The influence of electrode structure on the performance of an SnS anode in Li-ion batteries: effect of the electrode particle, conductive support shape and additive

Abstract

The electrochemical performance of tin sulfide (SnS) nanorods (NRs) as an anode for lithium-ion batteries has been evaluated, after adding a carbon coating and reduced graphene oxide (r-GO) as a conductive support. Raman spectroscopic analysis of such types of carbon-coated SnS nanorod clearly shows the influence of the size and shape of the conductive graphite crystallites on their electrochemical performance against Li/Li⁺. The incorporation of an r-GO support for the SnS nanorods enhances the electrochemical performance. The SnS NRs/r-GO composite with both reduced graphene oxide and a carboxymethyl cellulose binder shows better performance than the carbon-coated sample. The ex situ transmission electron microscopy studies show that the carbon coating of the SnS nanorod is ruptured during the lithiation process and the particle size is not maintained uniformly, while the r-GO composite is able to maintain its shape and size during the continuous charge–discharge process. The discharge capacity of the SnS NRs/r-GO composite was 602 mA h g⁻¹ at a current rate of 160 mA h g⁻¹ after fifty continuous charge–discharge cycles. The current observations suggest that the practical energy density need not be sacrificed for power density, provided that the carbon coatings are optimized by the careful selection of additives.