微纳组装LiNi_(0.5)Mn_(1.5)O_4微球正极材料

Micro-/nano-assembled LiNi_(0.5)Mn_(1.5)O_4 microsphere cathode materials

基于水合肼和乙二醇的协同作用,在甘氨酸辅助下通过水热液相合成法微纳组装制备LiNi_(0.5)Mn_(1.5)O_4微球。微纳组装结构兼具微米和纳米材料的优点:二次微米结构可缓解Li^+嵌脱过程中材料体积的变化,改善材料振实密度;一次纳米粒子可缩短离子扩散路径,扩大电极-电解液接触面积。该特殊结构使材料的比容量、循环性能和倍率性能都得到提高。在3.3~5.0 V充放电,0.1 C放电比容量可达135.0 mAh/g;以1.0 C循环200次,放电比容量稳定在120.0 mAh/g,容量保持率为89%。

Based on the synergistic effect of hydrazine hydrate and ethylene glycol, the micro-/nano- assembled LiNi0.5 Mnj.5 04 microspheres were prepared by a hydrothermal liquid-phase synthesis under the aid of glycine. The micro-/nano- assembly structure combined the advantages of micro- and nano-materials, and the secondary micro-structure could relieve the change of the material volume during the Li ＋ embedding process and improve the tap density of the material, the primary nano-particle could shorten the ion diffusion path and enlarge the electrode-electrolyte contact area. The specific capacity, cycle performance and rate performance of special structure material were improved. The discharge specific capacity could reach 135. 0 mAh/g at 0. 1 C in 3.3 - 5.0 V. The discharge specific capacity was stable at 120. 0 mAh/g,the capacity retention rate was 89% in the 200th cycle at 1.0 C.