Murata Manufacturing Co., Ltd.

Murata Manufacturingco., Ltd.

Yuto Horiuchi

Masatomo Tanaka

Shigetaka Tomiya

Yoshifumi Shimizu

Kazuhiko Morizawa

Naoki Koshitani

A charge and discharge control device is provide. The charge and discharge control device includes a determination circuitry configured to determine an ion diffusion rate associated with electric conduction in a secondary battery, and determine a time integrated value of an overcharged amount of an active material based on the ion diffusion rate and a charge condition; an evaluation circuitry configured to evaluate the charge condition of the secondary battery based on a determination result obtained by the determination circuitry; and a charge and discharge controller configured to control state of current application and voltage application to the secondary battery at a time of charging or discharging the secondary battery based on an evaluation result obtained by the evaluation circuitry.

Charge and discharge control device, charge and discharge control method, battery pack, electronic equipment, electric vehicle, power tool and power storage system

In a secondary battery charging method, constant current charging is performed until a first predetermined voltage Vis attained, constant voltage charging is then performed at the first predetermined voltage V, the first constant voltage charging is completed when a charge current becomes (I&#x2212;&#x394;I) from I, and then n is incremented by one; and constant voltage charging is performed at a voltage V=V+&#x394;V, a step of completing the n-th constant voltage charging when the charge current becomes (I&#x2212;&#x394;I) from Iis repeated by incrementing n by one, and the N-th constant voltage charging in which a value of the voltage Vreaches a second predetermined voltage V(&#x3e;V) is completed to terminate the constant voltage charging.

Secondary battery charging method, charging control apparatus, and secondary battery

Provided is a technology that can improve a cycle property without lowering a volume energy density. The present technology provides a method for evaluating a secondary battery, including conducting at least: a determination step of determining a degree of diffusion defect of an ion that performs electric conduction; an evaluation step of evaluating a state of the secondary battery on the basis the result of the determination in the determination step; and a control step of controlling states of current application and voltage application on the secondary battery during charging or during discharging of the secondary battery on the basis of the result of the evaluation in the evaluation step.

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Kanagawa, Japan

Yuto Horiuchi