Nonaqueous electrolyte secondary battery positive electrode active material and method for manufacturing same, and nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2018241072-A1
Application number	US-201615752989-A
Country	US
Kind code	A1
Filing date	Aug 22, 2016
Priority date	Aug 24, 2015
Publication date	Aug 23, 2018
Grant date	—

Abstract

Provided are: a nonaqueous electrolyte secondary battery positive electrode active material that has high crystallinity, that causes less amount of Mn deposition on a negative electrode, and that can form a secondary battery having excellent cycle characteristics; and a nonaqueous electrolyte secondary battery using the nonaqueous electrolyte secondary battery positive electrode active material. The nonaqueous electrolyte secondary battery positive electrode active material according to the present invention is formed of a lithium-manganese-nickel complex oxide including a spinel-type crystal structure, wherein the lithium-manganese-nickel complex oxide has a crystallite diameter not smaller than 1000 Å and is formed of primary particles that have a polyhedron shape having more than eight surfaces. The proportion of ungrown particles not having the polyhedron shape of the primary particles in the lithium-manganese-nickel complex oxide is preferably not higher than 5%.

First claim

1 . A nonaqueous electrolyte secondary battery positive electrode active material comprising lithium-manganese-nickel complex oxide including a spinel-type crystal structure, wherein
the lithium-manganese-nickel complex oxide is formed of primary particles having a polyhedral shape having more than eight faces and has a crystallite diameter of 1000 Å or more.

2 . The nonaqueous electrolyte secondary battery positive electrode active material according to claim 1 , wherein
an atomic ratio among Li, Mn, Ni, and element M in the lithium-manganese-nickel complex oxide has a relationship of Li:Mn:Ni:M=1+x:2−y−x−z:y:z (where 0≤x≤0.2, 0.4≤y≤0.6, 0≤z≤0.2, and M is one or more selected from the group consisting of Mg, Al, Si, Ti, Cr, Fe, Co, Cu, and Zn).

3 . The nonaqueous electrolyte secondary battery positive electrode active material according to claim 1 , wherein
a proportion of ungrown particles which are contained in the lithium-manganese-nickel complex oxide and of which primary particles do not have a polyhedral shape is 5% or less.

4 . A method for manufacturing a nonaqueous electrolyte secondary battery positive electrode active material formed of lithium-manganese-nickel complex oxide, the method comprising:
a crystallization step of crystallizing manganese-nickel complex hydroxide from a mixed solution of manganese chloride and nickel chloride; a calcination step of mixing the manganese-nickel complex hydroxide obtained and a lithium compound and calcining the mixture at 800° C. or higher and 1000° C. or lower to obtain lithium-manganese-nickel complex oxide; and a recalcination step of recalcining the lithium-manganese-nickel complex oxide obtained at 500° C. or higher and 800° C. or lower for 5 hours or longer and 40 hours or shorter.

5 . A nonaqueous electrolyte secondary battery comprising the nonaqueous electrolyte secondary battery positive electrode active material according to claim 1 .

6 . The nonaqueous electrolyte secondary battery positive electrode active material according to claim 2 , wherein
a proportion of ungrown particles which are contained in the lithium-manganese-nickel complex oxide and of which primary particles do not have a polyhedral shape is 5% or less.

7 . A nonaqueous electrolyte secondary battery comprising the nonaqueous electrolyte secondary battery positive electrode active material according to claim 2 .

8 . A nonaqueous electrolyte secondary battery comprising the nonaqueous electrolyte secondary battery positive electrode active material according to claim 3 .

9 . A nonaqueous electrolyte secondary battery comprising the nonaqueous electrolyte secondary battery positive electrode active material according to claim 6 .

Assignees

• Sumitomo Metal Mining Co

Inventors

• Takahashi Tatsuya
• Okamoto Ryosuke

Classifications

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M2/14

  Electricity · mapped topic

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title