The design and fabrication of electrode materials with excellent electrochemical performance are the key measures to improve the energy density of devices. Since cobalt-based materials have excellent conductivity and stability while nickel-based materials have ultra-high theoretical capacitance, a series of bimetal Ni/Co metal–organic-framework materials with adjustable components were synthesized via a facile one-step solvothermal method. Moreover, due to the similarity of the atomic radius and chemical valence state between Co and Ni, the in situ replacement was achieved by adjusting the initial proportion of Co²⁺ to Ni²⁺ during the synthetic process. The optimal sample not only retained the stability and electrical conductivity of Co-based MOF materials, but also demonstrated outstanding electrochemical performance with a high specific capacitance (1230.3 F g⁻¹ at 1 A g⁻¹), excellent rate capability (87.0%, from 1 A g⁻¹ to 10 A g⁻¹) and great cycle stability (80%, 4000 cycles at 10 A g⁻¹). Besides, the assembled solid-state supercapacitor using the optimal sample as the positive electrode and active carbon as the negative electrode exhibited an ultra-high energy density of 116 W h kg⁻¹ at a power density of 0.795 kW kg⁻¹ and a superior stability with 92.1% initial capacity retention even after 6000 cycles at 10 A g⁻¹. In brief, this work could provide novel insight into the controllable synthesis of high performance polymetallic-based MOF materials with adjustable components for energy storage and conversion.

中文翻译：

---

花状双金属镍/钴基金属有机骨架材料，具有可调节组件的高性能固态超级电容器

设计和制备具有优异电化学性能的电极材料是提高器件能量密度的关键措施。由于钴基材料具有优异的导电性和稳定性，而镍基材料具有超高的理论电容，因此通过简便的一步溶剂热法合成了一系列组分可调的双金属Ni/Co金属-有机骨架材料。此外，由于Co和Ni之间原子半径和化学价态的相似性，通过调整Co ²⁺与Ni ²⁺的初始比例来实现原位置换。在合成过程中。最佳样品不仅保留了 Co 基 MOF 材料的稳定性和导电性，而且表现出优异的电化学性能，具有高比电容（1230.3 F g ^-1 at 1 A g ^-1）、优异的倍率性能（87.0%，从 1 A g ^-1到 10 A g ^-1）和良好的循环稳定性（80%，10 A g ^{-1 下}4000 次循环）。此外，以最佳样品为正极，活性炭为负极的组装固态超级电容器在0.795 kW kg ^-1的功率密度下表现出116 W h kg ^-1的超高能量密度并且即使在 10 A g ^{-1 下}循环 6000 次后仍具有 92.1% 的初始容量保持率的卓越稳定性。简而言之，这项工作可以为高性能多金属基 MOF 材料的可控合成提供新的见解，该材料具有用于能量存储和转换的可调组件。