ELECTROLYTES FOR RECHARGEABLE Zn-METAL BATTERY

Patent metadata

Field	Value
Publication number	US-2021005937-A1
Application number	US-201916982537-A
Country	US
Kind code	A1
Filing date	Mar 20, 2019
Priority date	Mar 20, 2018
Publication date	Jan 7, 2021
Grant date	—

Abstract

The present invention provides an electrolyte for a rechargeable zinc-metal battery. The electrolyte comprises an aqueous solution having a pH of from about 3 to about 7; a zinc-ion based electrolyte comprising zinc ion and a fluorine containing anion; and a lithium salt of said fluorine containing anion. The electrolyte of the present invention not only enables substantially dendrite-free Zn plating/stripping at nearly 100% CE, but also retains water in the open atmosphere.

First claim

What is claimed is:

1 . An electrolyte for a rechargeable zinc-metal anode battery comprising:
an aqueous solution having a pH of from about 4 to about 7; a zinc-ion based electrolyte comprising zinc ion and a first fluorine containing anion; and a secondary salt comprising a cation and a second fluorine containing anion.

2 . The electrolyte of claim 1 , wherein said first or said second fluorine containing anion suppresses hydrolysis of said zinc-ion based electrolyte.

3 . The electrolyte of claim 2 , wherein said first or said second fluorine containing anion and said lithium salt of said fluorine containing anion inhibits formation of zinc oxide, zinc hydroxide, or both.

4 . The electrolyte of claim 1 , wherein said electrolyte is capable of retaining water in open atmosphere.

5 . The electrolyte of claim 1 , wherein said zinc-ion based electrolyte provides dendrite-free plating/stripping of Zn anode at a coulombic efficiency of at least about 95%.

6 . The electrolyte of claim 1 , wherein the ratio of said lithium salt of said fluorine containing anion to said zinc-ion based electrolyte is at least about 10 to 1.

7 . The electrolyte of claim 1 , wherein the ratio of said lithium salt of said fluorine containing anion to said zinc-ion based electrolyte is at least about 20 to 1.

8 . The electrolyte of claim 1 , wherein said fluorine containing anion comprises a fluoroalkylsulfonyl group of the formula: R—SO 2 —, wherein R is a C 1-20 fluoroalkyl.

9 . The electrolyte of claim 8 , wherein R is a C 1-5 perfluoroalkyl.

10 . The electrolyte of claim 1 , wherein said fluorine containing anion is of the formula:

wherein each of R 1 and R 2 is C 1-20 alkyl or C 1-20 fluoroalkyl,
provided at least one of R 1 or R 2 is C 1-20 fluoroalkyl.

11 . The electrolyte of claim 10 , wherein at least one of R 1 or R 2 is a C 1-5 perfluoroalkyl.

12 . The electrolyte of claim 1 , wherein said aqueous solution comprises a non-aqueous solvent.

13 . The electrolyte of claim 1 , wherein said non-aqueous solvent is selected from the group consisting a linear ether, a cyclic ether, an ester, a carbonate, a formate, a phosphate, a lactone, a nitrile, an amide, a sulfone, and a sulfolane.

14 . The electrolyte of claim 13 , wherein said non-aqueous solvent is selected from the group consisting of propylene carbonate (PC), dimethyl carbonate (DMC), trimethyl phosphate (TMP), dimethylsulfoxide (DMSO), and dimethylformamide (DMF).

15 . An aqueous rechargeable zinc-metal anode battery comprising:
(a) a zinc-metal anode; (b) a cathode; and (c) an aqueous electrolyte comprising:
(i) a zinc-ion based electrolyte comprising zinc ion and a fluorine containing anion; and
(ii) a secondary salt comprising a cation and a second fluorine containing anion,

wherein the coulombic efficiency of said rechargeable zinc-metal anode battery is at least about 99% after 5 recharging cycle, and wherein the pH of said aqueous electrolyte ranges from about pH 3 to about pH 7.

16 . The aqueous rechargeable zinc-metal anode battery of claim 15 , wherein said rechargeable zinc-metal anode battery is capable of being recharged for at least 100 cycles.

17 . The aqueous rechargeable zinc-metal anode battery of claim 15 , wherein the ratio of said lithium salt of said fluorine containing anion to said zinc-ion based electrolyte is at least about 10 to 1.

18 . The rechargeable zinc-metal anode battery of claim 15 , wherein said cathode comprises an oxide, a sulfide, a selenide, or a combination thereof.

19 . The rechargeable zinc-metal anode battery of claim 15 , wherein said fluorine containing anion is of the formula:

wherein each of R 1 and R 2 is C 1-5 alkyl or C 1-5 fluoroalkyl,
provided at least one of R 1 or R 2 is C 1-5 fluoroalkyl.

20 . The rechargeable zinc-metal anode battery of claim 15 , wherein said fluorine containing anion comprises trifluorosulfonylimide, bis(fluorosulfonyl)imide, or a moiety of the formula: R—SO 2 —, wherein R is a C 1-20 fluoroalkyl.

Assignees

• Univ Maryland

Inventors

• Wang Chunsheng
• Wang Fei

Classifications

• H01M2300/0002

  Aqueous electrolytes · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/36 Primary

  Accumulators not provided for in groups H01M10/05-H01M10/34 · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M10/0569

  characterised by the solvents · CPC title