Fe-Doped CoP Flower-Like Microstructure on Carbon Membrane as Integrated Electrode with Enhanced Sodium Ion Storage
Fe-Doped CoP Flower-Like Microstructure on Carbon Membrane as Integrated Electrode with Enhanced Sodium Ion Storage
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碳膜上的铁掺杂 CoP 花状微结构作为增强钠离子存储的集成电极
DOI：
10.1002/chem.201904637
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Dan Yuanyuan
中科院分区：
文献类型：
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作者：
Xu Yalin;Li Xueying;Wang Jiangang;Yu Qing;Qian Xiu;Chen Lizhuang;Dan Yuanyuan
循环性能差和倍率性能一直是阻碍过渡金属磷化物基负极材料发展的瓶颈。为了解决上述问题，人们采取了许多策略，如设计层次化结构、与碳材料结合以及掺杂其他金属元素等。在此基础上，设计了一种花状掺铁CoP材料。该合成方法是通过水热法在碳膜(CM，树叶为前驱体)上生长微片，并在 中进行原位磷化。在晶体生长过程中，Fe掺杂和碳膜协同诱导形成花状的层状微结构。独特的层次化微结构增加了电极与电解液的接触面积，并适应了循环过程中的体积膨胀。直接在碳膜上层次化生长的Fe掺杂CoP增加了钠物种嵌入的活性中心，进一步促进了Fe掺杂CoP/CM电极的内电子传导。因此，掺杂Fe的CoP/CM作为钠离子电池负极材料，经100 循环后，在100 mA g−1下的比容量达到515 mA h g−1。即使电流密度增加到500 mA g−1,500 循环后的比容量仍保持在324 mA h g−1，表现出优异的倍率性能和循环性能。
Poor cyclability and rate performance always impede the development of transition metal phosphide‐based anode materials. Many strategies have been used to address the above problems, such as the designing of hierarchical structures, combination with carbon materials, and doping with other metal elements. Considering those strategies, a flower‐like Fe‐doped CoP material is designed. The synthesis consists of microsheets grown on a carbon membrane (CM, leaves as precursor) through a hydrothermal method and in situ phosphorization. The Fe doping and carbon membrane synergistically induce the formation of a flower‐like hierarchical microstructure during the crystal‐growing process. The unique hierarchical microstructure increases the contact area between electrode and electrolyte, and accommodates the volume expansion during cycling. The hierarchical Fe‐doped CoP grown directly on the carbon membrane increases the active sites for intercalation of sodium species and further promotes the internal electron conduction in the Fe‐doped CoP/CM electrode. Thereby, the Fe‐doped CoP/CM as the anode electrode for sodium ion batteries exhibits a high specific capacity of 515 mA h g−1at 100 mA g−1after 100 cycles. Even if the current density rises to 500 mA g−1, the specific capacity is still maintained at 324 mA h g−1after 500 cycles, showing superior rate performances and cyclability.