Alkali metal batteries have high energy densities required to power future devices; however, uneven metal deposition is a critical barrier to achieving long lifespans. We have developed an elegant noncryogenic transmission electron microscopy method which has facilitated the first observations of epitaxial deposition in alkali metal batteries. Using this method, we have confirmed epitaxial interactions between (002) sodium crystallite planes and (01-11) planes in zinc current collectors. Such epitaxial interactions decrease nucleation energy barriers and promote even metal growth. This study offers fresh inspiration for the development of electron microscopy techniques tailored to electron-sensitive battery materials and sets a new agenda for the development of battery technologies.
Keywords: alkali metal; anode-free battery; current collector; epitaxy; metal battery; nucleation.