Thin-Layer LiMn2O4, Carbon Nanotubes Composite Electrodes in Lithium Prototype Accumulator

Abstract

The analysis of electrochemical and impedance characteristics of thin-layer composite LiMn2O4 spinel, carbon nanotubes (CNT)-electrodes in redox reaction with lithium was provided to gain a better discharge characteristics at long cycling and low temperature. The comparison of parameters of impedance spectra (IS) for LiMn2O4, CNT-electrodes in contact with electrolyte and also conductivity of pressed LiMn2O4 spinel, its pressed composites with CNT and electro conductivity of electrolyte (1 mole-l LiClO4, ethylencarbonate, dimethylcarbonate) on dependence temperature and composite mass was performed. It was established undoubted contribution of transfer processes in Solid electrolyte interface (SEI) film of composite, electro conductivity of composite in efficiency of electrochemical performance of spinel composite at low temperatures. Activation energy of Li+-diffusion in LiMn2O4 composite volume exceeds one of migration of ions in SEI film and of charge transfer through phase boundary at room temperatures. Key role in decreasing of discharge characteristics of LiMn2O4 spinel composition with CNT at low temperatures and long cycling due to charge transfer through SEI film /spinel composite interface complicated by diffusion Li+ in composite volume which resistance rises in the most extensively measure than other parameters. Electrolyte of 1 mole l-1 LiClO4, ethylencarbonate, dimethylcarbonate is not recommended use for effective performance of LiMn2O4 spinel, CNT-composite in redox reaction with lithium at low temperatures and it is need its substitution. Improvement of low temperature discharge characteristic of spinal composite in further may be attaining by optimization of its perspective Co-doping.