Synergetic effects of blended materials for Lithium-ion batteries

LiNi_1/3Co_1/3Mn_1/3O₂, LiMn₂O₄ and LiCoO₂ are paired to make the blended materials for the cathode of lithium-ion batteries. The factors impacting on the characteristics of blended materials are studied using constant current charge/discharge measurement and electrochemical impedance spectroscopy. The results show that the three pairs of blended materials exhibit very different synergetic effects in high C-rate discharging. The mechanism of particle synergetic effect has a physical root on the compensating material property of blending components, which fundamentally correlates with their similarity and difference in crystalline and electronic structures. The AC impedance show the obvious changes that alternate the high C-rate performance, due to reduced particle impedance in blended materials. The pairs of LiNi_1/3Co_1/3Mn_1/3O₂-LiMn₂O and LiCoO₂-LiMn₂O₄ present obvious increases in high C-rate reversible capacities than does the pair LiCoO₂-LiNi_1/3Co_1/3Mn_1/3O₂.