Low-Cost Li∥SPAN Batteries Enabled by Sustained Additive Release

Batteries with energy densities exceeding that of current lithium-ion cells with reduced materials cost are vital to the future of electric transportation. Although Li parallel to sulfurized polyacrylonitrile (SPAN) batteries have the potential to meet both of these goals, the integration of low-cost electrolytes that are simultaneously stable with both Li and SPAN limits their application. Herein, we present a scalable approach to remedy this issue. This approach utilizes LiNO3 as a solid additive to the cathode, which is specifically enabled by an electrolyte based on diethyl ether (DEE), having sparing solubility to LiNO3 and a Li metal cycling efficiency of 99.0%. The sustained release of LiNO3 into the electrolyte was found to produce a cathode electrolyte interphase (CEI) composed of S-O and F species that is correlated with a SPAN cycling retention of 85% after 200 cycles. This interphase was characterized via X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and scanning transmission electron spectroscopy (STEM). This endowed stability on the cathode side, in addition to the high Li metal reversibility, allowed for the assembly of a 40 mu m Li parallel to 3.5 mAh cm(-2) SPAN (2 wt % LiNO3) full-cell that exhibited stable cycling over 100 cycles. This study provides a viable method for the construction of Li parallel to SPAN batteries with a nonfluorinated electrolyte at a dilute salt concentration, allowing for the low intrinsic cost of SPAN to carry over to the system level.

Automated summary

The study introduces a feasible method to address the integration issue of low-cost electrolytes in lithium parallel to sulfurized polyacrylonitrile (SPAN) batteries by adding solid LiNO3 to the electrolyte. This approach achieves high cycling retention and stable cycling performance, providing a viable method for constructing Li parallel to SPAN batteries with a non-fluorinated electrolyte.