Electrolyte for lithium-metal battery having improved stability

Patent metadata

Field	Value
Publication number	US-2022190388-A1
Application number	US-202117538866-A
Country	US
Kind code	A1
Filing date	Nov 30, 2021
Priority date	Dec 11, 2020
Publication date	Jun 16, 2022
Grant date	—

Abstract

An electrolyte capable of lip roving the stability of a lithium-metal battery is provided. The electrolyte includes an organic solvent, a cosolvent, which is different from the organic solvent and includes a fluorine-based compound, and an additive having a lower lowest unoccupied molecular orbital (LUMO) value than the organic solvent.

First claim

What is claimed is:

1 . An electrolyte, comprising:
an organic solvent; a cosolvent, wherein the cosolvent is different from the organic solvent and comprises a fluorine-based compound; and an additive having a lower lowest unoccupied molecular orbital (LUMO) value than the organic solvent.

2 . The electrolyte of claim 1 , wherein the organic solvent comprises at least one selected from the group consisting of dimethyl ether, 1,2-dimethoxyethane, 1,3-dioxolane, diethylene glycol, tetraethylene glycol, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and combinations thereof.

3 . The electrolyte of claim 1 , wherein the cosolvent has a lower HOMO (highest occupied molecular orbital) value than the organic solvent.

4 . The electrolyte of claim 1 , wherein a HOMO value of the cosolvent satisfies −11 eV≤HOMO≤−7.5 eV.

5 . The electrolyte of claim 1 , wherein the cosolvent comprises at least one selected from the group consisting of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), 1,1,2,2-tetrafluoroethyl-1H,1H,5H-octafluoropentyl ether (TFOFE), fluoroethylene carbonate (FEC), bis(2,2,2-trifluoroethyl)ether (BTFE), ethyl 4,4,4-trifluorobutyrate (ETFB), bis(2,2,2-trifluoroethyl)carbonate (TFEC), and combinations thereof.

6 . The electrolyte of claim 1 , wherein a volume ratio of the organic solvent and the cosolvent is 5:5 to 9:1.

7 . The electrolyte of claim 1 , wherein the additive has a LUMO value of 1.5 eV or less.

8 . The electrolyte of claim 1 , wherein the additive comprises at least one selected from the group consisting of lithium difluorophosphate (LiPO 2 F 2 ), lithium hexafluorophosphate (LiPF 6 ), lithium difluoro(oxalate)borate (LiFOB), and combinations thereof.

9 . The electrolyte of claim 1 , wherein an amount of the additive is 0.1 wt % to 10 wt %.

10 . The electrolyte of claim 1 , further comprising a lithium salt, comprising at least one selected from the group consisting of LiFSI, LiTFSI, LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiN(SO 2 CF 3 ) 2 , LiC 4 F 9 SO 3 , LiClO 4 , LiAlO 2 , LiAlCl 4 , LiCl, LiI, and combinations thereof.

11 . The electrolyte of claim 10 , wherein a concentration of the lithium salt is 1.5 mol/L to 3 mol/L.

12 . A lithium-metal battery, comprising:
a cathode; an anode comprising lithium metal; a separator; and the electrolyte of claim 1 .

13 . The lithium-metal battery of claim 12 , further comprising a passivation layer on the anode, in which the passivation layer comprises a reduced decomposition product of an additive.

14 . The lithium-metal battery of claim 13 , wherein the reduced decomposition product comprises lithium fluoride (LiF).

Assignees

• Hyundai Motor Co Ltd
• Kia Corproation
• Ulsan National Institute Of Science And Tech

Inventors

• Lee Ji Yong
• Song Jong Chan
• Choi Nam Soon
• Lee Won Joon
• Kim Sae Hun
• Lee Min Young
• Ahn Young Joon

Classifications

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0569 Primary

  characterised by the solvents · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M2300/0091

  in the form of mixtures · CPC title

• H01M2300/0037

  Mixture of solvents · CPC title