Abstract: A non-aqueous rechargeable battery includes an electrode body formed by rolling a stack of a positive electrode plate and a negative electrode plate with a separator arranged in between. At least one of the positive electrode plate and the negative electrode plate includes a substrate, a first mixture layer located on an outer side of the substrate, and a second mixture layer located on an inner side of the substrate. The second mixture layer includes an active material having a BET specific surface area that is greater than that of an active material included in the first mixture layer.

Abstract: A method for producing a negative electrode active material realizing both of improvement in tolerance against the deposition of lithium and improvement in life performance is provided. A method for producing a negative electrode active material includes the steps of preparing graphite particles having a BET specific surface area of 10.3 m2/g or larger and 12.2 m2/g or smaller; and coating at least a part of a surface of the graphite particles with amorphous carbon. In the step of coating, at least the part of the surface of the graphite particles is coated with the amorphous carbon such that a value obtained by subtracting a BET specific surface area of the negative electrode active material from a BET specific surface area of the graphite particles is 6.9 m2/g or larger and 8.3 m2/g or smaller.

Abstract: A method for manufacturing an electrode plate including a current collector and an active material layer includes preparing, forming, and pressing. In the preparing, a mixture is prepared by kneading an active material. In the forming, the active material layer is formed on the current collector by applying the mixture to the current collector. In the pressing, the active material layer is pressed so that active material layer has a predetermined thickness. The mixture applied to the current collector has a weight per unit area based on a specific surface area of the active material used in the mixture and a tapped density of the active material used in the mixture.

Abstract: A battery state estimation device for estimating a charged electric charge quantity of a rechargeable battery includes an impedance measurement unit configured to measure a plurality of complex impedances of the rechargeable battery by supplying measurement power to the rechargeable battery, a parameter calculation unit configured to calculate a parameter that includes a ratio of a difference between measurement angular velocities of two complex impedances in a diffusion region among the measured complex impedances to a difference between components of the two complex impedances, and an electric charge quantity estimation unit configured to estimate a charged electric charge quantity of the rechargeable battery based on the calculated parameter and preset correlated information between the charged electric charge quantity of the rechargeable battery and the parameter.

Abstract: A battery state estimation device for estimating a charged electric charge quantity of a rechargeable battery includes an impedance measurement unit configured to measure a plurality of complex impedances of the rechargeable battery by supplying measurement power to the rechargeable battery, a parameter calculation unit configured to calculate a parameter that includes a ratio of a difference between measurement angular velocities of two complex impedances in a diffusion region among the measured complex impedances to a difference between components of the two complex impedances, and an electric charge quantity estimation unit configured to estimate a charged electric charge quantity of the rechargeable battery based on the calculated parameter and preset correlated information between the charged electric charge quantity of the rechargeable battery and the parameter.