Disclosed is an electrochemical cell, which may be used for advanced rechargeable batteries. The electrochemical cell comprises two or more electrodes within an electrolyte solution, where the electrolyte solution containing (i) an aliphatic or cyclic sulfone and (ii) a metal perfluoroalkylsulfonylimide salt.

The present disclosure relates to electric double layer capacitors (EDLCs) that include an alkylating or arylating agent additive capable of scavenging nucleophilic species generated during operation of the EDLC. The additives for the electric double layer capacitors (EDLCs) including an alkylating or arylating agent are described herein. The alkylating or arylating reagent comprises a compound of the formula I:
R—X  (I)
wherein R and X are described herein.

The present disclosure relates to electric double layer capacitors (EDLCs) that include an alkylating or arylating agent additive capable of scavenging nucleophilic species generated during operation of the EDLC. The additives for the electric double layer capacitors (EDLCs) including an alkylating or arylating agent are described herein. The alkylating or arylating reagent comprises a compound of the formula I:
R—X  (I)
wherein R and X are described herein.

A nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution containing a lithium salt having a specific α,β-dihydroxy carboxylic acid ester structure, phosphono hydroxy carboxylic acid structure, alkoxycarbonyl hydroxy carboxylic acid structure, or formyloxy structure; an energy storage device using the nonaqueous electrolytic solution; and a lithium salt used for the nonaqueous electrolytic solution. This nonaqueous electrolytic solution makes it possible not only to improve the electrochemical characteristics when the energy storage device is used at a high temperature and a high voltage and to improve the capacity retention rate after high-voltage and high-temperature storage, but also to suppress gas generation.

An electrolyte composition includes: a sulfonylimide compound represented by the following general formula (1) as an electrolyte salt; and an amidosulfuric acid component.

LiN(X.sup.1SO.sub.2)(X.sup.2SO.sub.2)  (1) (where X.sup.1 and X.sup.2 are identical to or different from each other, and each represent a fluorine atom, an alkyl group with a carbon number of 1 to 6, or a fluoroalkyl group with a carbon number of 1 to 6).

An electrolytic capacitor includes a capacitor element. The capacitor element includes an anode including a dielectric layer thereon and a cathode member including a conductive polymer and in contact with the dielectric layer. The capacitor element is impregnated with a liquid containing at least one of polyalkylene glycol and derivatives of polyalkylene glycol. The liquid further contains an oxidation inhibitor.

An electrolytic capacitor includes a capacitor element. The capacitor element includes an anode including a dielectric layer thereon and a cathode member including a conductive polymer and in contact with the dielectric layer. The capacitor element is impregnated with a liquid containing at least one of polyalkylene glycol and derivatives of polyalkylene glycol. The liquid further contains an oxidation inhibitor.

An energy storage device can include a cathode, an anode, and a separator between the cathode and the anode, and an electrolyte where the electrolyte includes one or more additives and/or solvent components selected from vinylene carbonate (VC), vinyl ethylene carbonate (VEC), dimethylacetamide (DMAc), hydro fluorinated ether branched cyclic carbonate, a hydro fluorinated ether ethylene carbonate (HFEEC), hydro fluorinated ether (HFE), and fluorinated ethylene carbonate (FEC). The electrolyte may include a carbonate based solvent and one or more solvent components and/or one or more of vinylene carbonate (VC), vinyl ethylene carbonate (VEC), dimethylacetamide (DMAc), hydro fluorinated ether branched cyclic carbonate, a hydro fluorinated ether ethylene carbonate (HFEEC), hydro fluorinated ether (HFE), and fluorinated ethylene carbonate (FEC).

An energy storage device can include a cathode, an anode, and a separator between the cathode and the anode, and an electrolyte where the electrolyte includes one or more additives and/or solvent components selected from vinylene carbonate (VC), vinyl ethylene carbonate (VEC), dimethylacetamide (DMAc), hydro fluorinated ether branched cyclic carbonate, a hydro fluorinated ether ethylene carbonate (HFEEC), hydro fluorinated ether (HFE), and fluorinated ethylene carbonate (FEC). The electrolyte may include a carbonate based solvent and one or more solvent components and/or one or more of vinylene carbonate (VC), vinyl ethylene carbonate (VEC), dimethylacetamide (DMAc), hydro fluorinated ether branched cyclic carbonate, a hydro fluorinated ether ethylene carbonate (HFEEC), hydro fluorinated ether (HFE), and fluorinated ethylene carbonate (FEC).

The present invention provides, as one aspect, an electrolytic solution comprising a compound represented by the following formula (1) and a compound represented by the following formula (2): ##STR00001##
wherein R.sup.1 to R.sup.3 each independently represent an alkyl group or a fluorine atom, R.sup.4 represents an alkylene group, and R.sup.5 represents an organic group comprising a sulfur atom and not comprising a nitrogen atom; and ##STR00002##
wherein R.sup.6 to R.sup.8 each independently represent an alkyl group or a fluorine atom, R.sup.9 represents an alkylene group, and R.sup.10 represents an organic group comprising a nitrogen atom and not comprising a sulfur atom.