Metal–Organic Framework-Assisted Synthesis of Compact Fe2O3 Nanotubes in Co3O4 Host with Enhanced Lithium Storage Properties

Lithium-ion batteries (LIBs) have drawn considerable research attention as a rechargeable power source for portable electronic devices and electric vehicles [ 1 , 2 ]. Until now, graphite has been the most commonly used anode material in commercial LIBs [ 3 ]. However, the relatively low theoretical capacity (372 mAh g −1 ) of graphite is inadequate to meet the growing demands of energy density and life span in next-generation batteries [ 4 , 5 , 6 , 7 ]. Transition metal oxides (TMOs) have been considered as promising electrode materials for LIBs owing to their high specific capacity, low cost, and synthetic versatility to diverse nanostructures [ 8 , 9 , 10 , 11 ]. As two representative TMOs, iron oxide and cobalt oxide have been actively investigated [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. However, the practical application of these anode materials still faces serious challenges, such as fast capacity fading, poor rate performance caused by large volume changes occurring during the lithiation/delithiation processes, and low intrinsic electric conductivity.