A solid‐state fibriform supercapacitor boosted by host – guest hybridization between the carbon nanotube scaffold and MXene nanosheets

• Main Authors: Yu, Chenyang, Gong, Yujiao, Chen, Ruyi, Zhang, Mingyi, Zhou, Jinyuan, An, Jianing, Lv, Fan, Guo, Shaojun, Sun, Gengzhi
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Mechanical engineering; Carbon Nanotubes; Fibers
• Online Access: https://hdl.handle.net/10356/138910
• Institution: Nanyang Technological University

Fiber-shaped supercapacitors with improved specific capacitance and high rate capability are a promising candidate as power supply for smart textiles. However, the synergistic interaction between conductive filaments and active nanomaterials remains a crucial challenge, especially when hydrothermal or electrochemical deposition is used to produce a core (fiber)-shell (active materials) fibrous structure. On the other hand, although 2D pseudocapacitive materials, e.g., Ti3 C2 T x (MXene), have demonstrated high volumetric capacitance, high electrical conductivity, and hydrophilic characteristics, MXene-based electrodes normally suffer from poor rate capability owing to the sheet restacking especially when the loading level is high and solid-state gel is used as electrolyte. Herein, by hosting MXene nanosheets (Ti3 C2 T x ) in the corridor of a scrolled carbon nanotube (CNT) scaffold, a MXene/CNT fiber with helical structure is successfully fabricated. These features offer open spaces for rapid ion diffusion and guarantee fast electron transport. The solid-state supercapacitor based on such hybrid fibers with gel electrolyte coating exhibits a volumetric capacitance of 22.7 F cm-3 at 0.1 A cm-3 with capacitance retention of 84% at current density of 1.0 A cm-3 (19.1 F cm-3 ), improved volumetric energy density of 2.55 mWh cm-3 at the power density of 45.9 mW cm-3 , and excellent mechanical robustness.