Materials Science and Engineering Program & Texas Materials Institute, The University of Texas at Austin , Austin, Texas 78712, United States.
ACS Appl Mater Interfaces. 2017 May 17;9(19):16221-16227. doi: 10.1021/acsami.7b02826. Epub 2017 May 3.
Phosphorus-rich CuP and its carbon composites have been investigated as an anode material for lithium-ion batteries. Through a facile, low-cost mechanochemical reaction, microsized composites composed of active CuP particles uniformly embedded in the carbon matrix have been successfully synthesized. Combined structural and electrochemical characterizations show that phosphorus-rich CuP undergoes irreversible reaction with lithium, giving metal-rich CuP and amorphous phosphorus at the end of the first cycle. Both CuP and phosphorus are reversibly formed in subsequent cycles, contributing to a high reversible capacity of >1000 mA h g. By controlling the carbon content, the electrochemical reversibility and stability of CuP are greatly improved. The carbon composite demonstrates a remarkable lithium-storage capability in terms of a stable capacity of >720 mA h g over 100 cycles at 200 mA g, a high initial Coulombic efficiency of ∼83%, and a good rate capability with a capacity of >637 mA h g at 1.6 A g. The performance improvement is mainly associated with the formation of the conductive carbon network that offers high conductivity and fast reaction kinetics, as well as enhanced structural stability of CuP anode.
富磷 CuP 及其碳复合材料已被研究作为锂离子电池的阳极材料。通过简便、低成本的机械化学反应，成功合成了由均匀嵌入碳基质中的活性 CuP 颗粒组成的微尺度复合材料。结构和电化学特性的综合研究表明，富磷 CuP 与锂发生不可逆反应，在第一个循环结束时生成富铜的 CuP 和无定形磷。在随后的循环中，CuP 和磷都可以可逆地形成，从而实现了超过 1000 mA h g 的高可逆容量。通过控制碳含量，可以大大提高 CuP 的电化学可逆性和稳定性。碳复合材料在 200 mA g 下 100 次循环后具有稳定的容量超过 720 mA h g、初始库仑效率约为 83%以及良好的倍率性能（在 1.6 A g 下容量超过 637 mA h g），展示了出色的储锂能力。性能的提高主要与形成的导电碳网络有关，该网络提供了高导电性和快速反应动力学，以及增强了 CuP 阳极的结构稳定性。
