Freestanding polypyrrole nanotube/reduced graphene oxide hybrid film as flexible scaffold for dendrite-free lithium metal anodes

Abstract

Lithium metal anode is the most potential anode material for the next generation high-energy rechargeable batteries owing to its highest specific capacity and lowest redox potential. Unfortunately, the uneven deposition of Li during plating/stripping and the formation of uncontrolled Li dendrites, which might cause poor battery performance and serious safety problems, are demonstrating to be a huge challenge for its practical application. Here, we show that a flexible and free-standing film hybriding with polypyrrole (PPy) nanotubes and reduced graphene oxide (rGO) can significantly regulate the Li nucleation and deposition, and further prohibit the formation of Li dendrites, owing to the large specific surface area, rich of nitrogen functional groups and porous structures. Finally, the high Coulombic efficiency and stable Li plating/stripping cycling performance with 98% for 230 cycles at 0.5 mA cm−2 and more than 900 hours stable lifespan are achieved. No Li dendrites form even at a Li deposition capacity as high as 4.0 mA h cm−2. Besides, the designed PPy/rGO hybrid anode scaffold can also drive a superior battery performance in the lithium-metal full cell applications.