG.
FIG. 3 is an enlarged vertical cross-sectional view of a main part of the drawings, and FIG. 3 and FIG. 4 respectively show (a) a state before insertion of an electrolyte holder and (b) a state after insertion of an electrolyte holder in another embodiment of the present invention. FIG. 5 is an enlarged vertical sectional view of an essential part, FIG. 5 is an enlarged vertical sectional view between an electrode plate and an electrolyte holder when a conventional electrolyte holder is used, and FIG. 6 is a rapid charge / discharge cycle characteristic of the product of the present invention and a conventional product. It is a comparison curve figure which shows. 1 is a positive electrode plate, 2 is a negative electrode plate, 3 is an electrolyte holder composed of the nonwoven fabric of the present invention and a gel electrolyte, 4 is a substrate for fixing an electrode plate group, 5 is a conventional electrolyte holder, and 6 is a gap. ,
7 is a gel electrolyte, 8 is a gas reservoir

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiji Akudo 1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Shoichi Shigen 1-16-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Michiko Sakai, Examiner, Nippon Telegraph and Telephone Corporation (56) References JP-A-58-108653 (JP, A) JP-A-63-250066 (JP, A) Shoukai-Sho 60-3658 (JP, U)

Claims (3)

(57) [Claims] 1. A sealed secondary battery in which the plate surfaces of a positive electrode plate and a negative electrode plate are arranged on the same plane of a substrate, and the end faces of the positive electrode plate and the negative electrode plate are set apart from each other. The thickness of the plate surface of the plate is thinner than the thickness of the plate surface of the positive electrode plate, in the space where the end faces of the positive electrode plate and the negative electrode plate are separated from each other, a non-woven fabric holding an electrolytic solution and a gel electrolyte. And a solid electrolyte of the gel electrolyte is distributed on the surfaces of the electrolyte holder facing the positive electrode plate and the negative electrode plate. . 2. The electrolyte holder has an original shape that is larger than the volume of a space in which the end faces of the positive electrode plate and the negative electrode plate are separated from each other, and a surface facing the positive electrode plate and the negative electrode plate in the space. The sealed secondary battery according to claim 1, wherein the sealed secondary battery is closely attached to. 3. The electrolyte holder has an original shape thicker than the thickness of the positive electrode plate and the negative electrode plate, and the end faces of the positive electrode plate and the negative electrode plate are in a space separated from each other with respect to the substrate. The sealed secondary battery according to claim 1, wherein the sealed secondary battery is in close contact with the surfaces facing the positive electrode plate and the negative electrode plate by being pressed in the vertical direction.