School of Materials Science and Engineering, Ocean University of China, Qingdao 266100, China.
Phys Chem Chem Phys. 2023 Mar 29;25(13):9104-9114. doi: 10.1039/d3cp00450c.
Flexible aqueous supercapacitors are promising candidates as safe power sources for wearable electronic devices (WEDs). However, the absence of advanced electrode materials with high structural stability has become the most critical factor hindering the development, which is closely related to the poor interface combination between the active substances and flexible collectors. Herein, a unique rigid layered double hydroxide (LDH) nanorod array with the mesocrystalline feature is created using the NiO-Ni layer as the inducer by the electrodeposition strategy. Differing from the traditional NiCo-LDH nanosheets directly grown on a carbon cloth, an elaborately designed NiO-Ni buffer can simultaneously and effectively improve the bidirectional combination with active substances and collectors, also the mesocrystalline LDH showed enhanced intrinsic stability through the reinforcing effect of grain boundaries. Benefiting from these, the assembled supercapacitor exhibited pre-eminent cycle stability (increased from 64% of the initial capacity after 10 000 cycles to no significant attenuation after 50 000 cycles) and ultrahigh energy density. When it was used as a flexible device, a remarkable energy density of 70.4 W h kg could be harvested and processed with high flexibility in the bending state and good temperature adaptability. This study provides an excellent design strategy for the development of next-generation flexible supercapacitors with the goal of better comprehensive performances.
柔性水系超级电容器作为可穿戴电子设备 (WEDs) 的安全电源具有广阔的应用前景。然而，由于缺乏具有高结构稳定性的先进电极材料，成为了阻碍其发展的最关键因素，这与活性物质和柔性集电器之间较差的界面结合密切相关。在此，通过电沉积策略，使用 NiO-Ni 层作为诱导剂，成功制备出具有介晶特征的独特刚性层状双氢氧化物 (LDH) 纳米棒阵列。与传统的直接在碳布上生长的 NiCo-LDH 纳米片不同，精心设计的 NiO-Ni 缓冲层可以同时有效地改善与活性物质和集电器的双向结合，同时介晶 LDH 通过晶界的增强作用表现出增强的固有稳定性。受益于这些特性，组装的超级电容器表现出卓越的循环稳定性（在 10000 次循环后，初始容量的 64%增加到 50000 次循环后没有明显衰减）和超高的能量密度。当用作柔性器件时，它可以在弯曲状态下保持高柔韧性和良好的温度适应性，以 70.4 W h kg 的优异能量密度进行高效的能量收集和处理。本研究为开发具有更好综合性能的下一代柔性超级电容器提供了一种卓越的设计策略。
