Effects of sonication power on electrochemical performance of ZrO 2 -decorated LiMn 2 O 4 cathode material for LIBs

The LiMn 2 O 4 (LMO) powder is decorated with ZrO 2 (denoted as Zr@LMO) particles by using sonication-assisted sol–gel method. Different sonication powers (10, 30 and 50%) are used to disperse ZrO 2 and the effects of ZrO 2 distribution at LiMn 2 O 4 ’s electrochemical performance are analysed. Scanning electron microscopy and energy dispersive spectroscopy analyses have been made on laminated samples. For the structural analyses of particles, X-ray diffractometer is used. Electrochemical performances of electrodes are tested with galvanostatic measurements, cyclic voltammograms and electrochemical impedance spectroscopy. The ZrO 2 distribution ratio on the particle surfaces is improved by 10% with the increase of sonication power from 10 to 50%. Therefore, at 50% sonication power, lower charge transfer resistance and side reactions (Mn dissolution) are accomplished, which leads to 41 and 9% specific capacity increase compared to pure and the lowest sonication power, respectively. After 100 cycles at 0.1C, 93.2 mAh g –1 specific discharge capacity and 73.4% capacity retention are attained for ZrO 2 -decorated LMO at 50% sonication power. Furthermore, at 2C rate, the specific discharge capacity of the decorated sample at 50% sonication power is 59% higher than the pure LMO. Graphic abstract