Selective Formation of Carbon-Coated, Metastable Amorphous ZnSnO3 Nanocubes Containing Mesopores for Use as High-Capacity Lithium-Ion Battery

• Published in: Small Vol. 10; no. 13; pp. 2637 - 2644
• Main Authors: Han, Fei, Li, Wen-Cui, Lei, Cheng, He, Bin, Oshida, Kyoichi, Lu, An-Hui
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 09.07.2014; Wiley; Wiley Subscription Services, Inc
• Subjects: amorphous structures; anodes; Carbon; high capacities; Lithium; lithium-ion batteries; Nanotechnology; zinc stannates; high capacities; anodes; zinc stannates; amorphous structures; lithium-ion batteries
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.201400371

Mesoporous and amorphous ZnSnO3 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 Li4.4Sn and LiZn to Sn and Zn) and conversion (i.e., oxidation of Sn and Zn to ZnSnO3) 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 ZnSnO3 and the continuous conductive framework produced by the interconnected carbon layers. Carbon‐coated amorphous ZnSnO3 nanocubes with well‐developed mesoporosity are synthesized and the core–shell particles are linked into an interconnected conductive framework. This ZnSnO3‐based anode exhibits an outstanding lithium storage performance, especially a high reversible capacity of 1060 mA h g−1 because of the integration of alloying and conversion reaction processes (reversible transformation of Li4.4Sn and LiZn alloys to pristine ZnSnO3).