An in-situ alloyed Ni-Fe Co-reaction electrode for high-stability and high-rate Na-metal halide batteries. (January 2022)

• Record Type: Journal Article
• Authors: Gao, Xingpeng; Hu, Yingying; Zha, Wenping; Li, Yanpei; Wang, Jingyi; Lai, Hongjian; Wu, Xiangwei; Yang, Jianhua; Chen, Chunhua; Wen, Zhaoyin
• Is Part Of: Materials today energy. Volume 23(2022)
• Publication Date: 2022-01
• Subjects: Ni-Fe alloy -- In-situ alloying reaction -- Na-MH batteries -- Electrodeposition -- Electrospinning -- ZEBRA battery; Energy development -- Periodicals; Energy industries -- Periodicals; Power resources -- Periodicals; Energy policy -- Periodicals; Energy development; Energy industries; Energy policy; Power resources; Electronic journals; Periodicals; 621.042
• DOI: 10.1016/j.mtener.2021.100894
• Languages: English
• ISSNs: 2468-6069

Abstract

Abstract: Na-metal halide batteries are regarded as one of the most promising candidates for large-scale energy storage systems owing to their high energy density and high safety. However, the problems of low kinetics and poor stability caused by the low-conductive chlorides have restricted the development of Na-metal halide batteries. Here, we design a facile approach that combines electrospinning and electrodeposition to prepare electrodes with a nanostructured composite containing carbon nanofibers and Ni-Fe alloy (CNF@Ni-Fe alloy). It is confirmed that the Ni-Fe alloy can stably be oxidized and reformed when discharges from 2.36 V to 2.32 V. Benefiting from the unique nanoscale arrangement of Ni-Fe, the heterogeneous distribution of FeCl2 and NiCl2 effectively overcomes the block of low-conductive chlorides. Furthermore, the coreaction of Ni 2+ and Fe 2+ directly decreases the polarization potential, resulting in the improvement of reaction kinetics. Notably, batteries with the CNF@Ni-Fe alloy display a high specific capacity of 199.7 mAh g −1 and a capacity retention rate of 99% after 50 cycles at 0.6 C. The CNF@Ni-Fe alloy cathodes also deliver long-term stability with 104.5 mAh g −1 capacity retention after 600 cycles at 2 C and a good rate capability of 5 C. Graphical abstract: Image 1 Highlights: Combination of electrospinning and electrodeposition to prepare carbon nanofiber and Ni–Fe (CNF@Ni-Fe) alloy. CNF@Ni-Fe alloy electrodes deliver high stability and good rate capability. Intercrystal heterogeneity of Ni-Fe alloy limits the growth of the low-conductive layer. The coreaction of Ni 2+ and Fe 2+ in the cathode is revealed.