Facile Synthesis of NiCo[sub.2]O[sub.4] Nanowire Arrays/Few-Layered Ti[sub.3]C[sub.2]-MXene Composite as Binder-Free Electrode for High-Performance Supercapacitors

• Published in: Molecules (Basel, Switzerland) Vol. 27; no. 19
• Main Authors: Li, Yanhua, Wang, Shuhuan, Ni, Guolong, Li, Qun
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.09.2022
• Subjects: Batteries; Capacitors; Climatic changes; China
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27196452

Herein, a 3D hierarchical structure is constructed by growing NiCo[sub.2]O[sub.4] nanowires on few-layer Ti[sub.3]C[sub.2] nanosheets using Ni foam (NF) as substrate via simple vacuum filtration and solvothermal treatment. Ti[sub.3]C[sub.2] nanosheets are directly anchored on NF surface without binders or surfactants, and NiCo[sub.2]O[sub.4] nanowires composed of about 15 nm nanoparticles uniformly grow on Ti[sub.3]C[sub.2]/NF skeleton, which can provide abundant active sites and ion diffusion pathways for enhancing electrochemical performance. Benefiting from the unique structure feature and the synergistic effects of active materials, NiCo[sub.2]O[sub.4]/Ti[sub.3]C[sub.2] exhibits a high specific capacitance of 2468 F g[sup.−1] at a current density of 0.5 A g[sup.−1] and a good rate performance. Based on this, an asymmetric supercapacitor (ASC) based on NiCo[sub.2]O[sub.4]/Ti[sub.3]C[sub.2] as positive electrode and activated carbon (AC)/NF as negative electrode is assembled. The ASC achieves a high specific capacitance of 253 F g[sup.−1] at 1 A g[sup.−1] along with 91.5% retention over 10,000 cycles at 15 A g[sup.−1]. Furthermore, the ACS presents an outstanding energy density of 90 Wh kg[sup.−1] at the power density of 2880 W kg[sup.−1]. This work provides promising guidance for the fabrication of binder-free, free-standing and hierarchical composites for energy storage application.