Smartwatches haven't been around for very long, and yet it is already clear that one of the most limiting factors to their performance (and, ultimately, their usefulness) is battery life. Batteries are generally rigid, bulky and heavy, which is exactly what you don't want to feel on your wrist all day long.
Flexible batteries are an attractive prospect that would lead to better wearable gadgets for consumers. We've seen examples before, but their performance hasn't been up to par when compared to their Li-ion counterparts. Now, researchers at Rice University have come up with a technology that looks very promising.
Rice chemist James Tour and colleagues created high-performance electrodes by etching a 900 nanometer-thick layer of nickel fluoride with regularly spaced holes that were only five nanometers in diameter, increasing surface area for added energy storage. They then enclosed the electrodes in an electrolyte made of potassium hydroxide in polyvinyl alcohol.