Li Jingqiu, Xie Yuming, Cao Mengjue, Feng Yi, Yao Jianfeng
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
J Colloid Interface Sci. 2023 Feb;631(Pt A):222-230. doi: 10.1016/j.jcis.2022.11.012. Epub 2022 Nov 8.
The metal ion etching induced transformation of zeolitic imidazolate frameworks (ZIFs) to layered double hydroxides (LDHs) is closely related to the etching conditions. Here, by tuning the Ni etching conditions (e.g., initial Ni concentration and etching time), Co-ZIF-L templated CoNi-LDH with diverse morphologies and tailorable compositions are obtained and their resultant electrochemical properties are optimized. Mechanism study reveals that the etching conditions significantly affect the disassembling rate of Co-ZIF-L as well as the formation rate of CoNi-LDH, leading to the morphological and compositional variance of etched samples, which further results in their distinct electrochemical activities. The resultant asymmetric supercapacitor assembled with Co-ZIF-L derived CoNi-LDH and activated carbon can achieve a maximum energy density of 77.3 Wh/kg at a power density of 700 W/kg with the capacity retention of 85.7 % after 2000 cycles, superior or comparable to other advanced CoNi-LDH based supercapacitors.
金属离子蚀刻诱导的沸石咪唑酯骨架（ZIFs）向层状双氢氧化物（LDHs）的转变与蚀刻条件密切相关。在此，通过调整镍蚀刻条件（如初始镍浓度和蚀刻时间），获得了具有不同形态和可定制组成的以Co-ZIF-L为模板的CoNi-LDH，并优化了其电化学性能。机理研究表明，蚀刻条件显著影响Co-ZIF-L的分解速率以及CoNi-LDH的形成速率，导致蚀刻样品的形态和组成发生变化，进而导致其不同的电化学活性。用Co-ZIF-L衍生的CoNi-LDH和活性炭组装而成的不对称超级电容器在功率密度为700 W/kg时可实现最大能量密度77.3 Wh/kg，在2000次循环后容量保持率为85.7%，优于或与其他先进的基于CoNi-LDH的超级电容器相当。
