Method of producing lithium ion cathode materials

Abstract

A method of producing Liy[NixCo1−2xMnx]O2 wherein 0.025≦x≦0.5 and 0.9≦y≦1.3. The method includes mixing [NixCo1−2xMnx]OH2 with LiOH or Li2CO3 and one or both of alkali metal fluorides and boron compounds, preferably one or both of LiF and B2O3. The mixture is heated sufficiently to obtain a composition of Liy[NixCo1−2xMnx]O2 sufficiently dense for use in a lithium-ion battery cathode. Compositions so densified exhibit a minimum reversible volumetric energy characterized by the formula [1833−333x] measured in Wh / L.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)[0001]This application is a divisional of U.S. patent application Ser. No. 10 / 757,645, filed Jan. 13, 2004, now allowed, which claims priority from provisional application 60 / 454,884 filed on Mar. 14, 2003, the disclosures of which are incorporated by reference in their entirety herein.FIELD OF THE INVENTION[0002]The present invention relates to lithium-ion batteries. More particularly, the present invention relates to a method of densifying compositions useful to make electrodes for lithium-ion batteries.BACKGROUND OF THE INVENTION[0003]Lithium-ion batteries typically include an anode, an electrolyte, and a cathode that contains lithium in the form of a lithium-transition metal oxide. Such lithium-transition metal oxides typically include LiCoO2, LiNiO2 and Li(NiCo)O2. A lithium-transition metal oxide that has been proposed as a replacement for LiCoO2 is Liy[NixCo1−2xMnx]O2 which adopts the α-NaFeO2 type structure and can be regarded as the ...

AI Technical Summary

Benefits of technology

The patent describes a method of making a dense material called Liy[NixCo1−2xMnx]O2, which can be used in lithium-ion batteries. The method involves mixing certain materials and heating them at a specific temperature for a specific time. The resulting material has a high density and low reversible capacity, which makes it useful in batteries. The method can be carried out at a temperature of about 900°C, which is more suitable for industrial applications than higher temperatures. The resulting material has a layered structure and requires a specific ratio of lithium to transition metal to oxygen.

Problems solved by technology

), such a heat treatment is not considered suitable for industrial applications because 1100° C. heating places severe constraints on furnaces that do not apply for about 900° C. heating.

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