An electrochemical device includes a positive electrode that includes an active layer containing a polyaniline compound. An infrared absorption spectrum of the active layer has a first peak, a second peak, a third peak, and a fourth peak that are derived from the polyaniline compound. The first peak appears at a wave number in a range from 1,100 cm.sup.−1 to 1,200 cm.sup.−1, inclusive. The second peak appears at a wave number in a range of more than 1,200 cm.sup.−1 and less than or equal to 1,400 cm.sup.−1. The third peak appears at a wave number in a range from 1,450 cm.sup.−1 to 1,550 cm.sup.−1, inclusive. And the fourth peak appears at a wave number in a range of more than 1,550 cm.sup.−1 and less than or equal to 1,650 cm.sup.−1. In a discharged state, a ratio I.sub.D3/I.sub.D0 of a height I.sub.D3 of the third peak to a total I.sub.D0 of heights of the first peak, the second peak, the third peak, and the fourth peak ranges from 0.18 to 1.42, inclusive.

Disclosed herein is a composite material that is formed from a polymer, acetylated collagen and graphene, which can be used as a super-capacitor material. Also disclosed herein are methods of making said composite material and its intermediates, as well as a supercapacitor made using said material.

Disclosed herein is a composite material that is formed from a polymer, acetylated collagen and graphene, which can be used as a super-capacitor material. Also disclosed herein are methods of making said composite material and its intermediates, as well as a supercapacitor made using said material.

An electricity storage device includes a negative electrode having a layered structure that includes an organic backbone layer containing an aromatic compound having an aromatic ring structure, the aromatic compound being in the form of dicarboxylate anions, and an alkali metal element layer containing an alkali metal element coordinated with oxygen in the dicarboxylate anions to form a backbone, a positive electrode that provides electric double-layer capacity, and a nonaqueous electrolyte solution provided between the negative electrode and the positive electrode, the nonaqueous electrolyte solution containing an alkali metal salt. The layered structure may be provided in layers by a π-electron interaction of the aromatic compound and may have a monoclinic crystal structure belonging to the space group P2.sub.1/c. The positive electrode may contain activated carbon having a specific surface area of 1,000 m.sup.2/g or more.

An electricity storage device includes a negative electrode having a layered structure that includes an organic backbone layer containing an aromatic compound having an aromatic ring structure, the aromatic compound being in the form of dicarboxylate anions, and an alkali metal element layer containing an alkali metal element coordinated with oxygen in the dicarboxylate anions to form a backbone, a positive electrode that provides electric double-layer capacity, and a nonaqueous electrolyte solution provided between the negative electrode and the positive electrode, the nonaqueous electrolyte solution containing an alkali metal salt. The layered structure may be provided in layers by a π-electron interaction of the aromatic compound and may have a monoclinic crystal structure belonging to the space group P2.sub.1/c. The positive electrode may contain activated carbon having a specific surface area of 1,000 m.sup.2/g or more.

An MOFs composite electrode material for supercapacitors includes: a Ni-BSC matrix, and a PEDOT coating layer coated on the Ni-BTC matrix, wherein a molar ratio of EDOT to Ni-BTC is 1:(1-4) based on a molar amount of EDOT monomer. A method for preparing the MOFs composite electrode material includes steps of: using nickel nitrate hexahydrate and benzenetricarboxylic acid as raw materials to synthesize Ni-BTC by a hydrothermal method; and using a liquid phase method to grow PEDOT on a surface of the Ni-BTC. An MOFs composite electrode slurry and a working electrode for the supercapacitors including the above MOFs composite electrode material or a MOFs composite electrode material prepared by the above method are also provided. The MOFs composite electrode material provided by the present invention combines advantages of Ni-BTC and PEDOT.

Described are energy storage devices employing a gas storage structure, which can accommodate or store gas evolved from the energy storage device. The energy storage device comprises an electrochemical cell with electrodes comprising metal-containing compositions, like metal oxides, metal nitrides, or metal hydrides, and a solid state electrolyte.

A solid electrolyte capacitor includes a sintered body formed by sintering a molded body containing a metal powder; and a solid electrolyte layer disposed on the sintered body, wherein the solid electrolyte layer includes a first layer containing an electrolytic polymerization conductive polymer disposed on the sintered body and a second layer containing a chemical polymerization conductive polymer disposed on the first layer.

A solid electrolyte capacitor includes a sintered body formed by sintering a molded body containing a metal powder; and a solid electrolyte layer disposed on the sintered body, wherein the solid electrolyte layer includes a first layer containing an electrolytic polymerization conductive polymer disposed on the sintered body and a second layer containing a chemical polymerization conductive polymer disposed on the first layer.

A solid electrolyte capacitor includes a sintered body formed by sintering a molded body containing metal powder; and a conductive polymer layer disposed above the sintered body. A ratio (t2/t1) of a thickness (t2) of the conductive polymer layer in an edge portion of the sintered body to a thickness (t1) of the conductive polymer layer in a central portion of the sintered body satisfies 0.35≤t2/t1≤0.9.