JPS60195877A - Positive electrode for cell - Google Patents

Abstract

PURPOSE:To obtain a positive electrode for cell capable of being used at a high temperature and stored in a high temperature by forming an ion conductive solid component with a polymer compound using an electrolyte, an organic polymer compound, and siloxane as a principal chain or a main constitutent. CONSTITUTION:Polydimethyl siloxane which has hydroxyl group as an end groups and the molecular weight of about 2,000 is processed with dehydration treatment in a vacuum heating/drying unit and is used for a polymer compound. Lithium perchlorate used as an electrolyte is added to acetone and stirred and dissolved, then polyvinylidene fluoride which is an organic polymer compound is added to it and is stirred and dissolved while being heated. Polydimethyl siloxane is added to this solution and is thoroughly mixed while being heated. Manganese dioxide used as a positive electrode active material and acethylene black used as a conductive agent are added to this solution and is further stirred and mixed while being heated to gasify acetone and obtain a mixture. After acetone is completely removed from this mixture, this mixture is crushed into powder, then the powder of this mixture is put into a molding pattern and is pressed and molded to obtain a disk-like positive electrode 1A.

Description

[Detailed description of the invention] (Technical field) The invention relates to a positive electrode body for batteries, and in particular, it combines excellent mechanical properties such as ease of processing and binding properties inherent in polymers and high ionic conductivity. The present invention relates to a battery positive electrode body containing an ionic 241r solid composition.

(Prior Art) In general, a positive electrode body for a pond (hereinafter referred to as a positive electrode body) consists of a positive electrode active material, a conductive agent, a binding agent, and an ion conductive material. Conventionally, as an ion conductive material, in a so-called wet battery, an electrolyte is dissolved in water or an organic solvent to form an fc'a electrolyte solution.

Furthermore, a solid electrolyte is used in a battery called a solid battery.

The above-mentioned electrolyte solution is used in many batteries because it has a high ion 4 content, but since water and FC use liquids such as organic solvents as materials, there is a risk of liquid leakage to the outside of the battery. There are always problems.

This leakage may cause deterioration of battery performance and loss of hot water in peripheral parts. Therefore, a battery using a positive electrode body containing this electrolyte solution has a drawback of lacking high eccentricity.

10,000, since solid electrolytes are solids, they inherently have a high 1B
It is an ion conductive material that can be applied to reliable and long-life batteries, and is suitable for making parts smaller and thinner. These solid electrolytes include beta alumina (β-AJ, 0
．． ), lithium aluminum iodide (L I I -A
lI Us ) + silver rubidium iodide (R,b-Ag
Various materials have been developed, such as 41sLi&lithium oxide (Li3N) and lithium iodide (Bi). However, in addition to the disadvantages in terms of characteristics such as low ionic conductivity at room temperature and poor dexterity, the material was expensive and had various disadvantages such as poor mechanical workability. has. Therefore, batteries using such solid electrolytes are used only for special purposes, and have not yet been put into widespread practical use. For the same reason, cathode bodies containing solid electrolytes are also hardly put into practical use.

In contrast, one inventor discovered in Japanese Patent Application No. 58-093563 that an ionically conductive circular body composition is suitable as an ionically conductive material for a positive electrode body. This ionically conductive circular body composition consisting of polyvinylidene fluoride, gamma-butyrolactone, and lithium perchlorate has high ionic conductivity as a solid body (substance that is apparently in a top surface state under usage conditions). It also has the good binding properties and easy processability of polyvinylidene fluoride. By using this as a substitute for the conventional ion 4 material,
A positive electrode body suitable for solid-state batteries was obtained.

However, because the boiling point of gamma-butyrolactone in this cathode body is not very high, gamma-butyrolactone gradually vaporizes from the cathode body under conditions such as high temperature use or storage at high temperatures, resulting in ionic conductivity. The disadvantage was that the properties deteriorated. This causes a significant deterioration of battery characteristics over time, and is a particularly serious problem for solid-state batteries, which are characterized by long life and long-term reliability.

(Object of the invention) The object of the invention is to provide a positive electrode body for a battery that improves the conventional drawbacks.

(Structure of the Invention) According to the invention, in a positive electrode body for a battery containing an ionic conductive circular body composition, the ionic 4Tlt solid body composition has an electrolyte, an organic polymer compound, and a siloxane in its main chain or main chain. A positive electrode body for a battery is obtained, which is characterized by being composed of a polymer compound as a component.

The most distinctive feature of the present invention lies in the use of conventional h-molecule compounds. here.

1 (and 1 mo') is an alkyl group, an alkokene group, or an aromatic derivative such as a perzyl group or a phenyl group.

Typical examples of such polymeric compounds include silicone compounds such as silicone oil and silicone varnish, which are known to have excellent heat resistance, chemical resistance, insulation properties, and the like. These polymer compounds generally have almost no vapor pressure and do not easily vaporize like conventional solvents. Therefore, by applying them to the positive electrode, they have high heat resistance and high 1g reliability. A positive electrode body is obtained.

The present invention will be explained below with reference to Examples.

[Example 1] In this example, a polymer compound including polydimethylsiloxane having a terminal group of hydroxyl group and a molecular weight of about zoooo was heated to a temperature of about 190°C in a vacuum heating dryer. It was used after being dehydrated for 20 hours at a vacuum degree of 1 O-2 torr or less.

After adding 100 CCKm of acetone and 0.5 gr of perchlorine [IJ thium] and stirring to dissolve it, add the organic polymer compound polyvinylidene fluoride, ogr'.

The mixture was stirred and dissolved while heating at a temperature of 40°C.

5. Add the above polydimethylsiloxane to this solution. QCC was added and thoroughly mixed while heating at a temperature of 40°. Add 25 gr of manganese dioxide, which is the positive electrode active material, to this solution.
and 4111 agent acetylene brane, ri1. Ogr money holder,
Further, while stirring and mixing with a rotary evaporator while heating at a temperature of 40'O, acetone was vaporized to obtain a mixture. This mixture was dried in a vacuum heating dryer at T vacuum degree IQ to
After drying at a temperature of 120° for 2 hours to completely remove acetone, the mixture was crushed to a powder state, and the powder of this mixture was placed in a 1.0grt molding die at a pressure of 2.000Kg/ Pressure molded in cm2, thickness 1.3
mm, ? ! A disk-shaped positive electrode body IA'lt with a diameter of 18 mm was used. This positive electrode body IA had strong binding properties and was not damaged at all during handling.

Next, the diaphragm 2 is made of ionic 4It solid composition gold consisting of polyvinylidene fluoride, gamma butyrolactone, and lithium perchlorate, each having a composition ratio of 2 in the J1j1' ratio.
0:4:1, diameter 20mm, thickness 0.1
mm(D#lI!'t'' was prepared.

The negative electrode body 3 is a lithium sheet with a thickness of Q and a diameter of 17 mm.
It was prepared by punching it out in mm.

Next, the positive electrode body IA, the diaphragm 2. The negative electrode body 3 was laminated in the outer cases 4 and 5 and the insulating ring 6 as shown in FIG. 1, and then caulked and sealed to produce a coin-shaped battery. A load resistance of 100 Kr was fully connected to this battery, and the discharge characteristics were measured. The results are shown in A of Figure 2.

[Example 2] In the non-example, a cathode body IB having the same shape was produced using materials and manufacturing methods similar to those in Example J, with a molecular weight of about L200 and 40 parts by weight. This cathode body IB and the cathode body IB produced in Example 1 Positive electrode body I and positive electrode body I using gamma petiloranoton by conventional means
Three types of positive electrode bodies of C were left at a temperature of 80° 0 for 20 days. When we examined the weight change of each cathode body before and after leaving it, we found that the cathode body using the uninvented polymer compound showed almost no weight loss, whereas the cathode body made by conventional means showed no weight loss due to the vaporization of gamma-butyrolactone. There was a weight reduction of approximately 380 inches.

Next, a coin type battery was produced according to Example 1 using each positive electrode body after being left at high temperature, and the discharge characteristics were measured with a load resistance of 100 KΩ. The results are shown in B of Figure 2.

H and CtIi in FIG. 2 shown in C and D are according to the present invention, and each contains polydimethylsiloxane,
It uses a copolymer of dimethylsiloxane and ethylene oxide. C in FIG. 2 is a conventional method using gamma-butyrolactone as an organic solvent.

The positive electrode body according to the present invention has a discharge quantity of electricity which is more than 40% higher than that produced by the conventional means, and A and B in FIG.
There was almost no difference when comparing the characteristics of the two, and there was almost no deterioration of the characteristics after being left at high temperatures.

In Examples 1 and 2, all the steps up to battery production were performed in an argon inert gas atmosphere.

(effect) As described above, non-invention has the following effects.

(:) A battery positive electrode body that can be used and stored at high temperatures is obtained.

A solid battery with a wide operating temperature range, long life, and long-term reliability can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a coin-type battery manufactured in a non-example, and FIG. 2 is a discharge characteristic diagram of a battery using a positive electrode body manufactured by the non-invention and conventional means. s A# lB+ s C...Positive electrode body, 2...
...Diaphragm, 3...Negative electrode body, 4 and 5...
...Exterior case, 6.Insulation ring, A...
...Those using polydimethylsiloxane as the polymer compound according to the present invention, B...Those using polydimethylsiloxane as the polymer compound and after high temperature storage %C...
... After high temperature storage using a copolymer of dimethylsiloxane and ethylene oxide as a polymer compound, D...
... after high temperature storage using gamma-butyrolactone by conventional means.

Claims (1)

[Claims] A positive electrode body for a battery containing an ionic 4i solid body composition, characterized in that the ionically conductive circular body composition consists of an electrolyte, an organic polymer compound, and a polymer compound having siloxane as a main chain or main component. Positive electrode body for batteries.