Features of improved capacity at high discharge rate of K-doped Li-rich cathodes for LIBs

Abstract

Li-rich oxides are one of the most promising cathode materials for the new generation of lithium-ion batteries (LIBs). This work describes the preparations of Li-rich cathode materials with composition Li1.20Ni0.13Co0.13Mn0.54O2 and the potassium – doped material Li1.15K0.05Ni0.13Co0.13Mn0.54O2. The oxides are synthesized from acetates of metals by sol-gel synthesis followed by high-temperature annealing. All materials are characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) with elemental analysis by EDX and elemental mapping. We also measure granulometric compositions of the powders by laser particle size analyzer. The samples were tested as cathode material in half-cells with lithium metal as the anode. The results of these electrochemical tests are presented in the article. Potassium – doped Li-rich oxides show more than 260 mAh/g discharge capacity, at current rate 0.1C and higher discharge capacity after increasing discharge current.