Materials for negative electrodes of lithium ion batteries

Abstract

The present invention provides materials for negative electrodes of lithium rechargeable batteries. These materials include lithium alloy composites. Each lithium alloy composite has a core-shell structure with one or more lithium alloy granules as its core and a carbon material as its shell. The average granule diameter of said lithium alloy granule is between 5 μm and 40 μm. The average thickness of the shell layer is between 50 Å and 1000 Å. The average diameter of said lithium alloy composite is between 10 μm to 50 μm. The methods of fabrication for said material includes the following steps: stirring lithium alloy granules in an organic solution with a coating substance, drying the solid product in said organic solution with a coating substance, calcining the dried product to obtain the negative electrode material with lithium alloy composites. The lithium alloy composites fabricated in this manner have lithium alloy granules as a core coated with a shell of carbon material. Lithium ion rechargeable batteries with a negative electrode of this invention or fabricated by the methods of this invention have excellent initial charge-discharge efficiency, battery capacity and cycle life.

Dependencies are inferred from the claim text.