Fmc Corporation

Titus Faulkner

Vesselin Manev

D Wayne Barnette

John F Engel

Yuan Gao

Wayne Barnette

Highly crystalline Mn2O3 or Mn3O4 manganese oxides

Lithium manganese oxide spinel compound and method of preparing same

The present invention includes a method of preparing secondary lithium and lithium-ion batteries with improved coulombic efficiency, improved cycling and storage performance at elevated temperatures, and lower rates of transition metal dissolution. In accordance with the present invention, the positive electrode material is thermally treated at a temperature of between 50&deg; C. and 120&deg; C. to produce a passivating film having lithium ion conductivity. The present invention also includes a secondary lithium or lithium-ion cell having positive electrode material covered with a thermally-activated thin passivating film having lithium ion conductivity and a positive electrode material formed of particles of a lithium intercalation compound with a passivating film on the surface of the particles.

Method of preliminarily heat treating positive electrodes of secondary lithium and lithium-ion Batteries and resulting positive electrodes and batteries

A novel method of preparing a spinel Li.sub.1+x Mn.sub.2-x O.sub.4 intercalation compound with low lattice distortion and a highly ordered and homogeneous structure for 4 V secondary lithium and lithium ion cells is provided. The method of preparing the spinel Li.sub.1+x Mn.sub.2-x O.sub.4 intercalation compound comprises mixing at least one manganese compound with at least one lithium compound and firing the mixture at three different temperature ranges with corresponding gas flow rates to form the spinel Li.sub.1+x Mn.sub.2-x O.sub.4 intercalation compounds. The spinel Li.sub.1+x Mn.sub.2-x O.sub.4 intercalation compounds have a mean X value of between about 0.01 and 0.05 and a full width at half maximum of the x-ray diffraction peaks at a diffraction angle 2.theta. of planes (400) and (440) using CuK.alpha..sub.1 rays of between about 0.10.degree. and 0.15.degree.. The spinel Li.sub.1+x Mn.sub.2-x O.sub.4 intercalation compounds may be used in the positive electrodes of secondary lithium and lithium ion cells to provide cells having high specific capacities and long cycling lives.

Highly homogeneous spinel Li.sub.1+x Mn.sub.2-x O.sub.4 intercalation

The present invention provides a positive electrode material for lithium and lithium-ion secondary cells which exhibits good cycleability, reversible specific capacity, and structural stability. The positive electrode material comprises a lithium multi metal oxide having a spinel structure and described by the general formula:

Multiple-doped oxide cathode material for secondary lithium and

A novel method of preparing a spinel Li.sub.1+X Mn.sub.2-X O.sub.4 intercalation compound with low lattice distortion and a highly ordered and homogeneous structure for 4 V secondary lithium and lithium ion cells is provided. The method of preparing the spinel Li.sub.1+X Mn.sub.2-X O.sub.4 intercalation compound comprises mixing at least one manganese compound with at least one lithium compound and firing the mixture at three different temperature ranges with corresponding gas flow rates to form the spinel Li.sub.1+X Mn.sub.2-X O.sub.4 intercalation compounds. The spinel Li.sub.1+X Mn.sub.2-X O.sub.4 intercalation compounds have a mean X value of between about 0.01 and 0.05 and a full width at half maximum of the x-ray diffraction peaks at a diffraction angle 2.theta. of planes (400) and (440) using CuK.alpha..sub.1 rays of between about 0.10.degree. and 0.15.degree.. The spinel Li.sub.1+X Mn.sub.2-X O.sub.4 intercalation compounds may be used in the positive electrodes of secondary lithium and lithium ion cells to provide cells having high specific capacities and long cycling lives.

Highly homogeneous spinel Li.sub.1+X Mn.sub.2-X O.sub.4 intercalation

A novel method of preparing a spinel Li.sub.1+X Mn.sub.2-X O.sub.4+Y intercalation compound with low lattice distortion and a highly ordered and homogeneous structure for 4 V secondary lithium and lithium ion cells is provided. The method of preparing the spinel Li.sub.1+X Mn.sub.2-X O.sub.4+Y intercalation compound comprises providing a spinel Li.sub.1+X Mn.sub.2-X O.sub.4 intercalation compound having a lithium to manganese mole ratio of between about 1.02:2 and 1.1:2 and firing the spinel at different temperature ranges with corresponding gas flow rates to form the spinel Li.sub.1+X Mn.sub.2-X O.sub.4+Y intercalation compounds. The spinel Li.sub.1+X Mn.sub.2-X O.sub.4+Y intercalation compounds have a mean X value of between about 0.01 and 0.05, a mean Y value of between about -0.02 and 0.04 and a full width at half maximum of the x-ray diffraction peaks at a diffraction angle 2.theta. of planes (400) and (440) using CuK.alpha..sub.1 rays of between about 0.08.degree. and 0.13.degree.. The spinel Li.sub.1+X Mn.sub.2-X O.sub.4+Y intercalation compounds may be used in the positive electrodes of secondary lithium and lithium ion cells to provide cells having high specific capacities and long cycling lives.

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Gastonia, NC, United States of America

Titus Faulkner