Toyota Jidosha Kabushiki Kaisha

Prime Planet Energy & Solutions, Inc.

Masahiro Yoshioka

Yoshitomo Takebayashi

Machiko Abe

The present disclosure provides a method for manufacturing a nonaqueous electrolyte capable of reducing the increase in electric resistance of a lithium ion secondary battery reusing an electrode. The method for manufacturing a nonaqueous electrolyte for a lithium ion secondary battery herein disclosed includes the steps of: mixing a prescribed organic solvent and a support electrolyte; and immersing a positive electrode active material, which has been previously subjected to a charging treatment as a positive electrode active material of a lithium ion secondary battery, in a mixed solution obtained by such mixing.

Method for manufacturing nonaqueous electrolyte for lithium ion secondary battery and method for manufacturing lithium ion secondary battery using the nonaqueous electrolyte

A nonaqueous electrolyte secondary battery includes an electrode body and a nonaqueous electrolyte solution. An electrolyte solution passage is a flow passage through which the nonaqueous electrolyte solution flows between the inside and the outside of the electrode body. A region of a negative-electrode composite material layer in contact with the electrolyte solution passage is a damming portion and a region located on the center side relative to the damming portion is a liquid retaining portion. The damming portion contains a negative electrode active material of which an electrical potential relative to a positive electrode active material is high and a ratio of expansion or contraction due to an increase or decrease in SOC is high, when compared to a negative electrode active material contained in the liquid retaining portion. The electrolyte solution passage can be closed by the damming portion in a charge state where the damming portion expands.

Nonaqueous electrolyte secondary battery and battery module

According to the present disclosure, it is possible to appropriately prevent a shortage of a nonaqueous electrolyte solution in an electrode body and keep battery performance of a nonaqueous electrolyte secondary battery at a favorable state. A nonaqueous electrolyte secondary battery disclosed herein includes an electrode body and a nonaqueous electrolyte solution. The electrode body includes an electrolyte solution passage that is a flow passage through which the nonaqueous electrolyte solution flows between the inside and the outside of the electrode body. When a region of a negative-electrode composite material layer that is in contact with the electrolyte solution passage is referred to as a damming portion and a region that is located on the center side relative to the damming portion is referred to as a liquid retaining portion, the damming portion contains a negative electrode active material of which an electrical potential relative to a positive electrode active material is high and a ratio of expansion or contraction due to an increase or decrease in SOC is high, when compared to a negative electrode active material contained in the liquid retaining portion. With this configuration, the electrolyte solution passage can be closed by the damming portion in a charge state where the damming portion expands, and therefore leakage of the nonaqueous electrolyte solution can be suppressed.

Provided is a non-aqueous electrolyte secondary battery in which the effect achieved by adding an oxalate complex compound is suitably exhibited and which can achieve battery characteristics during normal usage and resistance to overcharging at high levels. This battery is provided with an electrode body obtained by laminating a positive electrode having a positive electrode active material layer and a negative electrode having a negative electrode active material layer. A coating film which is derived substantially from an oxalate complex compound and which contains boron atoms and/or phosphorus atoms is formed on the negative electrode active material layer. In addition, in the negative electrode active material layer that constitutes the electrode body, the standard deviation (&#x3c3;) of resistance values, which are measured at a plurality of points at equal intervals in a line direction extending linearly from one prescribed layering surface to the layering surface on the opposite side, is 3.0 to 7.2.

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Toyota, Japan

Masahiro Yoshioka