Surface modifications for carbon lithium intercalation anodes
AssigneeThe Regents of the University of California
InventorsTri D. Tran, Kimio Kinoshita
Life of this patent
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Abstract
A prefabricated carbon anode containing predetermined amounts of passivating film components is assembled into a lithium-ion rechargeable battery. The modified carbon anode enhances the reduction of the irreversible capacity loss during the first discharge of a cathode-loaded cell. The passivating film components, such as Li.sub.2 O and Li.sub.2 CO.sub.3, of a predetermined amount effective for optimal passivation of carbon, are incorporated into carbon anode materials to produce dry anodes that are essentially free of battery electrolyte prior to battery assembly.
Claims33
A method for modifying a surface property of a carbon anode useful in a lithium-ion rechargeable battery, said method comprising:
- contacting a solid carbonaceous material with one or more lithium-containing passivating film components,
- heating said solid carbonaceous material containing said passivating film components in the presence of a gas to form a lithium-containing passivating layer on a surface of said solid carbonaceous material.
A method for preparing a carbonaceous anode useful in a lithium-ion rechargeable battery, said method comprising:
- contacting one or more lithium-containing passivating film components with a solid carbonaceous material to form a solid carbonaceous material containing said passivating film components,
- heating said solid carbonaceous material containing said passivating film components in the presence of CO.sub.2 at above about 20 degrees to about 120 degrees C. to form a passivating layer on a surface of solid carbonaceous material.
A dry carbon-containing composition useful for anodes in a lithium-ion rechargeable battery, said composition comprising:
- solid carbonaceous material having a surface area less than 5 m.sup.2 /g,
- a passivating layer comprising about 0.01 to about 2 weight percent of lithium carbonate on a surface of said solid carbonaceous material.
A method for reducing the irreversible capacity loss during first cycle in a lithium-ion rechargeable battery, said method comprising:
- constructing a lithium-ion rechargeable battery containing a carbonaceous anode comprising a passivating layer containing a predetermined amount of lithium-containing passivating film component selected from the group consisting of lithium carbonate, lithium oxide, lithium hydroxide and a lithium halide, and
- wherein prior to said constructing, said predetermined amount of lithium-containing passivating film component impregnated onto a porous surface of said carbonaceous anode and heated in the presence of CO.sub.2 to a temperature from above about 20 degrees C. to about 120 degrees C.
A rechargeable lithium-ion battery comprising:
- a cathode containing lithium ions in its structure,
- an anode containing carbonaceous material having a passivating layer on its surface,
- a non-aqueous, electrolyte conductive of lithium ions between said anode and said cathode, and
- wherein said passivating layer comprising one or more passivating film components in a non-electrochemically-produced ratio.
A carbonaceous anode of a lithium-ion rechargeable battery, said anode comprising one or more passivating film components in a passivating layer on a surface of said anode in a weight ratio other than a weight ratio derived from said battery at the end of the first cycle of said battery.
A dry carbon-containing composition useful for anodes in a lithium-ion rechargeable battery, said composition comprising:
- solid carbonaceous material having a surface area less than 15 m.sup.2 /g,
- a passivating layer comprising about 0.001 to about 1.5 weight percent, calculated as Li, of additional lithium-containing passivating film component on a surface of said solid carbonaceous material compared to the amount of said passivating film component on said surface at the end of the first cycle of said battery.
A method for producing a carbon anode for use in a lithium-ion rechargeable battery, said method comprising:
- contacting a solid carbonaceous material with one or more lithium-containing passivating film components, and
- drying said solid carbonaceous material containing said passivating film components to form a lithium-containing passivating layer on a surface of said solid carbonaceous material.
Dependencies are inferred from the claim text.