Copolymer for bipolar battery

Patent metadata

Field	Value
Publication number	US-10044068-B2
Application number	US-201415037810-A
Country	US
Kind code	B2
Filing date	Nov 17, 2014
Priority date	Nov 20, 2013
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

The invention relates to the use of a liquid/solid reversible phase change electrolyte to prepare a bipolar lithium-ion battery. Said use is characterized in that said electrolyte contains at least one block copolymer containing at least one polymer segment A, soluble in said electrolyte, and at least one polymer segment B, having a temperature T for solubilization in said electrolyte. The polymer segments A and B are present in sufficient amounts to allow physical gelling of the electrolyte at a temperature greater than or equal to the temperature T.

First claim

The invention claimed is:

1. Method for preparing a bipolar lithium-ion battery or accumulator, the method comprising: using an electrolyte having a reversible liquid/solid phase change wherein said electrolyte contains at least one block copolymer comprising at least one polymeric segment A which is soluble in the said electrolyte and at least one polymeric segment B having a temperature for dissolution “T” in the said electrolyte, the polymeric segments A and B being present in amounts sufficient to make possible the physical gelling of the electrolyte at a temperature greater than or equal to the temperature “T”,
said electrolyte being handled, during the preparation of the said battery or of the said accumulator, in the gelled form, at a temperature greater than the temperature “T”.

2. Method according to claim 1 wherein the temperature “T” varies from 40° C. to 80° C.

3. Method according to claim 1 wherein the electrolyte in the gelled form exhibits a shear storage modulus G′ of greater than 500 Pa and a shear loss modulus G″ of less than G′.

4. Method according to claim 1 wherein the electrolyte exhibits a conductivity C1 varying from 10 −4 S·cm −1 to 0.1 S·cm −1 at a temperature of less than “T”.

5. Method according to claim 1 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.

6. Method according to claim 1 wherein 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 alkylmethacrylamides, saccharides, vinylidene fluoride or hexafluoropropylene.

7. Method according to claim 1 wherein the block copolymer comprises at least one polymeric segment C which is insoluble in the electrolyte.

8. Method according to claim 7 , in which the block copolymer comprises at least one polymeric segment C chosen from saturated or unsaturated and branched or unbranched polyolefins, polystyrene and their mixtures and their copolymers.

9. Method according to claim 1 , in which the block copolymer(s) is/are present in an amount ranging from 1 to 25% by weight, with respect to the total weight of the electrolyte.

10. Method for preparing a lithium battery or accumulator comprising at least one electrochemical cell (C), composed of at least one anode and one cathode on either side of a separator impregnated with an electrolyte, and one compartment constructed in order to contain the electrochemical cell(s) with leaktightness while being traversed by a portion of the current collectors forming the poles, wherein:
the said electrolyte is one having a reversible liquid/solid phase change and contains at least one block copolymer comprising at least one polymeric segment A which is dissolved in the said electrolyte and at least one polymeric segment B having a transition temperature for dissolution “T” in the said electrolyte, the polymeric segments A and B being present in amounts sufficient to make possible the physical gelling of the electrolyte at a temperature greater than or equal to the temperature “T”, and
the said process comprises at least the stages consisting in:
handling the said electrolyte during the production of the said cell in the gelled form temperature greater than or equal to the temperature “T” and
lowering the temperature of the said electrolyte, after the leaktightness of the said cell containing the said gelled electrolyte has been obtained, to a temperature less than the temperature T at which the said electrolyte is in the liquid form.

11. Method according to claim 10 , wherein the said electrolyte is employed in the form of a gelled layer which is deposited at the surface of the said anode or cathode.

12. Method according to claim 11 wherein the gelled layer of the said electrolyte already incorporates the said separator.

13. Method according to claim 12 wherein the gelled electrolyte/separator combination is obtained by coating/spraying the said gelled electrolyte over the separator.

14. Method according to claim 10 , comprising a stack of several electrochemical cells (C).

Assignees

• Commissariat Energie Atomique

Inventors

• Moreau Gilles
• Pricard Lionel

Classifications

• H01M50/406

  Moulding; Embossing; Cutting · CPC title

• H01M10/0565

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

• H01M10/0525

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

• H01M10/058 Primary

  Construction or manufacture · CPC title

• H01M10/4235

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