The effect of K-Ion on the electrochemical performance of spinel LiMn2O4

Spinel LiMn2O4 is regarded as one of the cathode active materials for rechargeable lithium-ion batteries with the most potential. K+-ion modified LiMn2O4 samples are synthesized by solid-state reaction. The SEM analysis shows that the modified samples exhibit uniform particle size distribution and much better crystallinity. The modified sample K1 exhibits ionic diffusion coefficient of 1.43 × 10-10 cm-2 s-1 and 2.04 × 10-10 cm-2 s-1, which is much higher than that of the un-modified spinel LiMn2O4 sample. The electrochemical measurements show that K+-ion modification could effectively reduce the charge transfer resistance, improve the capacity retention and rate capacity of the spinel materials.