Waseda University

Panasonic Corporation

Hiroki Nara

Tetsuya Osaka

Tokihiko Yokoshima

Daikichi Mukoyama

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

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

Hiroki Nara