Electrochemical Performance of GeO₂/C Core Shell based Electrodes for Li-ion Batteries
By Ngo, Duc Tung; Kalubarme, Ramchandra S.; Chourashiya, M.G.; Park, Choong-Nyeon & Park, Chan-Jin
Published in Electrochimica Acta
2014
Abstract
In the present study, a nanocrystalline GeO₂/C core shell was synthesized by a cost-effective and simple citric-gel method for various parameters, and the effects of these parameters on the microstructural and electrochemical properties of the GeO2/C core shell were investigated. Thermo-gravimetric-analysis showed that the combustion of gel-complexes occurred in the temperature range from 178 to 247 °C. Among the samples pre-heated at 150 °C, the sample pre-heated for 4 h had the highest surface area (11.12 m2 g⁻¹ particle size ~ 30 nm). TEM analysis revealed that the citric-gel synthesized GeO₂ was encapsulated with carbon. This carbon encapsulation acted as a critical buffer layer against capacity degradation in the fabricated electrodes. The optimized sample showed a specific capacity of 738 mA h g⁻¹ and maintained its reversibility after 50 cycles at a capacity of 697 mA h g⁻¹. The electrode containing the optimized sample showed a reversible capacity of 530 mA h g⁻¹ at 1 C rate