Stabilized electrochemical cell active material
AssigneeValence Technology, Inc.
InventorsJeremy Barker, M. Yazid Saidi, Chariclea A. Scordilis-Kelley
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Abstract
A composition and a method for forming the composition stabilized against capacity degradation comprises particles of spinel lithium manganese oxide (LMO) enriched with lithium by a decomposition product of lithium carbonate forming a part of each said particle and characterized by a reduced surface area and increased capacity expressed in milliamp hours per gram as compared to non-enriched spinel.
Claims28
An active material composition comprising a lithium rich spinel represented by Li1+yMn2−yO4, where 0≦y≦0.20, the composition characterized by a retention of more than about 92% of its capacity over 100 cycles with cycling in an electrochemical cell, the active material composition formed from particles of spinel lithium manganese oxide of formula
- Li1+xMn2−xO4
- wherein x<y, the particles being enriched with lithium by a decomposition product of lithium carbonate forming a part of each said particle and characterized by a reduced surface area and improved capacity retention with cycling as compared to non-enriched spinel.
A composition comprising a first group of particles, wherein the first group of particles comprises a lithium enriched cubic spinel lithium manganese oxide represented by Li1+yMn2−yO4, where 0.08<y≦0.20, wherein the lithium enriched spinel comprises the product of heating a mixture of lithium carbonate and lithium manganese oxide of formula Li1+xMn2−xO4, wherein 0<x≦0.08, and x<y.
An active material made by a process comprising the step of heat treating lithium manganese oxide of formula
- Li1+xMn2−xO4, 0<x≦0.08
- with lithium carbonate to form a lithium rich spinel represented by Li1+yMn2−yO4, where 0.08<y≦0.20, wherein the active material composition has an improved capacity retention with cycling in an electrochemical cell and is further characterized by a retention of more than 92% of its capacity over 100 cycles.
Dependencies are inferred from the claim text.