Boosting fast lithium ion storage of Li4Ti5O12 by synergistic effect of vertical graphene and nitrogen doping

Abstract

The advancement of power-type lithium ion batteries (LIBs) mainly depends on the construction of electrodes with superior electronic & ionic conductivity. In this work, a synergistic combination of nitrogen doped Li 4 Ti 5 O 12 (N-LTO) nanoparticles and highly conductive vertical graphene (VG) skeleton is proposed to obtain ultrafast Li ion storage performance via a facile hydrothermal-nitridation method. The as-synthesized composite nanosheets are composed of interconnected N-LTO shell and VG core to form the final N-LTO/VG core-shell arrays, which are systematically studied as the anodes of LIBs. In virtue of the positive synergistic effect of high conductive VG backbone and nitrogen doping, overwhelming advantages including high specific surface area, superb structural stability and enhanced conductivity are achieved in the well-designed N-LTO/VG electrodes. Accordingly, the as-synthesized N-LTO/VG electrode shows outstanding high rate capacity (142.5 mAh g −1 at 20 C) and superior long-term cycling stability (capacity retention of 98.9% after 10000 cycles at 5 C), better than LTO/VG electrode without N doping. Our research provides a new strategy for the synthesis of high-performance hybrid electrodes for application in power-type LIBs. N-doped Li 4 Ti 5 O 12 (N-LTO) are rationally anchored on highly conductive vertical graphene (VG) skeleton forming N-LTO/VG core-shell arrays and demonstrated with noticeable lithium ion storage performance with superior high-rate capability and good cycling stability.