Carbon Encapsulated Tin Oxide Nanocomposites: An Efficient Anode for High Performance Sodium-Ion Batteries

다국어 초록 (Multilingual Abstract)

<P>The major obstacle in realizing sodium (Na)-ion batteries (NIBs) is the absence of suitable negative electrodes. This is because graphite, a commercially well known anode material for lithium-ion batteries, cannot be utilized as an insertion host for Na ions due to its large ionic size. In this study, a simple and cost-effective hydrothermal method to prepare carbon coated tin oxide (SnO<SUB>2</SUB>) nanostructures as an efficient anode material for NIBs was reported as a function of the solvent used. A single phase SnO<SUB>2</SUB> resulted for the ethanol solvent, while a blend of SnO and SnO<SUB>2</SUB> resulted for the DI water and ethylene glycol solvents. The elemental mapping in the transmission electron microscopy confirmed the presence of carbon coating on the SnO<SUB>2</SUB> nanoparticles. In cell tests, the anodes of carbon coated SnO<SUB>2</SUB> prepared in ethanol solvent exhibited stable cycling performance and attained a capacity of about 514 mAh g<SUP>–1</SUP> on the first charge. With the help of the conductive carbon coating, the SnO<SUB>2</SUB> delivers more capacity at high rates: 304 mAh g<SUP>–1</SUP> at the 1 C rate, 213 mAh g<SUP>–1</SUP> at the 2 C rate and 133 mAh g<SUP>–1</SUP> at the 5 C rate. The excellent cyclability and high rate capability are the result of the formation of a mixed conducting network and uniform carbon coating on the SnO<SUB>2</SUB> nanoparticles.</P><P><B>Graphic Abstract</B>
<IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-31/acsami.5b04178/production/images/medium/am-2015-04178y_0017.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b04178'>ACS Electronic Supporting Info</A></P>