Electrodes are formed with a porous layer of particulate electrode material bonded to each of the two major sides of a compatible metal current collector. In one embodiment, opposing electrodes are formed with like lithium-ion battery anode materials or like cathode materials or capacitor materials on both sides of the current collector. In another embodiment, a battery electrode material is applied to one side of a current collector and capacitor material is applied to the other side. In general, the electrodes are formed by combining a suitable grouping of capacitor layers with un-equal numbers of anode and cathode battery layers. One or more pairs of opposing electrodes are assembled to provide a combination of battery and capacitor energy and power properties in a hybrid electrochemical cell. The cells may be formed by stacking or winding rolls of the opposing electrodes with interposed separators.

Electrodes are formed with a porous layer of particulate electrode material bonded to each of the two major sides of a compatible metal current collector. In one embodiment, opposing electrodes are formed with like lithium-ion battery anode materials or like cathode materials or capacitor materials on both sides of the current collector. In another embodiment, a battery electrode material is applied to one side of a current collector and capacitor material is applied to the other side. In general, the electrodes are formed by combining a suitable grouping of capacitor layers with un-equal numbers of anode and cathode battery layers. One or more pairs of opposing electrodes are assembled to provide a combination of battery and capacitor energy and power properties in a hybrid electrochemical cell. The cells may be formed by stacking or winding rolls of the opposing electrodes with interposed separators.

Electrolytes and electrolyte additives for energy storage devices comprising functional thiophene compounds are disclosed. The energy storage device comprises a first electrode and a second electrode, wherein at least one of the first electrode and the second electrode is a Si-based electrode, a separator between the first electrode and the second electrode, an electrolyte, and at least one electrolyte additive selected from a thiophene compound.

Electrolytes and electrolyte additives for energy storage devices comprising functional thiophene compounds are disclosed. The energy storage device comprises a first electrode and a second electrode, wherein at least one of the first electrode and the second electrode is a Si-based electrode, a separator between the first electrode and the second electrode, an electrolyte, and at least one electrolyte additive selected from a thiophene compound.

An electrochemical device which is an alkali metal battery or an alkaline earth metal battery, wherein only a positive electrode is an electrode having a perfluoropolyether group-containing compound in a surface thereof.

An electrochemical device which is an alkali metal battery or an alkaline earth metal battery, wherein only a positive electrode is an electrode having a perfluoropolyether group-containing compound in a surface thereof.

An aspect of the present invention is a nonaqueous electrolyte energy storage device that includes a negative electrode including a lithium alloy and a nonaqueous electrolyte containing a fluorinated solvent, in which the lithium alloy contains silver, and the content of silver with respect to the total content of lithium and silver in the lithium alloy is 3% by mass or more and 20% by mass or less. Another aspect of the present invention is a nonaqueous electrolyte energy storage device that includes a negative electrode including a lithium alloy and a nonaqueous electrolyte including a lithium salt containing fluorine, in which the lithium alloy contains silver, and the content of silver with respect to the total content of lithium and silver in the lithium alloy is 3% by mass or more and 20% by mass or less.

A conductive two-dimensional particle of a layered material comprising one layer or one layer and plural layers, wherein the layer includes a layer body represented by: M.sub.mX.sub.n, and a modifier or terminal T exists on a surface of the layer body, wherein T is at least one selected from the group consisting of a hydroxyl group, a fluorine atom, a chlorine atom, an oxygen atom, or a hydrogen atom; and a monovalent metal ion, wherein the conductive two-dimensional particle does not contain an amine, a total content of chlorine and bromine in the conductive two-dimensional particle is 1,500 ppm by mass or less, and an average value of a major diameter of a two-dimensional surface of the conductive two-dimensional particle is 1.0 μm to 20 μm.

An electrolytic solution is provided and includes an electrolytic solution for an electrochemical device including a magnesium electrode as a negative electrode and a positive electrode, the electrolytic solution containing: a solvent; and a first magnesium salt having a disilazide structure represented by General Formula (1):

(R.sub.3Si).sub.2N  (1) wherein R is an aliphatic hydrocarbon group having 1 or more and 10 or less carbon atoms, and each R may be the same as or different from each other, the electrolytic solution substantially comprising no halogen.

A purpose of the present invention is to provide a method for manufacturing, etc., a member for an electrochemical device in which the problem of irreversible change in the composition of the electrochemical device due to solvent depletion, moisture absorption, etc., during manufacturing of the electrochemical devices is unlikely to occur. This method for manufacturing a member for an electrochemical device includes performing at least one shaping operation described in the present specification on a shaping material composition that comprises: at least one filler (F); a plasticizer (P-S), being water, an ionic liquid, or a mixture thereof; and a polymer (P1), the shaping material composition being substantially free of an organic solvent and having plasticity and self-supporting property.