Multilayered electrodes help batteries flex and conduct

Abstract

Researchers trying to build flexible electronics often face a roadblock: electronic components can be stretchy or conductive, but they are rarely both. A new study, however, reports the use of multiscale engineering to fabricate a durable, stretchy battery that maintains 72% of its charge capacity while enduring 30% strain (Sci. Adv. 2019, DOI: 10.1126/sciadv.aaw1879). To make the battery, an international research team made composite sheets containing negatively charged gold nanoparticles suspended in positively charged polyurethane. By changing the percentage of nanoparticles, the researchers could tune the sheets’ conductivity and stretchiness. Still, they faced the familiar conductivity-stretchiness trade-off. The breakthrough came when the team tried stacking sheets of the composites with varying nanoparticle concentrations. These stacks could stretch and flex while still conducting electricity. “These properties are not easy to combine; they are contrarian to each other,” says Nicholas Kotov, one of...