Liang Jianwen, Wei Denghu, Cheng Qiushi, Zhu Yongchun, Li Xiaona, Fan Long, Zhang Jingjing, Qian Yitai
Hefei National Laboratory for Physical Science at Micro-scale, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (P.R. China), Fax: (+86) 551-63600006.
Chempluschem. 2014 Jan;79(1):143-150. doi: 10.1002/cplu.201300324. Epub 2013 Oct 22.
A new thread for improving the cycling stability of Fe O nanorice is proposed through combining the electrochemical porousness (EP) effect and solid-electrolyte interphase (SEI) thermolysis approach. Starting from solid Fe O nanorice, this process could be applied to prepare porous Fe O nanorice with a good coating of a porous SEI thermolysis layer composed of carbon and Li O. The interconnecting pores and full coating of the SEI thermolysis layer provides not only mechanical resistance of the Fe O nanorice against pulverization, but also high electrical and ionic conductivity over the electrode throughout long cell cycles. This method results in the enhancement of cycling ability and capacity, which is demonstrated by comparison with the starting Fe O nanorice. After the EP and SEI thermolysis approach, the Fe O nanorice exhibits an energy capacity retention about of 680 mAh g at a current density of 1000 mA g over 250 cycles, which is more than 82 % of the initial reversible capacity. Moreover, it also has an excellent rate capability and high coulombic efficiency. This strategy provides a simple and convenient route toward stable charge/discharge cycling for not only Fe O , but also for other electrode materials that are subject to large volume changes and low charge voltages. At the same time, it also contributes to a fundamental understanding of improved cycling stability and reversible capacity for electrode materials.
通过结合电化学多孔性（EP）效应和固体电解质界面（SEI）热解方法，提出了一种提高FeO纳米棒循环稳定性的新思路。从固态FeO纳米棒出发，该过程可用于制备具有由碳和LiO组成的多孔SEI热解层良好涂层的多孔FeO纳米棒。SEI热解层的相互连通的孔隙和完整涂层不仅为FeO纳米棒提供了抗粉碎的机械阻力，而且在整个长电池循环过程中在电极上提供了高电导率和离子电导率。与起始的FeO纳米棒相比，该方法提高了循环能力和容量。经过EP和SEI热解方法后，FeO纳米棒在1000 mA g的电流密度下经过250次循环后表现出约680 mAh g的能量容量保持率，这超过了初始可逆容量的82％。此外，它还具有出色的倍率性能和高库仑效率。该策略不仅为FeO，也为其他易发生大体积变化和低充电电压的电极材料提供了一条简单便捷的稳定充放电循环途径。同时，它也有助于从根本上理解电极材料改善的循环稳定性和可逆容量。
