Constructing an Ion‐Wall to Achieve Excellent Lithium Anodes in Li–O 2 Batteries with High DN Electrolytes

For the lithium (Li) metal anode, constructing a strong and durable protective layer with lithium‐ion permeability is crucial, especially in high donor number (DN) solvent system. High DN solvent‐based electrolytes can support both higher capacity and lower charge overpotential in the rechargeable lithium–oxygen batteries (LOBs). However, Li anodes in high DN solvent system suffer from severe corrosion and uncontrolled dendrite growth due to the unstable solid‐electrolyte interphase (SEI). Typically, this interface is formed in situ through electrochemical processes with complicated component and spatial distribution. Here, a functional molecule is introduced to construct an ion‐wall (IW) on Li surface by prechemical sequential reactions (p‐CSRs), through which the crystalline nanoparticles as bricks and amorphous hybrid compounds as the mortar can be produced to build such a “wall.” Different from the conventional SEI, this wall is not only compact and uniform, but also possess high strength, excellent passivation properties and high ionic conductivity. With these properties, the IW could suppress Li dendrites and inhabit the side reaction, supporting highly reversible Li plating/stripping behavior in high DN solvent system. As a result, the cycle stability of LOBs based on the IW protected Li anode is significantly improved.