Toyota Jidosha Kabushiki Kaisha

Primearth Ev Energy Co., Ltd.

Kansai Paint Company, Ltd.

Sachio Takeda

Daisuke Koba

Yasuhiro Takahashi

Masahiko Mitsui

Tetsuya Osaka

Takanori Ito

Koichi Ichikawa

Katsunori Maegawa

Akira Kuroda

Kosuke Iwase

Naoto Sato

Hideki Hagiwara

Machiko Abe

Atsuya Kato

Kazuyuki Kuwano

Koji Endo

Yasuhiko Sakai

Junji Akahane

You Kato

Hirochika Habu

The present invention pertains to the detection of the state of charge of a battery, whereby the complex impedance in the diffusion region of the battery is used. An arithmetic device such as a computer determines the slope of the complex impedance at least two different frequencies in the diffusion region of a rechargeable battery when a straight-line approximation has been made. The state of charge of the rechargeable battery is detected by using the slope that has been determined, and the relationship between the state of charge and slopes that have been stored in advance in a storage means.

State of charge detection device

This invention relates to a conductive paste for lithium-ion battery positive electrodes and a mixture paste for a lithium ion battery positive electrode that have an easy-to-apply viscosity, even when a relatively small amount of a dispersion resin is incorporated. More specifically, the invention provides a conductive paste for lithium-ion battery positive electrodes, the conductive paste comprising a dispersion resin (A), conductive carbon (B), and a solvent (C), the dispersion resin (A) containing a resin (A1), the resin (A1) containing, as one constituent component, a polymerizable unsaturated group-containing monomer (A1-1) represented by a specific formula.

Conductive paste for lithium-ion battery positive electrodes and mixture paste for lithium-ion battery positive electrodes

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.

Battery state determination device determining a micro-short-circuiting tendency of a rechargeable battery

This battery state determination device () is provided with: a voltage detection unit () that detects the voltage (V) of a rechargeable battery (M) to be evaluated; a current detection unit () that detects the current of the rechargeable battery (M); a charge state detection unit () that detects the state of charge (SOC) of the rechargeable battery (M); and a determination unit () configured so as to calculate the absolute value of the voltage gradient (G), which indicates the change in voltage with respect to the discharge amount (Ah), when the state of charge (SOC) of the rechargeable battery (M) is less than 40%, compare the absolute value of the voltage gradient (G) to a pre-set upper limit value (Gmax), and, when the absolute value of the voltage gradient (G) is greater than the upper limit value (Gmax), determine that a small short circuit has occurred in the rechargeable battery (M).

Battery state determination device

This method for restoring battery capacity is provided with an oxygen-generating/exhausting step for charging a nickel-metal-hydride storage battery, causing the generation of oxygen gas in a positive electrode, opening a safety valve device, and discharging at least a portion of the oxygen gas through the safety valve device to the outside of the battery. The battery temperature when starting the step is in the range of &#x2212;30 to 10&#xb0; C. and the SOC is in the range of (30-Ta) to 100%, or the battery temperature (Ta) is in the range of 10 to 50&#xb0; C. and the SOC is in the range of 20-100%.

Method for restoring battery capacity, method for restoring battery pack capacity, device for restoring battery capacity, and device for restoring battery pack capacity

A method of selecting a used secondary battery includes an internal resistance measurement step of measuring a specific internal resistance (second internal resistance) at a specific battery temperature (second battery temperature) of each of used secondary batteries, and a selection step of selecting a used secondary battery or batteries having the specific internal resistance (second internal resistance) smaller than a preset threshold from the plurality of used secondary batteries whose specific internal resistances (second internal resistance) have been measured in order to exclude an electrode-deteriorated battery from the used secondary batteries.

Method of selecting used secondary battery and method of manufacturing battery pack

In a method for adjusting a nickel-metal hydride storage battery, based on a correlation between a charge amount after valve opening and an increased amount of a discharge reserve capacity which are previously ascertained, the charge amount after valve opening corresponding to a target value of the set increased amount of the discharge reserve capacity is calculated and this calculated value is set as a target charge amount after valve opening. In a discharge reserve adjusting step, when a charge amount of the battery from the time when a safety valve device is opened after start of overcharge of the battery reaches the set target charge amount after valve opening, overcharge of the battery is terminated.

Method for adjusting nickel-metal hydride storage battery

This device and method use the complex impedance of a rechargeable battery to detect the state of the rechargeable battery. A computer determines the slope of the complex impedance at least two different frequencies in a diffusion region of the rechargeable battery when a straight-line approximation has been made, and compares the slope with a threshold value. If the slope is greater than or equal to the threshold value, the computer determines that the battery has a normal capacity balance, and if the slope is less than the threshold value, the computer determines that the battery has an abnormal unbalanced capacity. Furthermore, if the magnitude of an imaginary axis component of the complex impedance in the diffusion region of the rechargeable battery is greater than the threshold battery, the computer determines that the battery has an abnormal capacity balance, and if said magnitude is less than or equal to the threshold value, the computer determines that the battery has a normal capacity balance.

Device for detecting normal, abnormal or deteriorated battery state

Each of battery cells () that constitute a battery module includes a flat-shaped rolled electrode body () formed by rolling a sheet-like anode collector () and a sheet-like cathode collector () along with a sheet-like separator, and a trailing edge (E) of the sheet-like anode collector () and a trailing edge (E) of the sheet-like cathode collector () are located at a position (B) outside a portion of the rolled electrode body () which substantially receives a restraining load. The battery module, in which the restraining load is applied to the cells, achieves long service life while maintaining good output characteristics.

Restrained battery module made up of cells having rolled electrode bodies, and method of making the same

In an assembled battery (), a plurality of rechargeable unit cells (), each of which is provided with an electrode body () that has a positive electrode () and a negative electrode (), a container () that houses the electrode body () and an electrolyte, and a positive electrode terminal () and a negative electrode terminal () which are arranged on an outside of the container (), the rechargeable unit cells being connected in series. The plurality of unit cells () are arranged in a predetermined direction and fastened together while a predetermined load is applied in the arranging direction. Insulating filler () is inserted into a gap between the electrode body () and an inside wall surface of the container () of at least one of the unit cells (), and a thickness in the arranging direction of each of the unit cells () in the fastened state is constant.

Growing community of inventors

Toyohashi, Japan

Sachio Takeda