METHOD FOR DETERMINING EFFECTIVENESS OF SUBSTITUENT ELEMENT IN IMPROVEMENT OF CAPACITY RECOVERY RATE AND METHOD FOR PREDICTING CAPACITY RECOVERY RATE IN PARTIAL SUBSTITUTION TYPE LITHIUM ION SECONDARY BATTERY

摘要

PPROBLEM TO BE SOLVED: To provide a method for determining the effectiveness of a substituent element in the improvement of a capacity recovery rate, which can improve a development efficiency by minimizing actual test production of batteries and actual measurement of the capacity recovery rate, and to provide a method for predicting the capacity recovery rate. PSOLUTION: By using a crystal structure model wherein a part of Mn in a Mn acid Li composition is substituted by another element Me to form a composition in which Mn atom or Me atom is arranged as a central atom, and each atom in constituent elements including Li, Mn, and O is arranged in its surrounding area based on the known crystallographic data, the charge Q of the central atom participating to ion bonds is computed by a molecular orbital calculation method, and by comparing the computed value QSB0/SBof the charge Q when the central atom is Mn with the computed value QSBe/SBof the charge Q when the central atom is Me, the effectiveness of the substituent element is determined. By using the computed QSB0/SBand QSBe/SBor actually measured values QSB0m/SBand QSBem/SBcorresponding to these, from F=1-(QSBe/SB-QSB0/SB)/QSB0/SBor F=1-(QSBem/SB-QSB0m/SB)/QSB0m/SB, the improvement of the capacity recovery rate due to the partial substitution is predicted. PCOPYRIGHT: (C)2003,JPO