The battery of the future could be pasted on the wall or incorporated in a tee-shirt or other item of clothing.

Yi Cui, an engineer at Stanford University has developed a way to store energy in paper and fabrics, creating lightweight batteries. The technique involves coating ordinary paper or fabric in an ink infused with nanoparticles of lithium cobalt oxide or carbon nanotubes, which can transmit and store electricity.

Paper and fabric treated in this way retain the properties of their non-coated counterparts and can be handled and treated in exactly the same way. Cui suggests the development could be used to make energy-storing wallpaper, or to allow people to charge their portable appliances on the go by plugging them into an outlet woven into their T-shirts.

Cui, an assistant professor of materials science and engineering specialises in developing new applications of nano-materials to take advantage of the different properties that are displayed at this scale, has been looking at ways to integrate nanotechnology into energy storage.

In another project, he has shown that it is possible to replacing the carbon (graphite) anodes in lithium ion batteries with anodes of silicon nanowires. This has the potential to increase their storage capacity by 10 times, according to experiments conducted by Cui’s team.

While silicon has been recognised as a favorable anode material because it can hold a larger amount of lithium than carbon, its use is limited by its inability to sustain physical stress that occurs when lithium ions attach themselves to a silicon anode in the process of charging a battery, and the shrinkage that occurs when lithium ions are drawn out as it discharges.

The result is that silicon structures disintegrate, causing anodes of this material to lose much, if not all of their storage capacity. But at the nanoscale, silicon nanowire electrodes are capable of withstanding the mechanical stress caused by the absorption and discharge of lithium ions.

This holds promise for the development of rechargeable lithium batteries with a longer life cycle and higher energy capacity.