Thermally enhanced SEI chemistry via LiNO3 decomposition for high-performance lithium metal batteries

• The high-temperature response of LiNO 3 decomposition is explored. • Accelerated LiNO 3 decomposition promotes Li 3 N abundant SEI with limited LiN x O y . • A uniform SEI (∼10 nm) rich in Li 3 N fosters dense, dendrite-free lithium deposition. • Such SEI on lithium metal anodes enhances durable electrochemical performance. Lithium nitrate (LiNO 3 ) serves as a highly effective electrolyte additive for lithium metal anodes (LMAs), promoting the formation of a Li 3 N-rich solid electrolyte interphase (SEI) that significantly enhances anode stability and extends the lifespan of lithium metal batteries (LMBs). However, the decomposition of LiNO 3 is kinetically hindered by the energy-intensive, eight-electron transfer process to generate Li 3 N. Herein, the temperature-dependent decomposition behavior of LiNO 3 during SEI formation on catalytic current collectors is investigated to accelerate LiNO 3 conversion kinetics and facilitate the formation of a Li 3 N-enriched SEI. Our results demonstrate that elevating the temperature to 60 °C markedly enhances the decomposition kinetics of LiNO 3 on carbon nanotube-coated copper current collectors (Cu@CNT). The increased temperature promotes the uniform and robust formation of ultrathin SEI layers (−10 nm). Consequently, the Cu@CNT electrode processed at 60 °C (denoted as CNT-60) induces the formation of a homogeneously distributed, Li 3 N-abundant SEI. This optimized SEI effectively suppresses lithium dendrite growth, enabling symmetric lithium cells with prelithiated CNT-60 anodes to achieve stable cycling performance for over 2500 h without degradation. Furthermore, the CNT-60 anode demonstrates excellent compatibility and performance in full cells paired with LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NCM622) cathodes. This work highlights the potential of temperature regulation and catalytic current collectors to enhance the utilization of electrolyte additives, providing a promising strategy to address dendrite formation and interface instability in LMAs.