Spatially Regulated Lithium Plating via Li 2 O‐Rich Interphase Enables Durable Fast‐Charging Hybrid Lithium Batteries

Abstract

ABSTRACT Improving energy density and fast‐charging capability in lithium‐ion batteries (LIBs) is increasingly constrained by the limitations of graphite intercalation. While reducing the negative‐to‐positive (N/P) capacity ratio enables higher energy density through hybrid lithium (Li) intercalation/plating, uncontrolled Li growth leads to rapid cell degradation. Here, we demonstrate a spatially regulated Li plating mechanism enabled by a lithium oxide (Li 2 O)‐rich solid electrolyte interphase (SEI). By tailoring the electrolyte solvation structure, we induce the formation of a homogeneous, Li 2 O‐dominant interphase that fundamentally alters Li nucleation and growth energetics. Quantitative analysis reveals that this engineered interphase promotes uniform Li deposition around graphite particles and throughout the electrode bulk, effectively suppressing localized Li accumulation. Consequently, hybrid cells operating at a low N/P ratio of 0.7 with commercial‐level NMC811 cathodes (3–5 mAh cm −2 ) achieve over 1000 cycles with 80% capacity retention and sustain 4C (15 min) fast charging for more than 1000 cycles. These results redefine the performance ceiling of hybrid Li‐ion/Li‐metal systems and establish interphase‐mediated spatial regulation as a governing design principle for next‐generation, high‐energy, and durable Li batteries.