# US 2014/0154589 A1 · Cathode material for an alkali-sulfur cell

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- Number: US 2014/0154589 A1
- Document ID: US20140154589A1
- Status: Published application
- Kind: A1
- Application number: 14/114,411
- Filed: 2012-03-07
- Published: 2014-06-05
- Earliest claimed: 2011-05-02
- Assignees: Robert Bosch GmbH
- Inventors: Marcus Wegner; Jens Grimminger; Martin Tenzer; Jean Fanous
- Web page: https://patentgrep.com/patent/US20140154589A1

## CPC

- H01M 4/364: {as mixtures}
- C08F 8/34: Introducing sulfur atoms or sulfur-containing groups
- H01M 4/1399: of electrodes based on electro-active polymers
- H01M 4/602: {Polymers}
- H01M 10/052: Li-accumulators
- H01M 10/39: working at high temperature
- H01M 4/137: Electrodes based on electro-active polymers
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

In a method for preparing a cathode material for an alkali-sulfur cell, e.g., a lithium-sulfur cell, at least one polyacrilonitrile-sulfur composite material and elemental sulfur are mixed, in order to increase the voltage, the capacitance and the energy density.

## Claims

### Claim at position 1

1-14. (canceled)

### Claim 15

A method for preparing a cathode material for an alkali-sulfur cell, comprising:
a) mixing at least one polyacrilonitrile-sulfur composite material having covalent sulfur-carbon bonds and elemental sulfur.

### Claim 16 (depends on 15)

The method as recited in claim 15, wherein in method step a) a polyacrilonitrile-sulfur composite material having covalent sulfur-carbon bonds is used, which is prepared by a reaction of polyacrilonitrile with sulfur at a temperature of ≧300° C.

### Claim 17 (depends on 15)

The method as recited in claim 15, wherein in method step a) a polyacrilonitrile-sulfur composite material having covalent sulfur-carbon bonds is used, which is prepared by a reaction of polyacrilonitrile with sulfur in the presence of a catalyst.

### Claim 18 (depends on 15)

The method as recited in claim 15, wherein in method step a), a polyacrilonitrile-sulfur composite material having covalent sulfur-carbon bonds is used, which has polysulfide chains bound covalently to a polyacrilonitrile skeleton, having a chain length of at least three sulfur atoms.

### Claim 19 (depends on 15)

The method as recited in claim 15, wherein in method step a), a polyacrilonitrile-sulfur composite material having covalent sulfur-carbon bonds is used, which is prepared by a method in which, in a first step, polyacrilonitrile is converted to cyclized polyacrilonitrile, and in a second step, the cyclized polyacrilonitrile is converted with sulfur to a polyacrilonitrile-sulfur composite material having covalent sulfur-carbon bonds.

### Claim 20 (depends on 15)

The method as recited in claim 15, wherein in method step a) a polyacrilonitrile-sulfur composite material having covalent sulfur-carbon bonds is used, whose proportion of sulfur atoms bound in a thioamide unit, in relation to the total number of sulfur atoms in the polyacrilonitrile-sulfur composite material, is ≦25 atom-percent.

### Claim 21 (depends on 15)

The method as recited in claim 15, further comprising:
b) admixing an electrically conductive additive including at least one of soot, graphite, carbon fibers, and carbon nanotubes.

### Claim 22 (depends on 21)

The method as recited in claim 21, further comprising:
c) admixing a binding agent including at least one of polyvinylidene fluoride and polytetrafluoroethylene.

### Claim 23 (depends on 22)

The method as recited in claim 22, wherein at least one of:
in method step a), ≧10 wt.-% to ≦30 wt.-% of polyacrilonitrile-sulfur composite material and ≧30 wt.-% to ≦60 wt.-% of elemental sulfur are mixed;
in method step b), ≧5 wt.-% to ≧20 wt.-% of the electrically conductive additive is admixed; and
in method step c), ≧5 wt.-% to ≦20 wt.-% of the binding agent is admixed.

### Claim 24 (depends on 22)

The method as recited in claim 22, wherein the amount of elemental sulfur used in method step a) is selected such that the sulfur proportion of the polyacrilonitrile-sulfur composite material and of the elemental sulfur, in total, amounts to ≧50 Gew.-% with reference to the total weight of the cathode material.

### Claim 25 (depends on 15)

A cathode material for an alkali-sulfur cell, wherein the cathode material is prepared in accordance with the method of claim 15.

### Claim 26 (depends on 15)

An alkali-sulfur cell, comprising:
an alkali-containing anode and a cathode;
wherein the cathode includes a cathode material prepared in accordance with the method of claim 15.

### Claim 27 (depends on 26)

The alkali-sulfur cell as recited in claim 26, wherein the alkali-sulfur cell includes an electrolyte made up of at least one electrolytic solution agent and at least one conducting salt, and wherein at least one of: (i) the electrolytic solution agent includes at least one of cyclic ethers and acyclic ethers; and (ii) the conducting salt includes lithium bis(trifluoromethylsulfonyl)imide.

### Claim 28 (depends on 26)

The alkali-sulfur cell as recited in claim 26, wherein the alkali-sulfur cell is part of an energy store.