Tao Song, Zhang Xinyue, Gao Zhaoyang, Chen Tsung-Yi, Min Huihua, Yang Hao, Chen Han-Yi, Shen Xiaodong, Wang Jin, Yang Hui
College of Materials Science and Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China.
Department of Materials Science and Engineering, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu, 300044, Taiwan.
Small. 2023 Nov;19(48):e2304200. doi: 10.1002/smll.202304200. Epub 2023 Jul 31.
Molybdenum selenium (MoSe ) has tremendous potential in potassium-ion batteries (PIBs) due to its large interlayer distance, favorable bandgap, and high theoretical specific capacity. However, the poor conductivity and large K insertion/extraction in MoSe inevitably leads to sluggish reaction kinetics and poor structural stability. Herein, Coinduced engineering is employed to illuminate high-conductivity electron pathway and mobile ion diffusion of MoSe nanosheets anchored on reduced graphene oxide substrate (Co-MoSe /rGO). Benefiting from the activated electronic conductivity and ion diffusion kinetics, and an expanded interlayer spacing resulting from Co doping, combined with the interface coupling with highly conductive reduced graphene oxide (rGO) substrate through Mo-C bonding, the Co-MoSe /rGO anode demonstrates remarkable reversible capacity, superior rate capability, and stable long-term cyclability for potassium storage, as well as superior energy density and high power density for potassium-ion capacitors. Systematic performance measurement, dynamic analysis, in-situ/ex-situ measurements, and density functional theory (DFT) calculations elucidate the performance-enhancing mechanism of Co-MoSe /rGO in view of the electronic and ionic transport kinetics. This work offers deep atomic insights into the fundamental factors of electrodes for potassium-ion batteries/capacitors with superior electrochemical performance.
钼硒（MoSe₂）由于其较大的层间距、合适的带隙和较高的理论比容量，在钾离子电池（PIBs）中具有巨大潜力。然而，MoSe₂中较差的导电性以及较大的钾嵌入/脱出量不可避免地导致反应动力学迟缓以及结构稳定性差。在此，采用钴诱导工程来阐明锚定在还原氧化石墨烯基底上的MoSe₂纳米片（Co-MoSe₂/rGO）的高导电性电子通路和可移动离子扩散。得益于活化的电子导电性和离子扩散动力学，以及钴掺杂导致的层间距扩大，再加上通过Mo-C键与高导电性还原氧化石墨烯（rGO）基底的界面耦合，Co-MoSe₂/rGO负极展现出卓越的可逆容量、优异的倍率性能以及稳定的长期钾存储循环稳定性，同时在钾离子电容器方面具有优异的能量密度和高功率密度。系统的性能测量、动力学分析、原位/非原位测量以及密度泛函理论（DFT）计算从电子和离子传输动力学的角度阐明了Co-MoSe₂/rGO的性能增强机制。这项工作为具有优异电化学性能的钾离子电池/电容器电极的基本因素提供了深入的原子层面见解。
