Directly growing nickel/cobalt-based cathode materials on current collectors as binder-free electrodes for rechargeable aqueous nickel/cobalt-Zn-based (NiCo//Zn) batteries have attracted tremendous attentions. However, most of the present binder-free cathodes suffer from low areal capacity and energy density, which severely restrict their practical applications. Herein, we demonstrate an efficient metal-organic framework (MOF)-involved strategy to rationally integration of the active NiCo₂O₄, CoMoO₄ and Co₃O₄ cathode materials into one hierarchical arrayed structure that uniformly grown on nickel foam (NF) substrate (denoted as NF–NCO@CMO@CO) with a high mass loading of 9.6 ​mg ​cm⁻². Such electrode design possesses favorable merits in the aspects of high electrical conductivity, robust arrayed architectures, abundant electrochemical active sites, rich redox reactions, facile ion diffusion and components’ synergetic effect. As a result, the aqueous NiCo//Zn battery based on NF–NCO@CMO@CO binder-free cathode exhibits an ultrahigh areal capacity of 2.51 ​mAh cm⁻² at a current density of 2 ​mA ​cm⁻², as well as good rate capability and long-term cycling stability. Impressively, the aqueous NF–NCO@CMO@CO//Zn battery shows a maximum areal energy density of 4.09 ​mWh cm⁻² (corresponding to 424.5 ​Wh kg⁻¹), which is superior to most of the previously reported aqueous NiCo//Zn batteries. Electrode reaction kinetics analysis reveals that both capacitive and diffusion-controlled behaviors are involved during the charge storage processes. Moreover, a quasi-solid-state NF–NCO@CMO@CO//Zn battery is also assembled by replacing the liquid electrolyte with gel electrolyte, suggesting the potential for practical applications. This work might shed light on the rational construction of advanced binder-free cathodes for high-performance aqueous NiCo//Zn batteries.

作为可再充电含水镍/钴-锌基（NiCo // Zn）电池的无粘结剂电极，在集电器上直接生长的镍/钴基阴极材料引起了极大的关注。然而，目前大多数的无粘结剂阴极的面积容量和能量密度低，这严重限制了它们的实际应用。在这里，我们展示了一种有效的金属有机框架（MOF）介入策略，可将活性NiCo ₂ O ₄，CoMoO ₄和Co ₃ O ₄阴极材料合理地整合到一个均匀分布在镍泡沫（NF）上的分层结构中质量负载为9.6 mg·cm ^-2的基底（表示为NF–NCO @ CMO @ CO）。这样的电极设计在高电导率，稳健的阵列结构，丰富的电化学活性位点，丰富的氧化还原反应，容易的离子扩散和组分的协同作用方面具有有利的优点。结果，基于NF–NCO @ CMO @ CO无粘合剂阴极的NiCo // Zn水性电池在电流密度为2 mA cm ^-2时显示出2.51 mAh cm ^-2的超高面容量，这是因为良好的速率能力和长期循环稳定性。令人印象深刻的是，NF-NCO @ CMO @ CO // Zn水性电池的最大面能量密度为4.09 mWh cm ^-2（相当于424.5 Wh kg ^-1），优于之前报道的大多数NiCo // Zn水性电池。电极反应动力学分析表明，电荷存储过程涉及电容和扩散控制行为。此外，通过用凝胶电解质代替液体电解质，还组装了准固态NF​​-NCO @ CMO @ CO // Zn电池，这表明了其在实际应用中的潜力。这项工作可能会为高性能含水NiCo // Zn电池的先进无粘结剂阴极的合理构造提供启示。