Intrinsic electrochemical activity of Ni in Ni3Sn4 anode accommodating high capacity and mechanical stability for fast-charging lithium-ion batteries

초록

Fast interfacial kinetics derived from bicontinuous three-dimensional (3D) architecture is a strategic feature for achieving fast-charging lithium-ion batteries (LIBs). One of the main reasons is its large active surface and short diffusion path. Yet, understanding of unusual electrochemical properties still remain great challenge due to its complexity. In this study, we proposed a nickel–tin compound (Ni3Sn4) supported by 3D Nickel scaffolds as main frame because the Ni3Sn4 clearly offers a higher reversible capacity and stable cycling performance than bare tin (Sn). In order to verify the role of Ni, atomic-scale simulation based on density functional theory systematically addressed to the reaction mechanism and structural evolution of Ni3Sn4 during the lithiation process. Our findings are that Ni enables Ni3Sn4 to possess higher mechanical stability in terms of reactive flow stress, subsequently lead to improve Li storage capability. This study elucidates an understanding of the lithiation mechanism of Ni3Sn4 and provides a new perspective for the design of high-capacity and high-power 3D anodes for fast-charging LIBs. © 2022

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