FUNCTIONAL MATERIALS BASED ON HARD CARBON DOPED WITH MOLYBDENUM: PREPARATION AND CHARACTERIZATION

Hard carbon is one of the most promising candidates for a negative electrode material for sodium-ion batteries. Now, the design and adaptation of methods for producing hard carbon have gained wide attention in terms of not only ensuring the required electrochemical performance but also reducing production costs and expenses. Herein, we report a method for preparing new functional materials based on hard carbon doped with molybdenum. A viscose was used as a carbon precursor because of its low cost and availability, which made it possible to scale the technology. An ammonium molybdate aqueous solution was applied as the molybdenum source. The synthesis involves following main steps: impregnation of the fiber with a solution of ammonium molybdate and annealing at high temperatures under controlled atmosphere. The study investigates the effects of the type of initial viscose raw material (microfiber, technical thread, non-woven material), molybdenum content (Mo/C weight ratio varied in the range up to 5.1%), temperature (up to 1050 °C), and annealing atmosphere (argon or nitrogen) on the structural parameters, specific surface area, and yield of hard carbon products. The doped hard carbon has an almost 10% higher yield in comparison with the undoped one. It was shown that doping with molybdenum, due to the catalytic effect, stimulates the growth and ordering of graphite-like nanoclusters under the temperature, inducing the structure formation of hard carbon. This leads to a decrease in the temperature of hard carbon production as compared to analogues. It was found that changing the specific surface area with temperature depends on the molybdenum content. The lowest values of specific surface area were found for doped samples synthesized at 1050 °C. For citation: Saenko N.S., Zheleznov V.V., Mayorov V.Yu., Opra D.P. Functional materials based on hard carbon doped with molybdenum: preparation and characterization. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 10. P. 122-130. DOI: 10.6060/ivkkt.20246710.7019.