Positive electrode active material and non-aqueous electrolyte secondary battery containing the same
AssigneesMatsushita Electric Industrial Co., Ltd., Osaka City Government, Tanaka Chemical Corporation
InventorsTsutomu Ohzuku, Hiroshi Yoshizawa, Masatoshi Nagayama
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Abstract
The present invention discloses a non-aqueous electrolyte secondary battery comprising: a negative electrode containing metallic lithium or a substance at least capable of absorbing/desorbing lithium ion; a separator; a positive electrode; and an electrolyte, wherein the active material for the positive electrode comprises an oxide containing nickel element and manganese element in substantially the same atomic ratios. The non-aqueous electrolyte secondary battery thus fabricated is low cost in construction and has a high capacity.
Claims17
A positive electrode active material for a non-aqueous electrolyte battery, comprising a crystalline particle of an oxide, said oxide containing nickel element and manganese element in substantially the same atomic ratios and having a rhombohedral crystal structure, wherein a c-axis attributed to a hexagonal system in the crystal structure of said crystalline particle is not shorter than 14.25 angstroms.
A method for producing a positive electrode active material for a non-aqueous electrolyte battery comprising the steps of:
- introducing an alkaline solution and an aqueous solution containing a nickel salt and a manganese salt simultaneously into a reactor, and coprecipitating said nickel and said manganese while passing an inert gas therethrough to obtain a nickel manganese hydroxide and/or a nickel manganese oxide;
- mixing said nickel manganese hydroxide and/or said nickel manganese oxide with a lithium compound to obtain a mixture;
- and
- baking said mixture at a temperature not lower than 950° C. to obtain a positive electrode material.
A method for producing a positive electrode active material for a non-aqueous electrolyte battery, comprising the steps of:
- dry mixing LiOH.H2O, Ni(OH)2 and MnOOH, each having a particle size of not larger than 0.3 μm to obtain a mixture;
- and
- baking said mixture at a temperature of not lower than 950° C. to obtain a positive electrode active material.
Dependencies are inferred from the claim text.