Lithium-ion batteries are everywhere these days. From cellphones to electric cars, they dominate the market for rechargeable devices. One of the main challenges faced by the electric vehicle industry is related to the energy density of electric car batteries.
Researchers at the Massachusetts Institute of Technology (MIT) say they have found a way to improve the energy density of a type of battery known as lithium-air or lithium-oxygen. The promise is that it could pack several times more energy per pound than lithium-ion batteries that currently dominate the market.
Last year, researchers had demonstrated that lithium-air batteries showed improved efficiency with catalysts based on noble metal. Now they have found they can further improve it by creating carbon-fiber-based electrodes that are substantially more porous than other carbon electrodes.
This means they can store the solid oxidized lithium that fills the pores more efficiently as the battery discharges.
“We grow vertically aligned arrays of carbon nanofibers using a chemical vapor deposition process. These carpet-like arrays provide a highly conductive, low-density scaffold for energy storage,” explained Robert Mitchell, co-author of the paper. “We were able to create a novel carpet-like material – composed of more than 90 percent void space – that can be filled by the reactive material during battery operation,” said Yang Shao-Horn, a senior author of the paper.
Article by Antonio Pasolini, a Brazilian writer and video art curator based in London, UK. He holds a BA in journalism and an MA in film and television.