标题：Designing 3D Biomorphic Nitrogen-Doped MoSe2/Graphene Composites toward High-Performance Potassium-Ion Capacitors
作者：Yuyang Yi1, Zhongti Sun1, Chao Li1, Zhengnan Tian1, Chen Lu1, Yuanlong Shao2, Jie Li3, Jingyu Sun1, and Zhongfan Liu1,4
单位：1. College of Energy, Soochow Institute for Energy and Materials Innovations (SIEMIS), Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies, Soochow University, Suzhou 215006, P. R. China
2. College Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
3. Helmholtz Institute Münster-Forschungszentrum Jülich GmbH (IEK 12), Corrensstrasse 46, D-48149 Münster, Germany
4. Center for Nanochemistry (CNC), College of Chemistry and Molecular Engineering, Peking University, 100871 Beijing, P. R. China
摘要：Potassium-ion hybrid capacitors (KICs) reconciling the advantages of batteries and supercapacitors have stimulated growing attentions for practical energy storages because of the high abundance and low cost of potassium sources. Nevertheless, daunting challenge remains for developing high-performance potassium accommodation materials due to the large radius of potassium ions. Molybdenum diselenide (MoSe2) has recently been recognized as a promising anode material for potassium-ion batteries, achieving high capacity and favorable cycling stability. However, KICs based on MoSe2 have scarcely been demonstrated by far. Herein, we devise a diatomite-templated synthetic strategy to fabricate nitrogen-doped MoSe2/graphene (N-MoSe2/G) composites with favorable pseudocapacitive potassium storage targeting a superior anode material for KICs. Benefiting from the unique biomorphic structure, high electron/K-ion conductivity, enriched active sites, and conspicuous pseudocapacitive effect of N-MoSe2/G, thus-derived KIC full-cell manifests high energy/power densities (maximum 119 Wh kg?1/7212 W kg?1), outperforming those of recently reported KIC counterparts. Furthermore, the potassium storage mechanism of N-MoSe2/G composite is systematically explored with the aid of first-principles calculations in combination of in situ X-ray diffraction and ex situ Raman spectroscopy/transmission electron microscopy/X-ray photoelectron spectroscopy.