High-Performance Lithium Metal Batteries with a Wide Operating Temperature Range in Carbonate Electrolyte by Manipulating Interfacial Chemistry

Development of high-performance lithium metal batteries with a wide operating temperature range is highly challenging, especially in carbonate electrolyte. Herein, a multifunctional high-donor-number solvent, tris(pyrrolidinophosphine) oxide (TPPO), is introduced into carbonate electrolyte to regulate both electrode-electrolyte interfaces. On the one hand, lithium nitrate can be easily dissolved in carbonate electrolyte because of the strong interaction between TPPO and Li+, resulting in the formation of a robust and ionic conductive Li3N-rich solid electrolyte interphase, which efficiently inhibits the formation of lithium dendrites. On the other hand, TPPO can be preferentially oxidized into an ultrathin and robust cathode electrolyte interphase, significantly suppressing electrolyte decomposition. As a result, the TPPO-containing electrolyte enables stable lithium stripping/plating cycling performance (1000 h at 3 mA cm(-2) and 3 mAh cm(-2)). Furthermore, Li/LiFePO4 cells exhibit stable cycling performance even at temperatures as high as 70 degrees C and as low as -15 degrees C, demonstrating their potential in temperature tolerance.

Automated summary

In this study, a new solvent TPPO was introduced to improve the carbonate electrolyte and achieve stable cycling performance of lithium metal batteries. The interaction between TPPO and Li+ can prevent the formation of lithium dendrites and suppress electrolyte decomposition, enabling high stability over a wide temperature range (-15 to 70 degrees Celsius).