Improving rate performances of Li-rich layered oxide by the co-doping of Sn and K ions
Improving rate performances of Li-rich layered oxide by the co-doping of Sn and K ions
复制标题
Sn、K离子共掺杂提高富锂层状氧化物的倍率性能
DOI：
10.1016/j.jmat.2019.01.005
复制
发表时间：
2019-06-01
影响因子：
9.4
通讯作者：
Dai, Dongmei
中科院分区：
文献类型：
--
作者：
Li, Bao;Wang, Xinbo;Dai, Dongmei
仍然需要进行常规阴极材料的特定能力和功率性能来改进以满足对电动车辆的需求。 Li富分层的氧化物具有很高的特异性，但速率性能较差。化学掺杂是由于晶格扩大而解决这一挑战的有效方法。与文献中的单个离子替代不同，在这里，SN和K掺杂了富含Li的层状氧化物，以实现喜欢的速率性能，其中SN和K分别替代了过渡金属离子和李离子。结果表明，共掺杂的样品导致能力保留量从107.9（对比样本）增加到10 c速率的151.5 mAh G（-1）（-1）（-1）（-1）。电化学阻抗光谱（EIS）和LI+计算的扩散系数也证实了共掺杂样品的最喜欢的速率性能。结合了Rietveld结构改进的结果，我们提出了速率性能的原因来自增大的晶体晶格，该晶体晶格在电荷/放电过程中为锂离子提供平滑的扩散隧道。采用方法提供了通过在不同晶体位点共同掺杂大尺寸离子来实现提高速率性能的可能性。 （c）2019年中国陶瓷学会。 Elsevier B.V.的生产和托管
The specific capacities and power performances of conventional cathode materials are still needed to improve in order to meet the demand for electrical vehicles. Li-rich layered oxide delivers a high specific capacity, but poor rate performances. Chemical doping is an effective way to address this challenge due to the expanded crystal lattice. Unlike a single ion substitution in the literature, here Li-rich layered oxides were doped by Sn and K to achieve the favorite rate performance, where Sn and K were assumed to replace transition metal ion and Li ion, respectively. Results indicate the co-doped samples result in an increasing capacity retention by more than 40% from 107.9 (contrast sample) to 151.5 mAh g(-1) (co-doped sample) at 10 C-rate. Electrochemical impedance spectroscopy (EIS) and calculated diffusion coefficient of Li+ also confirmed the favorite rate performances for co-doped sample. Combining results of Rietveld structure refinement, we proposed that the reason for rate performances comes from the enlarged crystal lattices, which provides a smooth diffusion tunnel for Lithium ions during the charge/discharge processes. The as-adopted method provides a possibility to achieve the improved rate performances by co-doping big-size ions at the different crystal sites. (C) 2019 The Chinese Ceramic Society. Production and hosting by Elsevier B.V.