Aqueous asymmetric supercapacitors (ASCs) are promising candidates for energy storage device because of their advanced merits of high power density, long cycling life, nontoxicity, and low cost. However, the energy density of the aqueous ASCs is still limited by the low operating voltage windows and the unmatchable capacitances of cathode and anode. Herein, pinecone‐like hollow Fe₂O₃/MnO₂ nano‐heterostructures (Fe₂O₃/MnO₂ NHs) cathode is developed with high potential window (0–1.2 V) and specific capacitance (297 F g⁻¹ at 1 A g⁻¹). Owing to the opposite operating voltage windows and similar capacitances value of the Fe₂O₃/MnO₂ NHs as cathode and reduced graphene oxide/Fe₂O₃ (rGO/Fe₂O₃) aerogels as anode (−1.1 to 0 V, 274 F g⁻¹ at 1 A g⁻¹), the assembled Fe₂O₃/MnO₂//rGO/Fe₂O₃ aqueous ASCs deliver a wide voltage window up to 2.4 V and a high energy density of 57.0 Wh kg⁻¹. The as‐fabricated ASC also presents outstanding cycling stability (with 88.9% retention after 10 000 cycles at 10 A g⁻¹) and well rate performance. Moreover, Fe₂O₃/MnO₂//rGO/Fe₂O₃ all‐solid‐state ASC exhibits excellent voltage window (2.3 V), capacitance, and ratability. Thus, this study provides a novel approach for constructing high‐voltage aqueous ASC with high energy density.

中文翻译：

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松果状中空Fe2O3 / MnO2纳米异质结构调控水不对称超级电容器的电压窗口和能量密度

水性不对称超级电容器（ASC）由于其高功率密度，长循环寿命，无毒和低成本等先进优点而成为储能设备的有希望的候选者。但是，水性ASC的能量密度仍然受到低工作电压窗口以及阴极和阳极不可匹配的电容的限制。在这里，松果状空心Fe ₂ O ₃ / MnO ₂纳米异质结构（Fe ₂ O ₃ / MnO ₂ NHs）阴极具有高电势窗口（0-1.2 V）和比电容（297 F g ^-1 at 1） a g ^-1）。由于相反的工作电压窗口和类似的Fe电容值₂ ö ₃ /的MnO ₂ NHS作为阴极和还原氧化石墨烯/ Fe的₂ ö ₃（RGO / Fe的₂ ö ₃）气凝胶阳极（-1.1到0V，274 F G ^-1 1 A G ^-1），则组装后的Fe ₂ O ₃ / MnO ₂ // rGO / Fe ₂ O ₃水性ASC可提供高达2.4 V的宽电压范围和57.0 Wh kg ^-1的高能量密度。制成的ASC还​​具有出色的循环稳定性（在10 A g ^{-1的条件下}进行10 000次循环后保留率达88.9％）和良好的速率性能。此外，Fe ₂O ₃ / MnO ₂ // rGO / Fe ₂ O ₃全固态ASC表现出出色的电压窗口（2.3 V），电容和可缩放性。因此，本研究为构建具有高能量密度的高压水性ASC提供了一种新颖的方法。