Ion-Conducting and Stretchable Organogel Polymer Interface Layer for Stabilizing Lithium Metal Anodes via In Situ Polymerization Strategy

Abstract

The uncontrollable growth of lithium dendrites and the unstable interface of the lithium metal anode/electrolyte inhibit potential large-scale applications of lithium metal batteries. The polymer artificial solid–electrolyte interface layer shows potential for the homogeneity of ion flux toward a lithium metal electrode. Herein, we design an ionic conductive and stretchable organogel polymer layer as the artificial protective layer via in situ polymerization on an active lithium metal anode, which can accommodate volume changes and maintain enhanced interfacial contact with the electrode. The propylene carbonate and the long alkyl ether in the polymer protective layer contribute to the inducing of uniform Li deposition and enhance ion transport. In addition, the in situ polymerization membrane adheres tightly to the lithium metal anode, which can effectively eliminate the barriers of ionic transport at heterogeneous interfaces and has stretchable strength tending to suppress Li dendrites. As a result, the Li/Li symmetric cell with this artificial polymeric protect layer can stably cycle for over 800 h under 1 mA cm^–2 without increased polarization voltage, while the corresponding lithium metal/LiFePO₄ full battery delivers high-capacity retention of 102.6, 127.7, and 136.7% after 244, 862, and 976 cycles at 0.3, 1, and 2 C. Furthermore, the lithium metal battery equipped with this artificial layer also shows longer cycling life and higher reversible specific capacity (130.24 mAh g^–1) under 1 C and enhanced rate performance than bare Li battery.