Prime Planet Energy & Solutions, Inc.

Shuhei Takeshita

Masanori Kitayoshi

Yutaka Oyama

Katsushi Enokihara

Shinsuke Matsuhara

Naohiro Mashimo

Haruka Shionoya

Aiko Nagano

Kiyohiko Nakano

Yusuke Araki

Provided is a graphite-based negative electrode active material that can impart both high output characteristics and high cycle characteristics to a nonaqueous electrolyte secondary battery. The graphite-based negative electrode active material disclosed herein is made up of particles having, in a cross-sectional view, a flat central portion made up of graphite, and a porous accumulation portion made up of accumulated graphite, on both sides of the flat central portion. The graphite that makes up the flat central portion is present more densely than the graphite that makes up the porous accumulation portion.

Graphite-based negative electrode active material

The method for producing a secondary battery electrode disclosed here includes steps of: preparing a moisture powder formed by aggregated particles that contain electrode active material particles, a binder resin, and solvent, wherein a solid phase, liquid phase, and gas phase in at least 50 number % or more of the aggregated particles in the moisture powder form a pendular or funicular state; forming a coating film composed of the moisture powder, on an electrode current collector, while the gas phase remains present; carrying out depression/elevation transfer into a surface part of the coating film; forming an electrode active material layer by drying the coating film; and pressing the electrode active material layer. The electrode active material particles are aspherical particles in which a ratio of a short side to a long side in a cross sectional view is less than 0.95.

Secondary battery electrode and method for producing the electrode

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Nagakute, Japan

Shuhei Takeshita