One-step hydrothermal preparation of TiO₂/RGO/Ni(OH)₂/NF electrode with high performance for supercapacitors

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• 作者：Chongjun Zhao ; ^{chongjunzhao@ecust.edu.cn" class="auth_mail" title="E-mail the corresponding author} (Prof.) ; Peiwen Ju ; Shengqi Wang ; Yuxiao Zhang ; Shudi Min ; Xiuzhen Qian
• 关键词：TiO2/RGO/Ni(OH)2 ; Ni foam ; Hydrothermal ; Supercapacitor
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：10 November 2016
• 年：2016
• 卷：218
• 期：Complete
• 页码：216-227
• 全文大小：4012 K

文摘

A facile one-step hydrothermal process is employed to synthesize a TiO₂/RGO/Ni(OH)₂ (reduced graphene oxide, RGO) composite on nickel foam (NF) by means of an in-situ growth route. In this case, NF acts as support, nickel source of Ni(OH)₂, and supplement reductant of GO. For comparison, RGO nanosheets serve as nano-sized flexible support for connecting TiO₂ and Ni(OH)₂ blocks, which improves the electron transfer and alleviates the volume changes during the repeated charge/discharge process thanks to its high conductivity and mechanical properties. Besides, P25 (commercial TiO₂ consisting of 80% anatase and 20% rutile) serves as TiO₂ source, at different GO/P25 ratio of 1%, 2%, 5%, 10% and 20%. Electrochemical performances of TiO₂/RGO/Ni(OH)₂/NF electrode were evaluated by using cyclic voltammetry (CV), galvanostatic charge/discharge tests (GCD) and electrochemical impedance spectroscopy (EIS) in 1 M KOH electrolyte. The TiO₂/RGO/Ni(OH)₂/NF electrode exhibited significantly enhanced capacitive performance when the weight ratio of GO/P25 was 10%. It delivered high capability of 4342 mF cm⁻² at a current density of 5 mA cm⁻² (374.3 F g⁻¹ at 0.43 A g⁻¹), and excellent charge-discharge cycling stability with 93.75% capacitance retention after 2000 cycles. An asymmetric supercapacitor (ASC) device consisting of this TiO₂/RGO/Ni(OH)₂/NF and an AC negative electrode was assembled.