Solvothermal preparation of spherical Bi₂O₃ nanoparticles uniformly distributed on Ti₃C₂T for enhanced capacitive...

Ti₃C₂T is a promising new two-dimensional layered material for supercapacitors with good electrical conductivity and chemical stability. However, Ti₃C₂T has problems such as collapse of the layered structure and low pseudocapacitance. In this paper, we propose Bi₂O₃-Ti₃C₂T 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 . Studies have shown that spherical Bi₂O₃ particles were uniformly dispersed in the interlayer and surface of Ti₃C₂T , which enlarged the interlayer spacing of the Ti₃C₂T and increased the pseudocapacitance. When the mass percentage of Bi₂O₃ and Ti₃C₂T 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 (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 as the negative electrode of supercapacitor has broad application prospects in the field of energy storage.