A 10-μm Ultrathin Lithium Metal Composite Anodes with Superior Electrochemical Kinetics and Cycling Stability

Lithium metal is a promising candidate for the promotion of the next generation high energy density batteries. The employment of ultrathin Li metal anode with controllable thickness could enable a higher efficiency of Li utilization. Herein, a simple method to fabricate free-standing 10 μm ultrathin Li metal anode is developed in this work. A three-dimensional MnO_x-coated CNT framework is constructed through a facile hydrothermal process, utilizing as a host for molten Li infusion, which could not only put forward a simple strategy to modulate the thickness of Li metal film but also restricts the volume expansion. The abundant MnO_x nanoparticles acting as lithiophilic sites reduce the Li nucleation barrier and optimize the electrochemical kinetics at the anode/electrolyte interface. As a result, the ultrathin Li composite anode exhibits a superior lifespan expanded to 2000 cycles in a symmetric cell, as well as a better capacity and rate capability than that of bare Li anode in full cell, fulfilling the requirements of high energy density and stable cycling life. Furthermore, a wave-shaped Li metal pouch cell based on the ultrathin Li composite anode is assembled that exhibits remarkable mechanical bending toleration and cyclic stability, demonstrating large potential application in the field of flexible wearable devices.