One-step synthesis of nickel cobalt sulphides particles: tuning the composition for high performance supercapacitors

Huaihao Zhang *, Bing Guan, Jiangna Gu, Yu Li, Chi Ma, Jing Zhao, Tianyi Wang and Changjing Cheng

College of Chemistry and Chemical Engineering, Yangzhou University

Abstract:NiS2–CoS2 composites with different Ni and Co molar ratios for supercapacitors (SCs) were synthesized by one-step hydrothermal co-deposition method using cheap Na2S2O3$5H2O as sulfur source. With the increase of Ni content, the composites particle size increases gradually and the hollow sphere structure becomes more obvious. The electrochemical measurements demonstrate that these composites possess a high specific capacitance (Cm) performance, good rate capability and long cycle stability. To be specific, the Cm of Ni/Co/S-1 composite is the largest, up to 954.3 F g_1 at 1 A g_1, and as high as 309.5 F g_1 even at large current density of 20 A g_1. Furthermore, the Ni/Co/S-1 maintains 99.9% of its initial Cm after 1000 cycles at 5 A g_1. Moreover, the asymmetric supercapacitors with Ni/Co/S-1 as positive electrode and active carbon as negative electrode are of prominent energy density of 29.3 W h_1 kg_1 at the power density of 0.7 kW kg_1, and superior cycling stability of 99.1% initial value retention after 1000 cycles.

RSC Advances, 2016, 6, 58916-58924

文章链接:http://pubs.rsc.org/en/Content/ArticleLanding/2016/RA/C6RA10048A#!divAbstract

文章附件:RSC ADV, 2016, 6, 58916