Polymer electrolyte for a lithium sulfur cell

Patent metadata

Field	Value
Publication number	US-10601031-B2
Application number	US-201515316063-A
Country	US
Kind code	B2
Filing date	Jun 5, 2015
Priority date	Jun 6, 2014
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A polymer or a polymer electrolyte and cathode material for an alkali metal cell, in particular for a lithium-sulfur cell. To improve the performance and reliability of alkali metal cells, for example lithium-sulfur cells, a polymer based on the general chemical formula (I) is provided, where -[A]- stands for a unit which forms a polymer backbone, X stands for a spacer, x stands for the number of spacers X and is 1 or 0, Q stands for a positively charged group Q+ and a counterion Z−, or Q stands for a negatively charged group Q− and a counterion Z+, or Q stands for an uncharged group. Moreover, the invention relates to the use thereof, and a cathode, a separator, a protective layer, and a cell.

First claim

What is claimed is:

1. A cathode material for an alkali metal cell, comprising:
at least one cathode active material containing sulfur;
at least one polymer electrolyte including at least one repeating unit of the general chemical formula:

 wherein:
-[A]- stands for a polymer backbone-forming unit,
X stands for a spacer,
x stands for the number of spacers X and is 1 or 0, and
Q stands for
a negatively charged group Q − and a counterion Z + , or
a positively charged group Q + and a counterion Z − ; and

at least one of (i) at least one copolymer which includes at least one first repeating unit and at least one second repeating unit that is different from the at least one first repeating unit, the at least one first repeating unit having the general chemical formula:

 wherein the at least one second repeating unit is a partially or completely fluorinated alkylene oxide unit, and/or is a repeating unit which bears a partially or completely fluorinated alkylene oxide function; and/or (ii) a polymer blend of at least one first polymer and at least one second polymer, the at least one first polymer including at least one repeating unit of the general chemical formula:

 wherein the at least one second polymer is a partially or completely fluorinated polyalkylene oxide and/or includes a repeating unit which bears a partially or completely fluorinated alkylene oxide function.

2. The cathode material of claim 1 , wherein
the at least one second repeating unit is an ethylene oxide unit and/or a repeating unit which bears an oligoethylene oxide function, and
the at least one second polymer is a polyethylene oxide and/or includes a repeating unit which bears an oligoethylene oxide function.

3. The cathode material of claim 1 , wherein
Q − stands for a group based on a lithium conducting salt anion or a group based on an anion of an ionic liquid, or a sulfonate group or a sulfate group or a carboxylate group or a group based on a phosphoric acid-based anion or a group based on an anion of an imide or a group based on an anion of an amide or a group based on an anion of a carboxylic acid amide, and Z + stands for a lithium ion, or
Q + stands for a group based on a cation of an ionic liquid and Z − stands for a lithium conducting salt anion.

4. The cathode material of claim 1 , wherein
Q − stands for a trifluoromethanesulfonylimide group or perfluoroethanesulfonylimide group or fluorosulfonylimide group or a sulfonate group or a trifluoromethanesulfonate group, and Z + stands for a lithium ion, or
Q + stands for a pyridinium group or an ammonium group or an imidazolium group or a piperidinium group or a pyrrolidinium group or a phosphonium group or a guanidinium group or a morpholinium group or a uronium group or a thiouronium group, and Z − stands for a lithium conducting salt anion.

5. The cathode material of claim 1 , wherein
Z − stands for bis(trifluoromethanesulfonyl)imide and/or bis(perfluoroethanesulfonyl)imide and/or bis(fluorosulfonyl)imide and/or trifluoromethanesulfonate and/or tetrafluoroborate and/or bisoxalatoborate and/or difluorooxalatoborate and/or bromide and/or iodide and/or chloride, or
Z + stands for a lithium ion.

6. The cathode material of claim 1 , wherein the polymer backbone-forming unit -[A]- includes an alkylene oxide unit and/or a unit which includes a carbonate group, and/or a siloxane unit and/or a phosphazene unit and/or a methyl methacrylate unit and/or a methacrylate unit and/or a phenylene unit and/or a phenylene oxide unit and/or a benzylene unit and/or an alkylene unit.

7. The cathode material of claim 1 , wherein the polymer backbone-forming unit -[A]- includes at least one polyfunctionalized siloxane unit and/or one polyfunctionalized phosphazene unit and/or one polyfunctionalized phenylene unit.

8. The cathode material of claim 1 , wherein the spacer X includes at least one oligoalkylene oxide group.

9. The cathode material of claim 1 , wherein the spacer X includes at least one carbonyl group and/or at least one lactone group and/or at least one cyclic carbamate group and/or at least one acyclic carbonate group and/or at least one acyclic carboxylic acid ester group and/or at least one acyclic carbamate group.

10. The cathode material of claim 1 , wherein the spacer X includes:
at least one other negatively charged group Q − that includes at least one sulfonylimide group and/or a sulfonate group, and a counterion Z + ; or
at least one other positively charged group Q + that includes at least one ammonium ion group and/or at least one pyridinium group and/or at least one imidazolium group and/or at least one piperidinium group and/or at least one pyrrolidinium group and/or at least one phosphonium group and/or at least one guanidinium group and/or at least one morpholinium group and/or at least one uronium group and/or at least one thiouronium group, and a counterion Z − .

11. The cathode material of claim 1 , wherein the polymer backbone-forming unit -[A]- and/or the spacer X and/or the group Q or Q + or Q − are/is fluorinated.

12. The cathode material of claim 1 , wherein the polymer backbone-forming unit -[A]- and/or the spacer X and/or the group Q + or Q − includes a fluorinated oligoalkylene oxide unit, and/or the polymer backbone-forming unit -[A]- and/or the spacer X and/or the group Q + or Q − are/is perfluorinated.

13. The cathode material of claim 1 , wherein the at least one polymer electrolyte has or includes at least one repeating unit of the general chemical formula:

wherein:
[A a ]-, -[A b ]-, -[A c ]-, -[A d ]-, -[A e ]-, -[A f ]-, -[A Z ]-, or -[A Z1 ]- stands for a polymer backbone-forming unit,
(X a ), (X b ), (X c ), (X d ), (X e ), (X f ), (X Z ), or (X Z1 ) stands for a spacer,
xa, xb, xc, xd, xe, xf, xz, or xz1 stands for the number of spacers and is 1 or 0,
the polymer backbone-forming unit -[A a ]-, -[A b ]-, -[A c ]-, -[A d ]-, -[A e ]-, -[A f ]-, -[A Z ]-, or -[A Z1 ]- stands for an alkylene oxide unit and/or an alkylene unit and/or a unit which includes a carbonate group, and/or a methacrylate unit and/or a methyl methacrylate unit and/or a siloxane unit and/or a phosphazene unit and/or a phenylene unit,
R10, R11, R13 and R14, or R30, R32 and R33, or R41, R41′, R42, R42′, R43, R43′, R44, R44′, R45, and R45′, or R51, R51′, R52, R52′, R53, R53′, R54, and R54′, or R200, R201, R202, and R203, or R210, R211, R212, R213, and R214 in each case independently stand for hydrogen or a halogen atom and/or an alkyl group and/or an alkylene oxide group and/or an alkoxy group and/or a phenylene oxide group and/or a phenoxy group and/or a phenylene group and/or a phenyl group and/or a benzylene group and/or a benzyl group and/or a carbonyl group and/or a cyclic or acyclic carbonate group and/or a cyclic or acyclic carboxylic acid ester group and/or a cyclic or acyclic carbamate group and/or a positively charged group and/or a negatively charged group, and
R12 or R20, R21, and R22, or R31 or R40 or R50, or R60, R61, and R62 in each case independently stand for an alkyl group and/or an alkylene oxide group and/or an alkoxy group and/or a phenylene oxide group and/or a phenoxy group and/or a phenylene group and/or a phenyl group and/or a benzy

Assignees

• Bosch Gmbh Robert

Inventors

• Fanous Jean
• Schumann Bernd
• Thielen Joerg

Classifications

• H01M2300/0082

  Organic polymers · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/362 Primary

  Composites · CPC title

• H01M4/622

  being polymers · CPC title

• H01M2004/028

  Positive electrodes · CPC title