Wang Tianqi, Liu Wei, Gao Xiang, Zhang Yuan, Du Yongxu, Feng Wenting, Fan Hongguang
School of Materials Science and Engineering, Ocean University of China. 238 Songling Road, Laoshan District, Qingdao, China.
Nanoscale. 2021 Jan 28;13(4):2481-2491. doi: 10.1039/d0nr08711d. Epub 2021 Jan 20.
The electrode materials of potassium ion storage system have attracted considerable attention given the promising prospect of a potassium ion system in large-scale electrochemical energy storage applications. Despite the excellent anode performance of metal oxides in Li and Na batteries, the study on their K storage performance is still rarely reported. In this study, we report a safe and low-cost strategy to prepare FeO/N-doped carbons by using NaHCO and Fe nanopowder. Benefiting from the oxidation of Fe to FeO, an interesting "one stone, two birds" role of the Fe powder can be identified in the heating process. As a reduction agent, the Fe powder can consume the excess oxygen in the bio-massed carbon framework, facilitating the formation of short-range-ordered domains in the biomass-derived carbon materials (FeO@GBHCs). Moreover, the close combination of oxidization products (FeO particles) and carbon matrix leads to numerous FeO clusters grafted on the surface of the carbon framework via the strong C-O-Fe binding. Therefore, the resultant FeO/porous carbon exhibits a high reversible capacity of 410 mA h g and an excellent cycling capability. The assembled FeO@GBHCs//AC potassium-ion hybrid supercapacitor delivers a high energy density of 133 W h kg at a power density of 700 W kg, demonstrating a potential prospect of metal oxides in boosting the potassium ion storage performance.
鉴于钾离子体系在大规模电化学储能应用中的广阔前景，钾离子存储体系的电极材料已引起了相当大的关注。尽管金属氧化物在锂和钠电池中具有优异的负极性能，但关于它们钾存储性能的研究仍鲜有报道。在本研究中，我们报道了一种安全且低成本的策略，即使用碳酸氢钠和铁纳米粉末制备FeO/氮掺杂碳。受益于铁氧化为FeO，在加热过程中可以发现铁粉具有有趣的“一石二鸟”作用。作为还原剂，铁粉可以消耗生物质碳骨架中过量的氧，促进生物质衍生碳材料（FeO@GBHCs）中短程有序域的形成。此外，氧化产物（FeO颗粒）与碳基体的紧密结合导致大量FeO簇通过强C-O-Fe键接枝在碳骨架表面。因此，所得的FeO/多孔碳表现出410 mA h g的高可逆容量和优异的循环性能。组装的FeO@GBHCs//AC钾离子混合超级电容器在700 W kg的功率密度下提供133 W h kg的高能量密度，证明了金属氧化物在提升钾离子存储性能方面的潜在前景。
