JPS5949155A - Primary battery having polythiadil cathode and alkaline metal anode - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Polythiazyl, also known as sulfur nitride polymer or poly(sulfur nitride) or (SN) It is a known inorganic f IJ mother material. Various methods are known to improve its conductivity (eg, exposure to halogens). “5olid, 5tat, eGommuni ca” by K. Kaneto
tions”, vol. 40, p. 889 (1981)
showed that polythiazyl can form a complex with sodium metal without decomposition.

R. J. Novak et al., in a talk at the Electrochemistry Society meeting held on May 10, 1982 at IJ All, Canada, stated that polythiazyl is a scale that reductively decomposes in a solution containing a tetraalkylammonium salt. pointed out.

A similar observation is made by “Elcstrocllimica Ac
C. Bernard et al. t, a-vol. 25, pp. 435-4, 9 (1980). They observed the surface decomposition of (SN)x at cathodic potential in acetonitrile solutions of either tetraalkyl or alkali metal salts.

It has been proposed for batteries, especially secondary batteries, to use a polymer cathode with a conjugated t, l backbone and a lithium ano-F deficient one. Especially MHeD1+lrmit1 (1 9
See U.S. Pat. No. 4,621,114 (82). The patent mainly discusses acetylene polymers (・-(・ru), but also examines other conjugated polymers (・°C・ru (44th, '.58-63). (see line)., 1
? There is no mention of inorganic rel-mers having a conjugated backbone such as +1 thiadyl.

It has been discovered that high energy and high power density primary cells can be made using polythiazyl or chloride yl''4 lithiazyl cathodes and lithium, sodium or alloy anodes.

Therefore, the present invention provides (α) polythiazyl and norogen treatment 1-ta,f
+) Inorganic ++'e selected from the group consisting of thiadyls
Remarker Casso-F; (51 Anode selected from the group consisting of lithium, lithium alloys, sodium and sodium alloys;
and (C) an electrolyte comprising an alkali metal salt dissolved in a polar organic solvent;

The battery of the present invention is a primary battery and cannot be recharged. - During discharge of the cell, the inorganic polymer cathode decomposes 1-5 as detailed below.

The cathode of the present invention includes an inorganic polymeric material, either yalithiazyl or...logen-treated polythiazyl. Among the halogen-treated polythiazils, chlorine- and bromine-treated (doped) polythiazils are preferred, and bromine-treated polythiazils are most preferred. Such materials are sometimes also referred to as ``rogenated'' or ``brominated'' materials.

Doping with bromine is more suitable. If the polythiazyl is halogenated, the discharge process involves first a reaction in which the halogen is separated from the cathode (e.g. by reduction or substitution or decompression 1f) and a second reaction in which the polythiazyl backbone is separated from the cathode by an arc T11''. The molecular weight of the inorganic polymers is not critical, but is preferably a molecular weight sufficient to form an infusible, insoluble conductive layer.Processes for the preparation of inorganic polymeric materials are described by G.B. Sl,re
el. 'Mol-ecu. J. arMeta. J
-s”, pages 501-326.

A composition in which the ratio of sulfur to nitrogen is 1:1 is preferred from the standpoint of minimizing the internal resistance of the battery;
: There is no necessity for it to be 1. This low internal resistance means that a one-to-one composition of formula (SN)
1 (compared to other compositions containing only (S=N) units,
This is due to the fact that the conductivity is high.

The physical form of the inorganic crystal is also not limited, and various forms are possible including pre-ret, single crystal, and thin film. In addition to the inorganic materials, other materials may also be present in making the battery, such as binders. One other suitable material is carbon powder.

The anode of the battery of the invention is lithium or a lithium alloy or a sodium or strium alloy. The most preferred anode material is lithium itself, although lithium/aluminum and lithium/boron alloys are the preferred species.

Again, the physical form is not limited, but lithium foils, plates or ronds are particularly suitable.

The electrolyte of the battery of the invention consists of an inorganic alkali metal salt dissolved in a polar organic solvent. The cation of the salt is usually lithium or sodium, depending on the anode, with lithium being preferred. It is also conceivable that an alkali metal salt other than lithium or sodium is present at least initially. Suitable salts include those in which the anion is a halide, a complex anion containing a halide (e.g., tetrafluoroborate, hexafluoroarsenate, hexafluorophosphate and trifluoromethanesulfonate) or a complex anion containing oxygen. Mention may be made of anions such as perchlorate and other complex anions such as tetraphenyl boride. Particularly preferred salts are lithium halides, especially lithium chloride or lithium bromide. When using halogenated polythiazyl,
The anion in the electrolyte corresponds to the halogen dopant in the inorganic 71'':rif.

The inert polar organic solvent used in the electrolyte may be any of those conventionally used to dissolve lithium salts, preferably esters (
(e.g. propylene carbonate), aliphatic ethers (e.g. dimethoxyethane) and cyclic ethers (e.g.
For example, tetrahydrofuran). Particularly preferred solvents are hydrogen carbonate and dimethoxyethane. Mixtures of these solvents may also be used. It is also conceivable to use solid electrolytes such as salts dispersed in polyethylene oxide.

Lithium to be present for inorganic polymers? The amount of the inorganic polymer is at least the amount necessary for reductive decomposition of the inorganic polymer. If the inorganic yN+)mer is halogenated, the additional lithium must be dehalogenated and decomposed (directly or indirectly by electrochemical means). Generally, at least one lithium is required for each -84N4- of the inorganic polymer of the inorganic polymer cathode, and at least one lithium is required for each halogen atom in the inorganic polymer. For lithium alloys, generally only lithium is counted.

Excesses of 200 to 400 inches or more of this minimum are contemplated.

The concentration and amount of lithium salt is not limited, but generally provides a conductivity of at least about 2 x 103 s/C of the solvent and electrolyte sufficient to wet both the cathode and anode.
Levels of IrL [limited by enough salt in the electrolyte to A3: Separation between the cathode and anode should be sufficient (including sufficient separators if used) to prevent significant self-discharge; long shelf life may not necessarily be necessary. For example, it is conceivable that a dry cell battery may be filled with an electrolyte solution immediately before use.

Are the following two examples the invention? This is the instruction manual.

Example 1 Under an inert atmosphere, a powdered "brominated"('5N)
SN Bro, 25)X and (SN Bro, 4)X
Two batteries were made with the mixture.

This powder contains 5% Sbawingan B, 1ac
(acetylene black from Gulf Oil Chemical Co.) and pressed into pellets. When this pellet was used as a cathode in a cell with a lithium anode and an electrolyte of propylene carbonate (PC) saturated with LiBr, the discharge curve (charge versus voltage) of this cell showed two plateaus. Ta. '54~6.2V
The upper plateau (shown later to be characteristic of brominated samples) is (SN BrO, 335)) (47)! Not
47.5 A 417 kg customer use was increased compared to the i-amount.

The lower Ara)-' (which seems to correspond to the reduction of (SN)X itself) of 27 to 2.4■ showed a capacity of 15.0 Ah/kg based on the weight of (SN)x alone. Solid (SN
) was observed to dissolve during discharge.

EXAMPLE 2 A cell was made with a small piece of (SN)x single crystal as the cathode, a lithium anode and an electrolyte consisting of Lj, Br in PC. A single discharge plateau was seen between 2.9V and 2.6V. The incomplete discharge of the cell was 139 Ah/kg based on the weight of (SN)x crystal. (Note: The discharge of one electron per 24 SN units was 9 in 144 A11/.) Patent applicant Allied Corporation 1゛1 Agent Patent attorney Kyo Yu Asa 3□ (4 others)

Claims (1)

[Scope of Claims] (I) (α) A cathode comprising an inorganic polymer selected from the group consisting of polythiazyl and (c) halogen-treated polythiazils; (h) the group consisting of lithium, lithium alloys, sodium and sodium alloys; Anode selected from;
and (C) an electrolyte comprising an alkali metal salt dissolved in a polar organic solvent; (2) The primary battery according to claim 11, wherein the inorganic polymer is polythiazyl. (3) The inorganic polymer is brominated polythiazyl.
A primary battery according to claim (1). (4) The primary battery according to any one of claims (1), (2), and (3), wherein the anode is lithium. (5) The primary battery according to claim (4), wherein the alkali metal is a lithium salt. (6) The primary battery according to any one of claims (1), (2), and (3), wherein the inert organic solvent is propylene carbonate.