Prime Planet Energy & Solutions, Inc.

Haruka Shionoya

Katsushi Enokihara

Naohiro Mashimo

Masanori Kitayoshi

Aiko Nagano

Shuhei Takeshita

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

A method for producing secondary battery electrodes includes a step of preparing a moisture powder formed of aggregated particles that contain electrode active material particles, a binder resin, and solvent, wherein the solid phase, liquid phase, and gas phase in at least 50 number % of the aggregated particles form a pendular state or a funicular state; a step of forming, using the moisture powder, a coating film while the gas phase remains present; a step of forming a first groove that extends in a first direction, by transferring depressions and elevations, using a first roll die, into the coating film; and a step of forming a second groove that extends in a different direction, by transferring depressions and elevations, using a second roll die, into the coating film. Depression/elevation transfer is carried out in such a manner that the second groove is made deeper than the first groove.

Method for producing secondary battery electrodes

The electrodes disclosed herein, a low-density region having a relatively low electrode density and a high-density region having a relatively high electrode density are repeated on a surface of the electrode active material layer in a predetermined pattern at a constant pitch. The electrode active material layer is evenly divided into three layers of an upper layer, an intermediate layer, and a lower layer in a thickness direction from the surface of the active material layer to the electrode current collector, and when the electrode densities (g/cm) of the upper layer, the intermediate layer, and the lower layer of the low-density region are respectively d, d, and dand the electrode densities (g/cm) of the upper layer, the intermediate layer, and the lower layer of the high-density region are respectively d, d, and d, a relation of d/d<d/dis satisfied.

An electrode having both high energy density and ion diffusivity includes an electrode active material layer on either a positive-or negative-electrode current collector, in which the electrode active material layer has a concave/convex shape on its surface in a predetermined pattern at a constant pitch. In a cross-sectional SEM image of the electrode active material layer, linear cracks are unevenly distributed in a concave portion compared to in a convex portion.

A method of producing an electrode disclosed here includes a step in which a moisture powder formed of agglomerated particles; a step in which by using the moisture powder, a coating film composed of the moisture powder is formed on an electrode current collector, with a gas phase of the coating film being remained so that the average film thickness of the coating film is 50 μm or more; a step in which the coating film on the current collector is transported, concavo-convex transfer is performed using a roll mold, and thus at least one groove extending in the transport direction is formed in a center of a surface part of the coating film, with the groove being formed to have a depth satisfying ( 9/10×t)>t; and a step in which the coating film formed on the current collector is dried to form an electrode active material layer.

Method of producing electrode for secondary battery

An electrode disclosed here includes a surface part of an electrode active material layer has a plurality of first grooves extending in a width direction of the electrode current collector and at least one second groove extending in a longitudinal direction of an electrode current collector. The first groove is formed to be continuous from one end to another end. Here, a region in which the first groove and the second groove are formed is uniformly divided into three layers, which are an upper layer, an intermediate layer and a lower layer, in a thickness direction from the surface of the electrode active material layer to the electrode current collector, and when electrode densities (g/cm) of the upper layer, the intermediate layer and the lower layer of the groove are d, d, and d, respectively, a relationship of 0.8<(d/d)<1.1 is satisfied.

Electrode for non-aqueous electrolyte solution secondary battery, method of producing electrode and non-aqueous electrolyte solution secondary battery including electrode

A method for producing secondary battery electrodes includes a step of preparing a moisture powder formed of aggregated particles that contain a plurality of electrode active material particles, a binder resin, and solvent, wherein the 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 state or a funicular state; a step of forming a coating film composed of the moisture powder on an electrode current collector, while the gas phase remains present; a step of forming a depression in the coating film by carrying out, using a die having an elevation of prescribed height, depression/elevation transfer into the coating film; and a step of carrying out depression/elevation transfer, using a die having an elevation higher than the elevation of prescribed height, by pressing the higher elevation into the depression that has been formed.

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Toyota, Japan

Haruka Shionoya