Boron-doped single crystal LiNi0.6Mn0.2Co0.2O2 with improved electrochemical performance for lithium-ion batteries

Single crystal boron-doped LiNi0.6Mn0.2Co0.2O2 cathode material with excellent electrochemical properties were synthesized in the study. X-ray diffraction revealed that boron doping promoted the unit cell expands along the c-direction which was conductive to improving the kinetic of lithium-ion transmission. Electrochemical tests showed that boron-doped cathode material exhibited remarkable improvement in cycling performance and rate capability compared to bare sample. After 50 cycles at 1.0 C, the boron-doped sample delivered 176.3 mAh g−1 with a retention of 96.1%, which was much higher than that of the undoped sample of 167.8 mAh g−1 with a retention of 90.7%. The highly ordered layered structure and improved structure stability during repeated intercalation/deintercalation of lithium ions were responsible for the enhanced electrochemical performance. Besides that, the unique single crystal morphology resulted in even faster lithium-ion transportation as a result of small particle size. Both the doping effects of boron and single crystal particles contributed to the excellent electrochemical performance of the doped cathode materials.