Electrochemical Study of Lithium Ion Cells Using LiMn2O4 as the Cathode and Carbon Nanotubes as the Anode for Different Binder Combinations
Lithium-ion batteries have been widely used as a key alternative in the advancement of new energy generation and storage technologies. However, some of their features can still be improved. Nanostructured electrode materials are at the forefront of research in the field of energy storage, showing superior performances, higher energy, power densities, and a more significant number of charge-discharge cycles. In this work, electrochemical reversibility studies were carried out through the cyclic voltammetry technique applying the Nicholson and Shain criteria in a cell constructed from an anode of multi-walled carbon nanotubes (MWCNT) and lithium tetraoxomanganate(VI) (LiMn2O4) as the cathode, using lithium tetrafluoroborate (LiBF4) as support electrolyte dissolved in propylene carbonate and an Ag/AgCl reference electrode. The products were also characterized by Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), and X-ray Diffraction (XRD) analysis. Combinations of binders were used in the composites to improve the electrical conductivity in the electrodes, the mechanical properties, and the reversibility process. The electrochemical characterization reported the existence of a pair of characteristic anodic and cathodic peaks associated with the intercalation/deintercalation process of lithium ions at the electrode/electrolyte interface, expected behavior in Li-ion cells. Results showed that combinations of 70% LiMn2O4/25% Carbon (C)/5% polytetrafluoroethylene (PTFE) for the cathode material and 90% MWCNT/10% PTFE at the anode presented optimal results both for the intercalation and deintercalation of lithium, as well as for the adherence of the composite.