Electrolyte additive for lithium-ion batrtery

Patent metadata

Field	Value
Publication number	US-2016301100-A1
Application number	US-201415037450-A
Country	US
Kind code	A1
Filing date	Nov 17, 2014
Priority date	Nov 20, 2013
Publication date	Oct 13, 2016
Grant date	—

Abstract

Electrolyte for a lithium-ion battery comprising at least one block copolymer, characterized in that said block copolymer comprises at least one polymeric segment A which is soluble in said electrolyte and at least one polymeric segment B having a temperature for dissolution “T” in said electrolyte, the polymeric segments A and B being present in amounts sufficient to make possible an increase in the viscosity of the electrolyte, preferably up to gelling of the electrolyte, at a temperature greater than or equal to the temperature “T”; the ionic conduction is produced by a solvent comprising the copolymer and lithium salts.

First claim

1 - 22 . (canceled)

23 . An electrolyte for a lithium-ion battery comprising at least one block copolymer, wherein said block copolymer comprises at least one polymeric segment A which is soluble in said electrolyte and at least one polymeric segment B having a temperature for dissolution “T” in said electrolyte, the polymeric segments A and B being present in amounts sufficient to make possible an increase in the viscosity of the electrolyte at a temperature greater than or equal to the temperature “T”, and then the return of the electrolyte to a liquid state when the temperature of the battery falls back below “T”.

24 . The electrolyte as claimed in claim 23 wherein the increase in the viscosity of the electrolyte is up to gelling of the electrolyte.

25 . The electrolyte as claimed in claim 23 , wherein the temperature T is less than or equal to 80° C.

26 . The electrolyte as claimed in claim 23 , in which the gelling of the electrolyte corresponds to a viscosity V at least greater than 10 Pa·s at 25° C.

27 . The electrolyte as claimed in claim 23 exhibiting a conductivity C1 ranging from 10 −4 S·cm −1 to 0.1 S·cm −1 at a temperature of less than T.

28 . The electrolyte as claimed in claim 23 , exhibiting a conductivity C2 of less than 10 −5 S·cm −1 at a temperature equal to or greater than T.

29 . The electrolyte as claimed in claim 23 , wherein the block copolymer comprises at least one polymeric segment A chosen from the following polymers: polyacrylates, polymethacrylates, polycarbonates, polyester carbonates, polylactones, polylactams, polyesters, polyethers, soluble homopolymers and random copolymers of polyethers.

30 . The electrolyte as claimed in claim 23 , in which the block copolymer comprises at least one polymeric segment B obtained from at least one monomer chosen from the following monomers: acrylic and methacrylic acids, N-alkylacrylamides or N-alkylmethacrylamides saccharides, vinylidene fluoride or hexafluoropropylene.

31 . The electrolyte as claimed in claim 23 , in which the block copolymer comprising at least one polymeric segment B is a polymer chosen from poly(N-alkylacrylamides), poly(N-alkylmethacrylamides), polysaccharides, polyvinylidene fluoride and poly(vinylidene fluoride-hexafluoropropylene) copolymers.

32 . The electrolyte as claimed in claim 23 , in which the block copolymer comprises at least one polymeric segment A and at least one polymeric segment B, the polymeric segments B/ polymeric segments A molar ratio being greater than 0.5.

33 . The electrolyte as claimed in claim 23 , in which the block copolymer comprises at least one polymeric segment C which is insoluble in the electrolyte.

34 . The electrolyte as claimed in claim 33 in which the block copolymer comprises at least one polymeric segment C chosen from saturated or unsaturated and branched or unbranched polyolefins.

35 . The electrolyte as claimed in claim 33 , comprising a block copolymer in which the polymeric segments A/ polymeric segments C molar ratio ranges from 0.5 to 10.

36 . The electrolyte as claimed in claim 33 , comprising a block copolymer in which the polymeric segments B/ polymeric segments C molar ratio ranges from 1 to 10.

37 . The electrolyte as claimed in claim 23 , in which the block copolymer(s) is/are present in an amount ranging from 1 to 15% by weight, with respect to the total weight of the electrolyte.

38 . The electrolyte as claimed in claim 33 , in which the block copolymer(s) is/are present in an amount ranging from 1 to 15% by weight, with respect to the total weight of the electrolyte.

39 . A lithium-ion battery comprising the electrolyte as claimed in claim 23 .

40 . A lithium-ion battery comprising the electrolyte as claimed in claim 33 .

41 . Method for modulating the ionic conductivity of the electrolyte of a lithium-ion battery as a function of the temperature of said electrolyte, using at least one block copolymer wherein said block copolymer comprises at least one polymeric segment A and at least one polymeric segment B such that said polymeric segment A is soluble in the electrolyte and said polymeric segment B has a temperature for dissolution “T” in said electrolyte, the polymeric segments A and B being present in amounts sufficient to make possible an increase in the viscosity of the electrolyte at a temperature greater than or equal to the temperature “T” and then the return of the electrolyte to a liquid state when the temperature of the battery falls back below “T”.

42 . The method as claimed in claim 41 wherein the increase in the viscosity is up to gelling of the electrolyte.

43 . The method as claimed in claim 41 , in which, at the temperature T, the conductivity of the electrolyte passes from a value C1 ranging from 10 −4 S·cm −1 to 0.1 S·cm −1 to a value C2 ranging from 10 −6 S·cm −1 to 10 −5 S·cm −1 .

44 . A method for modulating the viscosity of a fluid medium as a function of the temperature of said medium, using at least one block copolymer wherein said block copolymer comprises at least one polymeric segment A and at least one polymeric segment B such that said polymeric segment A is soluble in the electrolyte and said polymeric segment B has a temperature for dissolution “T” in said electrolyte, the polymeric segments A and B being present in amounts sufficient to make possible an increase in the viscosity, preferably up to gelling, of the electrolyte at a temperature greater than or equal to the temperature “T” and then the return of the electrolyte to a liquid state when the temperature of the battery falls back below “T”.

Assignees

• Commissariat Energie Atomique

Inventors

• Picard Lionel
• Moreau Gilles

Classifications

• H01M10/0525

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

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M10/0565 Primary

  Polymeric materials, e.g. gel-type or solid-type · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/0564

  the electrolyte being constituted of organic materials only · CPC title