Pentafluoropyridine additive induced SEI film regulation and remarkable performance improvement of the lithium primary batteries

Lithium primary batteries with lithium metal anode are extensively applied in the portable appliances and electronic fields for the high specific energy and power, low self-discharge and wide operating temperature. However, the application of lithium metal anode causes the safety and stability issues. Herein, the pentafluoropyridine (C5F5N) was applied as an electrolyte additive in lithium primary battery, to construct a suitable surface layer on lithium anode to increase the stabilization and electrochemical performance. With C5F5N additive, the discharge capacity of the Li primary battery increases to 422.1 mAh/g at 0.01 C, compared to 62.2 mAh/g of the pristine battery. Meanwhile, the storage performance of the batteries was also greatly enhanced with the C5F5N additive. After stored for 60 days at room temperature, the Li primary battery with additive displays a specific discharge capacity of 180.7 mAh/g, much higher than the pristine battery without additive (43.6 mAh/g). The significant improvements in capacitive and storage performances are attributed to the additive induced inhibition of decomposition of solvents and lithium salts and tuning of SEI composition on lithium anode surface. The C5F5N is a promising electrolyte additive for the further development and application of high-performance Li primary batteries.