Stabilizing black phosphorus-based anodes with MXene and carbon nanotubes for high-rate sodium-ion batteries

Sodium-ion batteries (SIBs) attract significant interest due to the abundance and affordability of sodium resources, alongside their environmentally sustainable profile. Nevertheless, further research is required to improve high-rate performance and long-term cycling stability. Black phosphorus (BP), with its high theoretical specific capacity, and MXenes, known for their excellent electrical conductivity and multiple functional groups, are both promising anode candidates for SIBs. To address these challenges, a composite anode of BP/Ti 3 C 2 T X MXene/carbon nanotubes (CNTs) (BMC) containing phosphorus-oxygen-titanium (P-O-Ti) bonds is prepared through a straightforward two-step ball milling process. The microstructure and bonding conformation of the BMC composite material are studied using a variety of characterization methods. Compared to the BP/CNTs (BC) anode, the BMC anode demonstrates superior cycling stability and high-rate performance. Kinetic analysis further reveals favorable electrochemical performance. The P-O-Ti bonds in BMC significantly enhance SIBs performance by stabilizing the BP-based composite structure. As a result, the reversible specific capacity of BMC anode reaches 630.7 mAh g −1 after 1400 cycles at 2.0 A g −1 . Furthermore, the reversible specific capacity remains stable at 281.1 mAh g −1 even after 1000 cycles at 10.0 A g −1 . This work presents a straightforward method for preparing BMC anodes.