Preparation And Electrochemical Properties Of MnCO₃-C Composite Materials

With the increasing demand for electric vehicles,the development of lithium-ion batteries with higher energy density and lower cost has become a research hotspot in the field of electrochemical.Transition metal carbonate is considered as a potential anode material due to its high specific capacity,simple preparation process and low cost.MnCO₃ with various morphologies such as spherical and bayberry-like shapes were synthesized by solvothermal method with sodium citrate as the morphology guide agent.The MnCO₃ was successfully grown on CNT and Cp to form the 3D networked MnCO₃-C composite via the in-situ hydrothermal method.The crystal structure,microstructure,pore size distribution and electrochemical properties of materials were characterized by XRD,FE-SEM and constant current charge discharge test.Compared with other morphologies,multi-branched microspherical MnCO₃ has better electrochemical performance,which delivers a reversible specific capacity of 66 m Ah g^-1 at100 m A g^-1 over 100 cycles.And the discharge specific capacities of it are 443.5?40.5?332.3 m Ah·g^-1 at current densities of 0.1A g^-1,1A g^-1and 0.1A g^-1.The broom like MnCO₃-DWCNT composites was prepared with the condition of180?/18 h,which maintains a reversible specific capacity of 494.7 m Ah·g^-1 at a current density of 100 m A·g^-1 after 100 cycles.And the discharge specific capacities of it are 637.3?187.9 and 489.7 m Ah·g^-1 at current densities of 0.1A g^-1,1A g^-1and 0.1A g^-1.The mesoporous spindle MnCO₃-Cp composites was prepared with the condition of180?/18 h,which presents a discharge specific capacity of 514.6 m Ah·g^-1 at a current density of 100 m A·g^-1 after 100 cycles.And the discharge specific capacities of it are 931.9?550.5 and 910.1 m Ah·g^-1 at current densities of 0.1A g^-1,1A g^-1and 0.1A g^-1.The improvement of the electrochemical properties of the composites is attributed to the higher conductivity and network structure of Cp and CNT,which can provid more reactive sites and inhibit and buffer the agglomeration and volume effect of MnCO₃.Figure 51;Table 2;Reference 106...