Solvothermal preparation of spherical Bi2O3 nanoparticles uniformly distributed on Ti3C2Tx for enhanced capacitive performance

Abstract

Ti₃C₂T_x is a promising new two-dimensional layered material for supercapacitors with good electrical conductivity and chemical stability. However, Ti₃C₂T_x has problems such as collapse of the layered structure and low pseudocapacitance. In this paper, we propose Bi₂O₃–Ti₃C₂T_x nanocomposites prepared by a solvothermal method, study the impact of Bi₂O₃ loading on the phase state and microstructure, and evaluate the electrochemical performance of Bi₂O₃–Ti₃C₂T_x. Studies have shown that spherical Bi₂O₃ particles were uniformly dispersed in the interlayer and surface of Ti₃C₂T_x, which enlarged the interlayer spacing of the Ti₃C₂T_x and increased the pseudocapacitance. When the mass percentage of Bi₂O₃ and Ti₃C₂T_x was 30% (TB30), the specific capacity of TB30 was as high as 183 F g⁻¹ at a current density of 0.2 A g⁻¹, which was about 2.8 times that of Ti₃C₂T_x (TB0). Moreover, a typical asymmetric supercapacitor device assembled with TB0 as the positive electrode and TB30 as the negative electrode exhibited a high energy density of 3.92 W h kg⁻¹ and a maximum power density of 36 000 W kg⁻¹ and maintained 77.4% of the initial capacitance after 5000 cycles at a current density of 2 A g⁻¹. Therefore, the Bi₂O₃–Ti₃C₂T_x as the negative electrode of supercapacitor has broad application prospects in the field of energy storage.