Electrolyte and lithium based batteries

Patent metadata

Field	Value
Publication number	US-9627716-B2
Application number	US-201514617463-A
Country	US
Kind code	B2
Filing date	Feb 9, 2015
Priority date	Dec 16, 2014
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

An example electrolyte includes a solvent mixture, a lithium salt, a non-polymerizing solid electrolyte interface (SEI) precursor additive, and a solvent additive. The solvent mixture includes dimethyl carbonate (DMC) and fluoroethylene carbonate (FEC) present in a volume to volume ratio ranging from 20 to 1 to 1 to 20. The non-polymerizing SEI precursor additive is present in an amount ranging from greater than 0 wt % to about 10 wt % of a total wt % of the electrolyte, and the solvent additive is present in an amount ranging from greater than 0 wt % to about 10 wt % of the total wt % of the electrolyte.

First claim

The invention claimed is:

1. An electrolyte, consisting of:
a solvent mixture of dimethyl carbonate (DMC) and fluoroethylene carbonate (FEC) present in a volume to volume ratio ranging from 20 to 1 to 1 to 20;
a lithium salt;
a non-polymerizing solid electrolyte interface (SEI) precursor additive present in an amount ranging from greater than 0 wt % to about 10 wt % of a total wt % of the electrolyte, wherein the non-polymerizing SEI precursor additive is selected from the group consisting of LiNO 3 and a 5-membered ring compound that is to undergo a reduction and form an SEI layer on a silicon based electrode, the 5-membered ring compound being selected from the group consisting of ethylene carbonate, lithium difluoro(oxalato)borate (LiODFB), 1,3-propanesultone, vinyl ethylene carbonate, sulfolane, and combinations thereof; and
a solvent additive, the solvent additive being present in an amount ranging from greater than 0 wt % to about 10 wt % of the total wt % of the electrolyte.

2. The electrolyte as defined in claim 1 wherein the solvent additive is selected from the group consisting of dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, ethyl methyl sulfone, gamma-butyrolactone, and combinations thereof.

3. The electrolyte as defined in claim 1 wherein the lithium salt is selected from the group consisting of lithium bis(trifluoromethylsulfonyl)imide (LiN(CF 3 SO 2 ) 2 or LiTFSI), LiNO 3 , LiPF 6 , LiBF 4 , LiI, LiBr, LiSCN, LiClO 4 , LiAlCl 4 , LiB(C 2 O 4 ) 2 (LiBOB), LiB(C 6 H 5 ) 4 , LiBF 2 (C 2 O 4 ) (LiODFB), LiN(SO 2 F) 2 (LiFSI), LiPF 3 (C 2 F 5 ) 3 (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 4 (C 2 O 4 ) (LiFOP), LiPF 3 (CF 3 ) 3 , LiSO 3 CF 3 , LiCF 3 SO 3 , LiAsF 6 , and combinations thereof.

4. The electrolyte as defined in claim 1 wherein:
the solvent mixture of DMC and FEC is present in a volume to volume ratio about 17:3;
the lithium salt is LiPF 6 ;
the non-polymerizing SEI precursor additive is lithium difluoro(oxalato)borate; and
the solvent additive is dimethyl sulfone.

5. A pre-lithiation kit, comprising:
a negative electrode having a silicon active material loading greater than 1.5 mg/cm 2 ; and
a pre-lithiation electrolyte, consisting of:
a solvent mixture of dimethyl carbonate (DMC) and fluoroethylene carbonate (FEC) present in a volume to volume ratio ranging from 20 to 1 to 1 to 20;
a lithium salt;
a non-polymerizing solid electrolyte interface (SEI) precursor additive present in an amount ranging from greater than 0 wt % to about 10 wt % of a total wt % of the electrolyte, wherein the non-polymerizing SEI precursor additive is selected from the group consisting of LiNO 3 and a 5-membered ring compound that is to undergo a reduction and form an SEI layer on a silicon based electrode, the 5-membered ring compound being selected from the group consisting of ethylene carbonate, lithium difluoro(oxalato)borate (LiODFB), 1,3-propanesultone, vinyl ethylene carbonate, sulfolane, and combinations thereof; and
a solvent additive, the solvent additive being present in an amount ranging from greater than 0 wt % to about 10 wt % of the total wt % of the electrolyte.

6. The pre-lithiation kit as defined in claim 5 wherein the solvent additive is selected from the group consisting of dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, ethyl methyl sulfone, gamma-butyrolactone, and combinations thereof.

7. The pre-lithiation kit as defined in claim 5 wherein the lithium salt is selected from the group consisting of lithium bis(trifluoromethylsulfonyl)imide (LiN(CF 3 SO 2 ) 2 or LiTFSI), LiNO 3 , LiPF 6 , LiBF 4 , LiI, LiBr, LiSCN, LiClO 4 , LiAlCl 4 , LiB(C 2 O 4 ) 2 (LiBOB), LiB(C 6 H 5 ) 4 , LiBF 2 (C 2 O 4 ) (LiODFB), LiN(SO 2 F) 2 (LiFSI), LiPF 3 (C 2 F 5 ) 3 (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 4 (C 2 O 4 ) (LiFOP), LiPF 3 (CF 3 ) 3 , LiSO 3 CF 3 , LiCF 3 SO 3 , LiAsF 6 , and combinations thereof.

8. A lithium ion battery, comprising:
a negative electrode having a silicon active material loading greater than 1.5 mg/cm 2 ;
a positive electrode;
a separator positioned between the negative electrode and the positive electrode; and
an electrolyte solution soaking each of the positive electrode, the negative electrode, and the separator, the electrolyte solution consisting of:
a solvent mixture of dimethyl carbonate (DMC) and fluoroethylene carbonate (FEC) present in a volume to volume ratio ranging from 20 to 1 to 1 to 20;
a lithium salt;
a non-polymerizing solid electrolyte interface (SEI) precursor additive present in an amount ranging from greater than 0 wt % to about 10 wt % of a total wt % of the electrolyte, wherein the non-polymerizing SEI precursor additive is selected from the group consisting of LiNO 3 and a 5-membered ring compound that is to undergo a reduction and form an SEI layer on a silicon based electrode, the 5-membered ring compound being selected from the group consisting of ethylene carbonate, lithium difluoro(oxalato)borate (LiODFB), 1,3-propane sultone, vinyl ethylene carbonate, sulfolane, and combinations thereof; and
a solvent additive present in an amount ranging from greater than 0 wt % to about 10 wt % of the total wt % of the electrolyte.

9. The lithium ion battery as defined in claim 8 wherein the solvent additive is selected from the group consisting of dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, ethyl methyl sulfone, gamma-butyrolactone, and combinations thereof.

10. The lithium ion battery as defined in claim 8 wherein the lithium salt is selected from the group consisting of lithium bis(trifluoromethylsulfonyl)imide (LiN(CF 3 SO 2 ) 2 or LiTFSI), LiNO 3 , LiPF 6 , LiBF 4 , LiI, LiBr, LiSCN, LiClO 4 , LiAlCl 4 , LiB(C 2 O 4 ) 2 (LiBOB), LiB(C 6 H 5 ) 4 , LiBF 2 (C 2 O 4 ) (LiODFB), LiN(SO 2 F) 2 (LiFSI), LiPF 3 (C 2 F 5 ) 3 (LiFAP), LiPF 4 (CF 3 ) 2 , LiPF 4 (C 2 O 4 ) (LiFOP), LiPF 3 (CF 3 ) 3 , LiSO 3 CF 3 , LiCF 3 SO 3 , LiAsF 6 , and combinations thereof.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Yang Li
• Cai Mei
• Xiao Qiangfeng
• Dai Fang
• Verbrugge Mark W

Classifications

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0567

  characterised by the additives · CPC title