Black phosphorus composites with engineered interfaces for high-rate high-capacity lithium storage

High-rate lithium (Li) ion batteries that can be charged in minutes and store enough energy for a 350-mile driving range are highly desired for all-electric vehicles. A high charging rate usually leads to sacrifices in capacity and cycling stability. We report use of black phosphorus (BP) as the active anode for high-rate, high-capacity Li storage. The formation of covalent bonds with graphitic carbon restrains edge reconstruction in layered BP particles to ensure open edges for fast Li⁺ entry; the coating of the covalently bonded BP-graphite particles with electrolyte-swollen polyaniline yields a stable solid-electrolyte interphase and inhibits the continuous growth of poorly conducting Li fluorides and carbonates to ensure efficient Li⁺ transport. The resultant composite anode demonstrates an excellent combination of capacity, rate, and cycling endurance.