Electrolytes for improved performance of cells with high-capacity anodes based on micron-scale moderate volume-changing particles

Patent metadata

Field	Value
Publication number	US-11710846-B2
Application number	US-202117453777-A
Country	US
Kind code	B2
Filing date	Nov 5, 2021
Priority date	Jan 17, 2017
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

A metal-ion battery cell is provided that comprises anode and cathode electrodes, a separator, and an electrolyte. The anode electrode may, for example, have a capacity loading in the range of about 2 mAh/cm2 to about 10 mAh/cm2 and comprise anode particles that (i) have an average particle size in the range of about 0.2 microns to about 40 microns, (ii) exhibit a volume expansion in the range of about 8 vol. % to about 180 vol. % during one or more charge-discharge cycles of the battery cell, and (iii) exhibit a specific capacity in the range of about 600 mAh/g to about 2600 mAh/g. The electrolyte may comprise, for example, (i) one or more metal-ion salts and (ii) a solvent composition that comprises one or more low-melting point solvents that each have a melting point below about −70° C. and a boiling point above about +70° C.

First claim

The invention claimed is:

1. A Li-ion battery cell, comprising:
an anode electrode with a capacity loading in a range of 2 mAh/cm 2 to about 10 mAh/cm 2 and comprising anode particles including an active material and having an average particle size in a range of about 0.2 microns to about 40 microns, the active material comprising one or more of silicon, germanium, antimony, aluminum, magnesium, zinc, gallium, arsenic, phosphorous, silver, cadmium, indium, tin, lead, bismuth, or an alloy thereof;
a cathode electrode;
a separator electrically separating the anode electrode and the cathode electrode; and
an electrolyte ionically coupling the anode electrode and the cathode electrode,
wherein:
the electrolyte comprises a Li-ion salt composition and an electrolyte solvent composition;
the electrolyte solvent composition comprises (a) one or more ester compounds, (b) a fluorinated solvent compound, and (c) a cyclic carbonate other than the fluorinated solvent compound;
each of the one or more ester compounds has a melting point below about −70° C. and a boiling point above +70° C.;
each of the fluorinated solvent compound and the cyclic carbonate has a melting point above about −60° C.; and
the electrolyte solvent composition additionally comprises a linear carbonate other than the fluorinated solvent compound, the linear carbonate having a melting point above about −60° C., a volume fraction of the linear carbonate in the electrolyte solvent composition being in a range of 15 vol. % to 30 vol. %.

2. The Li-ion battery cell of claim 1 ,
wherein the capacity loading is in a range of 4 mAh/cm 2 to about 10 mAh/cm 2 .

3. The Li-ion battery cell of claim 1 , wherein a volume fraction of the one or more ester compounds in the electrolyte solvent composition ranges between about 20 vol. % and about 80 vol. %.

4. The Li-ion battery cell of claim 3 , wherein the volume fraction ranges between about 30 vol. % and about 70 vol. %.

5. The Li-ion battery cell of claim 4 , wherein the volume fraction ranges between about 40 vol. % and about 60 vol. %.

6. The Li-ion battery cell of claim 1 , wherein at least a majority of the one or more ester compounds have a chemical formula of C 5 H 10 O 2 .

7. The Li-ion battery cell of claim 1 , wherein the fluorinated solvent compound is fluoroethylene carbonate (FEC).

8. The Li-ion battery cell of claim 7 , wherein a volume fraction of the FEC in the electrolyte solvent composition ranges between about 5 vol. % and about 30 vol. %.

9. The Li-ion battery cell of claim 1 , wherein the linear carbonate is selected from ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC).

10. The Li-ion battery cell of claim 1 , wherein the cyclic carbonate is propylene carbonate (PC).

11. The Li-ion battery cell of claim 1 , wherein the cyclic carbonate is vinylene carbonate (VC) and a volume fraction of the VC in the electrolyte solvent composition ranges between about 0.1 vol. % and about 3 vol. %.

12. The Li-ion battery cell of claim 1 , wherein a concentration of the Li-ion salt composition in the electrolyte is in a range of 1.2 M to 2.0 M.

13. The Li-ion battery cell of claim 1 , wherein the Li-ion salt composition comprises one or more of: lithium hexafluorophosphate (LiPF 6 ), lithium bix(oxalato)borate (LiBOB), and lithium bis(fluorosulfonyl)imide (LiFSI).

14. The Li-ion battery cell of claim 1 , wherein the electrolyte solvent composition comprises at least one nitrile compound, at a volume fraction of less than 5 vol. % of the electrolyte solvent composition.

15. The Li-ion battery cell of claim 14 , wherein the at least one nitrile compound comprises a dinitrile compound.

16. The Li-ion battery cell of claim 15 , wherein the dinitrile compound is selected from succinonitrile, adiponitrile, and glutaronitrile.

17. The Li-ion battery cell of claim 1 , wherein the electrolyte solvent composition comprises a sulfur-comprising compound.

18. The Li-ion battery cell of claim 17 , wherein the sulfur-comprising compound is a sulfone or a sulfoxide.

19. The Li-ion battery cell of claim 18 , wherein the sulfur-comprising compound is dimethyl sulfone or ethyl methyl sulfone.

20. The Li-ion battery cell of claim 1 , wherein the electrolyte solvent composition comprises a phosphorus-comprising compound and a volume fraction of the phosphorus-comprising compound in the electrolyte solvent composition ranges between 0.1 vol. % and 5 vol. %.

21. The Li-ion battery cell of claim 20 , wherein the phosphorus-comprising compound is selected from dimethyl methylphosphonate and triphenyl phosphate.

22. The Li-ion battery cell of claim 1 , wherein the anode particles have a specific surface area in a range of about 0.3 m 2 /g to about 60 m 2 /g.

23. The Li-ion battery cell of claim 1 , wherein the Li-ion battery cell exhibits a charging potential of at least about 4.3V.

24. The Li-ion battery cell of claim 1 , wherein the anode particles comprise composite particles comprising silicon.

25. A method of forming a Li-ion battery cell, the method comprising:
assembling the Li-ion battery cell comprising an anode electrode, a cathode electrode, a separator electrically separating the anode electrode and the cathode electrode, and an electrolyte ionically coupling the anode electrode and the cathode electrode;
charging and/or discharging the Li-ion battery cell to a state in which the anode electrode is partially or fully expanded; and
curing the Li-ion battery cell at an elevated temperature in a range of around 30° C. to around 100° C., wherein at least part of the curing occurs while the anode electrode is partially or fully expanded,
wherein:
the anode electrode has a capacity loading in a range of 2 mAh/cm 2 to about 10 mAh/cm 2 and comprises anode particles including an active material and having an average particle size in a range of about 0.2 microns to about 40 microns, the active material comprising one or more of silicon, germanium, antimony, aluminum, magnesium, zinc, gallium, arsenic, phosphorous, silver, cadmium, indium, tin, lead, bismuth, or an alloy thereof;
the electrolyte comprises a Li-ion salt composition and an electrolyte solvent composition;
the electrolyte solvent composition comprises (a) one or more ester compounds, (b) a fluorinated solvent compound, and (c) a cyclic carbonate other than the fluorinated solvent compound;
each of the one or more ester compounds has a melting point below about −70° C. and a boiling point above +70° C.;
each of the fluorinated solvent compound and the cyclic carbonate has a melting point above about −60° C.; and
the electrolyte solvent composition additionally comprises a linear carbonate other than the fluorinated solvent compound, the linear carbonate having a melting point above about −60° C., a volume fraction of the linear carbonate in the electrolyte solvent composition being in a range of 15 vol. % to 30 vol. %.

Assignees

• Sila Nanotechnologies Inc

Inventors

• Yushin Gleb
• Ward Ashleigh
• Roberts Gregory

Classifications

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M10/0561

  the electrolyte being constituted of inorganic materials only · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• H01M10/0567

  characterised by the additives · CPC title