Nec Corporation

Tanaka Chemical Corporation

National Institute of Advanced Industrial Science and Technology

Nec C Orporation

Hideka Shibuya

Ryota Yuge

Mitsuharu Tabuchi

Noriyuki Tamura

Kyousuke Doumae

Sadanori Hattori

Kentaro Kuratani

Kaoru Narita

Kentaro Nakahara

Takashi Ohtomo

Naoki Kawano

A lithium-manganese composite oxide containing a lithium-iron-manganese composite oxide represented by the composition formula. Li(FeNiMn)O, where 0&#x3c;x&#x3c;&#x2153;, 0&#x2264;w&#x3c;0.8, 0&#x3c;y&#x3c;1, 0&#x3c;z&#x3c;0.5, y+z&#x3c;1, and 0&#x2264;&#x3b4;&#x3c;0.5, in which at least in a state of charge of a lithium ion battery using the lithium-manganese composite oxide as a positive-electrode active material, at least some of iron atoms are pentavalent.

Lithium-manganese composite oxide, and method for producing same, and positive electrode material, positive electrode and lithium ion secondary battery using same

A lithium-manganese composite oxide represented by formula (1): Li[(FeNi)Mn]O(1) wherein x, y, and z satisfy the following: 0&#x3c;x&#x2264;&#x2153;, 0&#x2264;y&#x3c;1.0, and 0&#x3c;z&#x2264;0.6, and wherein the content ratio of Li to the total content of Fe, Ni, and Mn (Li/(Fe+Ni+Mn)) is 1.55 or less on a molar ratio basis, the lithium-manganese composite oxide containing a crystalline phase having a layered rock-salt structure. This composite oxide is a novel material made from less resource-constrained and cheaper elements, and exhibits a high specific capacity, excellent charge-and-discharge cycle characteristics, and a high discharge capacity at a high current density (excellent rate characteristics), when used in the positive electrode material for lithium-ion secondary batteries.

Lithium-manganese complex oxide and method for producing same

There is provided a lithium-iron-manganese-based composite oxide capable of providing a lithium-ion secondary battery which has a high capacity retention rate in charge/discharge cycles and in which the generation of a gas caused by charge/discharge cycles is suppressed. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of the surface of a lithium-iron-manganese-based composite oxide represented by the following formula is coated with an oxide of at least one metal selected from the group consisting of La, Pr, Nd, Sm and Eu:LiMMnMFeO wherein 1.05&#x2264;x&#x2264;1.32, 0.33&#x2264;y&#x2264;0.63, 0.06&#x2264;z&#x2264;0.50, 0&#x3c;p&#x2264;0.63, 0.06&#x2264;q&#x2264;0.50, 0&#x2264;&#x3b4;&#x2264;0.80, y&#x2265;p, and z&#x2265;q; Mis at least one element selected from Ti and Zr; and Mis at least one element selected from the group consisting of Co, Ni and Mn.

Lithium-iron-manganese-based composite oxide and lithium-ion secondary battery using same

There is provided a lithium-iron-manganese-based composite oxide capable of providing a lithium-ion secondary battery which has a high capacity retention rate in charge/discharge cycles and in which the generation of a gas caused by charge/discharge cycles is reduced. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of the surface of a lithium-iron-manganese-based composite oxide represented by the following formula (1) is coated with an inorganic material: LiMMnMFeO(1) (wherein 1.05&#x2264;x&#x2264;1.32, 0.33&#x2264;y&#x2264;0.63, 0.06&#x2264;z&#x2264;0.50, 0&#x3c;p&#x2264;0.63, 0.06&#x2264;q&#x2264;0.50, 0&#x2264;&#x3b4;&#x2264;0.80, y&#x2265;p, and z&#x2265;q; Mis at least one element selected from Ti and Zr; and Mis at least one element selected from the group consisting of Co, Ni and Mn).

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Fukui, Japan

Hideka Shibuya