采用固相法合成掺杂镁和铝尖晶石LiCoMnO4材料,研究镁和铝掺杂量对尖晶石LiCoMnO4电极的初始容量、放电平台以及循环性能的影响. 利用扫描电子显微镜、粉末X-射线衍射仪观察分析材料形貌及结构. 结果表明,所合成材料的粒径分布均匀,结晶性较佳. LiCoMnO4电极初始容量为87.0 mAh.g-1,少量镁或铝掺杂使电极初始容量有所增加,LiCo0.98Mg0.02MnO4和LiCo0.98Al0.02MnO4电极初始容量分别为91.3和93.6 mAh.g-1,提高了其5 V放电平台的比例,过量掺杂则其容量降低. 此外,掺杂Al显著改善了LiCoMnO4电极的循环性能,而掺杂镁对电极的循环性能其影响不明显.
游美玲
,
童庆松
,
李秀华
,
林忞
,
黄行康
,
杨勇
. 锂离子正极材料LiCo1-xMgxMnO4与LiCo1-xAlxMnO4 (x = 0, 0.02, 0.05, 0.1)的制备及其电化学性能[J]. 电化学, 2014
, 20(1)
: 22
-27
.
DOI: 10.13208/j.electrochem.121122
The Al-doped and Mg-doped LiCoMnO4 materials were synthesized through solid-state reaction. The effects of doping amounts of Mg and Al on the initial capacities, discharge plateaus, and cycle performances were investigated. The morphologies and structures of the as-prepared materials were studied by scanning electron microscopy and powder X-ray diffraction. The results indicate that the as-prepared samples were composed of uniform, well-crystallized particles. The pristine LiCoMnO4 possessed an initial capacity of 87.0 mAh·g-1, while LiCo0.98Mg0.02MnO4 and LiCo0.98Al0.02MnO4 delivered 91.3 and 93.6 mAh·g-1, respectively. The proper doping amount increased the capacity and the ratio of discharge plateau at 5 V, while over-doping decreased the discharge capacity of LiCoMnO4. In addition, Al doping significantly improved the cycle performance of LiCoMnO4, while no apparent influence with Mg doping.
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