Synthesis and performances of Li-Rich@AlF₃@Graphene as cathode of lithium ion battery

Highlights: • Li-Rich@AlF₃@Graphene was developed as cathode of lithium ion battery. • Coating of 2 nm AlF₃ does not cause capacity loss but is beneficial to rate capability. • Concurrent AlF₃ coating and graphene wrapping significantly improve Li-Rich performance. - Abstract: A novel composite of layered lithium-rich oxide with AlF₃ and graphene, Li-Rich@AlF₃@Graphene, is synthesized as high performance cathode of lithium ion battery in terms of rate capability and cyclic stability. Physical characterizations from X-ray diffraction, scanning electron microscope and transmission electron microscope, demonstrate that the layered lithium-rich oxide in Li-Rich@AlF₃@Graphene is composed of uniform nanoparticles of 100 nm, which are coated with a layer of 2 nm AlF₃ and wrapped with graphene sheets. Charge/discharge tests indicate that the naked lithium-rich oxide exhibits poor cyclic stability and rate capability as cathode of lithium ion battery, which can be improved to some extent by the only contribution of AlF₃ but significantly by the concurrent contribution of AlF₃ and graphene.