Highly read on www.wiley.com in March

A graphene-based material can store energy at seven times the density of commercial carbon-based products.

Supercapacitors — which could be used to power electric vehicles — recharge and release energy faster than batteries, but their energy density is lower. Theoretically, graphene — an unusual material made of atomically thick layers of carbon — is a good candidate for a supercapacitor, but its carbon layers tend to stack together, degrading its performance. Pei Kang Shen and his colleagues at Sun Yat-sen University in Guangzhou, China, created a porous graphene-based structure using an acrylic resin as a template. The researchers rinsed the resin with a nickel acetate solution followed by acid to produce a network of graphene layers with interconnected pores. When the material was filled with an electrolyte solution, it showed stable performance and had an energy density comparable to that of a lead-acid battery.

Adv. Mater. 25, 2474–2480 (2013)