Zhong Jianjian, Li Jianling
State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing, 100083, China.
Small. 2024 Mar;20(9):e2306241. doi: 10.1002/smll.202306241. Epub 2023 Oct 19.
2D layer Ti C T material attracts enormous attention in lithium ion energy storage field owing to the unique surface chemistry properties, but the material still suffers from restacking issue and the restriction on capacity. Herein, copper phosphide (Cu P) nanostructures@Ti C T composites are prepared by the in situ generation of Cu-BDC precursor in the bulk material followed with phosphorization. The uniformly distributed copper phosphide nanostructures effectively expand the interlayer spacing promoting the structural stability, and achieves the effective connection with the bulk material accelerating the diffusion and migration of lithium ions. The electrochemical activity of Cu P also provides more lithium ion active sites for lithium storage. The X-ray photoelectron spectroscopy (XPS) analysis verifies that Ti─O─P bond with strong covalency allows the upper shift of maximum valence band and Fermi level, stimulating the charge transportation between Cu P and the bulk Ti C T for better electrode kinetics. 3Cu P@Ti C T exhibits excellent rate performance of 165.4 mAh g at 3000 mA g and the assembled 3Cu P@Ti C T //AC Lithium-ion hybrid capacitorsLIC exhibits superior energy density of 93.0 Wh kg at the power density of 2367.3 W kg . The results suggest that the interfacial modification of Ti C T with transition metal phosphides will be advantageous to its high energy density application in lithium-ion storage.
二维层状Ti C T材料因其独特的表面化学性质在锂离子储能领域引起了极大关注，但该材料仍存在重新堆叠问题和容量受限的情况。在此，通过在块状材料中原位生成Cu-BDC前驱体并随后进行磷化处理，制备了磷化铜（Cu P）纳米结构@Ti C T复合材料。均匀分布的磷化铜纳米结构有效地扩大了层间距，促进了结构稳定性，并实现了与块状材料的有效连接，加速了锂离子的扩散和迁移。Cu P的电化学活性也为锂存储提供了更多的锂离子活性位点。X射线光电子能谱（XPS）分析证实，具有强共价性的Ti─O─P键使最高价带和费米能级上移，促进了Cu P与块状Ti C T之间的电荷传输，从而实现更好的电极动力学。3Cu P@Ti C T在3000 mA g下表现出165.4 mAh g的优异倍率性能，组装的3Cu P@Ti C T//AC锂离子混合电容器（LIC）在功率密度为236,7.3 W kg时表现出93.0 Wh kg的优异能量密度。结果表明，用过渡金属磷化物对Ti C T进行界面改性将有利于其在锂离子存储中的高能量密度应用。
