Method for preventing dendritic growth in secondary cells

• US 4,139,680 A
• Filed: 03/09/1977
• Issued: 02/13/1979
• Est. Priority Date: 09/03/1975
• Status: Expired due to Term

• Current Assignee: Duracell Incorporated (Berkshire Hathaway Incorporated)
• Original Assignee: P R Mallory & Company Incorporated (Tupperware Brands Corporation)
• Inventors: Schlaikjer, Carl R.
• Primary Examiner(s): Walton, Donald L.
• Application Number:
  US05/775,829
• Time in Patent Office: 706 Days
• Field of Search: 429/50, 429/196, 429/197
• US Class Current: 429/50
• CPC Class Codes: C01B 35/06 Boron halogen compounds
• CPC Class Codes: C01B 35/10 Compounds containing boron and oxygen C01B35/06 takes precedence
• CPC Class Codes: C01B 6/00 Hydrides of metals including fully or partially hydrided metals, alloys or intermetallic compounds use of some thereof for reversible sorption of hydrogen C01B3/0005, C01B3/508; Compounds containing at least one metal-hydrogen bond, e.g. (GeH3)2S, SiH GeH; Monoborane or diborane; Addition complexes thereof higher hydrides of boron, substituted hydrides of boron C01B35/00
• CPC Class Codes: H01M 10/0563 Liquid materials, e.g. for Li-SOCl2 cells
• CPC Class Codes: H01M 6/14 Cells with non-aqueous electrolyte
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A high conductivity stable clovoborate electrolyte salt is used in alkali and alkaline earth metal non-aqueous secondary cells to prevent dendritic formation of the plated alkali or alkaline earth metal.

Claims

1. A method for preventing dendrite formation in a rechargeable electrochemical cell having an anode comprising at least one metal which is subject to dendrite formation upon charging of said cell, a non-aqueous electrolyte solvent, and a cathode;

comprising the steps of dissolving in said solvent an electrolyte salt having a metal cation and a clovoborate anion and charging said cell while in the discharged state whereby said electrolyte salt prevents said dendrite formation.

2. The method of claim 1 wherein said clovoborate anion has a formula (B_m X_n)^-k wherein m, n and k are integers with m ranging from 6-20, n ranging from 6-18 and k ranging from 1-4, B is boron, and X is selected from the group consisting of H,F, Cl, Br, I, OH and combinations thereof.

3. The method of claim 2 wherein said clovoborate anion has the formula (B₁₀ Cl₁₀)^--.

4. The method of claim 1 wherein said non-aqueous electrolyte solvent is inorganic.

5. The method of claim 4 wherein said inorganic solvent is selected from the group consisting of sulfur dioxide and thionyl chloride.

6. The method of claim 1 wherein said metal subject to dendrite formation is lithium.

7. The method of claim 5 wherein said metal subject to dendrite formation is lithium.

8. The method of claim 1 wherein said metal subject to dendrite formation is sodium.

9. The method of claim 1 wherein said metal cation is the same metal as that of at least one metal of said anode.

10. The method of claim 7 wherein said metal of said metal cation is lithium.

11. The method of claim 10 wherein said electrolyte salt has the formula Li₂ B₁₀ Cl₁₀.

12. The method of claim 8 wherein said electrolyte salt has the formula Na₂ B₁₀ Cl₁₀.

13. The method of claim 1 wherein said metal is selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium and barium.