3D Grid of Carbon Tubes with Mn ₃ O ₄ ‐NPs / CNTs Filled in their Inner Cavity as Ultrahigh‐Rate and Stable Lithium Anode

Transition metal oxides are regarded as promising candidates of anode for next‐generation lithium‐ion batteries (LIBs) due to their ultrahigh theoretical capacity and low cost, but are restricted by their low conductivity and large volume expansion during Li + intercalation. Herein, we designed and constructed a structurally integrated 3D carbon tube (3D‐CT) grid film with Mn 3 O 4 nanoparticles (Mn 3 O 4 ‐NPs) and carbon nanotubes (CNTs) filled in the inner cavity of CTs (denoted as Mn 3 O 4 ‐NPs/CNTs@3D‐CT) as high‐performance free‐standing anode for LIBs. The Mn 3 O 4 ‐NPs/CNTs@3D‐CT grid with Mn 3 O 4 ‐NPs filled in the inner cavity of 3D‐CT not only afford sufficient space to overcome the damage caused by the volume expansion of Mn 3 O 4 ‐NPs during charge and discharge processes, but also achieves highly efficient channels for the fast transport of both electrons and Li + during cycling, thus offering outstanding electrochemical performance (865 mAh g −1 at 1 A g −1 after 300 cycles) and excellent rate capability (418 mAh g −1 at 4 A g −1 ) based on the total mass of electrode. The unique 3D‐CT framework structure would open up a new route to the highly stable, high‐capacity, and excellent cycle and high‐rate performance free‐standing electrodes for high‐performance Li‐ion storage.