Investigation of cathode material based on the LixLayMn1-yO2 system proposed as an electrode of lithium ion battery

Issue 24(3) 2019
Pages 56-65

E.S. Guseva, Engels Technological institute (Branch) of Saratov State Technical University named after Yu.A. Gagarin, Engels, Russian Federation

S.S. Popova, Engels Technological institute (Branch) of Saratov State Technical University named after Yu.A. Gagarin, Engels, Russian Federation


Keywords: electrochemical modification, intercalation, lithium, manganese dioxide, lithium, fullerene, lanthanum

http://www.doi.org/10.31615/j.corros.prot.2019.93.3-7

 

The creation of new effective ways to increase the capacitance characteristics of cathode materials for lithium-ion batteries (LIA) and enhance their electrical conductivity and chemical resistance to electrolyte by modifying their composition and structure is crucial in the field of electrochemical materials science. The studies were aimed at improving the electrochemical characteristics of LIA system Li/MnO2 by modifying MnO2 electrode by lanthanum, which contributes to the formation of additional vacancies for the movement of lithium ions in the structure of the cathode material and provides an increase in the density of the discharge current and duration of the discharge, improving the cyclability of the electrode. Not insignificant problem was to choose an anode with corrosion resistance to electrolyte during cycling. Inhibition of anode processes on the lithium anode, which actively interact with the electrolyte, reduces the life of the battery, due to the embrittlement of the electrode and further provokes a short circuit and the battery failure. Our chosen intermetallic compounds based on LaLiAl anode contributed to the inhibition of corrosion in the solution of aprotic electrolyte during сycling and stability of the electrode morphology. The influence of the magnitude of cathodic polarization and temperature of the solution of salicylate of lanthanum was studied on the kinetics of the formation of electrode LаyMn1-yO2. The composition of formed phases LixMnO2, LayMn1-yO2, LixLayMn1-yO2 was defined by the method of current-free chronopotentiometry. The stability of chemical compounds of lanthanum formed in the MnO2 electrode structure was established. The results of galvanostatic cycling showed that the discharge capacity of the electrodes increases in a number of: LixMnO2 > LixLayMn1-yO2 > LiхLayMn1-yO2-σ(C60)n. Using cyclic chronovoltamperometry a good reversibility of LiхLayMn1-yO2-σ(C60)n electrode was shown.