In situ synthesis of graphene-like N, S co-doped carbon nanosheets/FeF 3 ·0.33H 2 O composite as cathode material for Li-ion battery

Nowadays, transition metal fluorides (Me x F y , Me = Fe, Co, Ni, etc.) have received extensive attention for high work voltage and large theoretical capacity. In this study, we aim to develop an effective approach to enhance its conductivity and thus improve the electrochemical performance. We propose a graphene-like N, S co-doped carbon nanosheets/FeF 3 ·0.33H 2 O (GNSCFF) composite derived from antibiotic bacterial residues (ABRs) via a facile liquefaction-calcination and fluorination-annealing process, where in situ formed FeF 3 ·0.33H 2 O practices intimately anchoring into conductive GNSC, allows the low conductivity FeF 3 ·0.33H 2 O particles to be wired up to the current collector with rapid electron transmission channel. The GNSCFF composite exhibits good performance for the Li-storage with a reversible discharge capability of 167.9 mAh g −1 at 40 mA g −1 after 100 cycles in the range of 2.0–4.5 V. Hence, this work gives a simple and low-cost approach to realize the high-value utilization of pharmaceutical wastes and provides a useful guidance for preparing high-performance iron fluorides cathode materials of rechargeable battery. Graphical abstract