Toyota Jidosha Kabushiki Kaisha

Satoshi Goto

Hiroshi Hamaguchi

Hiroki Nagai

Tomohiro Nakano

Hideki Sano

Tomohide Sumi

Aiko Nagano

Takashi Kuzuya

Hidekazu Hiratsuka

Yoshiyuki Ryogoku

A state of charge estimation method includes: measuring a voltage of a lithium ion secondary battery that is being charged at a predetermined current rate higher than or equal to a predetermined charging rate; obtaining a rate of increase in the measured voltage; and estimating a state of charge of the lithium ion secondary battery based on the rate of increase in the measured voltage and first reference data. The first reference data are data including a correlation between a state of charge of a reference lithium ion secondary battery and a rate of increase in voltage of the reference lithium ion secondary battery when the reference lithium ion secondary battery is charged at the predetermined current rate.

State of charge estimation method and state of charge estimation apparatus

Provided is a nonaqueous electrolyte secondary battery in which the following are housed in a battery case: a nonaqueous electrolyte, a boron atom-containing oxalato complex compound, and an electrode assembly in which a positive electrode having a positive electrode active material and a negative electrode having a negative electrode active material are disposed facing each other. Here, a coat containing boron atoms originating from the oxalato complex compound is formed on the surface of the negative electrode active material, and the amount B(&#x3bc;g/cm) of the boron atom as measured based on inductively coupled plasma-atomic emission spectroscopic analysis and the intensity Bfor a tricoordinate boron atom as measured based on x-ray absorption fine structure analysis satisfy 0.5&#x2264;B/B&#x2264;1.0.

Nonaqueous electrolyte secondary battery

A deterioration rate estimation method for a lithium-ion battery of estimating the deterioration rate of the lithium-ion battery including a negative electrode having stage structures switching depending on an electric storage amount includes a first step of acquiring first information about the stage structure, a second step of acquiring second information about the battery temperature of the lithium-ion battery, and a third step of estimating the deterioration rate from the first information and the second information.

Degradation speed estimation method, and degradation speed estimation device, of lithium-ion battery

A positive electrode active material provided in the present invention is characterized in that it is substantially formed of a lithium nickel cobalt manganese composite oxide and that a molar content ratio (Ni/Ni) of bivalent nickel atoms (Ni) and trivalent nickel atoms (Ni) of nickel atoms constituting the composite oxide is 0.15&#x2266;(Ni/Ni)&#x2266;0.95.

Positive electrode active material for lithium secondary battery, and use thereof

A battery system (SV) comprises a lithium ion secondary battery (), charge and discharge control means (S, S-S), and internal resistance detecting means (M). The charge and discharge control means comprises: mode control means including increasing mode control means (S) for increasing the internal resistance of the lithium ion secondary battery and decreasing mode control means (S) for decreasing the internal resistance; and mode selecting means (S, S) for selecting the decreasing mode control means (S) or the increasing mode control means (S) when a level of the internal resistance is estimated by the internal resistance detecting means.

Battery system, vehicle, and battery mounted device

Provided is a method for evaluating a positive electrode active material. The method evaluates the performance of a positive electrode active material comprising a lithium transition metal oxide that contains a manganese-containing transition metal oxide. In this method, the lithium penetration rate into a transition metal site in the lithium transition metal oxide is evaluated based on the intensity ratio P between a first-neighbor Mn&#x2014;O peak intensity A and a second-neighbor Mn-M peak intensity B in a radial distribution function obtained from EXAFS at the K absorption edge of manganese (Mn). Moreover, the ratio of excess lithium present in the positive electrode active material may also be evaluated based on the excess amount of added lithium Q contained in excess of the stoichiometric ratio of the lithium transition metal oxide and the intensity ratio P.

Method for evaluating positive electrode active material

Provided are a lithium-ion secondary battery capable of measuring the concentration of lithium ions in an stored electrolyte in a predetermined portion, an assembled battery using the same, a vehicle and a battery-equipped device equipped with the battery or the assembled battery, a battery system capable of acquiring the concentration-correlated physical quantity in the lithium-ion secondary battery, and a method for detecting the deterioration of the lithium-ion secondary battery. A lithium-ion secondary battery comprises a power generation element including a positive electrode plate and a negative electrode plate, a battery case housing the power generation element, and an electrolyte containing lithium ions and held in the battery case, and further comprises a stored-electrolyte physical quantity measuring means capable of measuring the concentration-correlated physical quantity having a correlation to the concentration of lithium ions in the stored electrolyte stored between the element and the case.

Lithium ion secondary battery, assembled battery, vehicle, battery-equipped device, battery system, and method for detecting deterioration of lithium ion secondary battery

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Toyota, Japan

Satoshi Goto