In Situ Construction of Zinc Carbodiimides‐Derived Composite Artificial Protective Layer for High Performance Lithium Metal Batteries

Due to high theoretical capacity and low electrochemical potential, lithium metal is regarded as an ideal anode material for high-energy-density rechargeable lithium metal batteries (LMBs). However, the practical application of LMBs is inevitably hindered by uncontrollable lithium dendrite growth and unstable heterogeneous interface during repeated Li plating/stripping cycles. Herein, a simple and effective strategy is proposed for lithium metal anode protection via an artificial organic-inorganic interfacial layer generated by the in situ reaction of Zn carbodiimide (ZnNCN) with lithium (ZC@Li). Benefiting from the organic Li₂NCN and inorganic metallic Zn generated by the in situ reaction, an interphase layer with fast Li⁺ transport kinetics and superior ionic conductivity is formed. Furthermore, during Li plating/stripping processes, the Li₃N-enriched interphase synergistically regulates uniform Li⁺ flux and suppresses lithium dendrite growth. Compared to cells using bare Li anodes, the assembled ZC@Li symmetric cell exhibited an extended cycling stability of more than 2000 cycles at 1 mA cm^-2, and the full cells based on LiFePO₄ cathode exhibited an excellent cycling stability of 124.78 mAh g^-1 after 1500 cycles at 1C, achieving high capacity and durability. This work provides a feasible pathway toward high-performance LMBs through simple and scalable interfacial modification.