Versatile MnO₂/CNT Putty-Like Composites for High-Rate Lithium-Ion Batteries

A facile and simple method is developed to synthesize putty-like MnO₂/carbon nanotube (CNT) nanostructured composite which shows promising performance as the anode for lithium-ion batteries (LIBs). The interwoven structure between CNTs and MnO₂ enables excellent putty-like processability, which can be easily molded to various shapes or rolled to a flexible film with different thickness. Furthermore, the morphology and structure of the composite can be easily controlled by adjusting the mass ratio of MnO₂ to CNT. Serving as anode materials in LIBs, a high-specific capacity of 796 mAh g⁻¹ is achieved at a current density of 500 mA g⁻¹ with a potential window from 0 to 3.0 V. And a specific capacity of 236 mA h g⁻¹ is maintained even at a high current density of 10 A g⁻¹. The high-specific capacity and outstanding high-rate performance of the material are attributed to the layered structure with unimpeded Li ions diffusion channels, high electron transport efficiency from the interlayered CNTs, and the high stability and flexibility of the skeleton. This work provides an insight for the scalable preparation of novel electrode materials with both enhanced electrochemical performance and increased mechanical properties/flexibility for future multifunctional energy storage devices.