A team of researchers at MIT have come up with an environmentally friendly way to generate electricity that harnesses heat but uses no metals or toxic materials.
The breakthrough is critical because most of the batteries that power everything from smartphones to computers are made of toxic materials like lithium, which can be difficult to dispose of and have a limited global supply. Lithium is also extremely flammable.
The breakthrough is based on a 2010 discovery by MIT’s Michael Strano, who found that a wire made from tiny cylinders of carbon known as carbon nanotubes can produce an electrical current when it is progressively heated from one end to the other – much as you would light a fuse.
The effect arises as a pulse of heat pushes electrons through the bundle of carbon nanotubes, carrying the electrons with it like surfers riding a wave.
Now, Strano and his team including grad students Sayalee Mahajan and Albert Liu have gone a step further, increasing the efficiency of this technique more than a thousandfold. In other words, they have produced devices that can put out power similar to what can be produced by today’s best batteries.
Their work was published in the journal Energy & Environmental Science.
The improvements in efficiency, Strano said in a statement, brings the technology “from a laboratory curiosity to being within striking distance of other portable energy technologies,” such as lithium-ion batteries or fuel cells.