CAJ | 학술논문

采用共沉淀法结合高温固相法制备Li1.07(Ni0.4Mn0.53)1-xAlxO2正极材料,利用SEM,XRD对所得试样的形貌和晶体结构进行表征,并研究材料的电化学性能.结果表明,少量Al的掺入减小材料的颗粒尺寸,降低材料的放电比容量,但可以提高材料的循环稳定性和倍率性能.其中x=0.01时所得试样在25 ℃,2.75~4.2 V,0.5 C倍率下的首次放电比容量为125.1 mAh/g,100次循环后的容量保持率达到99.5%.此外,掺入适量Al后可以降低Li+在材料中的电荷传递阻抗,改善材料的低温放电性能.
채용공침정법결합고온고상법제비Li1.07(Ni0.4Mn0.53)1-xAlxO2정겁재료,이용SEM,XRD대소득시양적형모화정체결구진행표정,병연구재료적전화학성능.결과표명,소량Al적참입감소재료적과립척촌,강저재료적방전비용량,단가이제고재료적순배은정성화배솔성능.기중x=0.01시소득시양재25 ℃,2.75~4.2 V,0.5 C배솔하적수차방전비용량위125.1 mAh/g,100차순배후적용량보지솔체도99.5%.차외,참입괄량Al후가이강저Li+재재료중적전하전체조항,개선재료적저온방전성능.
Li1.07 (Ni0.4Mn0.53)1-xAlxO2 cathode materials were synthesized by co-precipitation method and high temperature solid-state method. The morphologies and crystal structure of Li 1.07 (Ni0.4Mn0.53)1 -xAlxO2 were characterized by SEM and XRD, respectively. The electrochemical properties were also investigated. The results show that the particle size and the discharge specific capacity are reduced by doping appropriate amount of Al with the improvement of the cycling stability and rate capability for the Al-doped cathode materials. When cycled at 25 ℃ with 0.5 C in the voltage range of 2.75-4.2 V, the sample with x=0.01 delivers an initial discharge specific capacity of 125.1 mAh/g with capacity retention rate of 99.5 % after 100 cycles. Besides, the charge transfer resistance is observed in a decreased tendency accompanied with low-temperature discharge performance applied with appropriate doped Al amount.