A novel all solid-state asymmetric supercapacitor with superior electrochemical performance in a wide temperature range using a hydroquinone modified graphene xerogel as the cathode and N-doped Ti3C2Tx as the anode

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 8; no. 4; pp. 1687 - 1696
• Main Authors: Sun, Qimeng, He, Tao, Li, Yueming
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2020
• Subjects: Adaptability; Anodes; Asymmetry; Capacitance; Cathodes; Conductivity; Electrochemical analysis; Electrochemistry; Electrode materials; Flux density; Graphene; Hydroquinone; Room temperature; Solid state; Sulfuric acid; Supercapacitors; Temperature; Xerogels
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c9ta09447d

To further improve the energy density of supercapacitors, novel asymmetric supercapacitors using electrode materials with a large potential window should be designed. In this report, a hydroquinone modified graphene xerogel as the cathode and N-doped Ti3C2Tx as the anode are first applied in all-solid-state asymmetric supercapacitors with a wide voltage window. The hydroquinone modified binder-free graphene xerogels are chosen as the cathode materials because of their high potential, high pseudocapacitance, and high conductivity, whereas the N-doped Ti3C2Tx are selected as the anode materials due to their low potential, high specific capacitance, and high conductivity. The as-fabricated asymmetric device shows a potential window of 1.7 V in a H2SO4 gel electrolyte, and excellent adaptability in a wide temperature range from room temperature to −20 °C. It is found that an excellent energy density of 33.9 W h kg−1 for the asymmetric supercapacitor is achieved at −20 °C. Furthermore, the operation of the asymmetric supercapacitor in a wide temperature range greatly increases the practical application potential of supercapacitors.