Panasonic Intellectual Property Management Co., Ltd.

Kenji Matsubara

Atsushi Fukui

Nobuhiko Hojo

Masanobu Takeuchi

Hiroyuki Matsumoto

Hiroshi Kawada

Kazuhiro Iida

Takayuki Nakatsutsumi

Provided is a negative electrode active material that is applied in an aqueous secondary battery in which is used an aqueous electrolyte containing water and a lithium salt. The negative electrode active material contains hardly-graphitizable carbon, and the hardly-graphitizable carbon has a C—F bond group on the surface thereof. In an XPS spectrum obtained through X-ray photoelectron spectroscopy, when the peak intensity near 688 eV originating from C—F bonds of the hardly-graphitizable carbon is denoted by I688eV, the peak intensity near 284 eV originating from C—C bonds is denoted by I284eV, a ratio of the peak intensity I688eV to the peak intensity I284eV (value of I688eV/I284eV) is denoted by X, and the BET specific surface area (m2/g) is denoted by Y, the X and Y satisfy Y<(−0.3X+3.75), 0.1≤X≤5, and Y≥2.

Negative electrode active material for aqueous secondary battery, negative electrode for aqueous secondary battery, and aqueous secondary battery

A secondary battery according to the present invention is provided with a positive electrode, a negative electrode and an electrolyte solution; the electrolyte solution contains water and a lithium salt; the negative electrode contains a negative electrode active material; a silane coupling agent, which is reductively decomposed at a potential that is higher than the reductive decomposition potential of water, is adhered to the surface of the negative electrode active material; and the silane coupling agent contains fluorine as a constituent element.

Secondary battery

A secondary battery including a positive electrode, a negative electrode, and an electrolytic solution. The negative electrode includes a carbon material electrochemically capable of absorbing and releasing lithium ions, and a solid electrolyte covering at least part of a surface of the carbon material and having lithium ion conductivity. The solid electrolyte includes a first compound represented by a general formula: LiM1O, where 0.5<x≤9, 1≤y<6, and the M1 includes at least one element selected from the group consisting of B, Al, Si, P, Ti, V, Zr, Nb, Ta, and La. The electrolytic solution includes a solvent and a lithium salt, and the solvent contains at least water.

An electrolyte solution according to one aspect of the present disclosure comprises water, a lithium salt, and a polycarboxylic acid having two or more carboxylic acid groups. A secondary battery according to one aspect of the present disclosure comprises a positive electrode, a negative electrode, and the electrolyte solution.

Electrolyte and secondary battery

A rechargeable battery including a positive electrode, a negative electrode, and an electrolyte solution is provided. The electrolyte solution contains water and one or more lithium salts, and the lithium salts include lithium fluorophosphate.

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Osaka, Japan

Kenji Matsubara