Hierarchically Multiporous Carbon Nanotube/Co₃ O₄ Composite as an Anode Material for High-Performance Lithium-Ion...

Carbon nanotubes (CNTs) and porous Co₃ O₄ nanorod (Co₃ O₄ p-NR) composites are self-assembled to form a hierarchical porous structure through a facile hydrothermal method to meet the requirements of long cycle life, high capacity, and excellent rate capability for next-generation lithium-ion batteries. CNTs are embedded in Co₃ O₄ p-NR clusters to form a 3D conductivity network, which reduces the transportation resistance of electrons and ions. Co₃ O₄ p-NRs are assembled from nanoparticles, which enlarge the contact area between electrode and electrolyte to provide more space to buffer the large volumetric changes associated with repeated electrochemical reactions and maintain the structural integrity. The obtained samples exhibit a high reversible capacity (1083 mA h g^-1 after 140 cycles at 0.5 Ag^-1 ), superior rate capability (521 mA h g^-1 at 8 Ag^-1 ), and excellent cyclic stability, with a capacity decay of 0.57 mA h g^-1 per cycle at a high current of 1 Ag^-1 over 200 cycles. The specific heterodimensional structure gives rise to a new approach to exploit high-performance electrode materials.