Toyota Jidosha Kabushiki Kaisha

Primearth Ev Energy Co., Ltd.

Kazuya Kodama

Masahiko Mitsui

Junta Izumi

Kenji Kimura

Yasushi Nakagiri

Shinichiro Ito

Daisuke Koba

Tamotsu Fukuma

Hiroshi Matsuno

A battery information processing system includes a control device configured to perform capacity calculation processing. The capacity calculation processing is processing for calculating a full charge capacity Q of the module based on a fitting curve Z calculated by fitting processing of a Nyquist plot representing a result of measurement of an AC impedance of the module. In an OCV-SOC curve of the module, there are a flat region in which a ratio of variation is lower than a reference value and a steep region in which the ratio of variation is higher than the reference value. The control device estimates an OCV of the module from a result of detection by a voltage sensor and performs the capacity calculation processing when the estimated OCV is in the flat region.

Battery information processing system, battery assembly, method of calculating capacity of battery module, and method of manufacturing battery assembly

A battery information processing system includes a storage device configured to store an equivalent circuit model which expresses an AC impedance of a battery module with a plurality of circuit constants. The plurality of circuit constants include first to eighth circuit constants. The first circuit constant is a junction inductance. The second circuit constant is a junction resistance. The third circuit constant is a solution resistance and the fourth circuit constant is a charge transfer resistance. The fifth circuit constant is a CPE index of a diffusion resistance. The sixth circuit constant is a CPE constant of the diffusion resistance. The seventh circuit constant is a CPE index of an electric double layer capacitance. The eighth circuit constant is a CPE constant of the electric double layer capacitance.

Battery information processing system, battery assembly, method of evaluating characteristic of battery module, and method of manufacturing battery assembly

A battery information processing system includes an analyzer configured to analyze a result of measurement of an AC impedance of a module M. The analyzer plots the result of measurement of the AC impedance on a first frequency characteristic diagram which is a Bode diagram (a first diagram) relating to a real number component of the AC impedance and on a second frequency characteristic diagram which is a Bode diagram (a second diagram) relating to an imaginary number component of the AC impedance, obtains a polynomial curve L1 by fitting processing onto a result of plotting on the first diagram and obtains a polynomial curve L2 by fitting processing onto a result of plotting on the second diagram, and converts the polynomial curves L1 and L2 into an impedance curve Z on a Nyquist diagram.

A recovering device includes a charging chamber configured to overcharge a nickel-metal hydride battery. The charging chamber is provided with: a first water bath; a fixing device configured to fix the nickel-metal hydride battery with a portion of a container of the nickel-metal hydride battery being immersed in the water coolant in the first water bath; a pump; a dial gauge configured to detect a deformation amount of the container of the nickel-metal hydride battery; and a collection container configured to collect the gas exhausted from the exhaust valve of the nickel-metal hydride battery and exhaust the gas to outside the recovering device. The recovering device further includes a controller configured to perform the overcharging process for the nickel-metal hydride battery. The controller is configured to halt the overcharging process when the deformation amount of the container exceeds a threshold value.

Recovering device and recovering method for recovering nickel-metal hydride battery

A method for determining a state of a rechargeable battery includes obtaining a complex impedance measured by applying AC voltage or AC current to a rechargeable battery that is subject to determination and determining a state of the rechargeable battery based on the obtained complex impedance. The determining a state of the rechargeable battery includes determining whether or not a first capacity shift is occurring based on a comparison of a value of the complex impedance at a predetermined frequency with a first determination value used to determine a negative electrode capacity shift, and when determined that the first capacity shift is not occurring, determining whether or not a second capacity shift is occurring based on a comparison of a gradient of the complex impedance with respect to a real axis in a diffusion resistance region with a second determination value used to determine a positive electrode capacity shift.

Method and device for determining state of rechargeable battery

(A) A used battery pack is prepared. (B) By disassembling the used battery pack, a cell etc. is collected from the used battery pack. The cell etc. are a nickel-metal hydride battery. (C) A state of charge of the collected cell etc. is adjusted to a state of charge within any of a first SOC range (0 to 3%), a second SOC range (3 to 20%), and a third SOC range (100 to 200%). (G) An amount of voltage lowering as a result of the cell etc. being left is calculated. (H) When the amount of voltage lowering is equal to or smaller than a reference value set in advance, the cell etc. is determined as a good product. (I) A battery pack including the cell etc. determined as the good product is manufactured.

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Tajimi, Japan

Kazuya Kodama