Method for producing lithium ion secondary battery with tap density and electrode density

摘要

A method for producing a lithium-ion secondary battery comprising positive and negative electrodes and a non-aqueous electrolyte solution is provided. The method comprises (A) with several different negative electrode active materials, determining density Xn (g/cm3) at several different number of taps applied, n, respectively; (B) determining density Y (g/cm3) of a negative electrode active material layer constituted with a mixture comprising each negative electrode active material; (C) based on a regression line, Y=aXn+b, determining the number of taps applied, n′, that gives a≦0.5 and a determination coefficient R2≧0.99; (D) based on a plot of Y=aXn′+b, determining a passing range of Xn′ where negative electrode active material layer density Y is in a prescribed range; (E) selecting a negative electrode active material having Xn′in the passing range, and fabricating a negative electrode with this material.

主权项

1. A method for producing a lithium-ion secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte solution, with the method comprising the following steps:
(A) with respect to several different negative electrode active materials, determining tap density Xn (g/cm3) at several different number of taps applied, n, respectively; (B) determining density Y (g/cm3) of a negative electrode active material layer constituted with a negative electrode material mixture comprising each negative electrode active material; (C) based on a regression line of Y versus tap density Xn, Y=aXn+b, determining the number of taps applied, n′, at which the regression line has a slope, a, of 0.5 or smaller and a coefficient of determination, R2, of 0.99 or larger; (D) based on a plot of a regression line Y=a Xn′+b for the number of taps applied, n′, determining a passing range of Xn′ within which negative electrode active material layer density Y is in a prescribed range; (E) selecting a negative electrode active material having a Xn′ in the passing range, and fabricating a negative electrode with the negative electrode active material; and (F) constituting a lithium-ion secondary battery using the negative electrode.