N, S Co-Doped Porous Carbon from Antibiotic Bacteria Residues Enables a High-Performance FeF₃ ⋅ 0.33H₂O Cathode for Li-Ion Batteries

FeF₃ ⋅ 0.33H₂O is considered as a potential candidate cathode material owing to the special structure with one-dimension (1D) tunnel. However, its practical application is hindered by the poor electric conductivity. In this work, FeF₃ ⋅ 0.33H₂O embedded into N, S co-doped porous carbon (NSPC) derived from antibiotic bacterial residues was synthesized by a facile wet-impregnation method. Close contact of FeF₃ ⋅ 0.33H₂O nanoparticles with NSPC can provide the rapid electron conduction channel and keep the structural stability, which endows that FeF₃ ⋅ 0.33H₂O@NSPC electrode achieves excellent cycling performance with a reversible capacity of 164.5 mAh g⁻¹ at 40 mA g⁻¹ after 100 cycles between 2.0 and 4.5 V and good rate performance. This study offers a new method for high-value utilization of antibiotic bacteria residues (ABRs) for application in energy storage.