Fluorine-free LiPCP electrolyte in Li-ion batteries: Insights from full-cell systems with aqueous-processed electrodes

As demand for energy storage grows, developing more sustainable lithium-ion batteries (LIBs) has become a priority, and fluorine-free cells offer an attractive solution. In this work, the performance of lithium 1,1,2,3,3-pentacyanopropenide (LiPCP), a novel salt is investigated in combination with lithium iron phosphate (LFP) cathode and synthetic graphite (SG) and silicon oxide (SiO x ) anodes all processed with water-based binders. The study spans from coin cell to monolayer pouch cell configuration, demonstrating proof-of-concept operation of this cell chemistry. The LFP||SG cells showed a capacity of 84.4 mAh g −1 at C/10 with 80% state of health (SOH) after 50 cycles, while post-cycling analysis revealed Na- and N-rich crystalline deposits on the electrode surfaces. X-ray photoelectron spectroscopy (XPS) analysis suggested higher solvent decomposition in LFP||SiO x cells, a trend also supported by FTIR analysis, while more anion-derived SEI was found in LFP||SG cells. These findings suggest that the improved performance of the LFP||SG cell can be attributed to differences in decomposition mechanisms and their impact on the interphase, without overlooking the intrinsic nature of SiO x in terms of conversion reactions and volume changes, which further contribute to performance degradation.