A facile approach to enhance high-cutoff voltage cycle stability of LiNi0.5Co0.2Mn0.3O2 cathode materials using lithium titanium oxide

Abstract Ni-based layered LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM) compounds coated with lithium titanium oxide for lithium ion batteries were successfully achieved through a simple solid state synthesis process using TiO 2 powder and CH 3 COOLi. Systematical measurements in structure, morphology and electrochemical properties have been applied. X-ray diffraction patterns showed the existence and conversion of lithium titanium oxide (Li 4 Ti 5 O 12 and Li 7 Ti 5 O 12 are labeled as LTO). A coating layer in the form of LTO could be observed and the thickness was approximately 10 nm with uniform distribution. Similarly, XPS was performed to confirm the existence of LTO. 1.0  wt .% LTO-coated NCM material exhibited higher capacity retentions of 91.0% than that of the bare one (64.3%) after 100 cycles at cutoff voltages of 4.5 V. Meanwhile, the LTO-coated NCM material showed significantly improved thermal stability compared with the pristine sample at an elevated 60 °C. In addition, it has proved that it is effective to enhance the electrochemical performances of electrodes by LTO modification.