Designing F/P Hybrid Polymer as Ultrastable Cationic Shielding Interphase for High-Performance Lithium Metal...

Dendrite growth on electrode-electrolyte interphase has severely limited applications of lithium metal batteries (LMBs). Here, we developed an ionic alternating polymer with fluorocarbons and phosphonium cations in repeating units to regulate Li deposition for the first time. The combined functionalities in the F/P hybrid polymer exhibit remarkable characteristics as a protective layer on top of Li anode, demonstrating outstanding electrochemical stability, ion flux redistributing capability and adaptive chain mobility. Based on characterizations and simulations, this cationic interlayer could effectively furnish long-standing electrostatic shielding for anodes, allowing restrained coating decomposition and homogenized electric field distribution to induce dendrite-free Li deposition, and enabling full cells with enhanced rate and long-term cycling performance. Given the importance of LMBs, this work will promote polymer design to stabilize anodes with superior electrochemical behavior.