Chemical Prelithiated 3D Lithiophilic/-Phobic Interlayer Enables Long-Term Li Plating/Stripping

The up-to-date lifespan of zero-excess lithium (Li) metal batteries is limited to a few dozen cycles due to irreversible Li-ion loss
caused by interfacial reactions during cycling. Herein, a chemical prelithiated composite interlayer, made of lithiophilic silver (Ag) and
lithiophobic copper (Cu) in a 3D porous carbon fiber matrix, is applied on a planar Cu current collector to regulate Li plating and stripping and
prevent undesired reactions. The Li-rich surface coating of lithium oxide (Li2O), lithium carboxylate (RCO2Li), lithium carbonates (ROCO2Li), and
lithium hydride (LiH) is formed by soaking and directly heating the interlayer in n-butyllithium hexane solution. Although only a thin coating
of ∼10 nm is created, it effectively regulates the ionic and electronic conductivity of the interlayer via these surface compounds and reduces defect sites by reactions of n-butyllithium with heteroatoms in the carbon fibers during formation. The spontaneously formed lithiophilic−lithiophobic gradient across
individual carbon fiber provides homogeneous Li-ion deposition, preventing concentrated Li deposition. The porous structure of the composite interlayer eliminates the built-in stress upon Li deposition, and the anisotropically distributed carbon fibers enable uniform charge compensation. ... mehrThese features synergistically minimize the side reactions and compensate for Li-ion loss whi