Self-healing artificial solid electrolyte interphase enhanced by quadruple hydrogen bonding for stable lithium metal anode

Abstract

Lithium metal is considered as the ultimate anode material for lithium batteries due to its high theoretical specific capacity and lowest redox potential. However, the growth of lithium dendrites and strong side reactions seriously hinder the commercialization of Li metal anode. Here, we modify the Li metal anode with a self-healing artificial solid electrolyte interphase (SEI), where PVA-Upy with quadruple hydrogen bonds is formed on Li metal by a simple drop-coating method. This polymer artificial SEI possesses self-healing hydrogen bonds and abundant lithiophilic bonds, which can simultaneously suppress the generation of microcracks in the SEI and enable uniform deposition of Li metal. Hence, the PVA-Upy@Li symmetric cell can stably cycle for more than 2000 h (1 mA cm−2, 1 mAh cm−2) with only about 10 mV of voltage polarization. This artificial SEI provides new insight into the subsequent modification strategies of Li metal anode and can be extended to the protection of other alkali metal anodes.