Lithium salt-concentrated organogels prepared via one-step polymer network formation in acetonitrile-based solutions

We report lithium (Li) salt-concentrated organogel prepared via one-step gelation conducted in an acetonitrile (AN)-based solution containing tetra-arm poly (ethylene glycol) (TetraPEG) and the lithium bis(tri-fluoromethanesulfonyl)amide (LiTFSA) salt at extremely high concentration. The polymer network formation via a Michael addition reaction between thiol-terminated and maleimide-terminated TetraPEG prepolymers suc-cessfully proceeded in concentrated LiTFSA/AN solutions under noncatalytic conditions at room temperature to yield a homogeneous polymer network with high reaction efficiency (>95%). We investigated the electro-chemical properties of the concentrated organogel to apply it as a quasi-solid electrolyte material to the Li-ion capacitors comprising a graphite anode and activated carbon (AC) cathode. The concentrated organogel affor-ded the reversible Li-ion insertion/desertion into/from graphite; however, reactivity depended on the polymer concentration in the organogels. The reversible adsorption/desorption of TFSA anions into/from the AC was observed in the concentrated organogel, which was comparable to that of the corresponding electrolyte solution.

Automated summary

In this study, a lithium salt-concentrated organogel was prepared via one-step gelation. The organogel exhibited efficient polymer network formation and good electrochemical properties, making it a promising quasi-solid electrolyte material for lithium-ion capacitors.