Adaptive formed dual-phase interface for highly durable lithium metal anode in lithium–air batteries

Li–air battery exhibits a promising prospect as energy conversion and storage devices due to its ultrahigh theoretical energy density. However, lithium metal as anode is hampered due to the intricate ambient electrochemical environment especially in the open and semi-open batteries. Herein a strategy that in situ fabricating dual-phase protective interface is proposed to improve the durability of lithium metal anode for Li–air battery. A thin film generates and contacts intimately on the surface via floating lithium foil on a silane mixed solution, then the inorganic particles Li6(Si2O7) appear adaptively and embeds in the Si-O-Si polymer during the initial lithium plating/stripping process. The in-situ integration of inorganic particles and polymer matrix enable the interface to possess a dense morphology, high mechanical rigidity, high lithium ions conductivity and high interface energy, defending the attack of moisture and O2− and furthermore keeping a homogeneous Li+ deposition even at high local current density. As a result, an outstanding improvement on the reversibility of Li–air battery is achieved with 180 cycles at a high current density of 1000 ​mA ​g−1 and capacity control of 1000 ​mAh g−1 in air atmosphere (O2:N2:H2O ​= ​4:16:3).