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

Automated summary

This study presents a trisalt electrolyte design to construct a stable inorganics-rich solid electrolyte interphase on the lithium metal anode. The resulting lithium metal batteries exhibit excellent electrochemical performance and thermal stability, leading to extended cycle life and improved safety compared to conventional cells.