Nonaqueous electrolyte secondary battery including separator with filler layers on opposite sides of substrate

Patent metadata

Field	Value
Publication number	US-12224452-B2
Application number	US-201816637034-A
Country	US
Kind code	B2
Filing date	Nov 2, 2018
Priority date	Nov 29, 2017
Publication date	Feb 11, 2025
Grant date	Feb 11, 2025

Abstract

In a nonaqueous electrolyte secondary battery, a separator includes a substrate, a first filler layer disposed on one side of the substrate and containing phosphate salt particles, and a second filler layer disposed on the other side of the substrate and containing inorganic particles. The separator is disposed between a positive electrode and a negative electrode in such a manner that the side of the substrate which bears the first filler layer is directed to the positive electrode side.

First claim

The invention claimed is:

1. A nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode and a separator, wherein
the separator comprises a substrate, a first filler layer disposed on one side of the substrate and containing phosphate salt particles, and a second filler layer disposed on the other side of the substrate and containing inorganic particles with a higher melting point than the phosphate salt particles, the separator being disposed between the positive electrode and the negative electrode in such a manner that the first filler layer is directed to the positive electrode side, and
the BET specific surface area of the phosphate salt particles is not less than 5 m 2 /g and not more than 100 m 2 /g,
wherein the average particle size of the phosphate salt particles is 0.05 μm to 1 μm and is smaller than the average pore size of the substrate,
wherein the separator further comprises a resin layer containing a polyolefin, said resin layer being disposed on the surface of the first filler layer and in contact with the positive electrode,
wherein the first filler layer comprises a continuous layer configured to cover an entirety of a surface of the substrate on which the first filler layer is disposed,
wherein the phosphate salt particles contained in the first filler layer are configured to undergo melting and polycondensation by heat and a potential of the positive electrode, so as to fill pores in the substrate upon generation of a heat, and
wherein a porosity of the first filler layer is 30% or more and 70% or less.

2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the BET specific surface area of the phosphate salt particles is not less than 20 m 2 /g and not more than 100 m 2 /g.

3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the phosphate salt particles are at least one selected from lithium phosphate, dilithium hydrogen phosphate and lithium dihydrogen phosphate.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Morikawa Yuki
• Sugimori Masanori
• Baba Yasunori
• Yanagida Katsunori
• Hirano Nobuhiro

Classifications

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/451

  comprising layers of only organic material and layers containing inorganic material · CPC title

• H01M50/423

  Polyamide resins · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M2004/028

  Positive electrodes · CPC title