A dendrite-free Li plating host towards high utilization of Li metal anode in Li-O2 battery

The intense interest of Li-O-2 battery stems from its ultrahigh theoretical energy density, but its application is still hindered by the issues of Li anode. Herein, RuO2-CNTs composite, a conventional O-2 cathode catalyst in Li-O-2 battery, is first utilized as an anode host for dendrite-free Li plating/stripping with high Coulombic efficiency. It is demonstrated that such excellent plating/stripping performance arises from the lithiophilicity characteristic of Ru nanoparticles (that is derived from the in-situ electrochemical conversion from RuO2 to Ru/Li2O) and buffer space provided by CNTs. Furthermore, the RuO2-CNTs electrode pre-deposited with limited Li (RuO2-CNTs@Li anode) is coupled with a RuO2-CNTs catalytic cathode to form a Li-O-2 full cell, which displays an extended cycle life with dramatically improved energy density. The achieved cell shows a high stability of 200 cycles with RuO2-CNTs@Li anode (1 mg Li) that sheds light on the efficient utilization of Li anode in Li-O-2 batteries. (C) 2019 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.