Electrolytes for lithium ion batteries

Patent metadata

Field	Value
Publication number	US-10199677-B2
Application number	US-201715844689-A
Country	US
Kind code	B2
Filing date	Dec 18, 2017
Priority date	Apr 7, 2016
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

Electrolytes, lithium ion cells and corresponding methods are provided, for extending the cycle life of fast charging lithium ion batteries. The electrolytes are based on fluoroethylene carbonate (FEC) and/or vinylene carbonate (VC) as the cyclic carbonate component, and possibly on ethyl acetate (EA) and/or ethyl methyl carbonate (EMC) as the linear component. Proposed electrolytes extend the cycle life by factors of two or more, as indicated by several complementary measurements.

First claim

The invention claimed is:

1. A lithium ion cell comprising:
at least one anode comprising anode active material which consists of Si, Ge and/or Sn,
at least one cathode, and
an electrolyte consisting of at least one solvent, at least one linear carbonate component, at least one cyclic carbonate component, at least one lithium salt and optional additives up to 2%,
wherein the at least one cyclic carbonate component comprises at least 20% vol of vinylene carbonate (VC),
and
wherein the lithium ion cell is configured to operate at a fast charging rate of at least 10C, and
wherein the electrolyte has a 3:7 ratio between the VC and the at least one linear carbonate component.

2. The lithium ion cell of claim 1 , wherein the at least one linear carbonate component comprises any of: ethyl acetate (EA), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), modified linear carbonates and fluorinated linear carbonates.

3. The lithium ion cell of claim 1 , wherein the at least one linear carbonate component comprises at least 30% of at least one of: ethyl acetate (EA), propyl acetate and propionates.

4. The lithium ion cell of claim 1 , wherein the electrolyte comprises, as the at least one linear carbonate component, at least 20% vol EA, propyl acetate and/or propionates, and at least 50% vol EMC.

5. The lithium ion cell of claim 1 , wherein the at least one solvent comprises any of: esters-based solvents, sulfones-based solvents, nitriles-based solvents, ethers-based solvents, alcohol-based solvents, hydrocarbons, aprotic-based solvents, a SEI forming additive, a HF scavenger additive, a phosphorous-containing compounds and mixtures thereof.

6. An energy storage device comprising the lithium ion cell of claim 1 .

7. A method comprising using an electrolyte in a lithium ion cell which comprises at least one anode with anode active material consisting of Si, Ge and/or Sn the lithium ion cell configured to operate at a fast charging rate of at least 10C, wherein all or most cyclic carbonates are VC, wherein the VC makes up 30% of the electrolyte, and wherein all or most linear carbonate components are EA and/or EMC.

8. A lithium ion cell comprising:
at least one anode comprising anode active material which consists of Si, Ge and/or Sn,
at least one cathode, and
an electrolyte consisting of at least one linear carbonate component, at least one cyclic carbonate component, at least one lithium salt and optional additives up to 2%,
wherein the at least one cyclic carbonate component comprises at least 20% vol of vinylene carbonate (VC) and/or fluoroethylene carbonate (FEC), and
wherein the lithium ion cell is configured to operate at a fast charging rate of at least 10C, and
wherein the electrolyte is selected from 1-1.3M LiPF 6 in FEC:DMC (1:1) and 2 wt % VC; 1M LiPF 6 in FEC:DMC (3:7) and 2 wt % VC; 1M LiPF 6 in FEC:DMC (3:7), 2 wt % VC and 10 wt % EC; 1M LiPF 6 in FEC:DEC (3:7) and 2 wt % VC; 1M LiPF 6 in FEC:EMC (3:7) and 2 wt % VC; 1M LiPF 6 in FEC:PC:EMC (2:3:5) and 2 wt % VC; 1M LiPF 6 in FEC:DMC (1:1), 2% VC, 10 wt % TMP (trimethyl phosphate) and 0.05M LIFOB (lithium difluoro(oxalato)borate); 1M LiPF 6 in FEC:DMC (1:1), 2 wt % VC, 10 wt % TMP and 0.5 wt % TMSP (tris(trimethylsilyl)phosphite); 1M LiPF 6 in FEC:DMC (1:1), 2 wt % VC, 10 wt % TMP, 0.05M LIFOB and 0.5 wt % TMSP; 1M LiPF 6 in FEC:DMC (1:1), 2 wt % VC, 10 wt % TMP, and 0.05M LIBOB (lithium bis(oxalato)borate); 1M LiPF 6 in FEC:DMC (1:1), 2 wt % VC 10 wt % TMP 1 wt % DPDMS (diphenyldimethoxysilane); 1M LiPF 6 in FEC:EMC (3:7), 2 wt % VC and 10 wt % TMP; 1M LiPF 6 in FEC:EMC (3:7), 2 wt % VC and 10 wt % MFE (methylperfluorobutylether); 1M LiPF 6 in FEC:DMC (3:7), 2 wt % VC and 10 wt % TMP; 1M LiPF 6 in FEC:DMC (1:1), 2 wt % VC and 10 wt % TMP; 1M LiPF 6 in FEC:EMC (2.5:7.5) and 1.5 wt % VC; 1M LiPF 6 in FEC:EMC:DMC (2.5:6.5:1) and 0.5 wt % VC; 1M LiPF 6 in VC:EA (ethylene acetate):EMC (3:3.5:3.5); 1M LiPF 6 in VC:EMC (3:7); and 1M LiPF 6 FEC:EMC (3:7).

9. The lithium ion cell of claim 8 , wherein the electrolyte is selected from 1.3M LiPF6 in FEC:DMC (1:1) and 2 wt % VC; 1M LiPF6 in FEC:DEC (3:7) and 2 wt % VC; 1M LiPF6 in FEC:DMC (1:1), 2 wt % VC, 10 wt % TMP and 0.5 wt % TMSP (tris(trimethylsilyl)phosphite); 1M LiPF6 in FEC:DMC (1:1), 2 wt % VC and 10 wt % TMP; 1M LiPF6 in FEC:EMC (2.5:7.5) and 1.5 wt % VC; 1M LiPF6 in FEC:EMC:DMC (2.5:6.5:1) and 0.5 wt % VC; 1M LiPF6 in VC:EA (ethylene acetate):EMC (3:3.5:3.5); 1M LiPF6 in VC:EMC (3:7); and 1M LiPF6 FEC:EMC (3:7).

10. A lithium ion cell comprising:
at least one anode comprising anode active material which consists of Si, Ge and/or Sn,
at least one cathode, and
an electrolyte consisting of at least one linear carbonate component, at least one cyclic carbonate component, at least one lithium salt and optional additives up to 2%,
wherein the at least one cyclic carbonate component comprises at least 20% vol of vinylene carbonate (VC), and
wherein the lithium ion cell is configured to operate at a fast charging rate of at least 10C, and
wherein the electrolyte consists of 0.9-1.3M LiPF 6 in 20-40% vol VC and one of: 20-40% vol EA, 20-40% vol EA, 40-60% vol EMC or 80-60% vol EMC, wherein the VC and EA and/or EMC add up to 100%.

Assignees

• Storedot Ltd

Inventors

• Drach Zohar
• Guchok Olga
• Krasovitsky Leonid
• Gotlib Vainshtein Ekaterina
• Amir Liron

Classifications

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M10/0567

  characterised by the additives · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• H01M2300/0051

  Carbonates · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title