NEGATIVE ELECTRODE ACTIVATOR FOR SECONDARY BATTERY, NEGATIVE ELECTRODE AND SECONDARY BATTERY USING THE SAME, AND MANUFACTURING METHOD OF NEGATIVE ELECTRODE ACTIVATOR FOR SECONDARY BATTERY AND NEGATIVE ELECTRODE FOR SECONDARY BATTERY USING THE ACTIVATOR

摘要

PPROBLEM TO BE SOLVED: To obtain a sufficient cycle property when using an Li storing substance which forms an alloy with lithium on a negative electrode. PSOLUTION: The secondary battery uses complex grains 30 including Li storing materials 34 in a carbonaceous material 32. The complex grain satisfies at least one condition out of following conditions (i) to (iii). (i) The center of gravity of a Li storing substance grain is located inside the complex grain. (ii) The center of gravity of all Li storing material grains contained in one complex grain is located on an inscribed circle of the complex grain with the center of gravity as a center, having a maximum area out of cross sectional planes of the complex grain. (iii) The coefficient of variation obtained by multiplying 100 on a value calculated by dividing the standard deviation of distances between center of gravity of the respective Li absorbing material grains contained in one complex grain and the center of gravity of the complex grain by a mean value of the distances, is not less than 10. PCOPYRIGHT: (C)2005,JPO&NCIPI