Abstract
The need for the higher specific capacity and relatively lower discharge voltage supercapacitor has become increasingly pressing. Although silicon is widely considered as the anode material, the factors affecting their actual are volume expansion and unstable SEI layer. Herein, it’s relatively new to report on the mechanism investigation of crystalline silicon during lithium storage via DFT and first-principles calculation, and calculations are performed to electrochemical lithiation of the perfect crystalline silicon and flawed silicon. In addition, the mechanistic problems including binding energy and average embed voltage and PDOS and charge density and volume change based on geometry and electronic structure were calculated and forecast. Moreover, from the aspects of atomic and electronic structure, this paper aimed at silicon-based anode materials to explore the primary mechanism of lithium intercalation and volume expansion. Indicating that the silicon-based nodes as the ideal candidate for next generation anode materials rely heavily on the thickness of the SEI layer and stable structure, which can effectively inhibit large volume expansion and structural damage, thus to improve the reversible capacity of supercapacitor.
