Provided is a lithium secondary battery comprising: a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; and a first functional layer between the positive electrode and the negative electrode, wherein the first functional layer includes plate-like polyolefin particles having an average diameter of 1 μm to 8 μm, and the positive electrode includes a positive electrode active material layer including a positive electrode active material and a flame retardant, or has a stacked structure including a positive electrode active material layer and a second functional layer including a flame retardant.

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.

Provided is an aqueous battery configured to use hydroxide ions (OH.sup.−) as carrier ions. The aqueous battery is an aqueous battery comprising a cathode layer, an anode layer and an aqueous liquid electrolyte, wherein the cathode layer contains, as a cathode active material, a graphite having a rhombohedral crystal structure; wherein the anode layer contains, as an anode active material, at least one selected from the group consisting of an elemental Zn, an elemental Cd, an elemental Fe, a Zn alloy, a Cd alloy, an Fe alloy, ZnO, Cd(OH).sub.2, Fe(OH).sub.2 and a hydrogen storage alloy; and wherein, as an electrolyte, at least one selected from the group consisting of KOH and NaOH is dissolved in the aqueous liquid electrolyte.

A rechargeable battery includes an iron electrode comprising carbonyl iron composition dispersed over a fibrous electrically conductive substrate. The carbonyl iron composition includes carbonyl iron and at least one additive. A counter-electrode is spaced from the iron electrode. An electrolyte is in contact with the iron electrode and the counter-electrode such that during discharge. Iron in the iron electrode is oxidized with reduction occurring at the counter-electrode such that an electric potential develops. During charging, iron oxides and hydroxides in the iron electrode are reduced with oxidation occurring at the counter-electrode (i.e., a nickel electrode or an air electrode).

Provided is a high quality and high performance nickel-iron battery comprising an iron electrode which is prepared by a continuous process. The process comprises preparing a formulation comprising an iron active material and a binder, and continuously coating a continuous substrate material on at least one side with the formulation. The coated continuous substrate material is dried, compacted and blanked. In one embodiment, the iron electrode comprises a PVA binder.

Provided is a Ni—Fe battery comprising a high quality, high performance iron electrode. In one embodiment the iron electrode comprises a polyvinyl alcohol binder. The iron electrode of the Ni—Fe battery comprises a single conductive substrate coated on one or both sides with an iron active material.

Provided is a positive electrode active material for non-aqueous electrolyte secondary batteries for making high capacity and high output compatible, non-aqueous electrolyte secondary batteries, having the positive electrode active material adopted thereto, and a production method for a positive electrode active material in which the positive electrode active material can be easily produced in an industrial scale. A positive electrode active material for non-aqueous electrolyte secondary batteries, contains: primary particles of a lithium nickel composite oxide represented by at least General Formula: Li.sub.zNi.sub.1-x-yCo.sub.xM.sub.yO.sub.2 (0.95≤z≤1.03, 0<x≤0.20, 0<y≤0.10, x+y≤0.20, and M is at least one type of element selected from Mg, Al, Ca, Ti, V, Cr, Mn, Nb, Zr, and Mo); and secondary particles configured by flocculating the primary particles, wherein an LiAl compound and an LiW compound are provided on surfaces of the primary particles.

Integrated devices comprising integrated circuits and energy storage devices are described. Disclosed energy storage devices correspond to an all-solid-state construction, and do not include any gels, liquids, or other materials that are incompatible with microfabrication techniques. Disclosed energy storage device comprises energy storage cells with electrodes comprising metal-containing compositions, like metal oxides, metal nitrides, or metal hydrides, and a solid state electrolyte.

Provided is a sodium secondary battery that has visible light transparency and is excellent in flexibility. A sodium secondary battery includes: a positive electrode film that contains a material formed on a flexible transparent film substrate, the material being capable of intercalating and deintercalating sodium ions; a transparent electrolyte having sodium ion conductivity; and a negative electrode film that if formed of a material formed on a flexible transparent film substrate, the material being capable of dissolving and depositing sodium or intercalating and deintercalating sodium ions. When the positive electrode film contains a sodium source, the negative electrode film is made to have a thickness of 30 nm to 200 nm by using, as a negative electrode material, any of tin oxide, silicon oxide, titanium oxide, tungsten oxide, niobium oxide, molybdenum oxide, metal phosphide, metal sulfide, metal nitride, metal fluoride, or metal titanium composite oxide.

A rechargeable lithium-ion battery includes a housing and a battery cell arranged in the housing. The battery cell includes a liquid electrolyte, a composite anode, a composite cathode, and a separator arranged between the composite anode and the composite cathode. The liquid electrolyte includes an ionic liquid, an organic compound, and a lithium salt. The composite anode includes a metal current collector coated with a layer which includes an active material and a binder. The composite cathode includes a metal current collector coated with a layer which includes an active material and a binder. The active material of the composite anode is a lithium titan oxide (LTO). The composite cathode, the composite anode, and the separator, when immersed in the liquid electrolyte, are heat resistant at temperatures of above 150° C. The rechargeable lithium-ion battery is rechargeable in a temperature range of from −30° C. to 150° C.