JPS5840309B2 - Keiryou Namari − Sanchikudenchiyoudenkiyoku Oyobi Sonoseizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a lightweight lead-acid battery with a novel lightweight electrode structure.

Various types of lead-acid batteries and electrode structures have been proposed in the past, with many electrodes using a heavy metal frame filled with a mixture of lead oxide powder and sulfuric acid.

However, this structure is not preferable for batteries that require light weight.

Accordingly, the present invention provides a lightweight lead-acid storage battery using a novel laminated electrode structure.

This laminated electrode consists of three layers, the center layer is a conductive plate, the other two layers are each composed of porous compressed sintered plates made of a homogeneous composite of fibers coated with active powder material, 90 to 100% of the fibers are synthetic fibers, and the remainder is natural fibers.

The reason for using this range of synthetic fibers and the balance natural fibers is that thermoplastic (e.g. synthetic) fibers are required to sinter the mat to obtain a porous compacted sintered board, and the synthetic fibers used are 90% This is because if it is less than that, a properly sintered mat cannot be obtained.

This lead-acid battery is lightweight.

This is because the electrode plate of the battery is composed of the three-layer laminated electrode structure described above.

These electrode plates are approximately 30-50% lighter than conventional paste battery grids containing the same amount of active material.

Additionally, these composite plates are much lighter and more flexible than regular battery grids and can be shaped into a wide range of irregular shapes, such as folded, curved, spiral, etc. It can also be formed into a cylindrical shape, which is not possible with conventional paste-type battery grids.

The central layer of the three-layer laminated structure consists of a thin plate of a conductive material, such as a thin metal plate or a paperboard containing a conductive material, preferably a thin porous lead plate, which is separated by two lightweight sheets. Compression sintered composite plates are sandwiched in a sandwich shape, and these composite plates are composed of fibers and an active material such as lead oxide, lead, tribasic lead sulfate, or tetrabasic lead sulfate.

Next, the configuration of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, two composite plates 13 and 14 made of synthetic fibers and lead oxide powder are laminated on a lead foil plate 11 having a large number of holes 12.

The lead plate is extended from the composite plate by about 1.27 CrrL to form an ear portion 15, which is connected to the electrode.

The lead foil board is electrically conductive, and the composite board is a porous compacted sintered board consisting of a homogeneous mixture of fibers and lead oxide.

FIG. 2 shows an example in which the laminated composite electrode shown in FIG. 1 is used as an electrode plate of a storage battery.

The storage battery consists of a plastic case 21 and seven laminated composite electrodes, three of which act as anode plates 22 and the remaining four as cathode plates 23.

The plates are separated from each other by separators 24 and mounted on a support 25 at the bottom.

These supports extend along the lateral width of the battery and provide sufficient clearance 26 to collect active material that falls off the plates during use.

The four cathode plates connect their cathode ears 2T to cathode terminals 28.
Connected by welding to.

Similarly, the three anode plates are connected by welding the anode ears 29 to the anode terminals 30.

The storage battery is provided with a lid 31, and the lid is provided with a terminal plug and an exhaust plug.

When using a storage battery, charge it with dilute sulfuric acid to the top of the electrode plate.

When the electrode structure according to the present invention is incorporated into a lead-acid storage battery, the battery becomes lightweight and exhibits high rate discharge characteristics with an excellent cycle life.

Furthermore, the electrode structure of the present invention has excellent mechanical strength and is simple and economical to manufacture.

This electrode structure is manufactured as follows.

The conductive plate forming the center layer of the three-layer laminated structure is
Use lead or lead alloy foil or metal plates or paperboard containing conductive materials.

Further, it is preferable that the center plate is made of a porous thin lead plate having an opening area of up to 9.0 mm relative to the total area of the conductive plate.

The use of this perforated plate is particularly desirable.

This is because when the three-layer structure is superimposed, the pores are filled with fibers and active material, resulting in the formation of a strong and airtight bonded laminate.

Additionally, the center plate may be constructed of conductive paperboard or the like containing, for example, fine graphite or granular lead metal particles that act as current collectors.

The conductive plate used as this current collector may be either flexible or rigid.

The synthetic fibers used in the composite board according to the present invention are (1)
The electrolyte, for example sulfuric acid present in the battery (2) The active material present or formed in the composite plate (3) Provided that it is not substantially attacked by the gases normally generated during charging and discharging of the battery. do.

These fibers include polyethylene and polypropylene.

Furthermore, it is desirable to use fibers having fiber length and fineness such that the value of fiber length x fineness is 25 or less.

Examples of these fibers include single fibers or fiber bundles that approximate cellulose fibers.

Furthermore, it has been found that up to about IO% of these synthetic fibers can be replaced with natural fibers if desired.

The active material that can be used in the composite board may be a lead metal powder or a lead compound that is normally used as an active material in the production of lead-acid batteries, such as lead oxide or lead,
Tribasic lead sulfate and tetrabasic lead sulfate are mentioned.

The amount of active material consisting of lead oxide powder used in the composite board is
Can be varied over a wide range.

However, the amount of active material in the composite board is preferably 50 to 99 parts by weight for each part of the synthetic fiber.

The electrode structure of this lightweight accumulator can be manufactured by simple and economical means.

That is, a composite board made of a homogeneous braid of synthetic fibers and an active material such as lead oxide powder can be manufactured by the same method as that used for manufacturing paperboard in the paper industry.

Typically, synthetic fibers coated with a surface treatment agent are dispersed in water with stirring and thoroughly mixed to a concentration of about 0.05 to 0.
A slurry containing 2% solids is formed.

Add lead oxide powder to this fiber slurry, mix well, and then add a coagulant.

Next, the pH of the slurry is lowered to obtain coarse agglomerates of fibers and lead oxide.

The coagulum is filtered and collected on a sieve to form a composite board consisting of a relatively homogeneous mat of fibers coated with lead oxide powder.

After air drying, the composite board is pasted on both sides of a conductive plate, for example a porous lead metal plate, and the thus obtained three-component structure is exposed to atmospheric pressure at a temperature of 120°C to 200°C. A three-layer laminated structure electrode body is obtained by heating and compressing under a pressure of 13,000 psi.

Next, embodiments of the present invention will be described below.

Example 1 The three-layer laminated electrode was manufactured as follows.

1,91 polypropylene fiber coated with a surface treatment agent (
Fineness 3 denier, fiber length 31ul, fiber width 0.0251
11jIl) 57727! moistened with isopropanol.

The wet fibers were placed into a rolling blender with 100 yd of water.

After the first kneading operation, 800 yards of water was added and mixed for about 1 minute.

After transferring to a large container, add water to bring the volume to 1200, then add 25.61 L of lead oxide (accumulator grade lead oxide).
was added to the fiber slurry and the mixture was thoroughly kneaded.

Xantham Gum (by Kelco Company)
Add 25 g of a 0.5 polyhydric solution (commercially available under the trade name JROL N) to the mixture and, with stirring, add Ming Chun solution at the level used by paper manufacturers to reduce the pH of the slurry from 9 to 4. , at this pH value the fiber-lead oxide mixture formed coarse agglomerates.

The slurry containing the coagulum was immediately poured into a flat mold and the mold was filled with water to obtain a raw consistency of 0.5% solids.

After thoroughly stirring the slurry, it was drained and the paperboard was formed into a 40 mesh border.

Next, the flat plate was removed along with the trim and allowed to dry.

The obtained plate material contained 95 weight φ of lead oxide.

The three-layer laminated electrode was manufactured as follows.

A conductive metal plate with dimensions of approximately 5.72 x 12.7 cIrL and a lead foil thickness of 19U was used.

A large number of holes were bored in the lead foil plate in a honeycomb structure, the hole diameter was about 4.767 ul, and the total opening area was 56 ul.

A portion of the narrow end of the foil plate was not drilled with a hole, but a solid foil ear of approximately 1.27 mm (near 71) was formed along the edge.

The composite board obtained in this way is approximately 4.44X5crI'L.
A porous metal foil plate was interposed between the two flat plates, and the two plates were laminated by heat-pressing at a temperature of 165°C for about 10 minutes under a pressure of 12,001 bs/sq.

A three-layer plate type storage battery using this electrode was completed as follows.

The laminated electrode was cut into plates of approximately 2°54 x 5.715 cfrL, the edges of the plates were coated with paraffin, and the diameter was approximately 3.1 cm.
A 75M lead rod was welded to a solid lead ear extending from the metal foil plate.

Three of these plates were placed in a longitudinal groove in a rectangular plastic box to form a triode battery.

The vertical groove has a polar plate of approximately 3.175 mm. Designed to be separated.

Fill the battery with an electrolyte (sulfuric acid with a specific gravity of 1.070) and use a constant current such that the current density of the positive electrode active material is 15 mA/g (milliampere per unit duram).
Time conversion was performed.

After chemical formation, the acid with a specific gravity of 1.070 was replaced with an acid with a specific gravity of 1,300.

Furthermore, adjustment charging of the positive electrode active material at 9 mA/g was performed for 16 hours.

Next, this storage battery was repeatedly discharged and charged for five cycles and tested in the following manner.

The battery was discharged through a 10 ohm resistor and the discharge time recorded during each cycle to determine the final voltage during discharge.
．． I set it to 8v.

The resistors were chosen such that each discharge period resulted in an average current density of 7 mA/y in the active material.

The cell was then charged for 16 hours with a voltage of 2.5V and a limited current of 120mA.

The above discharge and charge steps were performed for a total of five complete cycles.

The average voltage of the storage battery for 5 cycles is 2. The average efficiency at OV was about 32.0%.

The storage battery capacity is 43mAH/? of the total plate weight? (milliampere hours per unit duram).

Example 2 In this example, a three-layer layered electrode was again produced as in Example 1, but in this case polyethylene fibers were used instead of polypropylene.

The composite board was manufactured by the method of Example 1, and the metal foil used in this example was the same as that used in Example 1.

A three-layer laminate structure was manufactured according to the process of Example 1, except that the temperature was 138°C.

The storage battery has an average of 2. It was held at a voltage of OV.

The average storage battery efficiency was 44%.

The storage battery capacity was 71 mAH/V of total electrode weight.

Examples 3-10 These examples demonstrate the effect of varying the amount of lead oxide active material in the composite board and the effect of varying pressure when heat-pressing the final laminated electrode.

Several three-layer laminated electrodes were manufactured in the same manner as in Example 1.

These composite plates had different contents of active material (lead oxide), and the final electrodes were manufactured by changing the heating pressure and compression time.

A battery case for testing was constructed, and the test was repeated for 5 cycles according to the storage battery test method of Example 1.

Table 1 shows the test results obtained according to the procedure of Example 1.

Example 11 This example shows the structure of a three-layer laminated electrode using graphite paper as the center layer instead of a porous lead plate.

A three-layer stacked electrode was manufactured in the same manner as in Example 1, but
In this case graphite paper was used as the center layer.

A battery case with a three-layer laminated electrode was constructed and tested in the same manner as in Example 1.

The battery was held at an average voltage of 2.5V for all five tests.

The average storage battery efficiency is 9%, and the battery capacity is 8m of the total electrode weight.
It was AH/f.

Example 12 In this example, a solid lead foil plate was used as the center layer instead of a porous lead plate.

A three-layer laminated electrode was formed according to the method of Example 1 using 35.2 S' lead oxide and 1.92 S' polypropylene fiber.

In this case, a solid lead foil plate was used as the center layer.

A three-layer laminated electrode container was constructed and tested according to the method of Example 1.

The battery case has an average of 2. It was held in OV.

The storage battery efficiency is 27%, and the battery capacity is 65m of the total plate weight.
It was AH/f.

Example 13 In this example, lead powder was used as the active material of the electrode instead of lead oxide.

A composite board consisting of 35.29% lead powder and 1.92% polypropylene/fiber was produced according to the method of Example 1.

The laminated electrodes were heat-pressed at a temperature of 165° C. and a pressure of 1200 psi for 15 minutes.

The resulting three-layer electrode type battery case was constructed and subjected to a 5-cycle test in the same manner as in Example 1.

The battery case was maintained at an average of 2 OV for an average time each time, and the average battery efficiency was 10%.

The battery capacity was 11 mAH/l of the total plate weight.

Examples 14-15 In these examples, tribasic lead sulfide and tetrabasic lead sulfide were used as the active materials of the electrode plates.

Composite boards were manufactured according to the method of Example 1, in which the content of active material was varied.

A three-layer laminate was constructed in the same manner as in Example 1, and a two-electrode test battery was constructed to test its cycle life.

The results were as follows.

The following example shows an example in which the laminated electrode described above is used in a 2V storage battery.

Both of these laminated electrodes were used as an anode plate and a cathode plate.

The anode and cathode plates were separated from each other using commercially available battery separators.

In this case, most commercially available separators can be used.

However, the most common separators are perforated or porous boards made of polyvinyl chloride, rubber, polyethylene, and resin-coated heavy paperboard.

Example 1 shows an example in which a stacked electrode is used in a 2V storage battery with three anode plates and four cathode plates.

7 using lead oxide as the active material according to the method of Example 1.
A laminated electrode was formed, and this was placed as an electrode plate in a rectangular Lucite container as shown in FIG.

Four of these plates were connected to the negative terminal, and the remaining three plates were connected to the positive terminal.

Both the positive and negative terminals extended above the container.

Six commercially available battery separators were interposed between the anode and cathode plates.

The separators used were constructed in a corrugated manner and used porous polyvinyl chloride plates.

A Lucite lid with positive and negative terminal plugs and a vent plug was placed on top of the container.

Fill the storage battery with a sulfuric acid electrolyte with a specific gravity of 1.070.
Temporal conversion was carried out using a constant current of 15 mA/S' for the active material.

After chemical formation, sulfuric acid was replaced with sulfuric acid having a specific gravity of 1.260.

Adjusted charging of positive electrode active material at 9 mA/f was carried out over a period of 16 hours.

The battery was tested for 5 cycles according to the battery test method of Example 1, with a discharge current of 0.5 using a 4 ohm resistor.
I gave it an A.

The battery was maintained at an average of 2, QV over 5 cycles.

The storage battery efficiency is 27.4% and the battery capacity is 6% of the total plate weight.
It was 5.9 m AH/f/.

Example 17 In this example, three of the 2V batteries described in Example 16 were installed in a hedge-trirrmer.
) A 6-inch storage battery was constructed by placing it inside the case.

Also, three 2V storage batteries successfully energized the head trimmer.

Example 18 In this example, a three-layer laminated electrode was produced as in Example 1, in this case using a braid of 95 weight fibers and 5 weight soft wood pulp fibers.

The polyethylene fiber had a fineness of 0.4 denier and a fiber length of 1 vIt, while the soft wood fiber had a fineness of 2 denier and a fiber length of 3712a.

A composite board was manufactured according to the method of Example 1, and the metal foil used was the same as the foil board used in Example 1.

A three-layer laminate structure was constructed using the method of Example 1,
However, in this case, the sintering temperature is 120'c and the pressure is 1150°C.
It was 0psi.

The storage battery has an average of 2. It was held in OV.

The average storage battery efficiency was 42.3%.

The battery capacity was 101 mAH/ff of the total plate weight.

The operating conditions and results obtained are shown in Table 1.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway vertical perspective view of a laminated electrode having a three-layer structure, and FIG. 2 is a partially cutaway vertical perspective view of a lightweight lead-acid storage battery using seven laminated composite electrodes as electrode plates. 11... Lead foil plate, 12... Hole, 13, 14...
Composite board, 15...Ear part, 21...Case, 22...
・Anode plate, 23... Cathode plate, 24... Separation plate, 25
... Support body, 26 ... Gap, 27 ... Cathode ear part,
28... Cathode terminal, 29... Anode ear part, 30...
Anode terminal, 31...lid body.

Claims (1)

[Claims] 1 Disperse fibers in water with stirring to form a slurry, 90 to ioo% of the fibers are synthetic fibers and the remainder are natural fibers, add powdered active material to the slurry, mix thoroughly, and then adjust the pH. A dispersed slurry is condensed while reducing to form a coarse condensed air consisting of fibers and active material, and the condensed air is filtered and dried to form a relatively homogeneous condensed air consisting of fibers coated with the active material. A matte composite board is formed, and the homogeneous matte composite board made of fibers coated with the active material is adhered to both sides of a conductive plate to form a sandwich structure, and the sandwich structure is A three-layer laminated electrode structure is formed by heating and compressing at a temperature of C to 200'C and a pressure of atmospheric pressure to 13,000 psi, and a porous compression sintered composite plate is used for each of the outer two layers. A method for producing a laminated electrode for a lightweight lead-acid storage battery, characterized by: