Honda Motor Co., Ltd.

Kazuki Chiba

Masahiro Ohta

Toru Sukigara

Hiroto Maeyama

Atsushi Ogawa

Ushio Harada

Toshiyuki Ariga

The battery unit includes: a battery module including a battery cell; a battery heat flow detector configured to detect a heat flow of the battery cell; a storage configured to store heat flow HF vs. state of charge SOC initial characteristics of the battery cell; and a battery state estimator configured to estimate a state of health SOH of the battery cell. The battery state estimator measures, during charge of the battery cell, HF vs. SOC present characteristics of the battery cell, based on the detected heat flow of the battery cell, and estimates a state of health SOH of the battery cell, from a ratio between a length mAh of a line segment between peaks of differential characteristics of the measured HF vs. SOC present characteristics and a length mAh of a line segment between peaks of differential characteristics of the stored HF vs. SOC initial characteristics.

Battery unit

A battery unit includes: a module including m cell groups that are connected in series and each include n cells connected in parallel; m voltage detectors; (m×(n−1)) heat flow detectors; a storage; and a state estimator. The storage stores a table map of OCV vs. SOC characteristics (A1) and a table map of HF vs. SOC characteristics (A2). For each of the m cell groups, the state estimator is configured to: determine, based on the (A2), a true SOC of (n−1) cells that corresponds to a heat flow detected; determine, based on the (A1), an OCV of the (n−1) cells that corresponds to the determined true SOC; calculates an OCV of a remaining cell from the determined OCV and a detected composite voltage; and determine, based on the (A1), a true SOC of the remaining cell that corresponds to the calculated OCV.

The battery unit includes a storage configured to store (A1) and (A2) below, and a battery state estimator. The battery state estimator estimates, based on (A1), a start SOC corresponding to a detected OCV at a start of charge; measures HF vs. SOC present characteristics and detects a peak of differential characteristics of the measured HF vs. SOC present characteristics during the charge; determines a SOC at the detected peak as a SOC(HF) based on (A2); calculates a charge capacity from the start of the charge to detection of the peak; calculates a SOC(OCV) based on the calculated charge capacity and the start SOC; and in a case where the SOC(OCV) deviates with respect to the SOC(HF) by an amount of deviation equal to or greater than a predetermined value, corrects (A1).

Provided is a solid electrolyte sheet having a self-supporting property while having a small thickness and flexibility. The solid electrolyte sheet is formed using a support having a specific porosity and a specific thickness. Specifically, the solid electrolyte sheet is formed in which a solid electrolyte is filled in a support having a porosity of 60% or more and 95% or less and a thickness of 5 &#x3bc;m or more and less than 20 &#x3bc;m.

Solid electrolyte sheet and solid state battery

Provided is a solid electrolyte laminated sheet having a self-supporting property and capable of realizing a solid state battery having high output characteristics. A plurality of supports are used, a solid electrolyte is filled in each support to form a self-supporting sheet, and the self-supporting sheets are superimposed to form a solid electrolyte laminated sheet. Specifically, the solid electrolyte laminated sheet is configured by setting a layer of the solid electrolyte laminated sheet in contact with a positive electrode layer being the outermost layer as a self-supporting sheet in which a solid electrolyte resistant to oxidation is filled, and a layer in contact with a negative electrode layer being the opposite outermost layer as a self-supporting sheet in which a solid electrolyte resistant to reduction is filled.

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Saitama, Japan

Kazuki Chiba