A nonaqueous electrolyte battery includes: a positive electrode, a negative electrode, and a nonaqueous electrolyte, wherein the positive electrode contains, as a positive electrode active material, a positive electrode material having a surface composition represented by the following formula (I); the nonaqueous electrolyte contains a halogenated carbonate represented by any of the following formulae (1) to (2) and an alkylbenzene represented by the following formula (3); a content of the halogenated carbonate is 0.1% by mass or more and not more than 50% by mass relative to the nonaqueous electrolyte; and a content of the alkylbenzene is 0.1% by mass or more and not more than 5% by mass relative to the nonaqueous electrolyte

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A nonaqueous electrolyte battery includes: a positive electrode, a negative electrode, and a nonaqueous electrolyte, wherein the positive electrode contains, as a positive electrode active material, a positive electrode material having a surface composition represented by the following formula (I); the nonaqueous electrolyte contains a halogenated carbonate represented by any of the following formulae (1) to (2) and an alkylbenzene represented by the following formula (3); a content of the halogenated carbonate is 0.1% by mass or more and not more than 50% by mass relative to the nonaqueous electrolyte; and a content of the alkylbenzene is 0.1% by mass or more and not more than 5% by mass relative to the nonaqueous electrolyte

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Electrolyte materials for use in electrochemical cells, electrochemical cells comprising the same, and methods of making such materials and cells, are generally described. In some embodiments, the materials, processes, and uses described herein relate to electrochemical cells comprising sulfur and lithium such as, for example, lithium sulfur batteries.

Various embodiments of the present disclosure describe energy storage devices. In one example, an energy storage device includes an anode having a plurality of active material particles, a cathode having a transition metal oxide material, and an electrolyte including a room temperature ionic liquid to couple the anode to the cathode. Each of the plurality of anode active material particles have a particle size of between about one micrometer and about fifty micrometers. One or more of the plurality of anode active material particles are enclosed by and in contact with a membrane coating permeable to lithium ions.

Various embodiments of the present disclosure describe energy storage devices. In one example, an energy storage device includes an anode having a plurality of active material particles, a cathode having a transition metal oxide material, and an electrolyte including a room temperature ionic liquid to couple the anode to the cathode. Each of the plurality of anode active material particles have a particle size of between about one micrometer and about fifty micrometers. One or more of the plurality of anode active material particles are enclosed by and in contact with a membrane coating permeable to lithium ions.

An electrolyte solution includes a solvent; an electrolyte salt; and a LA:LB complex represented by the following general formula I: [(FnA)x-L] (I) In formula I, A is boron or phosphorous, F is fluorine, L is an aprotic organic amine, n is 3 or 5, when n=3, A is boron, and when n=5, A is phosphorous, x is an integer from 1-3, and at least one N atom of the aprotic organic amine, L, is bonded directly to A. The LA:LB complex is present in the solution in an amount of between 0.01 and 5.0 wt. %, based on the total weight of the electrolyte solution.

[(F.sub.nA).sub.x-L]  (I)

An electrolyte solution includes a solvent; an electrolyte salt; and a LA:LB complex represented by the following general formula I: [(FnA)x-L] (I) In formula I, A is boron or phosphorous, F is fluorine, L is an aprotic organic amine, n is 3 or 5, when n=3, A is boron, and when n=5, A is phosphorous, x is an integer from 1-3, and at least one N atom of the aprotic organic amine, L, is bonded directly to A. The LA:LB complex is present in the solution in an amount of between 0.01 and 5.0 wt. %, based on the total weight of the electrolyte solution.

[(F.sub.nA).sub.x-L]  (I)

Disclosed are: a non-aqueous electrolyte for a lithium secondary battery containing 1-20 parts by weight of a cyano group-containing pyrimidine-based compound on the basis of 100 parts by weight of an organic solvent; and a lithium secondary battery comprising the same.

Disclosed are: a non-aqueous electrolyte for a lithium secondary battery containing 1-20 parts by weight of a cyano group-containing pyrimidine-based compound on the basis of 100 parts by weight of an organic solvent; and a lithium secondary battery comprising the same.

Provided are a nonaqueous electrolyte capable of providing a nonaqueous electrolyte energy storage device with reduced direct current resistance and an increased capacity retention ratio after charge-discharge cycles, a nonaqueous electrolyte energy storage device including such a nonaqueous electrolyte, and a method for producing such a nonaqueous electrolyte energy storage device. One mode of the present invention is a nonaqueous electrolyte for an energy storage device, containing an additive represented by the following Formula (1) or Formula (2). In Formula (1), R.sup.1 to R.sup.4 are each independently a hydrogen atom or a group represented by —NR.sup.a.sub.2, —OR.sup.a, —SR.sup.a, etc., with the proviso that at least one of R.sup.1 to R.sup.4 is a group represented by —OR.sup.a, —SR.sup.a, —COOR.sup.a, —COR.sup.a, —SO.sub.2R.sup.a, or —SO.sub.3R.sup.a. In Formula (2), R.sup.5 to R.sup.7 are each independently a hydrogen atom or a group represented by —NR.sup.b.sub.2, —OR.sup.b, or —SR.sup.b, with the proviso that at least one of R.sup.5 to R.sup.7 is a group represented by —SR.sup.b. ##STR00001##