Silicon–carbon–nitrogen material (SiCN) is pyrolyzed from polysilylethylenediamine (PSEDA) derivation, followed by a heat-treating process at 1000 °C in Ar atmosphere. This heat-treated SiCN material has an excellent electrochemical performance as an anode for lithium ion batteries. Charge–discharge cycle measurements show that the heat-treated SiCN material exhibits a high first cycle discharge capacity of 829.0 mAh g−1 and stays between 400 and 370 mAh g−1 after 30 cycles. The discharge capacity remains above 300 mAh g−1 at the high current density of 80 and 160 mA g−1. These values are higher than untreated SiCN and commercial graphite anodes, which indicates that the heat-treating process improves the charge–discharge capacity, cycle stability and high-rate ability of SiCN anode. It is seemed that changes of SiCN structure, the formation of loose nano-holes on material surface and the formation of graphitic carbon phase in heat-treating process contribute to the improvement of electrochemical properties for SiCN anode.

LiFePO4-MWCNTs (multi-walled carbon nanotubes) composite cathode materials were prepared by mixing LiFePO4 and MWCNTs in ethanol followed by heat-treatment at 500 °C for 5 h. The structural, morphology and electrochemical performances of LiFePO4-MWCNTs composite materials were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), galvanostatic charge–discharge cycle tests, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results indicated that MWCNTs adding improved the electronic conductivity, the discharge capacity, cycle stability and lithium ion diffusion kinetics of LiFePO4, but MWCNTs adding did not charge the orthorhombic olivine-type structure of LiFePO4. In all these prepared LiFePO4 with x wt.% MWCNTs (x = 4, 7, 10) composites, 7 wt.% MWCNTs adding composite cathode shows the best electrochemical performance, which gets an initial discharge capacity of 152.7 mAh g−1 at 0.18 C discharge rates with capacity retention ratio of 97.77% after 100 cycles.

FeB and MgNi–FeB composite were both prepared by mechanical alloying (MA) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), charge–discharge cycles, Tafel polarization, electrochemical impedance spectroscopy (EIS), potentiostatic polarization and linear polarization were carried out to evaluate the effect of FeB on the structural and electrochemical characteristics of MgNi alloy. The results indicated that FeB doping improved the cycle stability of MgNi. The MgNi–FeB (weight ratio 100:15) composite which was MA 15 h exhibited the best electrochemical characteristics. After 100 charge–discharge cycles, the discharge capacity of this composite electrode was above 210 mA h g−1, and the capacity retention was 60.62%, which was much higher than that of MgNi. FeB doping also improved the anticorrosion, the electrochemical kinetic properties and the high rate performance of MgNi.