Stable 4 V-class bicontinuous cathodes by hierarchically porous carbon coating on Li₃V₂(PO₄)₃ nanospheres

A high performance, durable cathode material for lithium ion batteries is achieved by incorporating ∼50 nm Li₃V₂(PO₄)₃/C core-shell nanospheres into a porous carbon framework. The Li₃V₂(PO₄)₃/C nanocomposite delivers an initial discharge capacity of 130 mA h g^-1, approaching its theoretical limit (133 mA h g^-1). At a high current rate (10 C), the nanocomposite displays an impressive long cycle life and remarkable capacity retention (90% after 1200 cycles). Notably, the Coulombic efficiency is above 99% during the course of cycling. The remarkable power capability and cycle stability derived from our simple and scalable synthesis suggests that this 4 V-class material could be one of the most promising candidates for future batteries.