JPS6316561A - Electrode for battery - Google Patents

Abstract

PURPOSE:To accomplish tight adherence between a solid electrolyte and an electrode active material by electrochemically and integrally forming the electrode active material on one side or both sides of the thin plate of the solid electrolyte made from the mixture of resin and salt. CONSTITUTION:A solid electrolyte made from the mixture of resin and salt is stuck over a prescribed electrically conductive substrate and this substrate is set in the electrodeposition liquid capable of electrically depositing an electrode active material as an electrode. Then, the electrode active material is integrally formed in the layer on one side or layers on both sides of the solid electrolyte by way of anode-oxidation or cathodedeoxidation of the electrode. Thus, the solid electrolyte and the electrode active material are tightly stuck to each other and also can be bent easily, so that, no peeling off of the electrode active material takes place even if they are bent. The electrode is very useful for industry for its excellent strength, etc. like disclosed above.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a battery electrode comprising a solid electrolyte and an electrode active material.

(Prior Art) It has recently been discovered that a specific polymeric substance and a salt form a complex, and that the complex has extremely high ionic electrical conductivity. That is, by mixing desired amounts of lithium persalt oxide and propylene cargo with polyvinylidene fluoride, a complex having a high lithium ion conductivity of 10 Lii is obtained.

(Etactroehamie Todoroki Acta 28 P5
91#'83) Also, polyphosphazene derivatives and Ag5O
By mixing with 3CF3, a complex having extremely high ionic conductivity such as RI10a/yn is obtained. (J,
AmeChem*Soc, IJllji P6&54
We found that these complexes can be formed into flexible films and retain the properties of the original polymer material, making them suitable for use as solid electrolytes in battery electrodes. . However, battery electrodes are formed by adhering an electrode active material to the solid electrolyte, and the quality of adhesion between the two significantly affects the characteristics of the battery.

In recent years, there has been an increase in demand for thin batteries of this kind, and in particular, card-shaped batteries with a thickness of several pots or less have become necessary.
In these batteries, various characteristics that are hardly required in conventional batteries, namely strength against bending and reliability, have become extremely important. Therefore, in terms of adhesion between the solid electrolyte and the electrode active material, the conventional adhesion strength is insufficient, and there is a demand for an even higher strength adhesion.

(Problems to be Solved by the Invention) As a result of intensive research in response to such demands, the present invention has developed a battery electrode that improves the adhesion strength between a solid electrolyte and an electrode active material.

(Means for Solving the Problems) The present invention involves sticking a solid electrolyte made of a mixture of a resin and a salt onto a predetermined conductive substrate, and placing it in an electrodeposition solution capable of electrodepositing an electrode active material. The electrode active material is integrally formed inside one or both sides of the solid electrolyte by installing the electrode as an electrode and then subjecting the electrode to anodic oxidation or cathodic reduction.

In the present invention, the resin is a common polymeric substance, preferably a polar polymeric substance such as polyethylene oxide, polypropylene oxide, polymethyl methacrylate, or polyvinylidene fluoride.

Polyvinyl chloride, broken vinylidene chloride, polyphosphazene, or derivatives thereof, and particularly preferred substances are polyethine oxide, polypropylene oxide, mortarized phosphazene, polyph, and vinylidene chloride.

In addition, in the present invention, salts include Ag5O, CF, AgCl
O4゜Ag BF 4e Ag I jRbA g 4
I s * Na S CN e Na So 3 C
F 3s Na C1Oa * Li5C) JILIS
O4CF, , L 1cto4# Li BF4. L
iPF4. LiAsF6. Cu (C1O4) 2゜Cu(AN)4PF6. Mg(C4O4)2 etc.,
Preferred are alkali metal salts.

A known method is used to mix the above resin and salt to obtain a solid electrolyte. That is, the resin and the salt are dissolved in a desired solvent to form a uniform solution, which is then dried. At this time, the solvent may be left to some extent without being sufficiently removed.

In addition, in the present invention, the electrodeposition solution that can electrodeposit the electrode active material is:
An inert conductive substrate is placed in the electrodeposition solution as an anode or cathode, and electrochemically oxidized or reduced.
For example, the electrode active material is deposited on the substrate by constant potential, constant voltage, potential scanning, single flow scanning, or the like. In addition, when using the constant potential method, it is necessary to set the potential to the reduction potential of the metal ion or the polymerization potential of the monomer, respectively. The electrode active materials include metals such as lithium d1 copper and magnesium, polypyrrole, and lianiline.

Organic polymeric substances such as polyazulene and polythiophene are preferred. When a metal is used as an electrode active material, the electrodepositing solution is limited to a solution containing a salt of the metal as an electrolyte, and when an organic polymer material is used as an electrode active material,
The electrodepositing solution is limited to monomers of the organic polymer material, such as virol, aniline azulene, thiophene, etc., and a desired supporting electrolyte. The anion of the supporting electrolyte must be one that can serve as a dopant for the organic polymer material, and preferably CtO4''eBF4-tAs.
F6-ePF6-, So, CF3-, etc.

In addition, the conductive substrate in the present invention must be inert in the potential region where the electrodeposition reaction occurs, and it is necessary to select an appropriate substrate according to the type of electrode active material to be electrodeposited. There is.

Preferred are platinum, gold, and indium tin oxide glasses, which can be used for the electrodeposition of most polar substances.

In addition, in the present invention, in order to adhere the solid electrolyte onto the conductive substrate, the solid electrolyte thin body "fr: is mechanically compressed, or a mixed solution of resin and salt is applied onto the conductive substrate. Alternatively, a conductive substrate is impregnated in the solution and then dried.

(Example) Example (1) 10CC of glopylene cardene) and 1.5% of polyvinylidene fluoride! A solution in which lithium perchlorate is dissolved in 4 cc of propylene carbonate is mixed with a solution in which lithium perchlorate is dissolved in 4 cc of propylene carbonate.
O glass was immersed for several seconds to coat the glass surface with the above solution, and vacuum-dried at 100° C. for 18 hours to obtain a solid Jgl film with a thickness of 0.31 mm on the glass surface.

The film was then placed in a solution containing 1 mol/l of total lithium perchlorate and 0.1 mol/l of hibirol dissolved in acetonitrile, and anodized with a constant current of 40 mA. . After 10 minutes, all traffic was stopped.

The ITO glass substrate was removed from the solution and dried, and a polypyrrole layer about 0.1 mm thick was deposited on the contact surface of the substrate. When peeled from the substrate, the thickness was approximately 0.3 m.
Free scounding and flexible solid ML electrolyte electrode activity? An electrode for a battery of the present invention made of a composite film with I (polypyrrole) was obtained.

The polypyrrole adhered well to the resin, and even though it was bent several dozen times, the falling acid did not cause any peeling.

A small piece of 2×3α was cut out from the composite film thus obtained, and a lithium foil 3 with a thickness of about 0.1 ml was placed on the side of the solid electrolyte 4 on which polypyrrole was not attached, as shown in FIG.
When a lithium/polypyrrole battery was created by crimping a nickel plate 1.1' with a thickness of about 0.1 m from both sides of the lithium foil 3 and polypyrrole 5 using adhesive 2, an open circuit was observed. It was a battery that could be charged and discharged at a voltage of approximately 3.2 volts.

Example (2) As shown in FIG. It was dried to obtain a solid electrolyte.Also, leads were taken out from the other side of the substrate, and polypyrrole was deposited in the same manner as in Example (1) to obtain an electrode for a battery of the present invention.The polypyrrole was formed on a nickel substrate 6. The nickel substrate, polypyrrole and the solid electrolyte were deposited near the nickel mesh, and the nickel substrate, polypyrrole and solid electrolyte adhered extremely well.

A battery was prepared in the same manner as in Example (1) using 6Li and lithium as a counter electrode for the thus obtained battery. The open circuit voltage of this battery was approximately 3.2 volts, and charging and discharging was possible.

Example (3) An ITO lath substrate coated with a solid electrolyte was prepared in the same manner as in Example (1), and the substrate was treated with lithium perchlorate at a concentration of 1 mol/l. It was placed in a solution of tolyl. This was used as a cathode for electrolysis at a constant current of 40 mA, and after 10 minutes it was pulled up, yielding a film-like electrode for a battery of the present invention in which a lithium electrode active material was deposited on the contact surface of the solid electrolyte with the ITO glass substrate.

This film was dried in vacuum, and a battery was prepared in the same manner as in Example (1) except that one electrode was bound and a sheet of manganese dioxide was used as a counter electrode.

The open circuit voltage of this battery was approximately 3.0 celts, and charging and discharging was possible.

Example (4) A polyvinylidene fluoride solution prepared in the same manner as in Example (1) was applied to two IT plates facing each other in parallel with an interval of 1+m.
It was dropped between O glass substrates, and a solid electrolyte film was obtained between the substrates in the same manner as in Example (1).

Then, the solid electrolyte films were brought into close contact with each other.
It was placed in the same solution as in 1), and a constant current of 40 mA was applied for 10 minutes using the ITO glass substrate as a pair of electrodes. As a result, polypyrrole was deposited on the cyanode side as in Example (1), and lithium was deposited on the cathode side as in Example (3). Lithium, solid electrolyte e from ITO glass substrate
1f! ') By peeling off the virole night coalescence, a flexible and free-standing film-like electrode for the battery of the present invention was obtained.

From this film, a small piece of 92x3z was cut out and a nickel plate was crimped onto it as shown in Figure 1 to prepare a battery. This battery was capable of charging and discharging at an open circuit pressure of about 3.2 holts.

Example (5) In Example (1), instead of vinylidene heptadide?
A film-shaped electrode for a battery of the present invention made of a composite of a solid electrolyte and polypyrrole was obtained in the same manner as in Example (1) except that methanol was used in place of propylene cardenate for polyethylene oxide.

A battery was produced using this electrode in the same manner as in Example (1). The open circuit voltage of this battery was approximately 3.2, and charging and discharging was possible.

(Effects) As detailed above, the battery electrode of the present invention has extremely good adhesion and flexibility because the electrode active material and the solid electrolyte are integrated, so even if it is bent, the electrode active material remains intact. It is extremely useful industrially as it does not peel and has excellent strength.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are schematic explanatory diagrams for producing an electrode for a battery according to the present invention. 1.1'... Exterior work, Kel board, 2... Sealing adhesive, 3... Lithium foil, 4... Solid electrolyte, 5...
...Polypyrrole, 6...2, Kel substrate. Applicant's agent Patent attorney Takehiko Suzue Figure 2

Claims (1)

[Claims] A battery electrode characterized in that an electrode active material is electrochemically formed integrally on one or both sides of a solid electrolyte thin body made of a mixture of a resin and a salt.