The LiMn$_2$O$_4$ (LMO) powder is decorated with ZrO$_2$ (denoted as Zr@LMO) particles by using sonicationassisted 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.