A battery includes a positive electrode containing sulfur, a negative electrode containing a material for occluding and releasing a lithium ion, and an electrolytic solution. The electrolytic solution contains at least one of a liquid complex and a liquid salt in which a polysulfide is insoluble or almost insoluble, and a solvent in which a polysulfide is soluble. The electrolytic solution has a Li.sub.2S.sub.8 saturation sulfur concentration of 10 mM or more and 400 mM or less.

Materials and methods for preparing electrode film mixtures and electrode films including reduced damage bulk active materials are provided. In a first aspect, a method for preparing an electrode film mixture for an energy storage device is provided, comprising providing an initial binder mixture comprising a first binder and a first active material, processing the initial binder mixture under high shear to form a secondary binder mixture, and nondestructively mixing the secondary binder mixture with a second portion of active materials to form an electrode film mixture.

Materials and methods for preparing electrode film mixtures and electrode films including reduced damage bulk active materials are provided. In a first aspect, a method for preparing an electrode film mixture for an energy storage device is provided, comprising providing an initial binder mixture comprising a first binder and a first active material, processing the initial binder mixture under high shear to form a secondary binder mixture, and nondestructively mixing the secondary binder mixture with a second portion of active materials to form an electrode film mixture.

Provided are plastic crystal-type solid electrolyte having high ion conductivity and a power storage device using the solid electrolyte. The solid electrolyte contains a plastic crystal doped with an electrolyte. The plastic crystal contains two or more types of cations in total, at least one of which is selected from the group of imidazoliums and quaternary ammoniums.

A battery having a metal sulfide electrode, and an aluminum containing electrolyte and methods are shown. In one example, the electrolyte includes one or more organic salts. In one example, the metal sulfide includes molybdenum sulfide. In one example, the metal sulfide includes titanium sulfide.

A battery having a metal sulfide electrode, and an aluminum containing electrolyte and methods are shown. In one example, the electrolyte includes one or more organic salts. In one example, the metal sulfide includes molybdenum sulfide. In one example, the metal sulfide includes titanium sulfide.

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The positive electrode includes a positive electrode active material. The positive electrode active material includes a lithium transition metal composite oxide including Ni, Al, and at least one of Co and Mn. The lithium transition metal composite oxide is represented by a composition formula below: Li.sub.αNi.sub.(1−s−x2−z) Co.sub.x1Mn.sub.x2Al.sub.yM.sub.zO.sub.2+β (where 0.95≤α≤1.05, 0.5≤1−x1−x2−y−z≤0.95, 0≤x1≤0.04, 0≤x2≤0.1, 0≤y≤0.1, 0≤z≤0.1, −0.05≤β≤0.05, M is at least one selected from the group consisting of Ti, Zr, Nb, Mo, W, Fe, Zn, B, Si, Mg, Ca, Sr, and Y). The nonaqueous electrolyte includes an isocyanuric acid ester component having at least one unsaturated organic group with an unsaturated carbon-carbon bond.

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The positive electrode includes a positive electrode active material. The positive electrode active material includes a lithium transition metal composite oxide including Ni, Al, and at least one of Co and Mn. The lithium transition metal composite oxide is represented by a composition formula below: Li.sub.αNi.sub.(1−s−x2−z) Co.sub.x1Mn.sub.x2Al.sub.yM.sub.zO.sub.2+β (where 0.95≤α≤1.05, 0.5≤1−x1−x2−y−z≤0.95, 0≤x1≤0.04, 0≤x2≤0.1, 0≤y≤0.1, 0≤z≤0.1, −0.05≤β≤0.05, M is at least one selected from the group consisting of Ti, Zr, Nb, Mo, W, Fe, Zn, B, Si, Mg, Ca, Sr, and Y). The nonaqueous electrolyte includes an isocyanuric acid ester component having at least one unsaturated organic group with an unsaturated carbon-carbon bond.

This electricity storage device which is configured to contain an ionic liquid represented by formula (1) in, for example, an electrolyte or an electrode has the advantage of being usable in a low-temperature environment in spite of the ionic liquid contained therein.

##STR00001##

(In the formula, each of R.sup.1 and R.sup.2 independently represents an alkyl group having 1-5 carbon atoms; and n represents 1 or 2.)

This electricity storage device which is configured to contain an ionic liquid represented by formula (1) in, for example, an electrolyte or an electrode has the advantage of being usable in a low-temperature environment in spite of the ionic liquid contained therein.

##STR00001##

(In the formula, each of R.sup.1 and R.sup.2 independently represents an alkyl group having 1-5 carbon atoms; and n represents 1 or 2.)