Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10892472-B2
Application number	US-201716471134-A
Country	US
Kind code	B2
Filing date	Dec 11, 2017
Priority date	Dec 28, 2016
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

A non-aqueous electrolyte secondary battery which uses a lithium titanium composite oxide as a negative electrode active material is configured to use a first positive electrode active material that is a Co-containing lithium transition metal oxide and has a volume per mass of 8 mm 3 /g or more with respect to pores having a pore diameter of 100 nm or less and a second positive electrode active material that has a volume per mass of 5 mm 3 /g or less with respect to pores having a pore diameter of 100 nm or less.

First claim

The invention claimed is:

1. A non-aqueous electrolyte secondary battery comprising:
a positive electrode having a positive electrode mixture layer containing a first positive electrode active material and a second positive electrode active material;
a negative electrode having a negative electrode mixture layer containing a lithium-titanium composite oxide as a negative electrode active material; and
a non-aqueous electrolyte containing a lithium salt having an oxalate complex as an anion, wherein
the first positive electrode active material is a Co-containing lithium transition metal oxide and has a pore volume, of pores each having a pore diameter of 100 nm or less, per mass of 8 mm 3 /g or more,
the second positive electrode active material has a pore volume, of pores each having a pore diameter of 100 nm or less, per mass of 5 mm 3 /g or less,
the pore volume, of pores each having a pore diameter of 100 nm or less, per mass of the first positive electrode active material is 4 or more times the pore volume, of pores each having a pore diameter of 100 nm or less, per mass of the second positive electrode active material,
the content of the first positive electrode active material is 30 mass % or less based on the total amount of the first positive electrode active material and the second positive electrode active material, and
the lithium salt having an oxalate complex as an anion is represented by the general formula: Li[M(C 2 O 4 ) x R y ], wherein M is B or P, R is a group selected from a halogen, an alkyl group or a halogen-substituted alkyl group, x is a positive integer, and y is 0 or a positive integer.

2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein
the negative electrode mixture layer contains a carbon material, and
the content of the carbon material in the negative electrode mixture layer from the surface to half of the thickness of the negative electrode mixture layer is 60 mass % to 80 mass % based on the total amount of the carbon material.

3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein
the first positive electrode active material is a lamellar lithium transition metal oxide represented by the general formula: Li 1+x Co a M b O 2+c , wherein x, a, b and c meet the conditions: a+b=1, −0.2x0.4, 0<a≤1 and −0.1≤c≤0.4, and M is a metal element including at least one element selected from the group consisting of Ni, Mn and Al, and
the second positive electrode active material is a lamellar lithium transition metal oxide represented by the general formula: Li 1+x M a O 2+b , wherein x, a and b meet the conditions: a=1, −0.2≤x≤0.4 and −0.1≤b≤0.4, and M is a metal element including at least one element selected from the group consisting of Ni, Co, Mn and Al.

4. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the concentration of the lithium salt having an oxalate complex as an anion in the non-aqueous electrolyte is 0.01 mol/L to 0.2 mol/L.

5. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the lithium salt having an oxalate complex as an anion is lithium bis(oxalato)borate (Li[B(C 2 O 4 ) 2 ].

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Morikawa Yuki
• Baba Yasunori
• Ko Takashi
• Niina Fumiharu
• Yanagida Katsunori

Classifications

• H01M10/0567

  characterised by the additives · CPC title

• H01M4/505

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

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title