POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, AND LITHIUM SECONDARY BATTERY

Title:

POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, AND LITHIUM SECONDARY BATTERY

Document Type and Number:

WIPO Patent Application WO/2010/150686

Kind Code:

A1

Abstract:

Disclosed is a positive electrode active material for a lithium secondary battery, which is capable of achieving high discharge capacity even when in LixMPO4 (wherein M represents transition metals), the atomic ratio of Mn, which can be obtained at low cost and is capable of achieving high operating potential, is set at 85% or more as one M element. Specifically disclosed is a positive electrode active material for a lithium secondary battery, which contains a lithium-transition metal compound that has an olivine-type crystal structure and contains at least Ni, Fe and Mn as transition metal elements. The positive electrode active material for a lithium secondary battery is characterized in that when the sum of the molar numbers of Ni, Fe and Mn atoms among the transition metal elements contained in the lithium-transition metal compound is taken as 1 and the atomic molar ratios of Ni, Fe and Mn are respectively represented by a, b and c (a + b + c = 1, a > 0, b > 0 and c > 0), the following relations are satisfied: 0.85 ≤ c ≤ 0.92 and 0.3 ≤ a/(a + b) ≤ 0.9. The positive electrode active material for a lithium secondary battery is also characterized in that the discharge capacity at the 7th cycle of a lithium secondary battery using the positive electrode active material is 60 mAh/g or more, or in the NiaFebMnc three phase diagram (fig. 1), (a, b, c) represent values that are on the boundary of or inside the octagon ABCDEFGH. Also specifically disclosed is a lithium secondary battery which comprises a positive electrode that contains the positive electrode active material, a negative electrode and a nonaqueous electrolyte.

Inventors:

KOHMOTO MARIKO (JP)
TABUCHI TORU (JP)
INAMASU TOKUO (JP)
NUKUDA TOSHIYUKI (JP)

Application Number:

PCT/JP2010/060170

Publication Date:

December 29, 2010

Filing Date:

June 16, 2010

Export Citation:

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Assignee:

GS YUASA INT LTD (JP)
KOHMOTO MARIKO (JP)
TABUCHI TORU (JP)
INAMASU TOKUO (JP)
NUKUDA TOSHIYUKI (JP)

International Classes:

H01M4/58

Foreign References:

JP2004063422A	2004-02-26
JP2006331992A	2006-12-07
JP2005071665A	2005-03-17
JP2008243662A	2008-10-09
JP2003323894A	2003-11-14
JP2001307732A	2001-11-02
JP2004063422A	2004-02-26
JP2008130525A	2008-06-05

Other References: