Improved Cycle Stability and Rate Capability of Graphene Oxide Wrapped Tavorite LiFeSO4F as Cathode Material for Lithium-Ion Batteries

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• 作者：Zhendong Guo ; Dong Zhang ; Hailong Qiu ; Tong Zhang ; Qiang Fu ; Lijie Zhang ; Xiao Yan ; Xing Meng ; Gang Chen ; Yingjin Wei
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：July 1, 2015
• 年：2015
• 卷：7
• 期：25
• 页码：13972-13979
• 全文大小：470K
• ISSN：1944-8252

文摘

Tavorite LiFeSO₄F has been regarded as a promising alternative to LiFePO₄ due to its high Li ionic conductivity. To overcome the low electronic conductivity of LiFeSO₄F, we prepared a graphene oxide (GO)/LiFeSO₄F composite material by the solvothermal method. The GO wraps on the surface of LiFeSO₄F and links the adjacent particles, thus providing an effective network for electrons transport. As a result, the electronic conductivity of the material is improved from 8.16 脳 10^鈥?1 S cm^鈥? to 1.65 脳 10^鈥? S cm^鈥?. In addition, the GO depresses the side reactions of the electrode and electrolyte, promotes the charge transfer reactions at the electrode/electrolyte interface, and facilitates the lithium diffusion in the electrode. The GO-wrapped LiFeSO₄F exhibits much better electrochemical performance than the pristine material. It showed a discharge capacity of 113.2 mAh g^鈥? at the 0.1 C rate with 99% capacity retention after 100 cycles. In addition, the material is able to deliver 85.1, 73.4, and 30.3 mAh g^鈥? at high current rates of 1 C, 2 C, and 10 C, respectively.