E. Iwuoha, M. Ndipingwi, C. Ikpo
University of the Western Cape Sensor Laboratories,
Keywords: lithium ion migration, orthorhombic lithium manganese silicate, quantum dot, supercapattery efficiency
Summary:Hydro-thermally synthesized nanocomposite of lithium manganese silicate-alumina (LMSA) was prepared for application as the positive electrode for supercapattery. Small angle X-ray scattering spectroscopic analysis depicted the presence of predominantly 7 nm center-to-center LMSA nanoparticles. The quantum dot size particles of the electrode material resulted in large surface area which enhanced the migration of Li ions and the efficiency of charge storage and consequently, improved the electrochemical performance of the supercapattery. Solid state nuclear magnetic resonance and X-ray diffraction spectroscopic interrogations pointed to an orthorhombic crystalline phase of the LMSA nanocomposite materials, which as expected provided a good migratory pathway for the Li ions. The LMSA supercapattery cell produced a maximum specific power and maximum specific capacitance values of 4020.8 W/kg and 141.5 F/g, respectively. It exhibited excellent cyclic stability with a capacitance retention value of 93.6% after 1000 cycles. Thus, LMSA nanocomposite showed much promise as a material for advanced supercapattery.