Enhancing Ultrafast Lithium Ion Storage of Li4Ti5O12 by Tailored TiC/C Core/Shell Skeleton Plus Nitrogen Doping

It is of great importance to reinforce electronic and ionic conductivity of Li4Ti5O12 electrodes to achieve fast reaction kinetics and good high-power capability. Herein, for the first time, a dual strategy of combing N-doped Li4Ti5O12 (N-LTO) with highly conductive TiC/C skeleton to realize enhanced ultrafast Li ion storage is reported. Interlinked hydrothermal-synthesized N-LTO nanosheets are homogeneously decorated on the chemical vapor deposition (CVD) derived TiC/C nanowires forming binder-free N-LTO@TiC/C core-branch arrays. Positive advantages including large surface area, strong mechanical stability, and enhanced electronic/ionic conductivity are obtained in the designed integrated arrays and rooted upon synergistic TiC/C matrix and N doping. The above appealing features can effectively boost kinetic properties throughout the N-LTO@TiC/C electrodes to realize outstanding high-rate capability at different working temperatures (143 mAh g(-1)/10 C at 25 degrees C and 122 mAh g(-1)/50 C at 50 degrees C) and notable cycling stability with a capacity retention of 99.3% after 10 000 cycles at 10 C. Moreover, superior high-rate cycling life is also demonstrated for the full cells with N-LTO@TiC/C anode and LiFePO4 cathode. The dual strategy may provoke wide interests in fast energy storage areas and motivate the further performance improvement of power-type lithium ion batteries (LIBs).