Reconstructing 2D metallic Sn4P3 with high-conductive interlayer towards high-rate lithium storage

Abstract

Lithium-ion batteries are extensively utilized in various applications but face challenges in terms of anode performance. Commercial graphite possesses a low theoretical capacity of mAh g−1, which falls short of the desired performance. Alternatively, tin phosphide (Sn4P3) possesses a remarkable theoretical capacity of 1230 mAh g−1, making it a highly promising candidate. However, Sn4P3, being a semiconductor, faces challenges such as poor conductivity as well as substantial volume expansions during the lithiation–delithiation process. Herein, we fabricated a 2D Sn4P3 nanocomposite with high-conductive-interlayer via a breaking-reconstructing strategy. In this process, the 2D Sn4P3 layers were first achieved by a liquid-exfoliation method, revealing their unique metallic properties by density-functional-theory calculations. Besides, the 2D conductive-interlayer Sn4P3 demonstrated good electrochemical performance, including high reversible capacity, stable cyclic life, and high-rate capabilities. Alternating current impedance spectroscopy analysis further revealed that low charge-transfer resistance and a high lithium ion diffusion coefficient, contributing to the enhanced electrochemical performance. These findings demonstrate the significance of exfoliating Sn4P3 into layered structures and highlight the potential of 2D conductive-interlayer Sn4P3 nanocomposites as promising candidates for high-performance anodes.