Tin nanocrystals for gen-next energy-storing devices
doi:10.1038/nindia.2019.27 Published online 6 March 2019
Researchers have synthesised tin nanocrystals that can be used to make micro-power systems such as micro-supercapacitors1. These supercapacitors possess excellent abilities to charge and discharge energy, and hence could potentially be used for making next-generation energy-storing devices.
Nanocrystals exhibit unusual crystal structures with large surface-to-volume ratios. Among metallic nanocrystals, tin nanocrystals are preferred for their high charge-storing capacity and low toxicity.
To exploit the potential of tin nanocrystals, an international research team, including an Indian scientist from the International Advanced Research Centre for Powder Metallurgy and New Materials in Hyderabad, India, prepared the tin nanocrystals using a plasma reactor, tin wire and helium gas at atmospheric pressure.
They produced two forms of tin nanocrystals, which exhibited average diameters of between 2 and 3 nm. Tin is more sustainable and eco-friendly than carbon for lithium-ion, magnesium-ion and sodium-ion batteries. Besides, tin possesses a charge-storing capacity that is three times as high as that of graphite.
One form of the tin nanocrystals displayed stability at room temperature without the use of any external agents such as surfactants. Electrochemical studies showed that charge can rapidly diffuse and migrate through the nanocrystals. This suggests that the nanocrystals are potential candidates for making electrical double-layer capacitors.
The supercapacitors made using the nanocrystals are as good as metallic-nanoparticle- and carbon-based supercapacitors. Since the plasma-based synthesis is a low-cost process, it could be utilised to scale up the production of the nanocrystal-based supercapacitors.
1. Haq, A. U. et al. Size-dependent stability of ultra-small α-/β-phase tin nanocrystals synthesized by microplasma. Nat. Commun. 10, 817 (2019)