PARTICLE-SIZE EFFECT OF CARBON POWDERS ON THE DISCHARGE CAPACITY OF LITHIUM ION BATTERIES

To improve the performance of the negative electrodes for lithium-ion batteries, a study has been made of the particle-size effect of carbon powder on discharge capacity and the optimum mixing ratio between lar ge (average diameter: 25.8 mu m) and small (average diameter: 4.2 mu m ) powder particle size has been found. The largest capacity is obtaine d when the large particle size fraction is about 70 wt.%. The smaller the particle size ratio, the larger the capacity, where the particle s ize ratio is the ratio of the average diameter of the smaller componen t to that of the larger one. These results indicate that discharge cap acity is closely related to carbon powder packing, which is controlled by the mixing weight and particle-size ratios. (C) 1998 Elsevier Scie nce S.A. All rights reserved.