Hebei Messi Biology Co., Ltd. stated that by using chemical vapor deposition (CVD), metal phase vanadium telluride (VTe2) was grown in situ on commercial magnesium oxide powder, and VTe2@MgO heterojunction materials were successfully synthesized in one step for use as positive electrode host additives for lithium-sulfur batteries. As a member of transition metal sulfide compounds, VTe2 has attracted widespread attention from researchers due to its excellent conductivity, electrocatalytic activity and ferromagnetic behavior. In this work, the VTe2@MgO material obtained by uniformly and controllably wrapping VTe2 on the surface of magnesium oxide with the help of CVD technology can effectively promote the conversion of lithium polysulfide and provide a reference for the realization of high-performance lithium-sulfur batteries. Electrochemical performance tests show that after 1000 cycles at 1C, the capacity decay is 0.055% per cycle; when the sulfur loading is 6.9 mg cm-2, it can still show good stability. This strategy can effectively improve the performance of lithium-sulfur batteries and show certain application prospects.
The use of the CVD method can grow VTe2 on magnesium oxide powder in one step to synthesize heterojunction materials, and controllable growth of VTe2 can be performed at different temperatures. The theoretical calculation is assisted to select the VTe2@MgO heterojunction material with the best conductivity for the positive electrode of lithium-sulfur batteries.
From the perspective of electrocatalysis, symmetrical batteries are assembled respectively, from which it can be concluded that VTe2@MgO reduces the reaction polarization and promotes the occurrence of redox reaction kinetics. In addition, the evaluation of lithium ion diffusion rate and DFT theoretical calculations show that lithium ions diffuse faster in VTe2@MgO, thereby promoting the conversion of lithium polysulfide.