High rate SnO2-Graphene Dual Aerogel anodes and their kinetics of lithiation and sodiation

We created a unique SnO2-Graphene Dual Aerogel (SnO2/GDA) nanocomposite with exquisite lithium and sodium ion battery anode performance (LIB, NIB NAB SIB). In parallel we employed electrochemical methods to be the first to analyze the transition from kinetic control to diffusion control for the conversion reaction (SnO2 + 4Li(+)+4e(-) <-> Sn + 2Li(2)O) vs. for the alloying reaction (Sn+xLi(+)+xe(-) <-> LixSn, x <= 4.4). The material displays a high reversible capacity (1299 mA h g(-1) for Li at 0.1 A g(-1), 448 mA h g(-1) for Na at 0.05 A g(-1)), very good cycling life (148% after 450 cycles for Li, 82% from 20 to 200 cycles for Na), and superb rate capacity retention (450 mA h g(-1) for Li at 25 A g(-1), 184 mA h g(-1) for Na at 1 A g(-1)). In fact, these rate capabilities are among the most favorable reported in literature for each system. (C) 2015 Elsevier Ltd. All rights reserved.