Lithium-ion batteries have enabled many of today's electronics, from portable gadgets to electric cars. But much to the frustration of consumers, none of these batteries last long without a recharge. Now scientists report in the journal ACS Nano the development of a new, "green" way to boost the performance of these batteries – with a material derived from silk.
Chuanbao Cao and colleagues note that carbon is a key component in commercial Li-ion energy storage devices including batteries and supercapacitors. Most commonly, graphite fills that role, but it has a limited energy capacity. To improve the energy storage, manufacturers are looking for an alternative material to replace graphite. Cao's team wanted to see if they could develop such a material using a sustainable source.
The researchers found a way to process natural silk to create carbon-based nanosheets that could potentially be used in energy storage devices. Their material stores five times more lithium than graphite can – a capacity that is critical to improving battery performance. It also worked for over 10,000 cycles with only a 9 percent loss in stability. The researchers successfully incorporated their material in prototype batteries and supercapacitors in a one-step method that could easily be scaled up, the researchers note.