聚吡咯-过渡金属-氧配合物储锂材料的结构与性能研究

Polypyrrole-Transition Metal-Oxygen Coordination Complexes as High Performance Lithium Storage Material

目前锂离子电池电极材料主要使用无机材料.近年来有机物电极材料虽有报道,但这些材料大都比容量低、倍率性能差.本文介绍一类新型有机金属配合物聚吡咯-过渡金属-氧储锂材料的合成、结构及电化学性能.结合扩展X-射线吸收精细结构谱分析和密度泛函理论计算,发现这类材料呈现多层结构特征,层内稳定的过渡金属-吡咯N的配位作用及循环过程中层间过渡金属-氧键的可逆断裂和结合使该类材料具有很高的储锂容量和循环稳定性,且聚吡咯导电网络使得该材料具有良好的倍率性能.这类新材料将有望成为锂离子电池的高比容量负极材料.

Polypyrrole-transition metal-oxygen（PPy-M-O,where M=Fe and Co） coordination complexes have been chemically and electrochemically synthesized and proved to be a brand-new high-performance lithium-storage material.Extended X-ray absorption fine structure（EXAFS） spectroscopy and density functional theory（DFT） calculations indicate that both PPy-Fe-O and PPy-Co-O complexes share a similar multilayer structure.The strong and stable intralayer M（Fe,Co）-N coordination permits the material to possess high specific capacity.The high reversibility of its interlayer M-O-M interaction during cycling ensures high cycling stability and the conducting PPy matrix endows PPy-M-O with outstanding rate performance.Similar lithium storage performances have been obtained in other complexes containing conducting polymers and transition metals.These findings pave new ways to construct a new type of high-performance organic anode materials for lithium ion batteries,high-efficient and inexpensive electrocatalysts for fuel cells,supercapacitors and various other applications.