Toyota Jidosha Kabushiki Kaisha

Primearth Ev Energy Co., Ltd.

Masahiko Mitsui

Junta Izumi

Yasuhiro Takahashi

Juni Yasoshima

Daisuke Koba

Koichi Ichikawa

Sachio Takeda

Kazuya Kodama

Yasushi Nakagiri

Shinichiro Ito

Masatoshi Uchida

Yoshiyuki Nakayama

Tamotsu Fukuma

Kenji Kimura

Yoshiaki Kikuchi

Kenji Takahashi

Kazuo Tojima

Hiroyuki Kaiya

Kouichi Ichikawa

Kotaro Shibuya

Hiroshi Matsuno

A control device classifies a plurality of batteries included in a battery string into a first battery (e.g., Ni-MH) and a second battery (e.g., LiB). When a predetermined first condition is satisfied, the control device connects, to a power supply circuit, only the first battery among the batteries included in the battery string. When a predetermined second condition is satisfied, the control device connects, to the power supply circuit, only the second battery among the batteries included in the battery string.

Power supply system and control device

A battery capacity estimation system executes a charging and discharging process (S), an alternating current impedance acquiring process (Sand S), and a battery capacity estimating process (Sto S). The charging and discharging process involves charging and discharging a target secondary battery. The alternating current impedance acquiring process involves acquiring a measurement result of an alternating current impedance of a target secondary battery, by applying an alternating current signal within a specific frequency range to the target secondary battery after completion of the charging and discharging in the charging and discharging process and before a predetermined maximum waiting time elapses. The battery capacity estimating step involves estimating a battery capacity of the target secondary battery based on the measurement result of the alternating current impedance.

Battery capacity estimation method and battery capacity estimation system

An analysis device determines, by the Maharanobis-Taguchi system using a plurality of explanatory variables, to which of a first group and a second group a module representing a nickel metal hydride battery will belong when the module is subjected to capacity restoration processing, the first group being defined as a group of modules of which battery capacity is lower than a reference capacity, the second group being defined as a group of modules of which battery capacity is higher than a reference capacity. The plurality of explanatory variables include a plurality of feature values extracted from a Nyquist plot of the module. The plurality of feature values include at least two AC impedance real number components plotted in a semicircular portion, at least two AC impedance imaginary number components plotted in the semicircular portion, and at least one AC impedance imaginary number component plotted in a linear portion.

Battery information processing system, battery information processing method, and battery assembly and method of manufacturing battery assembly

A battery capacity estimation method includes first to third steps. The first step involves obtaining information about a Nyquist plot by a predetermined AC-IR measurement. The second step involves obtaining image data of a Nyquist diagram that is obtained when the AC-IR measurement is performed at a predetermined first temperature, based on the information about the Nyquist plot obtained in the first step and on an ambient temperature at which the AC-IR measurement is performed in the first step. The third step involves inputting the image data of the Nyquist diagram obtained in the second step to an input layer of a pre-trained neural network model, to obtain a battery capacity estimate value of a battery to be measured.

Battery capacity estimation method and battery capacity estimation device

A trained neural network model is a neural network model which has been trained based on Nyquist plots of a plurality of modules of which full charge capacity is within a reference range. A processing system determines to which of a first group of modules of which full charge capacity is within the reference range and a second group of modules of which full charge capacity is out of the reference range a module belongs, based on discriminant analysis in which at least one feature value extracted from the Nyquist plot of the module is adopted as an explanatory variable. When the processing system determines that the module M belongs to the first group, the processing system estimates a full charge capacity of the module by using the trained neural network model.

Battery information processing system, method of estimating capacity of secondary battery, and battery assembly and method of manufacturing battery assembly

A battery performance evaluation device executes an alternating current impedance acquiring process (S), an OCV acquiring process (S), and an SOC estimating process (S). The alternating current impedance acquiring process involves acquiring a measurement result of an alternating current impedance of a target secondary battery, the alternating current impedance measured by applying an application signal to the target secondary battery within a specific frequency range. The OCV acquiring process involves acquiring an OCV of the target secondary battery. The SOC estimating process involves estimating an SOC of the target secondary battery to be 0%, if an imaginary component of the measurement result of the acquired alternating current impedance at a predetermined frequency within the specific frequency range is greater than or equal to a first threshold value and the acquired OCV value is less than or equal to a second threshold value.

Battery performance evaluation device, and battery performance evaluation method

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 capacity estimation method includes a first step and a second step. The first step is a step of obtaining image data of a Nyquist diagram drawn by a predetermined method, based on a Nyquist plot obtained by a predetermined AC-IR measurement. The second step is a step of obtaining a battery capacity estimate value of a battery to be measured by inputting the image data of the Nyquist diagram obtained in the first step into an input layer of a pre-trained neural network model.

A method for manufacturing a nickel-metal hydride battery includes: a first step of preparing a first nickel-metal hydride battery having a positive electrode including nickel hydroxide (Ni(OH)); and a second step of manufacturing the second nickel-metal hydride battery by performing 600% overcharging to the prepared first nickel-metal hydride battery. The 600% overcharging is a process for supplying the first nickel-metal hydride battery with an amount of electric power of 600% of the rated capacity of the first nickel-metal hydride battery.

Method for manufacturing nickel-metal hydride battery and nickel-metal hydride battery

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.

Method of manufacturing battery pack

A method for reusing a vehicle rechargeable battery to rebuild an assembled battery from a plurality of battery units having a usage history is provided. The method includes measuring a remaining charge of each of a plurality of battery units obtained by dismantling an assembled battery having a usage history. The method further includes selecting from the battery units a battery unit in which the measured remaining charge is greater than or equal to a remaining charge lower limit value, which is set in a range that is greater than zero and less than a lower limit value of a remaining charge control range of a vehicle in which the assembled battery was installed, and assembling a new assembled battery using the selected battery unit.

Method for reusing vehicle rechargeable battery

A battery state determination device, which determines a micro-short-circuiting tendency state, includes an impedance meter that applies an AC voltage or an AC current of a measurement frequency to a rechargeable battery, which is subject to determination, and measures complex impedance. The device further includes a detector that detects an absolute value of an imaginary axis component of the complex impedance. The device further includes a determiner that compares the absolute value of the imaginary axis component detected by the detector with a lower limit threshold value. The lower limit threshold value is set based on a measurement result of the absolute value of the imaginary axis component of the rechargeable battery in the micro-short-circuiting tendency state. When the absolute value of the imaginary axis component is smaller than the lower limit threshold value, the determiner determines that the rechargeable battery is in the micro-short-circuiting tendency state.

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Toyota, Japan

Masahiko Mitsui