In situ potential-regulated architecture of an ultrafine Ru-based electrocatalyst for ultralow overpotential lithium-oxygen batteries.

An in situ electrochemical reduction strategy is proposed to avoid the aggregation of nano-Ru in lithium batteries for the first time. The high-dispersion face-centered cubic (fcc) nano-Ru is successfully synthesized with an average diameter of 2.0 nm, and the as-assembled lithium-oxygen batteries deliver an excellent cycling performance of 185 cycles and an ultralow overpotential of only 0.20 V at 100 mA g -1 .