Manganese oxide, lithium manganese complex oxide and cobalt-coated lithium manganese complex oxide, and preparation processes thereof
AssigneeToda Kogyo Corporation
InventorsShoichi Fujino, Hiroshi Takahama, Mitsuaki Hatatani, Norimiki Sugiyama, Hideaki Sadamura
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Abstract
A manganese oxide which has a calcium or/and magnesium content of 0.01 to 2.50 mol % based on the moles of manganese, a lithium manganese complex oxide using the manganese oxide, and a cobalt-coated lithium manganese complex oxide are disclosed. These provide a particularly high discharge capacity and are useful for the improvement of cycle characteristics of a secondary battery as an active material of a positive electrode for a secondary battery with a nonaqueous electrolyte.
Claims4
A process for preparing a lithium manganese complex oxide, which comprises the steps of:
- mixing a manganese oxide which has a calcium and/or magnesium content of 0.01 to 2.50 mol % based on the moles of manganese with a particle size distribution of not greater than 0.4 with a lithium compound such that the molar ratio of lithium to manganese (Li/Mn) is 0.505 to 0.550,
- compression molding the mixture to obtain a formed body,
- sintering the formed body in an oxidizing atmosphere, and
- pulverizing the sintered body.
A process for preparing a lithium manganese complex oxide, which comprises the steps of:
- mixing a manganese oxide which has a calcium and/or magnesium content of 0.01 to 2.50 mol % based on the moles of manganese, a BET specific surface area of 1 to 100 m2/g and a particle size distribution of not greater than 0.4 with a lithium compound such that the molar ratio of lithium to manganese (Li/Mn) is 0.505 to 0.550,
- compression molding the mixture to obtain a formed body,
- sintering the formed body in an oxidizing atmosphere, and
- pulverizing the sintered body.
Dependencies are inferred from the claim text.