Toyota Jidosha Kabushiki Kaisha

Waseda University

Daikichi Mukoyama

Tetsuya Osaka

Tokihiko Yokoshima

Kazuaki Utsumi

Yasumasa Oguma

Shingo Tsuda

Hiroki Nara

Toshiyuki Momma

A battery moduleincludes a group batteryin which batteries(to) are connected in series, and an assessment evaluation unitconfigured to calculate respective states of health of battery cells, in which the group batteryincludes label elementsrespectively connected in parallel with the battery cellsand configured such that respective impedance characteristics of the batteriesdiffer from one another, and the assessment evaluation unitincludes a measurement unitconfigured to measure a first Cole-Cole plot of the group battery, a first calculation unitconfigured to decompose the first Cole-Cole plot into respective second Cole-Cole plots of the batteries, a second calculation unitconfigured to calculate respective third Cole-Cole plots of the battery cellsfrom the second Cole-Cole plots, and a third calculation unitconfigured to calculate respective states of the battery cellsfrom the third Cole-Cole plots.

Group battery, battery module, and method for evaluating battery module

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

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.

An electrochemical analysis apparatusincludes a power controllerthat generates a rectangular wave signal having a first frequency (f1) and applies the rectangular wave signal to an electrochemical cellincluding a plurality of electrodestoand an electrolyte, a Fourier transform sectionthat Fourier-transforms a response signal of the electrochemical cellto the rectangular wave signal and calculates frequency characteristics including a component of a second frequency f2 of an integer multiple of the first frequency f1, and a calculating sectionthat calculates an impedance characteristic of the electrochemical cellbased on the frequency characteristics calculated by the Fourier transform section

Electrochemical analysis apparatus and electrochemical system

A battery system includes: a secondary battery; a memory portion that stores information which includes a measurement frequency, a measurement temperature, and an initial limiting capacitance of one secondary battery; a temperature measuring section; a power supply section which applies an AC signal of 0.5 mHz to 10 mHz, to the secondary battery at 40&#xb0; C. to 70&#xb0; C.; a measuring portion which measures an impedance of the secondary battery by the AC signal; and a calculating portion that calculates the degree of degradation of the secondary battery.

Growing community of inventors

Tokyo, Japan

Daikichi Mukoyama