I-containing Polymer/Alloy Layer-Based Li Anode Mediating High-Performance Lithium-Air Batteries

Lithium (Li)-air batteries with super-high energy density have attracted wide attention, but they usually exhibit poor performance due to dendrite/passivation on anode and insoluble discharge products on cathode. Many recent works have just designed highly efficient catalysts or only prepared stable anodes to solve one aspect of the above issues. Herein, an iodine (I)-containing polymer/alloy layer-based Li (IPA-Li) via the replacement reaction of zinc iodide (ZnI2) and Li and subsequent polymerization of ethyl alpha-cyanoacrylate (ECA) is designed to tackle both the anode and cathode problems. The homogeneous polymer layer and LiZn alloy in IPA-Li not only suppress the passivation caused by attack of O-2/H2O, but also guide uniform Li plating/stripping behavior to inhibit dendrite formation. Moreover, soluble I-containing species in IPA-Li obviously promote decomposition of discharge products at low voltages. Compared with bare Li, IPA-Li shows a longer lifespan (1200 h at 1 mA cm(-2)) in the symmetric cell. Hence, the electrochemical performance of IPA-Li-based Li-O-2 batteries is also much better than Li-based cells. Moreover, IPA-Li-based Li-air battery operates stably >120 cycles with low-overpotential of <1.6 V in ambient air, while the Li-air battery fast decays only after 25 cycles. This strategy provides a new way to construct high-performance Li-air batteries.