All-Purpose Electrode Design of Flexible Conductive Scaffold toward High-Performance Li-S Batteries

The main obstacles that hinder the development of efficient lithium sulfur (Li-S) batteries are the polysulfide shuttling effect in sulfur cathode and the uncontrollable growth of dendritic Li in the anode. An all-purpose flexible electrode that can be used both in sulfur cathode and Li metal anode is reported, and its application in wearable and portable storage electronic devices is demonstrated. The flexible electrode consists of a bimetallic CoNi nanoparticle-embedded porous conductive scaffold with multiple Co/Ni-N active sites (CoNi@PNCFs). Both experimental and theoretical analysis show that, when used as the cathode, the CoNi and Co/Ni-N active sites implanted on the porous CoNi@PNCFs significantly promote chemical immobilization toward soluble lithium polysulfides and their rapid conversion into insoluble Li2S, and therefore effectively mitigates the polysulfide shuttling effect. Additionally, a 3D matrix constructed with porous carbonous skeleton and multiple active centers successfully induces homogenous Li growth, realizing a dendrite-free Li metal anode. A Li-S battery assembled with S/CoNi@PNCFs cathode and Li/CoNi@PNCFs anode exhibits a high reversible specific capacity of 785 mAh g(-1) and long cycle performance at 5 C (capacity fading rate of 0.016% over 1500 cycles).