Au-doped Li1.2Ni0.7Co0.1Mn0.2O2 electrospun nanofibers: synthesis and enhanced capacity retention performance for lithium-ion batteries

Abstract

The Au-doped Li_1.2Ni_0.7Co_0.1Mn_0.2O₂ (Au = 0%, 1%, 2%, 3%, 4%) nanofibers are successfully prepared by electrospinning technology. The impact of Au doping on the structure, morphology and electrochemical properties of samples is studied in detail. The X-ray diffraction patterns demonstrate that appropriate Au-doping does not significantly change the structure of Li_1.2Ni_0.7Co_0.1Mn_0.2O₂. Scanning electron microscope images revealed the electrospun nanofibers have uniform particle size in the range of 300–400 nm. The optimum doping amount of Au is 2% in Li_1.2Ni_0.7Co_0.1Mn_0.2O₂ to obtain high discharge capacity and excellent capacity retention. Electrochemical impedance spectroscopy test results elucidated that the LNCMA-2% cell has excellent Li⁺ electrical conductivity and lower charge transfer resistance. The results show that stable structure with good particle contact of the Au-doped cathode materials can enhance electrochemical properties, which can be interpreted as an important inhibition of phase transitions and increased charge transfer impedance during cycling.