An objective is to provide a novel aqueous electrolytic solution constituting an aqueous power storage device that stably operates even at a high voltage.

An electrolytic solution for a power storage device contains water as a solvent and has a composition in which an amount of the solvent is not greater than 4 mol with respect to 1 mol of an alkali metal salt.

An objective is to provide a novel aqueous electrolytic solution constituting an aqueous power storage device that stably operates even at a high voltage.

An electrolytic solution for a power storage device contains water as a solvent and has a composition in which an amount of the solvent is not greater than 4 mol with respect to 1 mol of an alkali metal salt.

Provided is a battery including a positive electrode; a negative electrode; an electrolytic solution being an aqueous alkali metal hydroxide solution; and a layered double hydroxide (LDH)-like compound provided so as to be in contact with the electrolytic solution. A metal compound containing at least one metal element constituting the LDH-like compound is dissolved in the electrolytic solution such that erosion of the LDH-like compound by the electrolytic solution is suppressed.

Provided is a battery including a positive electrode; a negative electrode; an electrolytic solution being an aqueous alkali metal hydroxide solution; and a layered double hydroxide (LDH)-like compound provided so as to be in contact with the electrolytic solution. A metal compound containing at least one metal element constituting the LDH-like compound is dissolved in the electrolytic solution such that erosion of the LDH-like compound by the electrolytic solution is suppressed.

An alkaline electrochemical cell includes a cathode, an anode which includes an anode active material, and a non-conductive separator disposed between the cathode and the anode, wherein from about 20% to about 50% by weight of the anode active material relative to a total amount of anode active material has a particle size of less than about 75 μm, and wherein the separator includes a unitary, cylindrical configuration having an open end, a side wall, and integrally formed closed end disposed distally to the open end.

A solid ionic conducting material for use in an electrochemical device comprises an oxyhydroxide or hydrated oxide derived from of an oxide with a perovskite, Brownmillerite, layered oxide, and/or K.sub.4CdCl.sub.6 structure, the elemental composition of the initial oxide being selected to provide suitable conduction properties for the derived anhydrous or hydrated oxyhydroxide or hydrated oxide. A method of making such a solid ionic conducting material, including treatment with water, and an electrochemical device incorporating such a solid ionic conducting material (optionally as an electrolyte) are also disclosed.

An alkaline battery includes a negative electrode. The negative electrode includes a negative electrode active material particle. The negative electrode active material particle includes a center part, a covering layer, and island-form layers. The center part includes zinc as a constituent element. The covering layer covers a surface of the center part and includes gallium as a constituent element. The island-form layers are present on a surface of the covering layer and include indium as a constituent element.

An alkaline battery includes a negative electrode. The negative electrode includes a negative electrode active material particle. The negative electrode active material particle includes a center part, a covering layer, and island-form layers. The center part includes zinc as a constituent element. The covering layer covers a surface of the center part and includes gallium as a constituent element. The island-form layers are present on a surface of the covering layer and include indium as a constituent element.

An alkaline electrochemical cell includes a cathode, an anode which includes an anode active material, and a non-conductive separator disposed between the cathode and the anode, wherein from about 20% to about 50% by weight of the anode active material relative to a total amount of anode active material has a particle size of less than about 75 μm, and wherein the separator includes a unitary, cylindrical configuration having an open end, a side wall, and integrally formed closed end disposed distally to the open end.

An alkaline electrochemical cell includes a cathode, an anode which includes an anode active material, and a non-conductive separator disposed between the cathode and the anode, wherein from about 20% to about 50% by weight of the anode active material relative to a total amount of anode active material has a particle size of less than about 75 μm, and wherein the separator includes a unitary, cylindrical configuration having an open end, a side wall, and integrally formed closed end disposed distally to the open end.