Lewis acid fluorine-donating additive enables an excellent semi-solid-state electrolyte for ultra-stable lithium metal batteries

Regulation of a Solid-Electrolyte Interphase and Ion Transfer via Organic Lewis Acid for Stable Li–S Pouch Cells

“…IPFB could coordinate with TFSI − to immobilize it, increase the amount of free Li + , and mitigate anion depletion near the anode surface, supplementing the LiF content in the SEI and improving Li + transfer, hence improving SEI and anode stability. 37 The existence of IPFB residuals in the SEI proved by the I 3d spectra and energy-dispersive spectroscopy (EDS) mappings (Figure S3) also confirms this coordination effect. Therefore, it could be concluded that a more stable SEI with a layered structure is realized via IPFB modulation (Figure 4d).…”

“…The F 1s spectra indicate an obvious preferential reduction tendency of TFSI – during Li deposition and formation of SEI under IPFB regulation, compared with the weaker reduction tendency without IPFB due to the competitive reduction of solvents. IPFB could coordinate with TFSI – to immobilize it, increase the amount of free Li + , and mitigate anion depletion near the anode surface, supplementing the LiF content in the SEI and improving Li + transfer, hence improving SEI and anode stability . The existence of IPFB residuals in the SEI proved by the I 3d spectra and energy-dispersive spectroscopy (EDS) mappings (Figure S3) also confirms this coordination effect.…”

Revealing the Influence of Electron Migration Inside Polymer Electrolyte on Li+ Transport and Interphase Reconfiguration for Li Metal Batteries

“…Unlike SEI in LSC/Zn‐PI/PVC electrolyte, the quantitative concentration of LiF on the surface of Li cycled with Zn‐PI/PVC electrolyte experiences a tendency of first rise and then fall, and the XPS signal of Li metal remains undetected throughout the whole etching course. Unfortunately, except for the sluggish Li + transport inside bulk Zn‐PI/PVC electrolyte, the high Li + diffusion barrier through thick LiF interphase may also exert adverse impact for Li deposition kinetics [21a] . More importantly, the loose LiF architecture also makes it challenging to prohibit electron penetration.…”

Solid Electrolyte Interphase on Lithium Metal Anodes

“…For example, AlF 3 can be incorporated as a Lewis acid additive into a polymer electrolyte through an in situ polymerization process. [109] This additive facilitates the formation of a robust and highly adhesive SEI film, promoting rapid Li + diffusion kinetics and effectively protecting the lithium metal anode from undesired side reactions. By incorporating this additive, the LiFePO 4 j Li battery exhibits long-term cycling performance with a capacity retention of 93.5 % over 340 cycles at 3 C. Researchers also fully utilized the synergistic effect of trimethyl phosphate and lithium difluoro(oxalate)borate (LiDFOB) in the in situ polymer electrolyte to promote the formation of a SEI film containing BÀ O, BÀ F, LiF, and Li 3 P on lithium metal anode.…”