Artificial Electron Channels Enable Contact Prelithiation of Li‐Ion Battery Anodes with Ultrahigh Li‐Source Utilization

Abstract Contact prelithiation is widely used to compensate for the initial capacity loss of lithium‐ion batteries (LIBs). However, the low utilization of the Li source, which suffers from the deteriorated contact interfaces, results in cycling degeneration. Herein, Li−Ag alloy‐based artificial electron channels (AECs) are established in Li source/graphite anode contact interfaces to promote Li‐source conversion. Due to the shielding effect of the Li−Ag alloy (50 at . % Li) on Li‐ion diffusion, the dry‐state interfacial corrosion is restricted. The unblocked electronic conduction across the AEC‐involved interface not only facilitates the Li‐source conversion but also accelerates the prelithiation kinetics during the wet‐state process, resulting in an ultrahigh Li‐source utilization (90.7 %). Implementing AEC‐assisted prelithiation in a LiNi 0.5 Co 0.2 Mn 0.3 O 2 pouch cell yields a 35.8 % increase in energy density and stable cycling over 600 cycles. This finding affords significant insights into the construction of an efficient prelithiation technology for the development of high‐energy LIBs.