Dual strategies of mild C-F scissoring fluorination and local high-concentration electrolyte to enable reversible Li-Fe-F conversion batteries.

Batteries taking conversion-type iron fluorides as energy-dense cathodes provide the possibility for the power electrification of the transportation and aviation industries. However, a safe and low-toxicity synthesis method for fluorides and the design of a compatible electrolyte formula are still challenging. Here, we propose a dual strategy of mild C-F scissoring fluorination and a local high-concentration electrolyte (LHCE) to enable highly reversible Li-Fe-F conversion batteries.

Dual fluorination of polymer electrolyte and conversion-type cathode for high-capacity all-solid-state lithium metal batteries.

All-solid-state batteries are appealing electrochemical energy storage devices because of their high energy content and safety. However, their practical development is hindered by inadequate cycling performances due to poor reaction reversibility, electrolyte thickening and electrode passivation. Here, to circumvent these issues, we propose a fluorination strategy for the positive electrode and solid polymeric electrolyte.

Construction of solid-liquid fluorine transport channel to enable highly reversible conversion cathodes.

Conversion-type iron fluoride is a promising alternative cathode to intercalation oxides because of its higher energy density. However, its intrinsic solid-solid conversion is sluggish during repeated splitting and rebonding of metal-fluorine moieties. Here, we propose a solid-liquid conversion mechanism to activate the fluorine transport kinetics of iron oxyfluorides enabled by fluoride anion receptor of tris(pentafluorophenyl)borane (TPFPB).

Lithium Ion Repulsion-Enrichment Synergism Induced by Core-Shell Ionic Complexes to Enable High-Loading Lithium Metal Batteries.

A core-shell additive with anionic Keggin-type polyoxometalate (POM) cluster as core and N-containing cation of ionic liquid (IL) as shell is proposed to stabilize Li-metal batteries (LMBs). The suspended POM derived complex in ether-based electrolyte is absorbed around the protuberances of anode and triggers a lithiophobic repulsion mechanism for the homogenization of Li redistribution. The gradually released POM cores with negative charge then enrich Li and co-assemble with Li.