Layered lithium-rich cathode materials synthesized by an ethanol-based one-step oxalate coprecipitation method

We synthesized layered lithium-rich cathode materials by a novel ethanol-based one-step oxalate coprecipitation method. Using this method, all the elements including lithium could be coprecipitated during the coprecipitation reaction process to realize a homogeneous mixture of lithium and transition metal elements. In addition, compared with the conventional ammonium oxalate coprecipitation method, the precursor preheating process was eliminated, which should decrease reaction time and cost. X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical measurements were used to investigate the differences in the crystal structure, morphology and electrochemical performance of samples synthesized using the above two methods. Compared with the samples synthesized by the conventional ammonium oxalate coprecipitation method, samples prepared by our novel one-step oxalate coprecipitation method exhibit higher crystallinity with larger interlayer spacing, and smaller, more homogeneous particles. Such crystal structure and morphology endow the samples prepared by the oxalate coprecipitation method with better discharge capacity, cycle performance and rate performance than those synthesized by the conventional method. The simple, efficient coprecipitation method developed here may provide a new approach to fabricate layered materials for highperformance lithium-ion batteries.