Electrochemically and Thermally Stable Inorganics-Rich Solid Electrolyte Interphase for Robust Lithium Metal Batteries

Severe dendrite growth and high-level activity of the lithium metal anode lead to a short life span and poor safety, seriously hindering the practical applications of lithium metal batteries. With a trisalt electrolyte design, an F-/N-containing inorganics-rich solid electrolyte interphase on a lithium anode is constructed, which is electrochemically and thermally stable over long-term cycles and safety abuse conditions. As a result, its Coulombic efficiency can be maintained over 98.98% for 400 cycles. An 85.0% capacity can be retained for coin-type full cells with a 3.14 mAh cm-2 LiNi0.5Co0.2Mn0.3O2 cathode after 200 cycles and 1.0 Ah pouch-type full cells with a 4.0 mAh cm-2 cathode after 72 cycles. During the thermal runaway tests of a cycled 1.0 Ah pouch cell, the onset and triggering temperatures were increased from 70.8 degrees C and 117.4 degrees C to 100.6 degrees C and 153.1 degrees C, respectively, indicating a greatly enhanced safety performance. This work gives novel insights into electrolyte and interface design, potentially paving the way for high-energy-density, long-life-span, and thermally safe lithium metal batteries. An F-/N-containing inorganics-rich solid electrolyte interphase is constructed, which is electrochemically and thermally stable during the long-term cycles and safety abuse conditions. More than 6 times longer cycles compared with routine cells are achieved in 1.0 Ah pouch-type cells. The onset and triggering temperatures during the thermal runaway are increased from 70.8 and 117.4 to 100.6 and 153.1 degrees C, respectively.image