Ultralight PEDOT Functionalized Separators toward High-Performance Lithium Metal Anodes

The practical application of lithium-metal batteries (LMBs) has been limited by the problems of uncontrolled lithium dendrite growth, resulting in a low Coulombic efficiency (CE) and rapid battery failure. Herein, we develop an ultralight poly(3, 4-ethylenedioxythiophene) (PEDOT) modifying Celgard polypropylene (PP) separator with a mass loading of 0.08 mg cm(2) by vapor phase polymerization. The increased affinity between the PEDOT/PP separator and electrolyte interface enables homogenous Li+ flux. Meanwhile, the lithiophilic thiophene functional groups of PEDOT guide uniform Li nucleation and growth through the formation of Li-S bond. As a result, dendrite-free Li deposition has been achieved with a high CE of 98.0 % over 150 cycles and flat stable overpotential of similar to 90 mV at an ultrahigh rate of 20 mA cm(-2) in the symmetric cell. Remarkably, the Li||PEDOT/PP||LiNi0.8Co0.1Mn0.1O2 full cells demonstrate superior stability up to 500 cycles with a discharge capacity of 119 mAh g(-1) at 1 C. This work paves way for modifying separator for high-performance LMBs.