Solvation Structure Tuning Induces LiF/Li3 N-Rich CEI and SEI Interfaces for Superior Li/CFx Batteries

Small. 2023 Dec;19(49):e2303149. doi: 10.1002/smll.202303149. Epub 2023 Aug 22.

Abstract

The electrode/electrolyte interfaces play an important role in the electrochemical reaction kinetics to alleviate the severe polarization and voltage hysteresis in lithium primary batteries. Herein, C5 F5 N is proposed as an electrolyte additive to tune the characteristics of the electrode/electrolyte interfaces. The Li/CFx primary battery with C5 F5 N additive exhibits an excellent discharge-specific capacity of 981.4 mAh g-1 (0.1 C), a remarkable high-rate capability of 598 mAh g-1 (15 C), and an outstanding energy/power density of 1068.7 Wh kg-1 /24362.5 W kg-1 . It also shows remarkable storage performance with 717.2 mAh g-1 at 0.1 C after storage at 55 °C for 2 months. The excellent performance of the Li/CFx batteries is closely related to the improved and stable Li3 N/LiF-rich homogeneous interfaces induced by the C5 F5 N additive, which results in uniform distribution of Li+ flux, facilitated electrochemical kinetics, and increased rate capability of Li/CFx battery. Therefore, C5 F5 N is expected to be a promising electrolyte additive, and the related electrode/electrolyte interface engineering provides an effective and facile strategy to increase the performance of the lithium primary battery.

Keywords: C5F5N electrolyte additive; Li/CFx batteries; cathode electrolyte interfaces; solid electrolyte interfaces; solvation structures.