Electrolyte for a metal-ion battery cell with high-capacity, micron-scale, volume-changing anode particles

Patent metadata

Field	Value
Publication number	US-2019081359-A1
Application number	US-201816128340-A
Country	US
Kind code	A1
Filing date	Sep 11, 2018
Priority date	Sep 12, 2017
Publication date	Mar 14, 2019
Grant date	—

Abstract

In an embodiment, a metal-ion battery cell comprises an anode electrode, a cathode electrode, a separator, and electrolyte ionically coupling the anode electrode and the cathode electrode. The anode electrode is a high-capacity electrode (e.g., in the range of about 2 mAh/cm 2 to about 10 mAh/cm 2 ). The electrolyte includes a solvent composition, the solvent composition including low-melting point (LMP) solvent(s) in the range from about 10 vol. % to about 80 vol. % of the solvent composition as well as regular-melting point (RMP) solvent(s) in the range from about 20 vol. % to about 90 vol. % of the solvent composition.

First claim

1 . A metal-ion battery cell, comprising:
anode and cathode electrodes, wherein the anode electrode has a capacity loading in the range of about 2 mAh/cm 2 to about 10 mAh/cm 2 and comprises anode particles that (i) have an average particle size in the range of about 0.2 microns to about 20 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 550 mAh/g to about 2200 mAh/g; 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 one or more metal-ion salts and a solvent composition, the solvent composition comprising:
one or more low-melting point solvents that each have a melting point in the range from about −140° C. to about −60° C. and are in the range from about 10 vol. % to about 80 vol. % of the solvent composition, and
one or more regular-melting point solvents that each have a melting point in the range from about −60° C. to about +30° C. and are in the range from about 20 vol. % to about 90 vol. % of the solvent composition.

2 . The battery cell of claim 1 , wherein the one or more low-melting point solvents comprise one or more phosphorous-comprising solvents, or one or more cyclic or linear esters, or one or more cyclic or linear ethers, or one or more fluorinated solvents, or one or more anhydrides, or any combination thereof.

3 . The battery cell of claim 1 , wherein the one or more regular-melting point solvents are selected from the group consisting of: carbonates, sulfones, lactones, phosphorus-comprising solvents, silicon-comprising solvents, sulfur-comprising solvents, esters, or a combination thereof.

4 . The battery cell of claim 1 , wherein the one or more low-melting point solvents are in the range from about 20 vol. % to about 60 vol. % of the solvent composition in the electrolyte.

5 . The battery cell of claim 1 , wherein the solvent composition further includes one or more functional additives.

6 . The battery cell of claim 5 , wherein the one or more functional additives include one or more electron donating materials or one or more electron withdrawing materials.

7 . The battery cell of claim 6 ,
wherein the one or more functional additives include the one or more electron withdrawing materials, and wherein the one or more low-melting point solvents and/or the one or more regular-melting point solvents are at least partially fluorinated.

8 . The battery cell of claim 1 , wherein the solvent composition further includes an additive solvent or solvent mixture.

9 . The battery cell of claim 8 , wherein the additive solvent or solvent mixture is in the range from about 0 vol. % to about 5 vol. % of the solvent composition.

10 . The battery cell of claim 1 , wherein the one or more low-melting point solvents and/or the one or more regular-melting point solvents include one or more solvent molecules that exhibit one or more double bonds.

11 . The battery cell of claim 10 , wherein the one or more solvent molecules is at least partially fluorinated and comprises one or more fluorine atoms per molecule.

12 . The battery cell of claim 1 , wherein the one or more low-melting point solvents and/or the one or more regular-melting point solvents include one or more solvent molecules that undergo ring opening polymerizations.

13 . The battery cell of claim 1 , wherein the one or more low-melting point solvents and/or the one or more regular-melting point solvents include (i) a first solvent with a first electrochemical stability window in combination with the one or more metal-ion salts, and (ii) a second solvent with a first electrochemical stability window in combination with the one or more metal-ion salts, the first electrochemical stability window is higher than the second electrochemical stability window.

14 . The battery cell of claim 13 , wherein a differential between the first and second electrochemical stability windows is greater than about 1 volt.

15 . The battery cell of claim 13 , wherein the first solvent is among the one or more one or more low-melting point solvents and the second solvent is among the one or more one or more regular-melting point solvents.

16 . The battery cell of claim 1 , wherein the one or more metal-ion salts are present in the electrolyte at a concentration in the range of about 1.2M to about 1.8M.

17 . The battery cell of claim 1 , wherein the one or more metal-ion salts comprise LiPF 6 or LiFSI.

18 . The battery cell of claim 1 , wherein the one or more metal-ion salts comprise two or more metal-ion salts.

19 . The battery cell of claim 18 , wherein the two or more metal-ion salts comprise LiPF 6 and LiFSI.

20 . The battery cell of claim 1 , wherein the electrolyte further includes one or more additional salts.

21 . The battery cell of claim 20 , wherein the one or more additional salts are present in the electrolyte at a concentration in the range of about 0.001M to about 0.500M.

22 . The battery cell of claim 20 , wherein the one or more additional salts include Mg, K, Ca or Na, one or more rare earth metals, or any combination thereof.

23 . The battery cell of claim 1 , wherein the anode particles have a specific surface area in the range of about 0.5 m 2 /g to about 50 m 2 /g.

24 . The battery cell of claim 1 ,
wherein the anode particles include a conversion-type active material, or wherein the anode particles include an alloying-type active material.

25 . The battery cell of claim 1 , wherein an amount of binder in the anode electrode is in the range from about 0.5 wt. % to about 14 wt. %.

26 . The battery cell of claim 1 , wherein a binder in the anode electrode swells by less than about 30 vol. % when exposed to the electrolyte.

27 . The battery cell of claim 1 , wherein the battery cell is a Li-ion battery cell.

28 . The battery cell of claim 1 , wherein the cathode electrode is of an intercalation-type, comprises nickel (Ni) or cobalt (Co) and exhibits a highest charging potential in the range from about 4.2 V vs. Li/Li+ to about 5.1 V vs. Li/Li+.

Assignees

• Sila Nanotechnologies Inc

Inventors

• Yushin Gleb
• Ward Ashleigh

Classifications

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M10/0567

  characterised by the additives · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0569 Primary

  characterised by the solvents · CPC title