Y_(2)O_(3)modification on nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)with improved electrochemical performance in lithium-ion batteries

Doping and coating are frequently employed for the improvement of the properties of Ni-rich NCM materials.In this work,we prepared stable LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)materials modified withY_(2)O_(3)via a wet chemical method.In order to investigate the action mechanism ofY_(2)O_(3)on NCM811,we analyzed the micro structures using X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).Also,to study the electrochemical performances,we conducted a charge/discharge test and cyclic voltammetry.Our results show thatY_(2)O_(3)modified NCM811 materials have good thermal stability,and proper content ofY_(2)O_(3)can effectively prevent the materials from damaging and significantly improve the electrochemical properties of the materials.Particularly,1%Y2 O3 modified NCM811 material show much better cycling performance than other samples.During cycling at 1.0 C the 1%Y2 O3 modified NCM811 shows capacity retention of 90.1%after 100 cycles,which is higher than 69.4%for pristine NMC811.We examined the microstructures of the materials before and after circulation.Using the SEM results,we conclude that structural changes are among the key factors that lead to the degradation of the electrochemical properties of materials.