B_(2)O_(3)包覆增强LiNi_(0.82)Co_(0.15)Al_(0.03)O_(2)的电化学性能

B_(2)O_(3) Coating Enhances the Electrochemical Performance of LiNi_(0.82)Co_(0.15)Al_(0.03)O_(2)

采用机械融合的方法制备了氧化硼包覆LiNi_(0.82)Co_(0.15)Al_(0.03)O_(2)的正极材料,讨论了氧化硼包覆层对正极材料的表面形貌,晶体结构以及电化学性能的影响。扫描电镜(SEM)与X射线光电子能谱(XPS)的分析结果表明,氧化硼成功的覆盖在LiNi_(0.82)Co_(0.15)Al_(0.03)O_(2)颗粒表面。电化学测试表明包覆物有效减缓了循环过程中的电荷转移电阻,因此循环性能,倍率性能都有所改善。氧化硼包覆量0.75%的电化学性能最好,与未包覆的材料相比,室温下在1 C电流密度下循环100圈容量保持率由75.6%上升至86.3%,在5 C电流密度下的可逆容量高达114.2 mAh·g^(-1)。EIS结果表明包覆层B_(2)O_(3)降低了表面的电荷转移电阻。

LiNi_(0.82)Co_(0.15)Al_(0.03)O_(2)cathode materials coated with boron oxide were prepared by mechanical fusion method.The effects of boron oxide coating on the surface morphology,crystal structure and electrochemical properties of the cathode materials were discussed.The results of scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS)showed that boron oxide successfully covered the surface of LiNi_(0.82)Co_(0.15)Al_(0.03)O_(2)particles.Electrochemical tests show that the coating can effectively reduce the charge transfer resistance in the cycle process,and the cycle performance and rate performance are improved to a certain extent.The best electrochemical performance of the boron oxide coated with 0.75%was obtained.Compared with the uncoated material,the capacity retention rate of 100 cycles at 1 C current density increased from 75.6%to 86.3%at room temperature,and the reversible capacity at 5 C current density was up to 114.2 mAh·g^(-1).EIS shows that the B_(2)O_(3)coating reduces the surface charge transfer resistance.