A straightforward, efficient, and environmentally friendly lithium storage tactic: solventless fabrication of N/S co-doped SiOx/C with carbon encapsulation

Abstract

A large body of research shows that reducing the particle size and applying carbon coatings can enhance the electrochemical performance of SiO_x-based anodes considerably. However, improving ionic and electronic conductivity within the active material through surface conditioning remains challenging. Doping can moderately improve the electronic conductivity and ion transport by altering the microstructure of active substances. However, traditional doping methods often rely on solvents, making it a struggle to achieve both environmental friendliness and high efficiency. This work presents a novel solvent-free doping technique, resulting in N/S-BM-SiO_x/C@C-2 (NSBMSCC-2). The incorporation of nitrogen and sulfur heteroatoms enhances the migration of Li⁺ and electrons, stimulates the electrochemical activity of the anode material, and expedites the lithiation/delithiation process. The NSBMSCC-2 anode boasts a quality reversible specific capacity (1289 mA h g⁻¹), high initial coulombic efficiency (74.2%), and outstanding durability (595 mA h g⁻¹ at 2 A g⁻¹ after 600 cycles with a capacity retention of 96.1%). This strategy not only broadens the doping techniques but also serves as a reference for the industrial application of silicon oxide, owing to its simplicity, environmental sustainability, and effectiveness.