Blow-Spinning Enabled Precise Doping and Coating for Improving High Voltage Lithium Cobalt Oxide Cathode Performance

Lithium cobalt oxide (LiCoO2) possesses an attractive theoretical specific capacity (274 mAh g-1) and high discharge voltage (~4.2 V vs. Li+/Li). However, only a half of theoretical capacity of LiCoO2 is available in commercialized lithium-ion battery because of the intrinsic structural instability and detrimental interface of LiCoO2 at the charging voltage over 4.2 V. Here, a facile blow-spinning synthetic method is developed to realize precise doping and simultaneous self-assembly coating of LiCoO2 particles, with achieving a record performance among present LiCoO2 cathodes. Owing to the spatial confinement effect of microfibers fabricated by blow-spinning, homogeneously Mn and La doped and uniformly Li-Ti-O segregated at LiCoO2 surface can be obtained in every batch samples. It is demonstrated that the Mn and La co-doping can suspend the intrinsic instability and increase the Li+ diffusivity of the LiCoO2 host, and the Ti-based coating can stabilize the interface of LiCoO2 particles at the charging vol...