Toyota Jidosha Kabushiki Kaisha

Prime Planet Energy & Solutions, Inc.

Toyota Battery Co., Ltd.

Shusaku Goto

Hiroaki Ikeda

Masahiro Morita

Kenta Ishii

A method for inspecting a battery in which an electrode body is accommodated in a case so that the electrode body is insulated from the case by an insulation film includes: adjusting the battery to a first voltage; measuring a first potential difference which is a potential difference between the case and a negative terminal that is exposed outside the case and electrically connected to a negative electrode plate to have a negative-electrode potential; measuring a second potential difference which is a potential difference between the case and the negative electrode plate after a lapse of a standby period of 24 hours or more; and determining whether or not a short circuit exists between the case and the negative electrode plate based on magnitude of the first and second potential differences and a change between the first potential difference and the second potential difference.

Method for inspecting a power storage device, method for manufacturing a power storage device, and method for manufacturing a device stack

An inspecting step includes a first period after a cooling step ends and a second period after the first period ends. Variations in a voltage drop value per unit time in a nonaqueous electrolyte rechargeable battery are smaller in the second period than in the first period. The cooling step cools the battery in a state where the electrode body is directly or indirectly pressurized and restrained in a thickness direction with a smaller pressure than that in the inspecting step or in a state where the electrode body is not restrained. The voltage value of the battery is measured when a specified time has passed after the voltage value of the battery was measured in the second period. The battery is determined as being normal when the voltage drop value per unit time based on the measured voltage value is less than or equal to a threshold value.

Method for inspecting nonaqueous electrolyte rechargeable battery

According to the present invention, there is provided a technique making it possible to improve suitably the performance of a nonaqueous electrolyte secondary cell in which a SEI film is formed on the surface of a negative electrode active material. The nonaqueous electrolyte secondary cell disclosed herein includes a positive electrode, a negative electrode, and a nonaqueous electrolytic solution, wherein a negative electrode SEI filmincluding at least a LiBOB skeleton and a fluorosulfonic acid skeleton is formed on the surface of a negative electrode active material, and a positive electrode SEI filmincluding at least a phosphoric acid skeleton is formed on the surface of a positive electrode active material. Where the component amount of the LiBOB skeleton in the negative electrode SEI filmis denoted by I, the component amount of the fluorosulfonic acid skeleton in the negative electrode SEI filmis denoted by I, and the component amount of the phosphoric acid skeleton in the positive electrode SEI filmis denoted by I, a formula (1) represented by 4&#x2264;I/I&#x2264;10 and a formula (2) represented by 5 &#x3bc;mol/m&#x2264;I&#x2264;15 &#x3bc;mol/mare satisfied. Furthermore, the BET specific surface area of the negative electrode active material is 3.5 m/g or more and 5.0 m/g or less, and the component amount Iof the LiBOB skeleton is 4.3 &#x3bc;mol/mor more.

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Hamamatsu, Japan

Shusaku Goto