Zeolitic imidazolate frameworks (ZIFs) are considered as a promising material for energy storage in recent years. Here, core-shell structured ZIF-7@ZIF-67 is synthesized in this work. The core-shell structured material can promote electron transfer of inner-outer metals ions of ZIF-7@ZIF-67, quicken diffusion of electrolyte ions and improve the capacitance performance compared to the ZIF-7 and ZIF-67. ZIF-7@ZIF-67 delivers good energy storage ability with a specific capacitance of 518.9 F g⁻¹ at a current density of 1 A g⁻¹ and remarkable stability with a retention of 99.6% after 4000 cycles in the three-electrode system. Furthermore, an all-solid-state asymmetric supercapacitor (ASC) device is assembled based on core-shell structured ZIF-7@ZIF-67 as positive electrode. Impressively, the ASC device displays an energy density of 31 Wh kg⁻¹ at a power density of 400 W kg⁻¹ and an excellent cyclic stability with 99.5% retention after 10,000 cycles at a current density of 10 A g⁻¹. Finally, two all-solid-state ASCs are contacted to power various lighting-emitting diodes (LED). The red LED can be kept glowing for over 10 min. These electrochemical characteristics suggest that core-shell structured ZIF-7@ZIF-67 is a potential material for energy storage device with long-life cyclic stability.

近年来，沸石咪唑酯骨架（ZIFs）被认为是一种很有前途的储能材料。在这里，在这项工作中合成了核壳结构的 ZIF-7@ZIF-67。与ZIF-7和ZIF-67相比，核壳结构材料可以促进ZIF-7@ZIF-67内外金属离子的电子转移，加快电解质离子的扩散，提高电容性能。ZIF-7@ZIF-67 具有良好的储能能力，在 1 A g ^-1的电流密度下具有 518.9 F g ^-1的比电容在三电极系统中，4000 次循环后保持率达 99.6%。此外，基于核壳结构的ZIF-7@ZIF-67作为正极组装了全固态非对称超级电容器（ASC）装置。令人印象深刻的是，ASC 器件在 400 W kg ^-1的功率密度下显示出 31 Wh kg ^-1的能量密度，以及在 10 A g ^-1的电流密度下 10,000 次循环后具有 99.5% 的出色循环稳定性. 最后，连接两个全固态 ASC 为各种发光二极管 (LED) 供电。红色 LED 可以保持发光超过 10 分钟。这些电化学特性表明核壳结构的 ZIF-7@ZIF-67 是一种具有长寿命循环稳定性的储能装置的潜在材料。