From Dendrites to Hemispheres: Changing Lithium Deposition by Highly Ordered Charge Transfer Channels.

Metallic lithium as an anode is an ultimate ideal for rechargeable lithium batteries with high energy density such as lithium-oxygen batteries and lithium-sulfur batteries. However, the excess reactivity and asymmetrical dissolution-deposition of the metallic lithium anode make it impossible to support a stable long charge-discharge cycling. To protect the metallic lithium anode, apparently it needs to adjust the dissolution and deposition of lithium ions, but more essentially, it should reasonably change the distribution and transport of electrons on the surface and interface of the metallic lithium. In this work, anodic aluminum oxide (AAO) membranes are used to build highly ordered channels on the lithium anode surface in which lithium ions can transfer in the channels and electrons can be transported by the lithiation reaction of alumina with an oxygen vacancy-involved process. As a result, the cyclic reaction actually is partially transferred to the AAO surface, and lithium deposition occurs there as a hemispherical appearance but not as dendrites. Meanwhile, the highly ordered characteristics provide a physical effect to make the deposited lithium hemispheres a uniform distribution on the AAO surface. The AAO-regulated lithium anodes could be widely used to improve the cycling performance for metal lithium batteries.