Standing pillar arrays of C-coated hollow SnO2 mesoscale tubules for a highly stable lithium ion storage electrode

Abstract

This work reports the direct growth of hollow one-dimensional nanostructure arrays on conducting substrates for use as efficient electrodes in Li-ion batteries. The C-coated hollow SnO₂ pillar array structures can be prepared by template-directed synthesis, selective wet etching, and a carbonization route. The well-oriented ZnO nanorod arrays, which are grown on titanium substrates, are used as a sacrificial template for the deposition of SnO₂ layers through a simple hydrothermal process. The ZnO portions are selectively removed by wet etching, producing hollow SnO₂ arrays that are consecutively covered with carbon layers via the carbonization of glucose. The lithium storage performance of the synthesized C-coated hollow SnO₂ pillar array structures is demonstrated by applying them directly to a working electrode without additive materials. The standing pillar array electrode, consisting of C-coated hollow SnO₂, exhibits an excellent discharge capacity of ca. 1251.9 mA h g⁻¹ on the first cycle, and it also shows promising cyclability, rate capability, and coulombic efficiency, indicating that C-coated hollow SnO₂ arrays fabricated on the current collector can be powerful candidates for a highly stable lithium storage electrode platform.