Method for Recycling the Electrolyte of a Li-Ion Battery and Method for Recycling Li-Ion Batteries

Patent metadata

Field	Value
Publication number	US-2017207503-A1
Application number	US-201515326778-A
Country	US
Kind code	A1
Filing date	Jul 21, 2015
Priority date	Jul 22, 2014
Publication date	Jul 20, 2017
Grant date	—

Abstract

The invention relates to a method for recycling the electrolyte of a lithium-ion battery and a method for recycling lithium-ion batteries. The method for recycling an electrolyte of the invention is a method for recycling an electrolyte containing a lithium salt of formula LiA, where A represents an anion selected from PF 6 , CF 3 SO 3 , BF 4 , ClO 4 and [(CF 3 SO 2 ) 2] N of a Li-ion battery, characterized in that it comprises the following steps: a) optionally, treatment of the battery in order to recover the electrolyte that it contains; b) addition of water to the electrolyte; c) optionally, when step a) is carried out, filtration (F 1 ) in order to separate the liquid phase containing the electrolyte from the solid phase comprising the residues of the battery; d) addition of an additional organic solvent to the liquid phase obtained in step b) or, when step a) is carried out, after the filtration (F 1 ) of step c); e) decantation of the liquid phase obtained after step b) of adding water or step d) of adding additional organic solvent, whereby an aqueous phase containing the lithium salt and an organic phase containing the electrolyte solvents and the additional organic solvent are obtained; f) distillation of the organic phase obtained in step e) in order to separate the solvents of the electrolyte and the additional organic solvent; g) precipitation

First claim

1 . A method for recycling an electrolyte containing a lithium salt of formula LiA, where A represents an anion selected from PF 6 − , CF 3 SO 3 − , BF 4 − , ClO 4 − and [(CF 3 SO 2 ) 2 ]N − of a Li-ion battery, comprising the following steps:
a) optionally, processing the battery to recover the electrolyte that it contains;
b) adding water to the electrolyte;
c) optionally, when step a) is employed, filtering (F 1 ) to separate the liquid phase containing the electrolyte from the solid phase comprising the residues of the battery;
d) adding an organic solvent of addition to the liquid phase obtained in step b) or, when step a) is employed, after filtering (F 1 ) in step c);
e) decanting the liquid phase obtained after step b) of adding water or step d) of adding organic solvent of addition, whereby an aqueous phase containing the lithium salt and an organic phase containing the electrolyte solvents and the organic solvent of addition are obtained;
f) distilling the organic phase obtained in step e) to separate the solvents of the electrolyte and the organic solvent of addition;
g) precipitating the anion A of the lithium salt by addition of pyridine and then filtering (F 2 );
h) adding at least one carbonate salt and/or of at least one phosphate salt to the filtrate obtained in step g) and then filtering (F 3 ), whereby a lithium salt and water are obtained.

2 . The method as claimed in claim 1 , wherein the method comprises step a) and in that said step a) and step b) are carried out at the same time by cutting up the battery under a high-pressure water jet.

3 . The method as claimed in claim 1 , wherein the method comprises step a), which is carried out by grinding the battery in a chamber under an inert atmosphere.

4 . The method as claimed in claim 1 , wherein:
the method comprises step a), which is a step of grinding the battery under an inert atmosphere; step d) of adding the organic solvent of addition is carried out either during step a), or just after step a); step c) of filtering (F 1 ) is carried out after step d), and step b) of adding water is carried out after step c) of filtering (F 1 ).

5 . The method as claimed in claim 1 , wherein the organic solvent of addition is a slightly polar aprotic organic solvent having a solubility below 20 gL −1 in water, a solubility of 100% in the organic solvents of the electrolyte without forming azeotropes, and a boiling point between 20 and 150° C.

6 . The method as claimed in claim 1 , wherein the organic solvent of addition is selected from:
dichloromethane, acetates, selected from butyl acetate, hexyl acetate, ethyl acetate, tert-butyl acetate; ethers, selected from 2-methoxy-2-methylpropane, 2-ethoxy-2-methylpropane, 2-methoxy-2-methylbutane, and ketones.

7 . The method as claimed in claim 1 , wherein the organic solvent of addition obtained after distillation of the organic phase in step f) is recycled in step d).

8 . The method as claimed in claim 1 , wherein the decanting step e) is repeated.

9 . The method as claimed in claim 1 , wherein the water obtained in step h) is recovered to be reused in step b).

10 . A method for recycling a Li-ion battery, wherein the method comprises a step of recycling the electrolyte of the Li-ion battery as claimed in claim 1 .

11 . The method as claimed in claim 10 , wherein the method comprises step a) of treatment of the battery and step c) of filtering (F 1 ), and further comprises a step a 1 ) in which the solids obtained after filtering (F 1 ) are washed with water, followed by a step a 2 ) of filtering (F 4 ) for separating the liquid phase from the solid phase and a step a 3 ) of mixing the liquid phase obtained in step a 2 ) before the decanting step e) of the method for recycling the electrolyte.

12 . The method as claimed in claim 1 , wherein the electrolyte is composed of a binary or ternary mixture of cyclic carbonates selected from ethylene carbonate, propylene carbonate and butylene carbonate, linear or branched carbonates selected from dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate and dimethoxyethane, in which a lithium salt is dissolved, selected from lithium hexafluorophosphate, lithium trifluoromethanesulfonate, lithium perchlorate and lithium tetrafluoroborate.

13 . The method as claimed in claim 6 , wherein the ketone is butanone.

Assignees

• Commissariat A I'Energie Atomique Et Aux Energies Alternatives
• Commissariat Energie Atomique

Inventors

• Billy Emmanuel
• Laucournet Richard

Classifications

• H01M10/0569

  characterised by the solvents · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/54 Primary

  Reclaiming serviceable parts of waste accumulators · CPC title

• H01M10/0525

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

• H01M2300/0037

  Mixture of solvents · CPC title