A method for preparing a battery electrolyte composition comprising: preparing in-situ in solution a plurality of metal oxide nanoparticles by reaction of a metal oxide precursor material; reacting in-situ in solution the plurality of metal oxide nanoparticles with an ionic-liquid functionalized coupling agent material comprising at least one of a nitrogen cation moiety selected from ammonium, pyridinium, piperidinium and pyrrolidinium nitrogen cation moieties, a phosphorus cation moiety and a sulfur cation moiety; and a counter anion, each nitrogen cation moiety selected from ammonium, pyridinium, piperidinium and pyrrolidinium nitrogen cation moieties, phosphorus cation moiety or sulfur cation moiety being tethered to only a single nanoparticle to provide a nanoparticle tethered ionic-liquid nanoscale ionic material; mixing the nanoparticle tethered ionic-liquid nanoscale ionic material with a host material, wherein the host material is not tethered to any of the plurality of nanoparticles; and adding a lithium salt, wherein the host material comprises a plurality of additional ionic liquid molecules, or wherein the host material comprises at least one material selected from the groups consisting of: solvents selected from the group consisting of carbonates, ethers, acetamides, acetontrile, symmetric sulfones, 1,3-dioxolanes, glymes, siloxanes and blends of the foregoing solvents; and polymers selected from the group consisting of polyethylene oxides, polypropylene oxides, polyacrylonitriles, polysiloxanes, polyimides, polyethers, sulfonated polyimides, perfluorinated polymers and blends of the foregoing polymers. preparing in-situ in solution a plurality of metal oxide nanoparticles by reaction of a metal oxide precursor material; reacting in-situ in solution the plurality of metal oxide nanoparticles with an ionic-liquid functionalized coupling agent material comprising at least one of a nitrogen cation moiety selected from ammonium, pyridinium, piperidinium and pyrrolidinium nitrogen cation moieties, a phosphorus cation moiety and a sulfur cation moiety; and a counter anion, each nitrogen cation moiety selected from ammonium, pyridinium, piperidinium and pyrrolidinium nitrogen cation moieties, phosphorus cation moiety or sulfur cation moiety being tethered to only a single nanoparticle to provide a nanoparticle tethered ionic-liquid nanoscale ionic material; at least one of a nitrogen cation moiety selected from ammonium, pyridinium, piperidinium and pyrrolidinium nitrogen cation moieties, a phosphorus cation moiety and a sulfur cation moiety; and a counter anion, each nitrogen cation moiety selected from ammonium, pyridinium, piperidinium and pyrrolidinium nitrogen cation moieties, phosphorus cation moiety or sulfur cation moiety being tethered to only a single nanoparticle to provide a nanoparticle tethered ionic-liquid nanoscale ionic material; mixing the nanoparticle tethered ionic-liquid nanoscale ionic material with a host material, wherein the host material is not tethered to any of the plurality of nanoparticles; and adding a lithium salt, wherein the host material comprises a plurality of additional ionic liquid molecules, or wherein the host material comprises at least one material selected from the groups consisting of: solvents selected from the group consisting of carbonates, ethers, acetamides, acetontrile, symmetric sulfones, 1,3-dioxolanes, glymes, siloxanes and blends of the foregoing solvents; and polymers selected from the group consisting of polyethylene oxides, polypropylene oxides, polyacrylonitriles, polysiloxanes, polyimides, polyethers, sulfonated polyimides, perfluorinated polymers and blends of the foregoing polymers. solvents selected from the group consisting of carbonates, ethers, acetamides, acetontrile, symmetric sulfones, 1,3-dioxolanes, glymes, siloxanes and blends of the foregoing solvents; and polymers selected from the group consisting of polyethylene oxides, polypropylene oxides, polyacrylonitriles, polysiloxanes, polyimides, polyethers, sulfonated polyimides, perfluorinated polymers and blends of the foregoing polymers.