The Research On Nano SnO₂ Anode Material For Lithium-ion Batteries

The structure and electrochemical performances of Nano Tin oxide fine particles used as the anode materials of lithium-ion batteries were studied in this paper by X-ray Diffraction (XRD) , Scanning Electron Microscope(SEM) , Transmission Electron Microscope(TEM), Cyclic Voltammetry(CV), Electrochemical Impedance Spectra(EIS) and Constant Current(CC). The influential factors of the fabrication technique of coin cells were also investigated using CMS as the anode materials.The SEM and TEM shows the dimension of granule was 30nm and uniformly dispersed.Using SnO₂ nano particals as active material, prepared the anode of lithium-ion batteries by casting. The impact of different kinds of binders and conductive additives were investigated by testing the performances of half-cells (Li metal | membrane (organic electrolyte) | SnO₂ anode). The first discharge-charge capacity,coulomb efficiency in the first cycle and interface impedance in different conditions were compared at different mass ratio, and the electric properties were also discussed.The results showed that adding acetylene black can reduce the inner resistance, ameliorate the conductivity, improve the reversible capacity in the first cycle of the half-cells.Applying aqueous binder in SnO₂ anode can get a good performance in half-cells, when the content reaches 5%, best integrate properties can be got, and Aqueous binder (latex) could be a good substitution of PVDF.Testing under different currents, After optimizing the formulation, testing the integrative electrochemical properties.The the SnO₂ nano particals with minor granule dimension and high specific surface area had high specific capacity of 909 mAh/g which was twice higher than CMS and high coulomb efficiency of 65.4% in the first cycle, The CV testing showed, the insert and disengage potential of SnO₂ is 0.35V and 0.5V, respectively.When the charge-discharge voltage range is 0.01～1.0V, the cells'capacity holding ability can keep 83.3% after 20 cycles. As the increasing of charge-discharge current, the charge-discharge capacity decrease.The SnO₂ nano particals had the best cycling performance at 0.01～1.0V voltage range and 0.5C rate charge-discharge current.The electron processes under different charge conditions were analysised by EIS.But the SnO₂ nano particals had poor performance in cycling,which affected the application in lithium-ion batteries.