Solvothermal preparation of spherical Bi 2 O 3 nanoparticles uniformly distributed on Ti 3 C 2 T x for enhanced capacitive performance.

Ti 3 C 2 T x is a promising new two-dimensional layered material for supercapacitors with good electrical conductivity and chemical stability. However, Ti 3 C 2 T x has problems such as collapse of the layered structure and low pseudocapacitance. In this paper, we propose Bi 2 O 3 -Ti 3 C 2 T x nanocomposites prepared by a solvothermal method, study the impact of Bi 2 O 3 loading on the phase state and microstructure, and evaluate the electrochemical performance of Bi 2 O 3 -Ti 3 C 2 T x . Studies have shown that spherical Bi 2 O 3 particles were uniformly dispersed in the interlayer and surface of Ti 3 C 2 T x , which enlarged the interlayer spacing of the Ti 3 C 2 T x and increased the pseudocapacitance. When the mass percentage of Bi 2 O 3 and Ti 3 C 2 T 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 Ti 3 C 2 T 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 Bi 2 O 3 -Ti 3 C 2 T x as the negative electrode of supercapacitor has broad application prospects in the field of energy storage.