Synthesis and electrochemical Properties of porous CuNi2Sn/C Composites as High-Performance Lithium-Ion battery anodes

Abstract

Tin (Sn) possesses an outstanding theoretical capacity of 992 mAh·g⁻¹ in lithium-ion batteries, making it a promising anode material. However, its significant volume expansion during cycling can lead to severe electrode pulverization, thereby affecting battery cycling performance. In this study, porous SnO₂ was synthesized using calcium carbonate (CaCO₃) as a template, followed by template removal through pickling. The porous structure of SnO₂ exhibits excellent cyclic stability, as the voids within the material effectively mitigate Sn volume expansion, prevent material pulverization, and enhance lithium ion transport kinetics. Subsequently, Cu and Ni elements were introduced via coprecipitation and calcination processes to successfully synthesize porous CuNi₂Sn/C. Results demonstrate that after 50 cycles at a current density of 50 mA·g⁻¹, the specific discharge capacity still reaches 817.1 mAh·g⁻¹. Even under a high current density of 200 mA·g⁻¹, the material maintains a specific capacity of 455.1 mAh·g⁻¹ after 300 cycles. This is because the incorporation of Cu and Ni stabilizes the structure of the material, thereby improving the cyclic stability of the material.