The invention relates to a device of the hybrid supercapacitor type comprising at least one cell comprising: a porous positive electrode comprising activated carbon; a negative electrode comprising a carbonaceous material capable of inserting an alkaline element other than lithium, this carbonaceous material being different from the activated carbon used at the positive electrode; and a non-aqueous electrolyte comprising a salt selected from salts of an alkaline metal other than lithium.

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.

An electrolytic solution including a heteroelement-containing organic solvent at a mole ratio of not greater than 1.5 relative to a metal salt, the heteroelement-containing organic solvent containing a linear carbonate represented by general formula (1) below, the metal salt being a metal salt whose cation is an alkali metal, an alkaline earth metal, or aluminum and whose anion has a chemical structure represented by general formula (2) below.

R.sup.10OCOOR.sup.11  general formula (1)

(R.sup.21X.sup.21)(R.sup.22SO.sub.2)N  general formula (2)

Disclosed is a high-capacity electrochemical energy storage device in which a conversion reaction proceeds as the oxidation-reduction reaction, and the separation (hysteresis) between the electrode potentials for oxidation and reduction is small. The electrochemical energy storage device includes a first electrode including a first active material, a second electrode including a second active material, and a non-aqueous electrolyte interposed between the first and second electrodes. At least one of the first and second active materials is a metal salt having a polyatomic anion and a metal ion, and the metal salt is capable of oxidation-reduction reaction involving reversible release and acceptance of the polyatomic anion.

Disclosed is a high-capacity electrochemical energy storage device in which a conversion reaction proceeds as the oxidation-reduction reaction, and the separation (hysteresis) between the electrode potentials for oxidation and reduction is small. The electrochemical energy storage device includes a first electrode including a first active material, a second electrode including a second active material, and a non-aqueous electrolyte interposed between the first and second electrodes. At least one of the first and second active materials is a metal salt having a polyatomic anion and a metal ion, and the metal salt is capable of oxidation-reduction reaction involving reversible release and acceptance of the polyatomic anion.

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).