Sulfur-based hybrid multilayers on Li metal anodes with excellent air stability for ultralong-life and high-performance batteries†

Abstract

Lithium metal anodes offer tremendous potential for next-generation rechargeable batteries due to their exceptionally high theoretical capacity and low electrochemical potential. However, their practical application has been limited by the formation of lithium dendrites during charging and discharging, which can compromise safety and performance by damaging the battery separator. To address these challenges, a sulfur-based organic–inorganic hybrid multilayer coating has been developed using precise molecular layer deposition. This artificial solid-electrolyte interphase multilayer, composed of Al-2,3-dimercapto-1-propanol (Al-DMP), enhances electrolyte wettability and creates lithiophilic interfaces, promoting uniform lithium plating and stripping. This leads to improved lithium-ion conductivity, with stable cycling performance achieved at high current densities (10 mA cm⁻²) and areal capacities (10 mAh cm⁻²), while effectively suppressing dendrite formation. The Al-DMP multilayer demonstrates an impressive ionic conductivity of 1.9 × 10⁻⁶ S cm⁻¹, driven by its lithiophilic interfaces and polar sulfur (S) species. This approach is further validated in lithium-sulfur batteries, where the multilayer-coated lithium metal anode is paired with a sulfur/Ketjen black composite cathode. Additionally, the incorporation of a superlattice structure, alternating Al₂O₃ nanolayers with hybrid monolayers, enhances air stability for up to 60 hours and ensures long-term cycling performance. These advancements represent a significant step forward in the development of high-energy-density lithium-metal batteries and solid-state battery technology.