Composite cathode materials having improved cycle life

摘要

Lithiated composite materials and methods of manufacture are provided that are capable of imparting excellent capacity and greatly improved cycle life in lithium-ion secondary cells. By supplementing a high nickel content lithium storage material with a transition metal oxide lithium storage material or a dopant at relatively low levels, the capacity of the high nickel content lithium storage materials is maintained while cycle life is dramatically improved. These characteristics are promoted by methods of producing the materials that intermix unlithiated precursor materials with a lithium source and sintering the materials together in a single sintering reaction. The resulting lithiated composite materials provide for the first time both high capacity and excellent cycle life to predominantly high nickel content electrodes.

主权项

1. An electrode material for a rechargeable lithium ion electrochemical cell, said electrode material comprising:
a non-lithiated high nickel content lithium storage material comprising NiaCob wherein a is from 81 to 99 and b is from 1 to 19 and where a+b=100; a non-lithiated transition metal dopant material; and a lithium source; said non-lithiated high nickel content lithium storage material, said non-lithiated transition metal dopant material and said lithium source intermixed and sintered to form a lithiated composite material; wherein said high nickel content lithium storage material is present as a predominant by weight relative to said transition metal dopant material; and wherein said composite material is characterized by a longer cycle life than that of the high nickel content lithium storage material.