Preparation and charging-discharging property of nano-microstructure Sn-C anode composites

Sn/C composites were synthesized via the anhydrous sol-gel method united with high temperature carbon thermal reduction method as a lithium battery of high reversible capacity anode. The morphology and granulometric distribution of the Sn/C composites were controlled by adjusting Sn/C ratio and the heating schedule during carbon thermal reduction. Physical and electrochemical properties were investigated by XRD, EDS, SEM, potential-sweep cyclic voltammetry, and galvanostatic charge and discharge tests. The results show that nano-scale Sn particles disperse evenly in a carbon matrix and form a kind of nano-micron structure when the mass ratio of the stannic oxide and phenolic resin is 80: 20 at the reduction temperature of 800 °C. The Sn/C composite exhibits an initial reversible capacity of 637.9 mAh/g at first cycle, decays to a stable value of 372.5 mAh/g after 30 cycles, and coulomb efficiencies of 97% are obtained after the first cycle at constant current density of 100 mA/g.