Long cycle life and high rate sodium-ion chemistry for hard carbon anodes

Long cycle life and high rate sodium-ion chemistry for hard carbon anodes is established by pre-engineering a protective “foreign solid-electrolyte-interphase” from an ester-based electrolyte and then cycled in an ether-based electrolyte. A high capacity of 200 mA h g-1 was retained after 1000 cycles at a high rate of 500 mA g-1, outperforming all hard carbon anodes reported in literature.326