Liu Guoping, Yang Yang, Lu Xiaoyi, Qi Fangya, Liang Yaohua, Trukhanov Alex, Wu Yanxue, Sun Zhipeng, Lu Xia
School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China.
School of Materials, Sun Yat-Sen University, Guangzhou 510275, China.
ACS Appl Mater Interfaces. 2022 Jul 20;14(28):31803-31813. doi: 10.1021/acsami.2c03813. Epub 2022 Jul 6.
Metal phosphides are promising candidates for sodium-ion battery (SIB) anode owing to their large capacities with suitable redox potential, while the reversibility and rate performances are limited due to some electrochemically inactive transition-metal components and sluggish reaction kinetics. Here, we report a fully active bimetallic phosphide ZnGeP anode and its composite (ZnGeP-C) with excellent performance attributed to the Zn, Ge, and P components exerting their respective Na-storage merit in a cation-disordered structure. During Na insertion, ZnGeP undergoes an alloying-type reaction, along with the generation of NaP, NaP, NaGe, and NaZn phases, and the uniform distribution of these phases ensures the electrochemical reversibility during desodiation. Based on this reaction mechanism, excellent electrochemical properties such as a high reversible capacity of 595 mAh g and an ultrafast charge-discharge capability of 377.8 mAh g at 50C for 500 stable cycles were achieved within the ZnGeP-C composite in a diglyme-based electrolyte. This work reveals the Na-storage reaction mechanism within ZnGeP and offers a new perspective on designing high-performance anodes.
金属磷化物因其具有合适的氧化还原电位和大容量，有望成为钠离子电池（SIB）的负极材料，然而，由于一些电化学惰性的过渡金属成分和缓慢的反应动力学，其可逆性和倍率性能受到限制。在此，我们报道了一种全活性双金属磷化物ZnGeP负极及其具有优异性能的复合材料（ZnGeP-C），这归因于Zn、Ge和P组分在阳离子无序结构中发挥各自的储钠优势。在钠嵌入过程中，ZnGeP发生合金化型反应，同时生成NaP、NaP、NaGe和NaZn相，这些相的均匀分布确保了脱钠过程中的电化学可逆性。基于这种反应机理，在基于二甘醇二甲醚的电解液中，ZnGeP-C复合材料实现了优异的电化学性能，如在50℃下500次稳定循环中具有595 mAh g的高可逆容量和377.8 mAh g的超快充放电能力。这项工作揭示了ZnGeP中的储钠反应机理，并为设计高性能负极提供了新的视角。
