Large-scale vertical graphene on nickel foil as a binder-free electrode for high performance battery-like supercapacitor with an aqueous redox electrolyte
2023; Elsevier BV; Volume: 575; Linguagem: Inglês
10.1016/j.jpowsour.2023.233183
ISSN1873-2755
AutoresXiaobo Chen, Yipei Li, Mingliang He, Binghua Zhou, Deliang Cheng, Shien Guo, Keng Xu, Cailei Yuan, Mingxi Wang, Hironori Ogata, Gan Jet Hong Melvin, Yoong Ahm Kim, Mauricio Terrones, Morinobu Endo, Zhipeng Wang,
Tópico(s)Advanced battery technologies research
ResumoDue to the special three-dimensional structures and excellent physicochemical properties, vertical graphene (VG) has been extensively investigated as potential material for supercapacitors. However, achieving VG-based supercapacitors with high-energy density and high-power density is a still tremendous challenge. Here we attempt to synthesize large-scale VG films on flexible substrates and design a novel battery-like supercapacitor (BSCs) with the VG on Ni foil (VG@Ni) as a binder-free electrode operating in the KOH electrolyte with the redox additives of K3Fe(CN)6 and/or K4Fe(CN)6. The VG@Ni electrodes demonstrate an ultrahigh areal capacitance of 1453 mF cm−2 at 5 mA cm−2 in 1 M KOH electrolyte with adding 0.07 M K3Fe(CN)6 and 0.07 M K4Fe(CN)6, coulombic efficiency greater than 90%, and long-life cycling stability (capacitance retention is 99.3% after 20000 charge-discharge cycles). The BSCs, which are assembled with two identical VG@Ni electrodes, deliver the areal capacitance of 231 mF cm−2 with energy density of 32 μWh cm−2 and power density of 2498 μW cm−2 at 1 mA cm−2. These outstanding performances can be ascribed to the special feature and excellent properties of VG materials, high electronic conductivity of binder-free VG@Ni electrode, faradaic properties of redox electrolyte, and synergistic effects between the VG film and redox electrolyte.
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