FeF₃ microspheres anchored on reduced graphene oxide as a high performance cathode material for lithium ion batteries

FeF₃ microspheres/reduced graphene oxide (r-GO) composites were synthesized by a simple hydrothermal route with HF vapor. The size of the microspheres was controllable simply by adjusting the amount of graphene oxide in the precursor solution from about 1 to 10 wt%. The FeF₃ microspheres/r-GO composites showed improved discharge capacity and cycling stability in the voltage ranges of 1.5–4.5 V and 2.0–4.5 Vat room temperature compared to those of bulk FeF₃. For example, the composites delivered an initial discharge capacity of about 196 mAhg⁻¹ at a rate of 0.1C with 0.28% fading per cycle during 50 cycles in the range of 2.0–4.5 V. The composites also showed significantly enhanced rate capabilities in the range of 0.1–20C (e.g., about 170 mAhg⁻¹ at a rate of 1C). - Highlights: • FeF₃ microspheres/r-GO composites were synthesized in a facile method. • FeF₃/r-GO nanocomposites showed improved electrochemical performances. • FeF₃/r-GO (11.7 wt%) has superior cycling stability and rate performances