醋酸钾对尖晶石锰酸锂电化学性能的影响

Effects of potassium acetate on electrochemical performance of spinel lithium manganese oxide

用恒流充放电、循环伏安、电化学阻抗谱(EIS)、XRD和能量色散谱(EDS)等方法,研究了醋酸钾(KAc)对尖晶石锰酸锂(LiMn2O4)电化学性能的影响。当n(KAc)∶n(LiMn2O4)=1∶1 000时,产物的高倍率性能最佳,以2.0 C在3.0～4.3 V循环,放电比容量比未添加时提高了6.7%;循环400次的容量保持率为83.64%。KAc的作用机理是:CH3COO-对质子氢的吸收,以及K+参与正极表面膜形成并进入晶格的协同效应。

Effects of potassium acetate（KAc） on electrochemical performance of spinel lithium manganese oxide （LiMn2O4 ） were studied by galvanostatic charge-discharge ,cyclic vohammetry, electrochemical impedance spectroscopy（ EIS）, XRD and energy dif-fraction spectrum（EDS） methods. When n（KAc） ： n（ LiMn2O4 ） = 1：1 000 ,the high rate performance of the product was the best. When cycled in 3.0-4. 3 V with 2. 0 C,the specific discharge capacity increased by 6. 7% compared with the blank one. The ca-pacity retention was 83.64% after 400 cycles. The promotion of KAc was achieved through the synergistic effect of adsorbing H^＋ by CH3 COO^- , participation in forming positive surface membrane and entrance into lattice by K^＋.