In Situ Construction of Zinc Carbodiimides-Derived Composite Artificial Protective Layer for High Performance Lithium...

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.