摘要
Integration of fast electrochemical double-layer capacitance and large pseudocapacitance is a practical way to improve the overall capability of supercapacitor,yet remains challenging.Herein,an effective cyanogel synthetic strategy was demonstrated to prepare ultrathin Ni(OH)2 nanosheets coupling with conductive reduced graphene oxide(rGO)(rGO-Ni(OH)2)at ambient condition.Ultrathin Ni(OH)2 nanosheet with 3–4 layers of edge-sharing octahedral MO6 maximally exposes the active surface of Faradic reaction and promotes the ion diffusion,while the conductive rGO sheet boosts the electron transport during the reaction.Even at 30 A g−1,the optimal sample can deliver a specific capacitance of 1119.52 F g−1,and maintain 82.3%after 2000 cycles,demonstrating much higher electrochemical capability than bare Ni(OH)2 nanosheets.A maximum specific energy of 44.3 W h kg^−1(148.5 W kg^−1)is obtained,when assembled in a two-electrode system rGO-Ni(OH)2//rGO.This study provides an insight into efficient construction of two dimensional hybrid electrodes with high performance for the new-generation energy storage system.
巧妙地将具有快速电化学过程的双电层电容与具有较大容量的赝电容相结合是提高超级电容器整体性能的实用途径,但是,实现这一目标仍具有挑战性.本文提出了一种氰胶-还原法,并在常温下制备了与导电r GO偶联的超薄Ni(OH)2纳米薄片二维复合材料(rGO-Ni(OH)2).超薄Ni(OH)2纳米片具有3–4层共边八面体MO6,最大限度地暴露了法拉第反应的活性表面,促进了离子扩散,同时导电的r GO在反应过程中促进了电子的传递.在30 A g^-1下,合成的rGO-Ni(OH)2样品的电容值仍可达1119.52 Fg^-1,经2000次循环后仍能保持82.3%的比容量,表现出比Ni(OH)2纳米片更好的电化学性能.组装的r GO-Ni(OH)2//r GO双电极系统,最大的能量密度为44.3 W h kg^-1(148.5 W kg^-1).本工作为制备高性能二维混合电极提供了新的思路.
作者
Xiaoyu Zhang
Hongsen Wang
Lingling Shui
Guofu Zhou
Xin Wang
Ruguang Ma
Jiacheng Wang
张晓雨;王泓森;水玲玲;周国富;王新;马汝广;王家成(South China Academy of Advanced Optoelectronics&International Academy of Optoelectronics at Zhaoqing,South China Normal University,Guangzhou,510631,China;School of Science,Wuhan University of Technology,Wuhan,430070,China;The State Key Laboratory of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai,200050,China)
基金
the National Natural Science Foundation of China(21875133)
Xijiang R&D Team(Wang X),the Science and Technology Program of Guangzhou(2019050001)
Science and Technology Commission of Shanghai Municipality(19ZR1479500)。
