Lithium mixed metal oxide and nonaqueous electrolyte secondary battery
A lithium mixed metal oxide comprising Ni, Mn and Fe and having a BET specific surface area of 2 m 2 /g or more and 30 m 2 /g or less. A method of producing a lithium mixed metal oxide, comprising bringing an aqueous solution containing Ni, Mn, Fe and Cl into contact with an alkali to obtain a coprecipitate, and calcining a mixture of the coprecipitate and a lithium compound by maintaining the mixture at a temperature of lower than 900° C. A positive electrode active material for nonaqueous electrolyte secondary battery, comprising the lithium mixed metal oxide described above or the lithium mixed metal oxide obtained by the method of producing a lithium mixed metal oxide described above as a main ingredient. A positive electrode for nonaqueous electrolyte secondary battery having the positive electrode active material for nonaqueous electrolyte secondary battery described above.
1. A lithium mixed metal oxide comprising Ni, Mn and Fe and having a BET specific surface area of 6.4 m 2 /g or more and 30 m 2 /g or less,
wherein the ratio of the amount (mol) of Fe with respect to the total amount (mol) of Ni, Mn and Fe is 0.01 or more and 0.1 or less.
2. The lithium mixed metal oxide according to claim 1 , wherein the lithium mixed metal oxide is shown by the following formula (A):
Li(Ni 1-x-y Mn x Fe y )O 2 (A)
wherein, 0<x<1, 0.01≦y≦0.1, and 0<x+y<1.
3. The lithium mixed metal oxide according to claim 1 , wherein the lithium mixed metal oxide is shown by the following formula (A′):
Li z (Ni 1-x-y Mn x Fe y )O 2 (A′)
wherein, 0<x<1, 0.01≦y≦0.01, 0<x+y<1, and 0.5≦z≦1.5.
4. The lithium mixed metal oxide according to claim 1 , wherein the ratio of the amount (mol) of Mn with respect to the total amount (mol) of Ni, Mn and Fe is 0.1 or more and 0.7 or less.
5. A positive electrode active material for nonaqueous electrolyte secondary battery, comprising the lithium mixed metal oxide according to claim 1 as a main ingredient.
6. A positive electrode for nonaqueous electrolyte secondary battery having the positive electrode active material for nonaqueous electrolyte secondary battery according to claim 5 .
7. A nonaqueous electrolyte secondary battery having the positive electrode for nonaqueous electrolyte secondary battery according to claim 6 .
8. The nonaqueous electrolyte secondary battery according to claim 7 , further having a separator.
9. The nonaqueous electrolyte secondary battery according to claim 8 , wherein the separator is a separator composed of a laminated film obtained by laminating a heat resistant porous layer and a porous film.