JPS62122077A - Nonaqueous secondary battery - Google Patents

Abstract

PURPOSE:To increase cycle performance of using a clad plate of a metal plate which is alloyed with lithium and a metal plate for negative case as a negative can, and locating the metal plate which is alloyed with lithium inside the case. CONSTITUTION:A positive electrode 2 is pressed against the inner bottom of a positive case 1 made of a 0.33mm thick stainless steel plate through a positive current collector 3. A negative can also serving as a negative electrode is made of a clad plate of a 0.1mm thick aluminum plate 5 acting as negative electrode and a 0.2mm thick stainless steel plate 6 serving as negative can, and the aluminum plate 5 locates inside the can. By using the negative can combined with the negative electrode, its thickness is increased to 0.3mm and mechanical strength in sealing part is increased. Thereby, the effective volume within a battery is increased and the volume of electrolyte is also increased and the cycle performance is improved.

Description

[Detailed Description of the Invention] U) Industrial Field of Application The present invention relates to a non-aqueous secondary battery that includes positive and negative electrode cans, an insulating backing that insulates them from each other, and uses lithium as the negative electrode active material. .

(B) Conventional technology This secondary battery uses a reaction in which lithium, which is a negative electrode oil substance, becomes ions and comes out of the negative electrode during discharge, and is deposited as lithium on the negative electrode by the reverse m reaction during photovoltage. There is, but'
There is a problem that lithium oxide tends to grow in a tree-like shape and eventually reaches the positive electrode, causing an internal short circuit.

In order to deal with these five inconveniences, for example,
It has been proposed to use a lithium-aluminum alloy as a lithium-aluminum alloy disclosed in Japanese Patent No. 5425 for a negative electrode. In addition to aluminum, metals that form alloys with lithium include zinc, indium, silicon, tin,
Examples include lead. The advantages of lithium alloys are as described above.

In other words, in the case of lithium alone, when the lithium is eluted as ions, the negative electrode surface becomes uneven, and during the temporary photovoltage, lithium is deposited intensively on the protrusions and grows in a dendritic shape. In the case of a lithium-aluminum alloy, the dendritic growth of lithium is suppressed because lithium is restored to form an alloy with aluminum, which is the base of the negative electrode.

However, a lithium alloy is used. There is a problem with people telling each other. In other words, when using a molded body of lithium alloy powder, there is a problem with mechanical frequency, so it is necessary to use a binder, which makes the manufacture of the binder complicated, and the addition of a binder reduces the performance of the binder. It is undeniable that the deterioration of Furthermore, when using a lithium alloy plate, it is difficult to obtain a good electrical connection between the negative electrode and the negative mtfs. For example, for a lithium-aluminum alloy plate as a negative electrode and a stainless steel plate as a negative electrode, spot welding is done by rotating magnetism, which saves one. A good electrical connection cannot be obtained just by using an IOE bond.

(c) While the invention is about to be resolved, the present invention basically uses a lithium alloy for the negative electrode,
Solving the above problems of lithium alloys and reducing cycle%
The purpose of the present invention is to obtain a pond in a non-aqueous secondary i1 with excellent performance. Clad with m&? use.

The feature is that gold NIi and gold alloying reaction with lithium are located inside the battery.

Metals that react with lithium include aluminum, zinc, indium, silicon, and tin.

Examples include lead, and can-forming metals include stainless steel,
Nickel, iron, etc. can be leathered.

(E) Effect According to the battery of the present invention, since the negative electrode and the negative electrode are integrated, there is a good 1! The air connection state is maintained. In addition, it is known that the larger the amount of tS liquid in this Hajiyaku Pond, the better the cycle characteristics, and in the case of the battery of the present invention, a part of the negative electrode constitutes the negative electrode! The above also has a friend cycle characteristic in which the movable volume within the pond increases and the amount of electrolyte can be increased.

(f) Implementation example Examples of the present invention will be described in detail below.

Example 1 Figure 1 shows a half-sectional view of a flat non-aqueous electrolyte secondary battery according to an example of the present invention, and in Figure VC, (1) has a thickness of C1.
A positive electrode can is made of a stainless steel plate, and a positive electrode (2) is pressure-welded to the inner bottom surface of the positive electrode can via a positive electrode current collector (3). For the positive electrode (2), a positive electrode mixture was mixed in a ratio of 85:10!5 with F3' disulfide as an active material, acetylene black as a conductive agent, and fluorinated africant oil as a binding agent. It was weighed and molded to be 7m%, and this molded body containing t lithium gourd was heated at 8 and a current was placed at 1.
It is demagnetized to 50% of the theoretical valley type at mA/- and doped with lithium ions as a negative electrode active material.

Therefore, (4) is a negative plate for the negative electrode which is an important feature of the present invention, and includes an aluminum plate (5) with a thickness of 0.1 m which acts as a negative electrode and a plate with a thickness α2 which acts as a negative plate. It consists of a cladding plate with a stainless steel plate (6), and an aluminum plate (5) is attached to the same side of '1a'. (7; is a polypropylene surface separator, (8) is a liquid-retaining layer made of Karasu 1 fiber, and this liquid-retaining layer is made by dissolving 1 mol/l of lithium perchlorate in propylene carbonate and using Yuho water electrolyte. (9) is an insulating package.

And since this phosphoric acid 4?1 is in a discharged state, it becomes a 2. The negative electrode is left in the state of an alloy of lithium and aluminum after being charged for 50 hours at OmA. The pond dimensions are 2 ton Qam in diameter and 50 ton Qam in height. This 11L pond of the present invention is referred to as (A1).

Implementation fl12 Negative pot can also be used as a negative electrode (4 is 5, thickness 0.5 is used as a negative electrode)
The clad plate consists of a 1# zinc plate and a 0゜2u thick stainless steel plate that acts as a negative surface.The zinc plate is inside the battery.
The 'ML Pond' was the same as in Example 1 except that it was located at 11111. This invention' electricity (A2
).

In addition, for comparison, a stainless steel plate with a thickness of 0.3 was used as the negative electrode, and the inner bottom surface had a thickness of Q, 1 as the negative electrode.
Other than press-welding M aluminum plate and using 7c
A first comparison 4 pond (Bt) similar to that in Example 1 and a stainless steel plate with a thickness of 0.3 fl were used as the negative plate, and the FF was
A second comparative battery (B2) was the same as Example 1, except that a 0.1 m thick zinc plate was fully pressure-welded as a negative electrode on the bottom surface of J (B2).

The table below shows the comparison of the amount of electrolyte used in each of these 6 types of batteries (A1) and (A2). It can be seen that the amount has increased by about 20% compared to the pond.

The reason why Dantoguchi won this Kameishi Prize is due to Shiide. That is, in order to maintain the mechanical 5G ratio of the sealing part in a battery having a structure in which the insulating backing is crimped, the thickness of the negative electrode is determined as ILiT (0.5- ) or more is safe.

Therefore, in cases where the negative electrode and the amount of negative electrode are separate, such as the comparison battery, the thickness of the negative electrode can material -'j'to, is set to 5M.
It is necessary to provide a separate negative electrode.

For crt and vc, if a negative electrode fE is used which integrates the negative electrode and the negative electrode amount as in the battery of the present invention, the mechanical strength of the sealing part can be improved by using a material with a thickness of 0.3 M. Since this can be maintained, the effective volume within the pond increases and the amount of electrolyte t can be increased.

Fig. 2 is a custom-made diagram of the cycle of the '4 cell, and the cycle conditions are the light 'RL current': QmA and the light 'ζ final voltage of 4.0.
■, -10,000 discharge current2. Discharge end voltage 15V at QmA
Then, a 6-hour cycle test was conducted. It can be seen from FIG. 2 that the batteries of the present invention (At) (Az) have improved cycle characteristics compared to the comparative batteries (B1) and (B2).

The reason for this is that in the 'lLa1'C of the present invention, the negative smoker and negative heating can are integrated, so a good electrical connection between the two can be maintained and the effective volume of W inside the battery is increased. This is because the amount of electrolyte increases.

In addition, when celebrating the present invention, the non-aqueous electrolyte secondary
All examples are shown in case a, but two vcit using solid electrolyte
It also applies to i-ike ponds.

(g) Effects of the invention As mentioned above, in the non-aqueous secondary tm, which is provided with an insulating backing that insulates the positive and negative electrodes and all of them, and uses lithium 74 as the negative electrode active material, alloyed with lithium as the negative electrode amount. By using a clad plate consisting of a reacting metal plate and a can-forming metal plate, and placing the metal plate that undergoes an alloying reaction with lithium on the g side of the battery, cycle characteristics can be improved. It is extremely important to be wise in expanding the uses of ponds.

[Brief explanation of drawings]

FIG. 1 is a half-sectional view of a flat non-aqueous electrolyte secondary battery according to an embodiment of the present invention, and FIG. 2 is a comparison diagram of cycle characteristics. (IJ...Positive electrode can, (2)...Positive electrode, (3)...
Positive electrode current source, (4)...Negative electrode ffi that also serves as negative electrode, (
51... Metal plate that undergoes an alloying reaction with lithium, (6).
... Can component metal plate, (7) ... Separator. (8)...Liquid retaining layer, (9)...Insulating backing.

Claims (1)

[Claims] (1) A device comprising positive and negative electrode cans and insulating packing for electrically insulating them, and using lithium as a negative electrode active material, wherein the negative electrode can is a cladding of a metal plate that undergoes an alloying reaction with lithium and a can-constituting metal plate. 1. A non-aqueous secondary battery comprising a plate, wherein the metal plate that undergoes an alloying reaction with lithium is located inside the battery.