Sandwich-Stacked SnO2/Cu Hybrid Nanosheets as Multichannel Anodes for Lithium Ion Batteries

Abstract

We have introduced a facile strategy to fabricate sandwich-stacked SnO₂/Cu hybrid nanosheets as multichannel anodes for lithium-ion batteries applying rolled-up nanotechnology with the use of carbon black as intersheet spacer. By employing a direct self-rolling and compressing approach, a much higher effective volume efficiency is achieved as compared to rolled-up hollow tubes. Benefiting from the nanogaps formed between each neighboring sheet, electron transport and ion diffusion are facilitated and SnO₂/Cu nanosheet overlapping is prevented. As a result, the sandwich-stacked SnO₂/Cu hybrid nanosheets exhibit a high reversible capacity of 764 mAh g^–1 at 100 mA g^–1 and a stable cycling performance of ∼75% capacity retention at 200 mA g^–1 after 150 cycles, as well as a superior rate capability of ∼470 mAh g^–1 at 1 A g^–1. This synthesis approach presents a promising route to design multichannel anodes for high performance Li-ion batteries.