Hierarchical hollow NiCo₂S₄ microspheres with a tunable interior architecture are synthesized by a facile and cost‐effective hydrothermal method, and used as a cathode material. A three‐dimensional (3D) porous reduced graphene oxide/Fe₂O₃ composite (rGO/Fe₂O₃) with precisely controlled particle size and morphology is successfully prepared through a scalable facile approach, with well‐dispersed Fe₂O₃ nanoparticles decorating the surface of rGO sheets. The fixed Fe₂O₃ nanoparticles in graphene efficiently prevent the intermediates during the redox reaction from dissolving into the electrolyte, resulting in long cycle life. KOH activation of the rGO/Fe₂O₃ composite is conducted for the preparation of an activated carbon material–based hybrid to transform into a 3D porous carbon material–based hybrid. An energy storage device consisting of hollow NiCo₂S₄ microspheres as the positive electrode, the 3D porous rGO/Fe₂O₃ composite as the negative electrode, and KOH solution as the electrolyte with a maximum energy density of 61.7 W h kg⁻¹ is achieved owing to its wide operating voltage range of 0–1.75 V and the designed 3D structure. Moreover, the device exhibits a high power density of 22 kW kg⁻¹ and a long cycle life with 90% retention after 1000 cycles at the current density of 1 A g⁻¹.

中文翻译：

---

空心NiCo2S4纳米球与3D分层多孔rGO / Fe2O3复合材料杂化成高性能储能装置

具有内部可调结构的分层空心NiCo ₂ S ₄微球是通过一种简便且经济高效的水热法合成的，并用作阴极材料。通过可扩展的简便方法成功地制备了具有精确控制的粒径和形态的三维（3D）多孔还原氧化石墨烯/ Fe ₂ O ₃复合材料（rGO / Fe ₂ O ₃），并具有良好分散的Fe ₂ O ₃纳米颗粒装饰rGO板的表面。固定的Fe ₂ O ₃石墨烯中的纳米颗粒有效地防止了氧化还原反应过程中的中间体溶解到电解质中，从而延长了循环寿命。进行了rGO / Fe ₂ O ₃复合材料的KOH活化，以制备基于活性炭材料的混合材料，从而转变为基于3D多孔碳材料的混合材料。一种能量存储装置，由空心NiCo ₂ S ₄微球作为正极，3D多孔rGO / Fe ₂ O ₃复合材料作为负极以及KOH溶液作为电解质，最大能量密度为61.7 W h kg ^-1由于其0至1.75 V的宽工作电压范围和设计的3D结构，因此可以实现该功能。此外，该装置表现出22 kW kg ^-1的高功率密度和长循环寿命，在1 A g ^-1的电流密度下1000次循环后具有90％的保持率。