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句式变化多样，句法方面做的很棒；作者词汇基本功不错，高级词汇表达灵活熟练；采用了简单的衔接手法，行文流畅。
Due to the safety issue of organic electrolytes, aqueous energy storage devices have attracted enormous attention for the next generation’s rechargeable energy supply source. Aqueous supercapacitors (SCs) have been extensively investigated owing to their fast charge transfer process, outstanding cycling performance, environmental friendliness etc. But their single-cell voltage was typically lower than 1.8 V and the practical operating voltage of SCs that use strong acids and bases were constrained within 1.0 V. While some potential high oxygen/hydrogen overpotential electrode materials such as Vanadium oxides and Manganese oxides were hindered by their low electrical conductivity and slow ion diffusion. Therefore, constructing aqueous SCs cathodes with high potential and fast electrode kinetics are urgently needed. Herein, Prof. Jinping Liu at Wuhan University of Technology designed and reported a new strategy to construct high voltage manganese oxide with fast charge/mass-transfer kinetics. With similar radius of 3d-metal elements and the same NaCl crystal structure, MnO could be easily form solid-solution with other metal oxides. By modulating the electronics and crystal structures via solid-solution and nanocarbon coating, the oxygen overpotential of Manganese oxides was kept (0-1.4 V vs. SCE) as well as practical capacitance (39.43 mF cm-2 of MnO to 242.86 mF cm-2 of Ni0.25Mn0.75O@C) and rate performance were improved. By paring with commercial activated carbon anode, an ultrahigh voltage asymmetric supercapacitor (2.4 V) in neutral aqueous LiCl electrolyte is assembled. Furthermore, by using a PVA-LiCl hydrogel electrolyte, a 2.4 V quasi-solid-state supercapacitor is developed with excellent coulombic efficiency of > 99 %, good rate capability, remarkable cycling life (> 5000 cycles with 95.5% capacity retention) and high volumetric energy density (maximum 4.72 mWh cm-3). This work presents that solid-solution of transition mental oxides is a novel effective method to design high-potential SCs cathodes for high-voltage SCs.
