Electrolyte additives for lithium sulfur rechargeable batteries
View Patent ↗An electrolyte solution for a lithium sulfur battery contains a lithium oxalatoborate compound in a 0.05-2 M solution in conventional lithium sulfur battery electrolyte solvents, optionally with other lithium compounds. Examples of solvents include dimethoxyethane (DME), dioxolane, and triethyleneglycol dimethyl ether (TEGDME). Electrochemical cells contain a lithium anode, a sulfur-containing cathode, and a non-aqueous electrolyte containing the lithium oxalatoborate compound. Lithium sulfur batteries contain a casing enclosing a plurality of the cells.
1. An electrolyte solution for a lithium sulfur battery comprising 0.05 to 4 M lithium oxalatoborate compound in a solvent comprising organic ethers, wherein the solution comprises dimethyl lithium malonato oxalato borate.
2. The electrolyte solution according to claim 1 comprising 0.1 to 1 M lithium oxalatoborate.
3. The electrolyte solution according to claim 1 comprising 0.1 to 0.5 M lithium oxalatoborate.
4. The electrolyte solution according to claim 1 comprising 0.3 M lithium oxalatoborate.
5. The electrolyte solution according to claim 1 , wherein the solvent comprises dimethoxymethane (DME), dioxolane (DIOX), or triethyleneglycol dimethyl ether (TEGDME).
6. The electrolyte solution according to claim 1 , wherein the solvent consists of one or more of DME, DIOX, and TEGDME.
7. The electrolyte solution according to claim 1 , further comprising additional lithium salts at a concentration of 0.05 to 4 M.
8. The electrolyte solution according to claim 7 , wherein the additional lithium salt comprises lithium bis trifluoro methylsulfonyl imide (LiTFSI).
9. The electrolyte solution according to claim 1 , further comprising lithium bisoxalatoborate (LiBOB).
10. The electrolyte solution according to claim 1 , further comprising lithium difluoro oxalatoborate (LiODFB).
11. The electrolyte solution according to claim 1 , further comprising lithium malonato oxalatoborate (LiMOB).
12. A lithium sulfur battery comprising the electrolyte solution according to claim 1 .
13. An electrochemical cell comprising:
a. a positive electrode comprising an electroactive sulfur containing material;
b. a negative electrode comprising lithium; and
c. a non-aqueous electrolyte, wherein the electrolyte comprises dimethyl lithium malonato oxalato borate.
14. The electrochemical cell according to claim 13 , wherein the electrolyte further comprises lithium bisoxalatoborate (LiBOB).
15. The electrochemical cell according to claim 13 , wherein the electrolyte further comprises lithium difluoro oxalatoborate (LiODFB).
16. The electrochemical cell according to claim 13 , wherein the electrolyte further comprises lithium malonato oxalatoborate (LiMOB).
17. The electrochemical cell according to claim 13 , wherein the electrolyte comprises a solvent selected from dimethoxymethane (DME), dioxolane (DIOX), and triethyleneglycol dimethyl ether (TEGDME).
18. The electrochemical cell according to claim 17 , wherein the solvent consists of one or more of DME, DIOX, and TEGDME.
19. The electrochemical cell according to claim 13 , wherein the electrolyte is 0.01 to 4 M in lithium oxalatoborate compound.