Plasma-Assisted Sulfur Doping of LiMn2O4 for High-Performance Lithium-Ion Batteries

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• 作者：Qianqian Jiang ; Dongdong Liu ; Han Zhang ; Shuangyin Wang
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：December 31, 2015
• 年：2015
• 卷：119
• 期：52
• 页码：28776-28782
• 全文大小：399K
• ISSN：1932-7455

文摘

Though considered as one of the most promising materials for rechargeable Li-ion batteries, spinel LiMn₂O₄ suffers from fast capacity fading during cycling due to the structural instability, Jahn–Teller distortion, and Mn dissolution into the electrolyte. In order to improve the electrochemical performance, in this work, we, for the first time, realize the sulfur doping by the plasma-assisted method in LiMn₂O₄. Physical properties of the synthesized materials LiMn₂O_4–xS_x are measured by XRD, SEM, and EDS, which confirm that S atoms have been successfully doped into the structure of LiMn₂O₄ (LiMn₂O_4–xS_x) with the high crystalline and uniform morphology. Compared to the pristine LiMn₂O₄ prepared by the conventional method (800 °C, 8 h), the LiMn₂O_4–xS_x prepared by the plasma-assisted method shows superior performance with higher capacity (125.3 mAh·g^–1) and significantly improved cycling stability (maintaining 97.76% of its initial discharge capacity after 60 cycles). In addition, the sulfur-doped LiMn₂O₄ demonstrates dramatically enhanced reversibility and stability even at the elevated temperature due to the improved structural stability and the suppressed Mn dissolution into the electrolyte by the doping of S. The sulfur doping into LiMn₂O₄ by the plasma-assisted method offers a new strategy for efficient modification of electrode materials for energy storage devices.