Toyota Jidosha Kabushiki Kaisha

Waseda University

Yasumasa Oguma

Tetsuya Osaka

Kazuaki Utsumi

Masatsugu Kawakami

Shingo Tsuda

Tokihiko Yokoshima

Daikichi Mukoyama

Hideyo Ebisuzaki

Kenichiro Nakashima

Shigenori Hama

Yoshihiro Iwano

Akira Tsujiko

Satoshi Wakasugi

Manabu Imano

Michiyuki Ide

Hiroshi Tsuno

Hiroaki Nishino

Hidetoshi Okada

A battery system that avoids an over discharge with a simple sensor element is provided. The battery system comprises: a battery pack including a plurality of battery cells connected in series, a monitoring unit that monitors a condition of the battery pack, and a control unit that controls a discharge of the battery pack. The control unit calculates capacity condition A of the battery pack at a first discharge cutoff voltage based on the total voltage and the total current, estimates capacity condition B of the battery pack at the first discharge cutoff voltage based on the total current and the temperature, determines an occurrence of an over discharge based on the capacity condition A and the capacity condition B, changes the first discharge cutoff voltage to a second discharge cutoff voltage that is higher than the first discharge cutoff voltage, when the occurrence of the over discharge is determined.

Battery system

A battery system avoids an over discharge with a simple sensor element is provided. The battery system comprises: a battery pack including a plurality of battery cells connected in series, a monitoring unit that monitors a condition of the battery pack, and a control unit that controls a discharge of the battery pack. The control unit calculates capacity condition A of the battery pack at a first discharge cutoff voltage based on the total voltage and the total current, estimates capacity condition B of the battery pack at the first discharge cutoff voltage based on the total current and the temperature, determines an occurrence of an over discharge based on the capacity condition A and the capacity condition B, changes the first discharge cutoff voltage to a second discharge cutoff voltage that is higher than the first discharge cutoff voltage, when the occurrence of the over discharge is determined.

The battery of the present disclosure comprises a plurality of electrode bodies, wherein one of the electrode bodies and another of the electrode bodies are connected via a conductive material, each of the electrode bodies includes a metal current collector, an active material layer, and an electrolyte layer, the metal current collector has a connection surface which contacts the conductive material and a laminate surface which contacts the active material layer, and a ten-point average roughness of the laminate surface is less than a ten-point average roughness of the connection surface. According to the battery of the present disclosure, both adhesion between the metal current collector and the active material layer in the electrode body and connectivity between the electrode bodies via the conductive material can be achieved.

Battery and battery production method

A battery module disposed in a battery pack includes a plurality of flat plate batteries that are stacked; a connection member having a connection member main body that has a plate-shape and disposed in parallel with the flat plate batteries in a stacking direction of the flat plate batteries; and insulation members disposed on side surfaces of the connection member main body in the stacking direction of the flat plate batteries. The connection member has two terminals, a first terminal of the two terminals is connected to a terminal of the flat plate batteries, and a second terminal is connected to a terminal of an adjacent battery module.

Battery module and battery pack

A module includes a first member that is a battery or a gas tank in which pressure fluctuation happens along one axis direction, a pair of second members, the second members being arranged on end portions of the first member in the one axis direction, respectively, and a binding member binding the first member and the second members while pressurizing them. The binding member is formed as fiber-reinforced plastic (FRP) containing fiber and resin is revolved. The FRP includes a base fiber layer with a fiber direction along a revolution direction, and a reinforcing fiber layer with a fiber direction different from that of the base fiber layer. The reinforcing fiber layer has a non-overlapping portion between both end portions in a revolved state. The non-overlapping portion is positioned in a region facing the first member.

Module with reduced deterioration of binding member

The invention provides a laminated all-solid-state battery that can increase volumetric energy density and maintain the shape of the all-solid-state battery, as well as a method for producing the laminated all-solid-state battery. The all-solid-state battery comprises a battery stack having two or more unit cells and an exterior film sealing the battery stack, wherein the battery stack has a hexahedron shape formed by a top surface and bottom surface in the stacking direction and first, second, third and fourth side walls, the exterior film is a single film covering the battery stack from the top surface and bottom surface in a manner covering the fourth side wall, and condition (i) is satisfied when collector tabs protrude from the first or third side wall or condition (ii) is satisfied when collector tabs protrude from the second side wall, as well as a method for producing the all-solid-state battery.

All-solid-state battery and method for producing the same

A battery module is provided whereby loss of productivity can be minimized even when producing multiple exterior body parts for different battery module sizes. The battery module of the disclosure has an exterior body and an all-solid-state battery stack encapsulated in the exterior body. The exterior body has a tubular body and a pair of covers. The tubular body has flanges at both open ends. The flanges at both ends of the tubular body and the outer edge sections of the pair of covers are each joined forming joints, with the exterior body being sealed by the joints. The all-solid-state battery stack has one or multiple constituent unit cells. The direction of stacking of each of the layers of the constituent unit cell is in the axial direction of the tubular body.

Battery module

A current collector in which, even in the case of using a copper substrate, an electroconductive layer comprising a thermoplastic resin and an electroconductive material and covering the copper substrate provides the same positive temperature coefficient resistance function as the case of using an aluminum substrate. The current collector may comprise: a copper substrate comprising a copper oxide layer that an average content of an oxygen element present within a thickness of 1.0 &#x3bc;m or less from a surface of the copper substrate, is 10.5 at % or more, and a positive temperature coefficient resistance layer comprising a thermoplastic resin and an electroconductive material and covering the copper oxide layer of the copper substrate.

Current collector, battery and methods for producing the same

A temperature estimating apparatus is provided with: a deriving device configured to derive a slope function, on the basis of a value of a complex impedance of a battery at a predetermined frequency out of values obtained at a plurality of different temperatures and on the basis of a temperature of the battery when the complex impedance is obtained, wherein the slope function indicates a relation between the value of the complex impedance at the predetermined frequency and an inverse of the temperature of the battery; and an estimator configured (i) to measure a value of the complex impedance at the predetermined frequency and (ii) to substitute the measured value of the complex impedance at the predetermined frequency into the slope function, thereby estimating a temperature of the battery when the value of the complex impedance is measured.

Temperature estimating apparatus

[Object] To provide a battery module that can prevent the breakage of batteries due to the expansion or contraction of the batteries when charging and discharging the batteries. [Solution To Problem] A battery module includes a plurality of stacked batteries and a restraint part for restraining the plurality of batteries. The restraint part is composed of a pair of end plates arranged at either end in the stacking direction of the plurality of batteries and tension bands for connecting the pair of end plates and constraining the plurality of batteries in a pressurized state. The tension bands include elastically deformable concave-convex parts.

A battery state estimating apparatus is provided with: an acquirer configured to obtain a plurality of complex impedances of a battery at a plurality of different temperatures; a calculator configured to calculate a slope of a straight line connecting values of the obtained plurality of complex impedances at a first predetermined frequency on a complex plane having an axis that is a real component of the complex impedance and an axis that is an imaginary component of the complex impedance, as a slope of the complex impedance; a storage configured to store in advance a relation between the slope of the complex impedance and a battery state associated with the battery; and an estimator configured to estimate the battery state on the basis of the calculated slope of the complex impedance and the stored relation.

Battery state estimating apparatus

A battery state estimating apparatus is provided with; a voltage detector configured to detect a voltage between a positive electrode and a negative electrode of a battery; an impedance detector configured to detect an impedance of the battery; a first estimator configured to estimate a first temporary value of a charge amount of the battery; a second estimator configured to estimate a second temporary value of the charge amount of the battery; and a determinator configured (i) to determine that the first temporary value is the charge amount of the battery if the first temporary value or the second temporary value is out of a predetermined range, and (ii) to determine that the second temporary value, or a corrected value of the first temporary value is the charge amount of the battery if the first temporary value or the second temporary value is within the predetermined range.

A battery state estimating apparatus is provided with: an acquirer configured to obtain complex impedances of a battery at a different temperatures; a calculator configured to calculate a slope of a first straight line or a slope of a second straight line as an impedance slope, wherein the first straight line connects values of the complex impedances at a first predetermined frequency, wherein the second straight line connects a convergence point and at least one of values of the plurality of complex impedances at a second predetermined frequency; and an estimator configured to estimate a battery state associated with the battery on the basis of the impedance slope and a relation stored in a storage, if it is determined by a determinator that a temperature of the battery is in a predetermined temperature area.

A battery state estimating apparatus is provided with: an acquirer configured to obtain a complex impedance of a battery; a calculator configured to calculate a ratio of a variation of a predetermined feature amount regarding the complex impedance; and an estimator configured to estimate a charge amount of the battery on the basis of the ratio of the variation of the predetermined feature amount with respect to an integrated current value, which is an integrated value of an electric current flowing through the battery.

Provided is a method for manufacturing a current collector provided with a conductive layer that can keep a high resistance only at a high temperature. The method includes dispersing a carbon material in an organic solvent to prepare a carbon material dispersion solution, dispersing polyvinylidene fluoride in an organic solvent to prepare a resin dispersion solution, mixing the carbon material dispersion solution, the resin dispersion solution, and water, to prepare a composition for conductive layer formation, and forming a conductive layer on a surface of a current collector by applying the composition for conductive layer formation and thereafter drying the composition.

Growing community of inventors

Tokyo-to, Japan

Yasumasa Oguma