Solvothermal preparation of spherical BiO nanoparticles uniformly distributed on TiCT for enhanced capacitive performance.

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