Mesh-like vertical structures enable both high areal capacity and excellent rate capability

• 作者: Ruyi Chen Jialu Xue Yujiao Gong Chenvang Yu Zengyu Hui Hai Xu Yue Sun Xi Zhao Jianing An Jinyuan Zhou Qiang Chen Gengzhi Sun Wei Huang
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（2）
• 页码范围: 226-233
• 页数: 8页
• 语种: 英文

摘要

In order to balance electrochemical kinetics with loading level for achieving efficient energy storage with high areal capacity and good rate capability simultaneously for wearable electronics,herein,2D meshlike vertical structures (NiCo2S4@Ni(OH)2) with a high mass loading of 2.17 mg cm-2 and combined merits of both 1 D nanowires and 2D nanosheets are designed for fabricating flexible hybrid supercapacitors.Particularly,the seamlessly interconnected NiCo2Sa core not only provides high capacity of 287.5 μAh cm-2 but also functions as conductive skeleton for fast electron transport;Ni(OH)2 sheath occupying the voids in NiCo2S4 meshes contributes extra capacity of 248.4 μAh cm-2;the holey features guarantee rapid ion diffusion along and across NiCo2S4@Ni(OH)2 meshes.The resultant flexible electrode exhibits a high areal capacity of 535.9 μAh cm-2 (246.9 mAh g-1) at 3 mA cm-2 and outstanding rate performance with 84.7％ retention at 30 mA cm-2,suggesting efficient utilization of both NiCo2S4 and Ni(OH)2 with specific capacities approaching to their theoretical values.The flexible solid-state hybrid device based on NiCo2Sa@Ni(OH)2 cathode and Fe2O3 anode delivers a high energy density of 315 μWh cm-2 at the power density of 2.14 mW cm-2 with excellent electrochemical cycling stability.