High-performance lithium storage of Co₃O₄ achieved by constructing porous nanotube structure

Co₃O₄ has been investigated intensively for its high specific capacity which makes it a promising candidate anode for high-performance lithium ion batteries (LIBs). However, rational design of Co₃O₄ electrode that is beneficial for its electrochemical performance is still a great challenge. Herein, we designed and fabricated porous Co₃O₄ nanotubes (P-Co₃O₄-NTs) by coaxial electrospinning method followed by a fine annealing treatment, which display one dimensional tubular structure with porous wall and hollow interior. The uniqueness of this strategy is that the morphologies of the P-Co₃O₄-NTs could be tuned by adjusting the mass ratio of reactants. The resultant P-Co₃O₄-NTs exhibit excellent lithium storage performance in terms of specific capacity, rate capability, and cycling stability, when used as an anode material for rechargeable LIBs. This unique structure endows a high reversible specific capacity of 1826.2 mA g^-1 at a current density of 0.3 A g^-1 after 100 cycles. Even at high current densities of 2 and 5 A g^-1, the P-Co₃O₄-NTs electrode still could deliver remarkable discharge capacities of 1506.2 and 1145.1 mAh g^-1, respectively. The excellent electrochemical performance can be attributed to the unique tubular and porous structure of P-Co₃O₄-NTs, which not only can accommodate the large volume change but also can provide an excellent ion diffusion and electronic conduction pathway. Therefore, the P-Co₃O₄-NTs have the potential for use as a high performance anode material in LIBs.