Revolutionizing Lithium–Metal Batteries: A Synergistic Effect of P2O5 and LiNO3 Composite Protection Layer in Stabilizing the Li-Metal Anode Electrode

Additives play a pivotal role in advancing lithium metal batteries by mitigating dendrite formation. Among these, lithium nitrate (LiNO3) and phosphorus pentoxide (P2O5) have demonstrated their potential in forming a stable solid electrolyte interphase (SEI) layer encompassing LiPO2F2, Li3PO4, and Li3N during electrochemical decomposition. This SEI layer effectively suppresses dendrite growth, thereby enhancing the cycling performance of lithium metal batteries. Nevertheless, both LiNO3 and P2O5 are relatively less soluble, especially in carbonate-based electrolytes. To surmount this limitation, we introduce an approach involving the incorporation of both salts in a ceramic composite protective layer applied to Li metal surface. This ceramic composite protective layer acts as a reservoir, enabling the gradual release of LiNO3 and P2O5 into the electrolyte during battery cycling. This controlled release mechanism fosters the formation of a stable SEI layer comprising LiPO2F2, Li3PO4, and Li3N, effectively suppressing dendrite growth and significantly improving the cycling performance of lithium metal batteries. Our innovative composite strategy opens avenues for advancing lithium–metal battery technology, addressing critical challenges, and unlocking the full potential of this energy storage system.