Regulating Lithium Intercalation/Plating Competition To Enhance Low-Temperature Performance of Li-Ion Batteries

The severe capacity degradation of Li-ion batteries at subzero temperatures stems from the premature onset of lithium plating at graphite anodes, which intrudes into the Li-ion intercalation regime and consumes active lithium. This work deepens the mechanistic understanding of this phenomenon by identifying the critical depth of discharge (DOD) and potential at which lithium plating begins and by revealing that Li-ion intercalation is intrinsically more sensitive to low temperatures than deintercalation. Guided by this insight, we propose and implement a strategy to delay the DOD threshold for the plating onset through interfacial engineering of the solid electrolyte interphase (SEI). An inorganic-rich SEI is constructed using a carbonate-based electrolyte (nff-LB005) containing LiNO₃, FEC, and LiFSI, which reduces interfacial resistance, mitigates the low-temperature rise in intercalation overpotential, and shifts the plating onset to higher DOD, enabling more complete intercalation before plating. As a result, graphite||Li cells achieve capacities of 320 mAh g^-1 at -20 °C and 260 mAh g^-1 at -30 °C, while NCM811||graphite full cells retain 98% capacity over 400 cycles at -30 °C. This interfacial-engineering approach offers an effective route to high-energy Li-ion batteries with superior low-temperature performance.