JPH10312795A - Electrode for battery and battery with it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the holding force of a metal active material, accelerate the electrochemical reaction of the active material and an electrolyte, reduce the internal resistance of a battery, and allow a quick charge/discharge by kneading the metal active material into the fibered metal of a fine wire-like random-orientation aggregate, and forming a plate-like body with the prescribed thickness. SOLUTION: This electrode 1 is provided with a fibered metal 3 and a metal active material 4, and the fibered metal 3 is formed as a fine wire-like random- orientation aggregate. Lead is gelatinized by dilute sulfuric acid as the metal active material 4 for a negative electrode, for example, and it is kneaded between the constituting metal fibers of the fibered metal 3 under pressure. The metal active material 4 entering complicated intervals can be firmly held by the complex shape of the fibered metal of the random-orientation aggregate constituting the electrode 1 and mutual entangling. When powdery activated carbon is mixed in the metal active material 4 constituting the electrode 1, the surface area is increased, the electrochemical reaction of the metal active material 4 and an electrolyte is accelerated, and a quick charging/discharing can be made.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode for a secondary battery (hereinafter, simply referred to as "electrode") and an improvement of a battery using the same.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
As a metal active material 16, lead is supported on a current collector 7 in the form of a metal casting lattice or a mesh lattice made of lead / antimony or a lead / calcium alloy, but the lead of the metal active material 16 has a large reaction surface area. In order to improve the reaction efficiency by improving the passage of the electrolyte solution, the porous structure is spongy granular. Further, as an example using activated carbon, for example, a lithium battery using a lithium alloy for a negative electrode, a positive electrode filled with a positive electrode active material between fibers and compression molding using an activated carbon fiber cloth is disclosed in No. 62-226561).

[0003]

In the conventional electrode having a cast grid shape, since the grid shape obtained by the casting method is simple, the supporting force of the sponge granular lead active material is insufficient and the sponge granular lead active material falls off. May be. In addition, the spongy pore structure of the lead active material lacks a function for satisfying the electrochemical reaction, and a shorter charging time has been required. In addition, a battery using an activated carbon fiber cloth which is filled with a positive electrode active material and compression-molded has characteristics such as characteristics of a capacitor and a small capacity as a battery. An object of the present invention is to obtain an electrode that enhances the metal active material supporting force, accelerates an electrochemical reaction between an active material and an electrolyte, reduces internal resistance of a battery, and enables rapid charging and discharging, and a battery using the same. With the goal.

[0004]

In order to achieve the above object, according to the first aspect of the present invention, a metal active material is kneaded between fibrous metals of a thin line and randomly oriented aggregate and has a predetermined thickness. The problem was solved by the battery electrode formed on the plate-like body. According to the second aspect of the present invention, in the battery electrode according to the first aspect, a battery electrode in which a mixture of a metal active material and powdered activated carbon is kneaded between fibrous metals can be provided. According to the third aspect of the present invention, an electrode for a battery is provided in which a mixture of a metal active material and powdered activated carbon is kneaded into a current collector of a metal casting grid shape or a mesh grid shape to form a plate having a predetermined thickness. Solved by. In the invention according to claim 4, in the battery electrode according to any one of claims 1 to 3, the fibrous metal and the metal active material include lead, manganese, iron,
Zinc, nickel, lithium, aluminum, copper, silver,
An electrode for a battery can be made of any one of titanium, zirconium, lanthanum, gold, and platinum, or an alloy thereof.

According to the invention of claim 5, claims 1 to 4 are provided.
The problem was solved by a battery in which the battery electrode described in any one of the above was disposed as a negative electrode and a positive electrode. According to the invention of claim 6, in the battery of claim 5, it is possible to provide a battery in which fibrous activated carbon is disposed along an appropriate portion around the electrode. According to the invention of claim 7, a battery is provided in which a fibrous activated carbon is disposed along an appropriate position around an electrode in which a metal active material is supported on a current collector in the form of a metal casting grid or a mesh grid. did.

[0006]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic (a) front view and (b) side view of an example of the electrode of the present invention. FIG. 2 is a schematic front view of another example of the electrode of the present invention. FIG. 3 is a schematic side sectional view of an example of a battery using the electrode of the present invention. FIG. 4 is a schematic front view of an example of a conventional electrode. FIG. 5 is a schematic side sectional view of an example of the battery of the present invention in which fibrous activated carbon is provided on the electrode of FIG. FIG. 6 is a graph showing the relationship between the discharge duration and the number of times of charging and discharging of the battery of FIG. 5 and an example of a conventional battery.

In FIG. 1, an electrode 1 of the present invention has a fibrous metal 3 and a metal active material 4. An opening of a U-shaped holding member 6 is sandwiched in the upper part of the electrode 1, and is connected to the holding member 6 so as to connect conductors 5 necessary for discharging from the electrode 1 to the outside or charging the electrode 1 from the outside. It has. The fibrous metal 3 is formed as a thin line and a random orientation aggregate. The fibrous metal 3 is preferably made of, for example, 0.3 mm fine linear stainless steel plated with lead and used as a randomly oriented aggregate to prevent chemical change between the stainless steel and dilute sulfuric acid. But lead, manganese, iron,
Zinc, nickel, lithium, aluminum, copper, silver,
Titanium, zirconium, lanthanum, gold, and any single or alloy of platinum can be selected as the material,
The same applies to other examples below. The metal active material 4 is, for negative electrode, for example, gelled with lead sulfuric acid or the like and kneaded under pressure between the constituent metal fibers of the fibrous metal 3. The other materials described above can be selected as the raw materials, and the same applies to the following other examples. The electrode 1 is obtained by forming a plate-like body having a predetermined thickness with the fibrous metal 3 and the metal active material 4 and then heating and drying the plate. For example, the electrode 1 is dried at 200 ° C. for 3 hours with a plate thickness of 2 mm.
For the positive electrode, for example, lead peroxide is gelled with diluted sulfuric acid or the like and kneaded under pressure between the constituent metal fibers of the fibrous metal 3. Due to the complicated shape and mutual interaction of the fibrous metal of the randomly oriented aggregate constituting the electrode 1, the metal active material 4 entering the complicated interval can be firmly supported.

In FIG. 2, the electrode 2 of the present invention comprises a current collector 7, a metal active material 4, and a powdered activated carbon 8. The wiring 5 is connected to the upper part of the current collector 7. The current collector 7 is made of, for example, lead / antimony or a lead / calcium alloy in the form of a metal casting lattice or a mesh lattice similar to that described with reference to FIG. For the metal active material 4, for example, lead is gelled with dilute sulfuric acid or the like for use as a negative electrode, and a gel-like mixture obtained by mixing powdered activated carbon 8 with the mixture is kneaded into the grid-like gap of the current collector 7 to obtain a predetermined thickness. The electrode 2 is obtained by drying after forming into a plate-shaped body. For the positive electrode, for example, lead peroxide is gelled with diluted sulfuric acid or the like, and a gel-like mixture obtained by mixing powdery activated carbon 8 with the gel is kneaded into the lattice-shaped gap of the current collector 7.
The increased surface area of the powdered activated carbon 8 mixed in the metal active material 4 constituting the electrode 2 accelerates the electrochemical reaction between the metal active material and the electrolyte in the electrode, reduces the internal resistance of the battery and enables rapid charging and discharging. I made it. When a gel-like mixture obtained by mixing a metal active material 4 and powdered activated carbon 8 between the fibrous metals 3 of the electrode 1 described in FIG. 1 is kneaded instead of the current collector 7 constituting the electrode 2, It is possible to have a function of firmly supporting the metal active material 4 and accelerating the electrochemical reaction.

In FIG. 3, a battery 10 using the electrode 1 of the present invention has a positive electrode 11 inside a container 15 opposite to the negative electrode 1.
Is provided in the gap between the negative electrode 1 and the positive electrode 11 as a porous insulator, for example, a separator 13 made of glass fiber mat.
Are provided, wirings 5 and 5 necessary for discharging to the outside or charging from the outside via a holding material (not shown) from the upper part of the negative electrode 1 and the positive electrode 11 are provided.
For example, diluted sulfuric acid 4 is filled so as to immerse the negative electrode 1, the positive electrode 11, and the separator 13. The negative electrode 1 is
For example, it is composed of a fibrous metal 3 plated with lead on stainless steel and a metal active material 4 of lead. The positive electrode 11 is made of, for example, a fibrous metal 3 lead-plated on stainless steel and a metal active material of lead peroxide. As a further optional configuration, FIG.
As shown in FIG. 7, it is desirable to arrange the felt-like fibrous activated carbon 12 in a contact state along a side surface of the negative electrode 1 without any special processing. The location of the fibrous activated carbon 12 is most preferably on the side surface of the negative electrode 1, but is not limited to this, and may be a suitable location around the top or bottom. Further, the disposition location may be the negative electrode 1 and / or the positive electrode 11. In the battery 10, the metal active material that has entered the spaces between the randomly oriented metal fibers constituting the electrodes 1 and 11 is firmly supported, and as a battery, the electrochemical reaction between the active material and the electrolyte is accelerated and maintained. In addition, the fibrous activated carbon 12 is
By disposing the fibrous activated carbon 12 at an appropriate position in the periphery of the electrode 11, the increased surface area of the fibrous activated carbon 12 can further accelerate the electrochemical reaction between the metal active material and the electrolyte in the electrode. In the battery 10, instead of the electrodes 1 and 11, the electrode 2
And a gel-like mixture obtained by mixing the metal active material 4 and the powdered activated carbon 8 into the fibrous metal 3 in place of the current collector 7 constituting the electrode 2. It may be.

In FIG. 5, a battery 19 of the present invention has a positive electrode 18 disposed inside a container 15 opposite to a negative electrode 17.
A separator 13 made of, for example, a glass fiber mat is inserted as a porous insulator into the gap between the negative electrode 17 and the positive electrode 18, and the separator 13 is provided from above the negative electrode 17 and the positive electrode 18 to the outside via a holding material (not shown). Wirings 5 and 5 necessary for discharging or charging from the outside are provided, and a container 15 is filled with, for example, dilute sulfuric acid as an electrolytic solution 14 so as to immerse the negative electrode 17, the positive electrode 18, and the separator 13. As described with reference to FIG. 4, for example, the negative electrode 17 supports lead as the metal active material 16 on the current collector 7 in the form of a metal casting lattice or mesh lattice made of lead / antimony or a lead / calcium alloy, and has a sponge grain shape. The positive electrode 18 is made of a lead peroxide metal active material instead of the lead of the negative electrode 17. In the same manner as the electrode 1 of FIG. 3, for example, a felt-like fibrous activated carbon 12 is arranged in a contact state along a side surface without special processing. The location of the fibrous activated carbon 12 is most preferably on the side surface of the negative electrode 17, but is not limited to this, and may be a suitable location on the top or bottom. Further, the disposition location may be the negative electrode 17 and / or the positive electrode 18. By arranging the fibrous activated carbon 12 in a suitable position around the electrodes 17 and 18, the increased surface area of the fibrous activated carbon 13 can accelerate the electrochemical reaction between the metal active material and the electrolyte in the electrode.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a container 15 described with reference to FIG. 5, lead is carried on a current collector 7 in the form of a metal casting lattice made of a lead / antimony alloy or the like. A supported positive electrode 18 is arranged, a separator 13 made of glass fiber mat is inserted into a gap between the negative electrode 17 and the positive electrode 18, and a dilute sulfuric acid is filled in the container 15 as an electrolyte 14. Activated carbon having a specific surface area of 2000 m ² / g using a phenol resin as a starting material.
The battery 19 provided with was used as an example. A battery using only the conventional electrode described with reference to FIG. 4 under the same conditions as the battery 19 with the amount of the lead active material, the size, the amount of the electrolytic solution, the charging time, the container, and the like was used as a comparative example. The first to sixth repeated charge / discharge tests were performed using the batteries of the examples and the comparative examples under the following conditions. Charge setting: 2.5V constant voltage, 60 minutes charge Discharge setting: 1A constant current discharge until 1.7V depth depth discharge: After 1.7V, both positive electrode and negative electrode wires are directly connected and 60 minutes deep discharge Battery external temperature : About 3 ° C. The test results are shown in FIG. 5 and as comparison data of the first charge / discharge to the sixth charge / discharge. Where "A"
Indicates the current flowing through the battery in amperes at the time of each charging time. "Internal resistance value" refers to the internal resistance of the battery after charging, and "Duration" is the time up to 1.7V IA discharge. Say.

First Charge / Discharge Comparison Data Example Comparative Example 10 minutes charge 1.77A 0.35A 20 minutes charge 1.15A 0.34A 30 minutes charge 0.79A 0.31A 40 minutes charge 0. 61A 0.28A At 50 minutes of charging 0.59A 0.27A At 60 minutes of charging 0.39A 0.19A Internal resistance after charging 33mmΩ 46mmΩ Duration of discharge 34 minutes 56 seconds 6 minutes 11 seconds Second charge / discharge comparison data Example Comparative Example 10 minutes charging 1.69A 0.21A 20 minutes charging 1.19A 0.22A 30 minutes charging 0.72A 0.19A 40 minutes charging 0.54A 0.16A 50 minutes charging 0.43A 0 .13A 60 minutes after charging 0.37A 0.11A Internal resistance after charging 33mmΩ 63mmΩ Discharge duration 31 minutes 44 seconds 3 minutes 33 seconds Third charge / discharge comparison data Example ratio Example 10 minutes charging 1.28A 0.18A 20 minutes charging 1.09A 0.19A 30 minutes charging 0.75A 0.14A 40 minutes charging 0.54A 0.10A 50 minutes charging 0.40A 0. 09A 60 minutes at charge 0.33A 0.07A Internal resistance after charge 33mmΩ 77mmΩ Duration of discharge 26 minutes 36 seconds 2 minutes 20 seconds 4th charge / discharge comparison data Example Comparative example 10 minutes at charge 1.02A 0.12A charge 20 minutes 0.85A 0.10A Charge 30 minutes 0.56A 0.08A Charge 40 minutes 0.38A 0.07A Charge 50 minutes 0.32A 0.07A Charge 60 minutes 0.28A 0.06A Charge Internal resistance after 34 mmΩ 149 mmΩ Discharge duration 16 minutes 50 seconds 0 minutes 22 seconds 5th charge / discharge comparison data Example Comparative example 10 minutes at charge 1.08A 0.04A Charge 2 0 minute 0.68A 0.10A 30 minute charge 0.37A 0.07A 40 minute charge 0.29A 0.06A 50 minute charge 0.25A 0.05A 60 minute charge 0.23A 0.05A charge Internal resistance after 34 mmΩ 145 mmΩ Discharge duration 16 minutes 46 minutes 16 seconds 6th charge / discharge comparison data Example Comparative example 10 minutes at charge 0.94A 0.09A 20 minutes at charge 0.74A 0.07A 30 minutes at charge 0.43A 0.05A Charge 40 minutes 0.27A 0.05A Charge 50 minutes 0.22A 0.04A Charge 60 minutes 0.20A 0.04A Internal resistance after charging 34mmΩ 159mmΩ Discharge duration 15 minutes 21 seconds 0 Minute 10 seconds

As is clear from the above test results, the discharge duration of the example significantly exceeds the discharge duration of the comparative example, and the discharge duration of both the example and the comparative example decreases each time the charge / discharge test is repeated. In the fourth to sixth charge-discharge tests, the discharge duration of the comparative example was 22 to 10 seconds, which was almost impossible to discharge.
A good discharge duration of 0 seconds to 15 minutes and 21 seconds was obtained. The fact that the example is superior to the comparative example in terms of the discharge duration is that a constant voltage of 2.5 V, 60
In the case of minute charging, this is supported by the fact that the embodiment is superior to the comparative example in charging efficiency and internal resistance after charging.

[0014]

According to the battery electrode of the present invention, due to the complicated shape and mutual interaction of the fibrous metal of the random orientation aggregate constituting the electrode, the metal active material that has entered the complicated interval can be firmly strengthened. It can be supported, and a battery using this electrode is effective for repeated use. In addition, the surface area is increased by mixing powdered activated carbon into the metal active material constituting the electrode, which accelerates the electrochemical reaction between the metal active material and the electrolyte at the electrode, and the battery using this electrode has a reduced internal resistance. And rapid charging and discharging is possible. In addition, the battery in which the fibrous activated carbon is disposed without special processing along the periphery of the electrode without special processing, the increased surface area of the fibrous activated carbon accelerates the electrochemical reaction between the metal active material and the electrolyte at the electrode. It is possible to extend the battery life economically.

[Brief description of the drawings]

FIG. 1 is a schematic (a) front view of an example of an electrode of the present invention,
(B) It is a side view.

FIG. 2 is a schematic front view of another example of the electrode of the present invention.

FIG. 3 is a schematic side sectional view of an example of a battery using the electrode of the present invention.

FIG. 4 is a schematic front view of an example of a conventional electrode.

5 is a schematic sectional side view of an example of the battery of the present invention in which fibrous activated carbon is provided on the electrode of FIG.

FIG. 6 is a graph showing the relationship between the discharge duration and the number of times of charging and discharging of the battery of FIG. 5 and an example of a conventional battery.

[Explanation of symbols]

 1, 2, 11, 17, 18 Electrode 3 Fibrous metal 4, 16 Metal active material 5 Wiring 6 Holding material 7 Current collector 8 Powdered activated carbon 9 10, 19 Battery 12 Fibrous activated carbon 13 Separator 14 Electrolyte 15 Container

Claims (7)

[Claims] 1. An electrode for a battery, wherein a metal active material is kneaded between fibrous metals of a thin line-shaped randomly oriented aggregate to form a plate having a predetermined thickness. 2. The battery electrode according to claim 1, wherein
An electrode for a battery, wherein a mixture of a metal active material and powdered activated carbon is kneaded between fibrous metals. 3. An electrode for a battery, wherein a mixture of a metal active material and powdered activated carbon is kneaded into a current collector in the form of a metal casting grid or a mesh grid to form a plate having a predetermined thickness. . 4. The battery electrode according to claim 1, wherein the fibrous metal and the metal active material are lead, manganese, iron, zinc, nickel, lithium, aluminum, copper, silver, titanium, An electrode for a battery, comprising a single substance or an alloy of zirconium, lanthanum, gold, and platinum. 5. A battery comprising the battery electrode according to claim 1 as a negative electrode and a positive electrode. 6. The battery according to claim 5, wherein a fibrous activated carbon is provided along a suitable portion around the electrode. 7. A battery characterized in that fibrous activated carbon is provided along an appropriate portion around an electrode on which a metal active material is supported on a current collector in the form of a metal casting grid or a mesh grid.