JPS6023953A - Enclosed lead storage battery - Google Patents

Abstract

PURPOSE:To obtain a battery having a long life and being low-priced while maintaining the former battery manufacturing process as it is where the separators having stiffness are used by inserting the separating plates, which are formed by filling the vacant space part of ceramic foam having continuous pores with inorganic powder, between the positive and negative pole plates. CONSTITUTION:Separators in use are formed by filling the vacant space part of ceramic foam 1 having continuous pores with inorganic powder 2. For instance, ceramic foam 1 having extremely large porosity (80-90%), large bending strength (5-15kg/cm<2>) and excellent acid-proofness as well as the super anti- oxidation properties is used as a supporter, while the vacant space part thereof is filled with inorganic powder 2 such as diatomite, parlite and white carbon. The separators thus formed are inserted between the negative and positive pole plates. Said separating plates can be used in the former manufacturing process as it is due to their superior stiffness.

Description

DETAILED DESCRIPTION OF THE INVENTION The object of the present invention is to provide Nagano Life with an inexpensive sealed lead-acid battery that can be used in the conventional battery manufacturing process using a rigid separator.

Lead-acid batteries can be hermetically sealed by using a so-called oxygen cycle in which oxygen gas generated from the anode plate during charging is recombined at the cathode plate. In order to improve the gas absorption ability and leakage resistance of this type of sealed lead acid battery, it is desirable that the amount of electrolyte be as small as possible. However, on the other hand, in order to secure the capacity, the amount of electrolyte must be sufficiently large. In order to satisfy this conventionally impossible request, the electrolyte solution is made non-fluidized by gelation, or the electrolyte is absorbed into a mat mainly composed of glass fibers of 1 μm or less (hereinafter referred to as fine glass mat). A method of apparently fixing the electrolyte has been adopted. however,
Not only is it difficult to create an IM when the W solution gels, but it also has the disadvantage that the internal resistance of the battery increases as charging and discharging are repeated, resulting in a decrease in battery performance. On the other hand, fine glass mats are used as separators in general sealed lead-acid batteries because they have an excellent active material retention function and an extremely good electrolyte retention ability. However, since this fine glass mat lacks rigidity, it has the disadvantage that the battery manufacturing process requires a different approach from that of conventional lead-acid batteries.

The present invention improves the above drawbacks by using a separator formed by filling the voids of a ceramic foam with continuous pores with inorganic powder. Namely, the sealed lead-acid battery of the present invention has an extremely high air heat rate (80 to 90%).
)1 Ceramic foam with high bending strength (5 to 15 A9/d) and excellent acid and oxidation resistance is used as a support, and the voids are filled with acid and oxidation resistant diatomaceous earth, pearlite, white carbon, etc. A separator formed by filling inorganic powder is used. It is characterized by being used by being inserted between the anode plates.91jjl ++L! Since the separator has excellent rigidity, it has the advantage that conventional electrical equipment & manufacturing processes can be used as is.

The ceramic foam used in the present invention has a structure completely different from that of conventional ceramic porous bodies. As a conventional ceramic porous body.

It was a porous body with continuous pores, similar to purple pottery or sintered grains.

The structure of the ceramic foam of the present invention is a C-shaped structure in which the ceramic part and the pore part of the conventional ceramic porous body are completely reversed, and is characterized by an extremely high porosity. This high porosity makes it possible to apply it as a separator for sealed lead-acid batteries. However, the currently available ceramic foams have a small pore diameter of several hundreds of micrometers, and therefore have poor electrolyte retention ability9, and cannot be used as is as a separator for a closed lead P3πI pond.

In the present invention, the voids of the ceramic foam are filled with inorganic powder such as diatomaceous earth, pearlite, white carbon, etc., which has excellent acid resistance (9) and oxidation resistance (1), and is hydrophilic, so that the pore diameter is reduced to several tens of μm or less. It is designed to be used as a separator for sealed lead-acid batteries.

Also, the pore structure of the ceramic foam used in the present invention is as follows. It is not as simple as a ceramic honeycomb, but has a complex spongy structure, so it has a high ability to retain the inorganic powder it fills.

The present invention will be explained in detail below based on examples.

Example 1. Porosity 84%, pore t'k 400/7
m.

A flat ceramic foam with a bending strength of 101 g/d and a width of 1.5 fl was immersed in a solution of diatomaceous earth dispersed in water. By drying, a separator filled with diatomaceous earth was formed in the voids of the ceramic foam [7] Example 2. A septum body was formed in the same manner as in Example 1, except that perlite was used instead of diatomaceous earth.

Actual Hu Example 5. A separator was formed in the same manner as in Example 2, except that a flat ceramic foam having a porosity of 82%, a pore diameter of 280 μin, a bending strength of 15/9/Cd, and a thickness of 1.5N was used. Table 1 shows the characteristics of the separators prototyped in Examples 1 to 6. Also. Table 1 shows, for comparison, the sample not filled with inorganic powder in Example 1 and the conventional 1.51
The characteristics of a fine Gawon mat with a thickness of 111 mm were also demonstrated.

Table 1 Note: After the test piece was immersed in holding crab 1°30d I12 S04, pulled up and held under 6G acceleration for 60 seconds, the test piece absorbed 1111 of the H2SO4fl remaining in the 9th test piece)
[Value expressed as a percentage of 2804fM.

Moreover, FIG. 1 is a schematic enlarged view of the separator ε according to the present invention. In FIG. 1, 1 is a ceramic foam. 2 is an inorganic powder filled in the empty FA part 1 of the ceramic foam.

As shown in Table 1, the bulk SF body d, which is made of only ceramic foam and is not filled with inorganic powder, has sufficient bending strength, but its large pore size has poor electrolyte retention ability, and compared to conventional The separator e consisting of a fine glass mat voice is 'Fj
! It can be seen that the holding power of the L solution is sufficient, but the bending strength is almost absent.

In addition, using the prototype bodies a-e as described above,
Prototype sealed lead-acid batteries A-E were produced. All of these electrode plates use a lead-calcium alloy as a grid.
It was assembled in the usual manner to a nominal capacity of 5.5 AH. Incidentally, the one using the separator e has a bending strength of 9 which is too weak to be applied to the battery manufacturing process using the conventional rigid separator.

This was subjected to a life test in which one cycle was 2/3 discharge of the nominal capacity and 160% charge, and the life cycle at that time was measured. The results are shown in Table 2. Note that the number of Ti and the number of ponds was two each.

Table 2 As shown in Table 2, Batteries A-C of the present invention are the same as Batteries E using the conventional fine gas "Pnumat" as a separator).
1. The pond exhibits high life performance, but uses only ceramic foam as a separator without being filled with inorganic powder.
It was an extremely short-lived event. This is because, as shown in Table 1, the pore diameter of the spacer nF body d is large, and the electrolyte retention capacity is poor. As a result of disassembling the battery, it was found that the deterioration of V was more severe due to the higher sulfuric acid gamma concentration in the lower part of the electrode plate, and that there were areas where the TL electrolyte had dried up. Although battery E has good life performance,
As shown in Table 1, the bending strength of the Nr separator is extremely low, so it cannot be applied to the battery manufacturing process using conventional rigid separators.

In the separator of the present invention, the ceramic foam that is its constituent material has the necessary rigidity for the separator and also plays the role of supporting the inorganic powder. In addition, the inorganic powder is filled into the voids of the ceramic foam, and by reducing the diameter of the voids, it serves to increase the holding power of the vinegar solution. The particle size of the inorganic powder is generally 0.01 to 20 μm. In addition, the filling amount should be selected depending on the intended use of the battery.

In general, the pore diameter is 50μ to increase the electrolyte holding power.
It is preferable to fill in an amount of less than m. However, if the amount of filling is too large and the porosity is less than 75%, the amount of electrolyte required to secure the capacity will be reduced, which is not desirable.

The above-mentioned IJ+4<, the present invention uses a separator formed by filling the voids of a ceramic foam with continuous pores with inorganic powder, thereby allowing the manufacturing process of batteries using conventional rigid separators to be directly performed. Can it be used similarly to batteries using fine guff mats, without the need to change conventional manufacturing processes, as is the case when fine guff mats are used as separators? [1: Pond performance can be obtained, and its technological value is great.

[Brief explanation of the drawing]

FIG. 1 is a schematic enlarged view of a separator according to the invention. 1: Ceramic foam 2: Nl1tNl) Last applicant: Yuasa Miike Co., Ltd. Figure M

Claims (1)

[Claims] A separator formed by filling inorganic powder into the voids of a ceramic foam having continuous pores. A sealed lead-acid battery characterized by being inserted between anode plates.