Tailoring the composition and nanostructure of transition metal compounds is critical for electrochemical energy storage materials. Transition metal oxalates, which are formed by oxalic acid (OA) with transition metals, have been regarded as potential battery-type electrode material for high-performance supercapatteries due to their excellent electrochemical stability, low cost, and adjustable pore sizes, yet still limited by their low conductivity. Herein, we report a facile way for fabricating trimetal oxalates with three-dimensional (3D) architecture assembled by interwoven nanosheets by a succinct-operated hydrothermal method. Benefiting from both unique 3D porous structures and the synergistic interactions of trimetal oxalates, the developed Mn_0.4Ni_0.1Co-OA shows a considerably high specific capacity (1141.6 C g⁻¹) and ultralong cyclic life (85% capacity retention over 10,000 cycles). Additionally, the supercapattery assembled with the Mn_0.4Ni_0.1Co-OA electrode and the activated carbon (AC) electrode displays a maximum energy density of 32.2 Wh kg⁻¹ at the power density of 770.2 W kg⁻¹ and outstanding cycle life (retention rate of 88.1% after 15,000 cycles). The results presented in this work that the rational design of the composition and structure of oxalates can provide a new idea for the preparation of high-performance energy storage materials.

调整过渡金属化合物的组成和纳米结构对于电化学储能材料至关重要。由草酸 (OA) 与过渡金属形成的过渡金属草酸盐由于其优异的电化学稳定性、低成本和可调节的孔径而被认为是用于高性能超级电容器的潜在电池型电极材料，但仍存在局限性由于它们的低导电性。在这里，我们报告了一种通过简洁操作的水热方法制造由交织纳米片组装的具有三维（3D）结构的三金属草酸盐的简便方法。受益于独特的 3D 多孔结构和三金属草酸盐的协同相互作用，开发的 Mn _0.4 Ni _0.1Co-OA 显示出相当高的比容量（1141.6 C g ^-1）和超长循环寿命（10,000 次循环后容量保持率为 85%）。此外，与 Mn _0.4 Ni _0.1 Co-OA 电极和活性炭 (AC) 电极组装在一起的超级电池在 770.2 W kg ^-1的功率密度下显示出 32.2 Wh kg ^-1的最大能量密度和出色的循环寿命（保留15,000 次循环后的比率为 88.1%）。本工作的结果表明，合理设计草酸盐的组成和结构可为制备高性能储能材料提供新思路。