In‐situ Construction of CNTs Decorated Titanium Carbide on Ti Mesh Towards the Synergetic Improvement of Energy Storage Properties for Aqueous Zinc Ion Capacitors

Abstract

The development of aqueous zinc‐ion capacitors (ZICs) is an effective approach to improve the safety and environmental friendliness of energy storage devices. In this paper, TiC/CNTs core‐shell array structures (TCT) were synthesized on titanium substrate through in‐situ simple chemical vapor deposition and carbon reduction and used as self‐supporting cathodes for aqueous ZICs. As expected, as‐prepared TCT electrode exhibited excellent electrochemical performance in aqueous electrolytes, demonstrating a high specific capacitance of 275.13 F g−1 at a current density of 1.0 A g−1 and maintaining 90.5 % of its initial capacity after 10000 charge‐discharge cycles. The assembled Zn//TCT ZIC displays excellent rate capability, delivering an excellent specific capacitance of 298.2 F g−1 at 0.5 A g−1 and 193.5 F g−1 at a high current density of 10 A g−1. Zn//TCT device can provide an ultra‐high energy density of 24.8 Wh kg−1 at a power of 6984.1 W kg−1. DFT calculations further demonstrate that a large number of electrons are transferred at the TiC/CNT interface and stable TIC−C bonds can be formed. This work provides a new strategy for rationally designing transition metal carbide electrodes and constructing ZICs with high energy and power densities.