Fluorinated alkali ion electrolytes with cyclic carbonate groups

Patent metadata

Field	Value
Publication number	US-9923236-B2
Application number	US-201615148863-A
Country	US
Kind code	B2
Filing date	May 6, 2016
Priority date	Apr 7, 2015
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

Perfluoropolyether electrolytes terminated with polar substituents such as cyclic carbonates show enhanced ionic conductivities when formulated with lithium bis(trifluoromethane)sulfonimide, making them useful as electrolytes for lithium cells.

First claim

We claim:

1. An electrolyte, comprising:
a mixture of
perfluoropolyethers, each having one or two terminal cyclic carbonate groups covalently coupled thereto; and
an alkali metal salt.

2. The electrolyte of claim 1 , wherein said alkali metal salt is a lithium salt.

3. The electrolyte of claim 1 , wherein said alkali metal salt is a sodium salt.

4. The electrolyte of claim 1 , wherein the salt comprises between 5 to 30 wt % of the composition.

5. The electrolyte of claim 1 , wherein the perfluoropolyethers are selected from the group consisting of:

wherein x is the mole fraction of difluoromethyleneoxy groups in the perfluoropolyether, and x ranges between 0 and 1;
1-x is the mole fraction of tetrafluoroethyleneoxy groups in the perfluoropolyether, and 1-x ranges between 0 and 1;
n is the average total number of randomly co-distributed difluoromethyleneoxy and tetrafluoroethyleneoxy groups in the perfluoropolyether and n ranges between 1 and 50;
X is either hydrogen or fluorine; and
R F is a perfluorinated C1-C8 straight or branched alkyl group.

6. An electrochemical cell, comprising:
an anode;
a cathode; and
an electrolyte between the anode and the cathode, the electrolyte in ionic communication with the anode and the cathode;
wherein the electrolyte is the electrolyte of claim 1 .

7. The cell of claim 6 , wherein the anode comprises a material selected from the group consisting of lithium metal and alloys, graphite, lithium titanante, silicon, silicon alloys, and combinations thereof.

8. The cell of claim 6 , wherein the cathode comprises a material selected from the group consisting of nickel cobalt aluminum oxide (NCA), nickel cobalt manganese (NCM), LiCoO 2 , LiFePO 4 , LiNiPO 4 , LiCoPO 4 , and LiMn 2 O 4 particles, and any combination thereof.

Assignees

• Seeo Inc

Inventors

• Pratt Russell Clayton
• WANG Xiao-liang
• Lam Steven
• Eitouni Hany Basam

Classifications

• H01M10/0569

  characterised by the solvents · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0565 Primary

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

• H01M2300/0034

  Fluorinated solvents · CPC title

• C08G65/007

  containing fluorine · CPC title