Mitsui Minings & Melting Co., Ltd.

Yuji Hoshi

Hideaki Matsushima

Teruaki Yagi

Yoshimi Hata

Hitohiko Ide

Daisuke Washida

A solid electrolyte: (compound A) a compound that has a crystal phase having an argyrodite-type crystal structure and that is represented by LiPSX, where X is at least one elemental halogen, a represents a number of 3.0 or more and 6.0 or less, b represents a number of 3.5 or more and 4.8 or less, and c represents a number of 0.1 or more and 3.0 or less; and (compound B) a compound that is represented by LiX, where X is as defined above. The compound B has a crystallite size of 25 nm or more. The solid electrolyte preferably has a BET specific surface area of 14.0 m/g or less.

Solid electrolyte, and electrode mixture, solid electrolyte layer and solid-state battery, each using same

A solid electrolyte includes: (compound A) a compound that has a crystal phase having an argyrodite-type crystal structure and that is represented by LiPSX, where X is at least one elemental halogen, a represents a number of 3.0 or more and 6.0 or less, b represents a number of 3.5 or more and 4.8 or less, and c represents a number of 0.1 or more and 3.0 or less; and (compound B) a compound that is represented by LiX, where X is as defined above. The compound B has a crystallite size of 60 nm or less. The solid electrolyte according to the present invention preferably exhibits a lithium ion conductivity at 25° C. of 4.0 mS/cm or more.

A solid electrolyte contains a compound that has a crystal phase having an argyrodite-type crystal structure and that is represented by LiPSX, where X is at least one elemental halogen, a represents a number of 3.0 or more and 6.0 or less, b represents a number of 3.5 or more and 4.8 or less, and c represents a number of 0.1 or more and 3.0 or less. The proportion of the crystal phase with an argyrodite-type structure relative to all crystal phases constituting the solid electrolyte is 97.0 wt % or more. The compound has a lattice strain of less than 0.10%. The solid electrolyte preferably exhibits a lithium ion conductivity of 4.0 mS/cm or more.

Provided is a spinel-type lithium metal composite oxide that makes it possible to achieve excellent high-temperature storage characteristics when used as a positive electrode active material of a lithium battery. The spinel-type (Fd-3m) lithium metal composite oxide is characterized by the oxygen occupancy (OCC) thereof as determined by the Rietveld method being 0.965-1.000, the lattice strain thereof as determined by the Williamson-Hall method being 0.015-0.090, and the ratio (Na/Mn) of the molar content of Na to the molar content of Mn satisfying 0.00&#x3c;Na/Mn&#x3c;1.00&#xd7;10.

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Takehara, Japan

Yuji Hoshi