Nondestructive CNT chained Fe₃O₄ anode materials for high-performance Li-ion batteries

Designing a realistic structure for transition metal oxides (TMOs) with high specific capacity and good stability is a critical challenge for the development of lithium-ion batteries (LIBs). Herein, we report an effective strategy to fabricate sulfonated carbon nanotubes (SCNT) chained Fe₃O₄ nanoparticles (SCNT/Fe₃O₄). Compared with acidized carbon nanotubes (CCNT), the nondestructive preparation process of SCNT made it retain high electron conductivity and acquired larger length-diameter ratio. The SCNT/Fe₃O₄ used as anode material delivered a high reversible capacity (674 mAh g⁻¹ at 500 mA g⁻¹ after 100 cycles) and excellent rate capability (402 mAh g⁻¹ at 2 A g⁻¹ after 200 cycles). The excellent performance may be related to the faster electron transmission network and the more stable three-dimensional framework provided by SCNT. This work presents an approach to fabricate high-performance TMO-based composites for LIBs.