In-situ formation of poly(ionic liquid)s with ionic liquid-based plasticizer and lithium salt in electrodes for solid-state lithium batteries

摘要

To realize a solid-state lithium-ion battery with high energy density, in-situ radical polymerization of diallyldimethyl ammonium bis(trifluoromethanesulfonyl)imide (DADMA-NTf2) in the presence of lithium bis(trifluoromethanesulfonyl)imide (LiNTf2) and 1-ethyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (P12NTf(2)) in an electrode with an active material is proposed. After permeating the ternary mixed solution (DADMA-NTf2/LiNTf2/P12NTf(2)) into the electrode, it is solidified by radical polymerization to form homogeneous ionogels directly in the electrodes without any detectable pores or defects. The ionic conductivity of such ionogel, obtained at a feed ratio of DADMA-NTf2:LiNTf2:P12NTf(2) = 56:14:30 wt-% during radical polymerization under air, exceeds 1.0 x 10(-3) S/cm at 50 degrees C. The battery fabricated by simply stacking Li4Ti5O12 anode/glass-fiber membranes/LiNi1/3Mn1/3Co1/3O2 cathodes, all of which involved in-situ formed ionogels, was successfully operated.