Preparation And Application Research Of Tin-based Oxide As Negative Material Of Lithium Ion Battery

As lithium ion battery is developed as the most potential power source, lithium storage materials become a key issue in the research on lithium ion battery. In recent years,many new materials of high energy density used for replacing the carbon anode materials have been extensively studied, among which the tin-based anode material has attracted great attention.In this paper, SnO₂ precursor is synthesized by using the improved chemical precipitation method and orthogonal experiment to determine the optimum conditions of tin tetrachloride dropping rate, pH value, dispersant and further determine the optimal calcination conditions. Sequently Use liquid and vapor diffusion method to synthesize SnO₂/C (MCMB) composite material and determine the optimum synthesis conditions. To further enhance the initial Coulombic efficiency, rheological phase method and the carbon thermal reduction method are adopted to synthesize Sn/C (MCMB) composites. Surface morphology and crystal are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) techniques. Finally, constant current charge-discharge and cyclic voltammetry (CV) techniques are used for studying the materials'electrochemical properties includihng the reversible capacity, coulombic efficiency, cycle performance.The results show that SnO₂ particles in the SnO₂/C(MCMB) materials prepared by vapor diffusion approach are smaller and the compound materials are more uniform. The SnO₂/C(MCMB) materials present a better electrochemical performance and the reversible capacity is still up to 422.2 mAh·g^-1 after 40 cycles and the capacity retention rate is 81.1%. The initial discharge capacity of Sn/C (MCMB) composite is 508.5 mAh·g^-1, and the first Coulombic efficiency rises to 80.0%.