Chu Heying, Li Yong, Liu Yuanjie, Chai Xueping, Zhang Hongzhou, Zhang Jingchuan
College of Mechanical and Electronic Engineering, Tarim University, Alar 843300, China.
Molecules. 2025 Feb 6;30(3):729. doi: 10.3390/molecules30030729.
Bismuth-based materials that adhere to the alloy/dealloy reaction mechanism are regarded as highly promising anode materials for potassium-ion batteries due to their high volume-specific capacity and moderate reaction potentials. However, their commercial viability has been limited by the effects of structural collapse due to volume distortion and impeded electron conduction, resulting in rapid capacity decline. In this work, a carbon-coated nanosized BiPO rod (BiPO@C) was designed and fabricated to overcome the aforementioned challenges through the architecture engineering and anionic-tuning strategy. In particular, the nanosized nanorods significantly reduce the volume expansion; the incorporation of the bulk and open-skeleton anion PO serves to mitigate the considerable volume distortion and generates the high ionic conductivity product (KPO) to ameliorate the poor ionic transport due to the structural deformation. The elaborated BiPO rods exhibit high specific capacity (310.3 mAh g, at 500 mA g), excellent cycling stability (over 700 cycles at 500 mA g) and superior rate performance (137.8 mAh g, at 1000 mA g). Systematic ex-situ XRD and TEM, as well as kinetic tests, have revealed the "conversion-multistep alloying" reaction process and the "battery-capacitance dual-mode" potassium storage mechanism. Moreover, the thick electrodes showed excellent specific capacity and rate performance, demonstrating their significant application potential in the next generation of SIBs.
基于铋的材料遵循合金/脱合金反应机制，由于其高体积比容量和适中的反应电位，被认为是极具潜力的钾离子电池负极材料。然而，由于体积畸变导致的结构坍塌以及电子传导受阻，其商业可行性受到限制，导致容量迅速下降。在这项工作中，通过结构工程和阴离子调控策略设计并制备了一种碳包覆的纳米BiPO棒（BiPO@C），以克服上述挑战。特别是，纳米棒显著降低了体积膨胀；大量开放骨架阴离子PO的引入有助于减轻显著的体积畸变，并生成高离子电导率产物（KPO），以改善由于结构变形导致的离子传输不良问题。精心制备的BiPO棒表现出高比容量（在500 mA g时为310.3 mAh g）、优异的循环稳定性（在500 mA g时超过700次循环）和出色的倍率性能（在1000 mA g时为137.8 mAh g）。系统的非原位XRD和TEM以及动力学测试揭示了“转化-多步合金化”反应过程和“电池-电容双模”钾存储机制。此外，厚电极表现出优异的比容量和倍率性能，证明了它们在下一代钾离子电池中的巨大应用潜力。
