electrode material

Nitrogen-doped carbon was derived from sorghum press cake following hydrothermal treatment. (SBET being 2668 m2 /g). Hydrothermal synthesis with thiourea was used to prepare NC_CoS and NC_NiS composites. SEM, N_2 adsorption and Raman spectroscopy revealed that Co forms a crystalline sulfide phase which is spread uniformly on the carbon network, whereas Ni yields an amorphous or highly dispersed sulfide. Electrochemical tests in 1 M of KOH showed that NC_CoS has a specific capacitance of 115 F/g at 1.3 A/g and retains 72% after 3500 cycles.

The optimal conditions for the synthesis of Na4Nb8P4O32 were found and the phase composition, morphology and electrochemical properties were studied in this work. The effect of the temperature and the synthesis time on the phase composition of Na4Nb8P4O32 were shown. According to the X-ray phase analysis data the optimal synthesis conditions were 900°C and 2.5 hours. The values of ionic and electronic conductivity were 2.7 · 10−7 S/cm and 6.1 · 10−6 S/cm, respectively.

In this paper we investigated the possibility of using of the planning of the multifactor experiment technique to optimize conditions of the solid phase synthesis of the cathode material LiFePO₄/C. Parameters of optimization were the carbon content in the samples, the temperature and duration of synthesis; response function – the value of the initial discharge capacity of the electrode. A polynom bounded by linear members was obtained.

УДК 541.136

DOI:  https://doi.org/10.18500/1608-4039-2016-16-3-100-121