Cr-doped Li2MnSiO4/carbon composite nanofibers as high-energy cathodes for Li-ion batteries

Abstract

Li2MnSiO4 with an extremely high theoretical capacity of 332 mA h g−1 has recently gained tremendous interest. However, only around half of this capacity has been realized in practice and the cycling performance is also poor due to the low intrinsic conductivity and unsatisfactory structure stability. In this study, Li2Mn(1−x)CrxSiO4/carbon composite nanofibers are prepared by the combination of electrospinning and Cr doping. The electrospinning process leads to the formation of a conductive carbon nanofiber matrix, which provides fast ion transport and charge transfer. Cr doping further improves crystal structure stability by increasing the unit cell volume and inducing defects in the lattice. The resultant Li2Mn(1−x)CrxSiO4/carbon composite nanofibers exhibit a high discharge capacity of 314 mA h g−1 at the 5th cycle and stable cycling performance.