Ultrathin Aluminum Nanosheets Grown on Carbon Nanotubes for High Performance Lithium Ion Batteries

Abstract

AbstractAluminum metal with high capacity has been regarded as a promising anode material for lithium ion batteries but suffers from pulverization and side reactions upon the lithiation and de‐lithiation process, which depend on the rational design and controllable synthesis of nanostructures. Here, it is proposed that ultrathin aluminum nanosheets (Al‐NS) grown on carbon nanotubes as anode materials for lithium ion batteries. Based on the preferential Al(111) crystal facet exposure and the rather limited thickness less than 5 nm, the batteries exhibit a high reversible capacity of 990 mAh g−1 at 1 C and an excellent rate capacity of 524.6 mAh g−1 at 24 C, and a long term stability with almost no capacity fading after 500 cycles at high C‐rates of 5, 10, and 20 C. Density functional theory based first principle calculation reveals that the high Young's modulus of Al(111) facet for fast Li+ diffusion and composite materials design with carbon nanotubes enable high rate capability and mitigate huge volume change during discharge/charge process. The results prove that ultrathin Al nanosheets can be a low cost and high‐performance anode material for lithium ion batteries.