Improved electrochemical performance in Sc-doped nanocrystalline LiMn2O4
Improved electrochemical performance in Sc-doped nanocrystalline LiMn2O4
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提高 Sc 掺杂纳米晶 LiMn2O4 的电化学性能
DOI：
10.1016/j.matlet.2022.132824
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发表时间：
2022
影响因子：
3
通讯作者：
Castro, Ricardo H.R.
中科院分区：
文献类型：
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作者：
Leong, Victor Gin;Hong, Seung Sae;Castro, Ricardo H.R.
众所周知，Jahn-Teller效应会导致LiMn 2 O 4（LMO）阴极材料中的容量衰减，这是由于Mn从阴极/电解质界面溶解所致。这种效应在纳米级材料中更为明显，因为它们具有高表面反应性。虽然表面涂层可以帮助减轻这种现象，但对掺杂剂自发偏析到界面和阴极电化学性能之间的相关性的理解仍然有限。这项工作表明，界面掺杂剂，Sc 3+，选择上的热力学原理，偏析到表面和晶界，并作为系统稳定剂。Li/LMO半电池中的电化学性能显示，与仅具有88.3%的等效未掺杂LMO相比，纳米结构的Sc 3+掺杂的LMO在0.2C下50次循环后提供97.3%的容量保持率。Sc掺杂降低了电荷转移电阻，同时保持了9.089 × 10- 11 cm 2/s的高特征扩散系数（DLi+）。这项工作强调，了解阴极材料的热力学稳定性可以为推进阴极技术甚至超越锂提供一条途径。
Jahn-Teller effects have been widely known to cause capacity fading in LiMn2O4(LMO) cathode materials due to Mn dissolution from the cathode/electrolyte interfaces. This effect is more pronounced in nanoscale materials due to their high surface reactivity. Although surface coatings can help mitigate the phenomenon, there is still limited understanding of the correlation between the spontaneous segregation of dopants to interfaces and the cathode electrochemical performance. This work demonstrates that an interfacial dopant, Sc3+, selected on a thermodynamic principle, segregates to surfaces and grain boundaries and acts as a system stabilizer. The electrochemical performance in Li/LMO half-cells showed nanostructured Sc3+-doped LMO delivers capacity retention of 97.3% after 50 cycles at 0.2C compared to an equivalent undoped LMO with only 88.3%. Sc-doping reduces the charge transfer resistance while maintaining its high characteristic diffusion coefficient (DLi+) of 9.089 × 10-11cm2/s. The work highlights that understanding the thermodynamic stabilization of cathode materials can provide a pathway to advance cathode technologies even beyond Lithium.
DOI：
10.1021/acs.jpclett.0c00936
发表时间：
2020-03
期刊：
The journal of physical chemistry letters
影响因子：
--
作者：
Ge Zhou;Xiaorui Sun;Qing-hao Li;Xuelong Wang;Jie-Nan Zhang;Wanli Yang;Xiqian Yu;Ruijuan Xiao;Hong Li
通讯作者：
Ge Zhou;Xiaorui Sun;Qing-hao Li;Xuelong Wang;Jie-Nan Zhang;Wanli Yang;Xiqian Yu;Ruijuan Xiao;Hong Li
影响因子：
6.7
作者：
Muche, Dereck N. F.;da Silva, Andre L.;Castro, Ricardo H. R.
通讯作者：
Castro, Ricardo H. R.