An electrolyte solution containing a compound represented by the following formula (1): ##STR00001##
wherein R.sup.101 and R.sup.102 are the same as or different from each other and are each a hydrogen atom, a fluorine atom, or an alkyl group optionally containing a fluorine atom; and R.sup.103 is an alkyl group or an organic group containing an unsaturated carbon-carbon bond. Also disclosed is an electrochemical device and lithium ion secondary battery including the electrolyte solution, and a module including the electrochemical device or lithium ion secondary battery.

A flexible energy storage device with a redox-active polymer hydrogel electrolyte is provided. The flexible energy storage device can include a pair of electrodes separated by the redox-active polymer hydrogel electrolyte. The redox-active polymer hydrogel electrolyte can include a polymer hydrogel, charge balancing anions and redox-active transition metal cations at least one selected from the group consisting of vanadium, chromium, manganese, cobalt, and copper. The flexible energy storage device may retain greater than 75% of an unbent specific capacitance when bent at an angle of 10° to 170°.

A method is disclosed for preparation of nitrogen-doped graphene having these steps: a) providing a dispersion of fluorinated graphite; b) subjecting the dispersion of fluorinated graphite to sonication and/or mechanical treatment and/or thermal treatment; c) contacting the product from step b) with an azide reagent at a temperature within the range of 40 to 200° C.; d) separating the solid product formed in step c) from the mixture; e) dialyzing the product obtained in step d) against water. A nitrogen-doped graphene containing at least 8.9 at. % of nitrogen and up to 16.6 at. % of fluorine is yielded, wherein the at. % are relative to the total atoms present in the sample and determined by X-ray photoelectron spectroscopy (XPS) using an Al-Kα source; and having a density above 1.2 g/cm3 when pressed at 80 kN for 1 min. This nitrogen-doped graphene is particularly useful as a supercapacitor material.

An electrolytic solution for an electrochemical device, including: a cation (C) that is a monovalent to trivalent metal ion; an anion (A); a solvent (SO) that is a compound having a molecular weight of 1,000 or less; and a polymer (P) that has a weight-average molecular weight of more than 10,000, wherein a content ratio of the solvent (SO) relative to 1 mol of the cation (C) is 0.5 to 4 mol, and a content ratio of the polymer (P) is 0.5% by weight or more. Also provided are a plastic composition, an electrode sheet, an insulating layer, and an electrochemical device including the electrolytic solution, as well as producing methods of these.

A technique that can improve ionic conductivity is provided.

An electrolyte includes an inorganic composite particle that is a composite of an inorganic particle with a compound having a betaine structure and one or more functional groups selected from a (meth)acryloxy group, a Si(OR).sub.3 group (R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), and an Al(OR).sub.2 group (R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms).

An ether-bridged dication is provided with two monovalent cations bonded via a carbon chain having ether group(s). The ether-bridged dication, monovalent cations, and anions are contained together within an ionic liquid electrolyte which is applied to a charge storage device. The ether-bridged dication, the ionic liquid electrolyte, and the charge storage device have operational abilities at room temperatures or below, and a reachable working potential of 3.5 V.

An ether-bridged dication is provided with two monovalent cations bonded via a carbon chain having ether group(s). The ether-bridged dication, monovalent cations, and anions are contained together within an ionic liquid electrolyte which is applied to a charge storage device. The ether-bridged dication, the ionic liquid electrolyte, and the charge storage device have operational abilities at room temperatures or below, and a reachable working potential of 3.5 V.

An electrolytic solution containing: a compound (1) represented by the following formula (1):

##STR00001##

wherein R.sup.101 is a C2-C7 organic group and optionally includes at least one selected from the group consisting of a hetero atom and an unsaturated bond; and R.sup.102 is a C1-C3 organic group and optionally includes at least one selected from the group consisting of a hetero atom and an unsaturated bond.

A current collector of an electrochemical actuator is proposed, the current collector being coated with an interfacing layer, the interfacing layer being formed by coating on the current collector with a composition, the composition being formed by particles, at least 50% of the particles having a mean diameter by volume of less than or equal to 10 micrometers.

A current collector of an electrochemical actuator is proposed, the current collector being coated with an interfacing layer, the interfacing layer being formed by coating on the current collector with a composition, the composition being formed by particles, at least 50% of the particles having a mean diameter by volume of less than or equal to 10 micrometers.