Gs Yuasa International Ltd.

Hidefumi Hasegawa

Sumio Mori

Tomonori Kako

Masashi Nakamura

Katsushi Nishie

Yoshihiko Mizuta

Shinya Kitano

Kenichi Sejima

Hiroshi Sekiguchi

Kie Tanaka

The energy storage device of the present invention includes: a negative electrode including a negative composite layer and a composite layer non-forming portion on both surfaces of a negative electrode current collecting foil respectively; a positive electrode including a positive composite layer on both surfaces of a positive electrode current collecting foil respectively; and a separator including an insulation layer which faces the positive electrode and is interposed between the negative electrode and the positive electrode. The negative electrode, the separator and the positive electrode are stacked in a first direction. The negative composite layer and the composite layer non-forming portion are disposed adjacently to each other in a second direction orthogonal to the first direction on the respective surfaces of the negative electrode. The separator is configured to project in the second direction from the positive composite layer at one end of the separator in the second direction. The separator contains a first bent portion including a recessed surface on a surface thereof which faces the negative electrode at a portion projecting in the second direction from the negative composite layer. The first bent portions of the separators disposed adjacently to each other in the first direction are brought into contact with each other.

Energy storage device, energy storage apparatus, and automobile

Provided is an electric storage device including a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, a nonaqueous electrolyte solution in which an electrolyte is dissolved in a nonaqueous solvent, wherein an inorganic filler layer is disposed between the positive electrode and the negative electrode and the nonaqueous electrolyte solution contains lithium difluorobis(oxalato)phosphate.

Electric storage device

A technology described herein is for accurately determining the SOC of a secondary battery. An open-circuit-voltage-to-state-of-charge (OCV-SOC) characteristic has a capacity decrease estimation OCV region in which a relationship between the OCV and the SOC is assumed not to change due to degradation of the secondary batterysince a reference time point. Charge currents or discharge currents in the capacity decrease estimation OCV region are accumulated in a process in which the secondary battery SOC changes among OCVs. From the accumulation, an accumulated current is obtained. A secondary battery capacity decrease is estimated based on the accumulated current. An OCV-SOC characteristic is specified based on the estimated secondary battery capacity decrease and a predetermined relationship between the battery capacity decrease of the secondary battery since the reference time point and the OCV-SOC characteristic. A secondary battery SOC is determined based on the OCV and the specified OCV-SOC characteristic.

Secondary battery state of charge determination apparatus, and method of determining state of charge of secondary battery

A condition estimation device includes a voltage measurement circuit, memory, and a controller. The voltage measurement circuit measures an open circuit voltage (OCV) of an electric storage device. The memory is configured to store first information on a correlation between a positive electrode potential and an electric storage capacity and second information on a correlation between a negative electrode potential and an electric storage capacity. The controller is configured to: measure an OCV under charge or discharge; calculate an electric storage capacity of the electric storage device having the OCV equal to a reference voltage; correct at least one of the first information and the second information such that a potential difference at the calculated capacity is equal to the reference voltage; and generate an OCV characteristic based on the first and the second information after the at least one of the first and the second information is corrected.

Growing community of inventors

Kyoto, Japan

Hidefumi Hasegawa