Stable TiVCTx/poly-o-phenylenediamine composites with three-dimensional tremella-like architecture for supercapacitor and Li-ion battery applications

Abstract

Two-dimensional double transition metal carbides and nitrides (MXenes) with unique out-of-plane ordering of the two metal atoms, have distinct and advantageous electrical properties owing to their chemical versatility and structural intricacy signify. However, MXenes are inclined to easily oxidized unstable surface, and lamellar structure agglomeration or stack, which impede their practicable application prospect in energy utilization and storage. Here, we propose a new strategy of spontaneous transforming few-layered TiVCTx MXene nanosheets directly into three-dimensional (3D) stable tremella-like architecture TiVCTx/poly-o-PD composites (N-TiVCTx) by utilizing o-phenylenediamine (oPD) as the monomer of oxidant-free polymerization. Meanwhile, the electrochemical performance of the supercapacitor using TiVCTx and N-TiVCTx in acidic and neutral electrolyte was examined for the first time. Notedly, N-TiVCTx composites show outstanding electrochemical capacitance property with a high specific capacitance of 282F g−1 at 10 mV s−1. Compared to TiVCTx, the capacitance was increased by 50 %. Besides, the 3D N-TiVCTx electrodes exhibit well stable pseudocapacitive charge storage with capacity up to 415.6 mAh g−1 at 0.1A g−1 and retain outstanding performance of 224 mAh g−1 at 2 A g−1 for lithium ion storage. The N-TiVCTx MXene greatly increased the stability consist of thermal stability, preferably chemical and electrochemical stability. Our work broadens the application of TiVCTx as electrode materials in energy storage domain and provides tactics to improve the other few-layered MXenes energy storage capacity as well as chemical stability.