Self-supported hierarchical porous Li_(4)Ti_(5)O_(12)/carbon arrays for boosted lithium ion storage

摘要

The development of fast rechargeable lithium ion batteries(LIBs)is highly dependent on the innovation of advanced high-power electrode materials.In this work,for the first time,we report a sacrificial NiO arrays template method for controllable synthesis of self-supported hierarchical porous Li_(4)Ti_(5)O_(12)/C(LTO/C)nanoflakes arrays,for use as fast rechargeable anodes for LIBs.The ultrathin(2-3 nm)carbon layer was uniformly coated on the LTO forming arrays architecture.The hierarchical porous LTO/C nanoflakes consisted of primary cross-linked nanoparticles of 50-100 nm and showed large porosity.Because of the enhanced electrical conductivity and accelerated ion transfer channels,the well-designed binderfree porous LTO/C nanoflakes arrays exhibited notable high-rate lithium ion storage performance with smaller polarization,better electrochemical reactivity,higher specific capacity(157 mAh g^(-1) at the current density of 20C)and improved long-term cycling life(96.2% after 6000 cycles at 20C),superior to the unmodified porous LTO arrays counterpart(126 mAh g^(-1) at 20C and 88.0%after 6000 cycles at 20C).Our work provides a new template for the construction of high-performance high-rate electrodes for electrochemical energy storage.