Theoretical studies of SiC van der Waals heterostructures as anodes of Li-ion batteries

• Published in: Applied surface science Vol. 563; p. 150269
• Main Authors: He, Xiaojie, Tang, Anwen, Li, Yi, Zhang, Yongfan, Chen, Wenkai, Huang, Shuping
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-10-2021
• Subjects: 2D-SiC; Anode materials; Density functional theory; Graphene-based heterostructures; Li-ion batteries; Density functional theory; 2D-SiC; Graphene-based heterostructures; Li-ion batteries; Anode materials
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2021.150269

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•2D SiC, defective SiC and their heterostructures were used as anodes for LIBs.•2D SW-SiC and heterostructures have better conductivity and lithiation abilities.•Heterostructures exhibit stable OCV and superior theoretical capacity.
By using density functional theory (DFT), the potential of two dimensional SiC, SiC with Stone-Wales defect (SW-SiC) and their van der Waals heterostructures with graphene (SiC/graphene and SW-SiC/graphene) as anode materials have been investigated, including corresponding geometry structural changes, electronic structures, Li+ diffusion property and related electrochemical properties during charging. Comparing with SiC monolayer, SW-SiC possesses better electric conductivity as well as the Li adsorption properties. By introduction of graphene, SiC/graphene and SW-SiC/graphene heterostructures present excellent electronic conductivity, lower anode voltage and higher specific capacity for the introduction of build-in electric field. Their maximum theoretical capacity both could reach as high as 1229.91 mAh/g, three times more than that of graphite (370 mAh/g), along with a small change of interlayer spacing. The lithiation open-circuit voltage ranges of those heterostructures are also appropriate to be used as anode materials. Besides, the calculated diffusion barriers of Li ions in the interlayer of SiC/graphene and SW-SiC/graphene heterostructures are comparable to those of several graphene heterostructures and are lower than that for SW-SiC. This research illustrated that the deployment of heterojunction in electrode materials can greatly improve the electrochemical performance and endow experimental synthesis with new perspective.