The energy storage capacity of lithium-ion batteries can be significantly increased thanks to an anode made from folded graphene. A device with a mass loading of 5 mg/cm2 of the graphene has an areal capacity of more than 4 mAh/cm2, which is well above that of commercial graphite anodes, and it can withstand at least 500 cycles of battery charging/discharging without any loss in its performance. The simple folding strategy could easily work for other electrode materials too, say the researchers in the Republic of Korea who report on this work.
“Small-sized, high-energy density batteries will increasingly be needed in applications such as portable electronics as well as in large-scale energy-storage devices, such as electric vehicles,” explains co-team leader Rodney Ruoff of the Institute of Basic Science (IBS) in Ulsan and the Ulsan National Institute of Science and Technology (UNIST). “To reduce battery size, electrodes with high areal and volumetric capacities are crucial, but the problem here is that much space in these structures is currently being ‘wasted’ by inactive materials or by pores that are present in traditional electrode configurations.
“These electrodes can be made of graphene, for example, and contain freestanding graphene composite films comprised of densely stacked layers but they suffer from low areal energy storage because of poor electron/ion transport kinetics. Our folded electrode, which is also made from graphene composite films, shows much improved electron/ion transport and thus a high areal capacity over multiple recharging cycles.”
The full article is available below.