Selective Formation of Carbon‐Coated, Metastable Amorphous ZnSnO 3 Nanocubes Containing Mesopores for Use as High‐Capacity Lithium‐Ion Battery

Mesoporous and amorphous ZnSnO 3 nanocubes of ∼37 nm size coated with a thin porous carbon layer have been prepared using monodisperse ZnSn(OH) 6 as the active precursor and low‐temperature synthesized polydopamine as the carbon precursor. The small single nanocubes cross‐link with each other to form a continuous conductive framework and interconnected porous channels with macropores of 74 nm width. Because of its multi‐featured nanostructure, this material exhibits greatly enhanced integration of reversible alloying/de‐alloying (i.e., transformation of Li 4.4 Sn and LiZn to Sn and Zn) and conversion (i.e., oxidation of Sn and Zn to ZnSnO 3 ) reaction processes with an extremely high capacity of 1060 mA h g −1 for up to 100 cycles. A high reversible capacity of 650 and 380 mA h g −1 can also be delivered at rates of 2 and 3 A g −1 , respectively. This excellent electrochemical performance is attributed to the small particle size, well‐developed mesoporosity, the amorphous nature of the ZnSnO 3 and the continuous conductive framework produced by the interconnected carbon layers.