Prospects for using silicene as an anode for lithium-ion batteries. A review

A single-layer silicon material with a honeycomb structure, called silicene, has been successfully produced by deposition onto certain metallic and non-metallic substrates, typically under high vacuum conditions. This twodimensional material has a number of unique properties that open up expanded possibilities for its application. This review discusses recent molecular dynamics and first-principles calculations regarding the use of silicene as a lithium-ion battery anode material. The strength characteristics and morphological properties of functional single- and two-layer silicene anodes, in which silicene is supported by Ag, Ni, Cu, Al, graphite and SiC thin layers, were calculated. The capacitances of the electrodes under consideration, the distribution of mechanical stresses associated with lithiation, the length and bond energy between atoms, the adhesion energy between silicene and the substrate as well as that between lithium medium and silicene, were determined. Open-circuit voltages and electronic properties of combined silicene anodes, such as band structure, partial spectrum of electronic states, and electrical charge redistribution between subsystems were established. An increase in the anode productivity was discovered when point defects in the form of mono- and bivacancies were created in silicene. Based on the calculated operational characteristics of the electrode, a conclusion is made about the advisability of using it as an anode is lithium-ion batteries. Estimates generally show no less than a threefold increase in the productivity of silicene anodes compared to the currently used graphite anodes. The problems and prospects for using silicene anodes are pointed out.