Knowing when small is better

摘要

All electrochemical energy storage devices involve the simultaneous transport of ions and electrons during operation. Resistance in a material scales with size and therefore charge transport in a battery can be improved by nanostructuring components in the device. Charge and discharge processes can, for example, be made more efficient, leading to increases in both power and energy density~1. However, studying the effect of length scale on the electrochemical properties of a device is not straightforward because the nanostructuring of an electrode typically results in high surface areas and a high density of internal defects such as grain boundaries. This leads to device properties that are highly specific to the details of the fabrication procedure. Writing in Nature Nanotechnology, Sang Bok Lee, Gary Rubloff and colleagues now show~2 that the opportunities and limitations of energy storage miniaturization can be explored with the help of a nanopore battery (Fig. 1a).