Yang Weijia, Huang Jun, Zheng Qinfeng, Chen Liwei, Orita Akihiro, Saito Nagahiro, Zhang Zhengxi, Zhang Yixiao, Yang Li
Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
School of Chemistry and Chemical Engineering, In situ Center for Physical Sciences Frontiers Science Center for Transformative Molecules, and Energy Device Research Center (SEED), Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
Angew Chem Int Ed Engl. 2024 Dec 20;63(52):e202412706. doi: 10.1002/anie.202412706. Epub 2024 Oct 25.
PIBs are emerging as a promising energy storage system due to high abundance of potassium resources and theoretical energy density, however, progress of PIBs is severely hindered by structural instability and poor cycling of anode material during continual insertion and extraction of larger-sized K. Hence, developing anode material with structural stability and stable cycling remains a great challenge. Herein, band gap-tuned Mo-doped and carbon-coated lead titanate (CMPTO) with zero-strain K storage is presented as ultra-stable PIBs anode. Mo doping introduces narrowed band gap and optimized crystal lattice for enhanced intrinsic electron and ion transfer. Demonstrated by in situ XRD characterizations, the crystal structure stays stable with unchanged peak positions, fully revealing zero-strain characteristic of CMPTO anode during potassium storage for stable cyclic capability. Ultimately, CMPTO anode achieved ultra-stable cycling performance of 7000 cycles at 500 mA g with high capacity retention of 90 % and considerable specific capacity of 130.9 mAh g after 600 cycles at 100 mA g; with relatively large density, CMPTO realized eminent volumetric capacity of 1111.09 mAh cm and ultra-long cycling life of 10000 cycles at 7041 mA cm. This work introduces a promisingly new route into developing anode materials with ultra-stable performance for PIBs.
由于钾资源丰富且理论能量密度高，钾离子电池正成为一种很有前景的储能系统。然而，在较大尺寸钾离子的持续嵌入和脱出过程中，阳极材料的结构不稳定性和较差的循环性能严重阻碍了钾离子电池的发展。因此，开发具有结构稳定性和稳定循环性能的阳极材料仍然是一个巨大的挑战。在此，提出了一种具有零应变钾存储能力的带隙调谐钼掺杂和碳包覆钛酸铅（CMPTO）作为超稳定钾离子电池阳极。钼掺杂引入了变窄的带隙并优化了晶格，以增强本征电子和离子传输。原位XRD表征表明，晶体结构在峰位不变的情况下保持稳定，充分揭示了CMPTO阳极在钾存储过程中的零应变特性，从而具有稳定的循环性能。最终，CMPTO阳极在500 mA g下实现了7000次循环的超稳定循环性能，在100 mA g下循环600次后具有90%的高容量保持率和130.9 mAh g的可观比容量；由于密度相对较大，CMPTO实现了1111.09 mAh cm的卓越体积容量和在7041 mA cm下10000次循环的超长循环寿命。这项工作为开发具有超稳定性能的钾离子电池阳极材料引入了一条很有前景的新途径。
