Sodium-ion batteries are a potentially low-cost and safe alternative to the prevailing lithium-ion battery technology. However, it is a great challenge to achieve fast charging and high power density for most sodium-ion electrodes because of the sluggish sodiation kinetics. Here we demonstrate a high-capacity and high-rate sodium-ion anode based on ultrathin layered tin(II) sulfide nanostructures, in which a maximized extrinsic pseudocapacitance contribution is identified and verified by kinetics analysis. The graphene foam supported tin(II) sulfide nanoarray anode delivers a high reversible capacity of ~1,100 mAh g^-1 at 30 mA g^-1 and ~420 mAh g^-1 at 30 A g^-1, which even outperforms its lithium-ion storage performance. The surface-dominated redox reaction rendered by our tailored ultrathin tin(II) sulfide nanostructures may also work in other layered materials for high-performance sodium-ion storage.

Nature Communications 7, Article number: 12122 doi:10.1038/ncomms12122
Received 04 December 2015 Accepted 02 June 2016 Published 30 June 2016

http://www.nature.com/ncomms/2016/160630/ncomms12122/full/ncomms12122.html