An electrode assembly and a secondary battery are provided. In an exemplary embodiment, an electrode assembly includes: a first electrode plate having a first electrode tab attached thereto; a second electrode plate having at least one second electrode tab attached thereto; and a separator between the first electrode plate and the second electrode plate, the electrode assembly wound in a state in which the first electrode plate, the separator, and the second electrode plate are stacked, and the first electrode plate includes coating portions formed by coating an active material on first and second surfaces thereof, and a half-coating portion formed by coating the active material on only one of the first and second surfaces at a region corresponding to a leading edge, on the basis of a winding direction, where an active material of the second electrode plate begins.

The present application relates to a secondary battery, which includes: a cathode sheet, an anode sheet, and an electrolyte; the cathode sheet includes a cathode film layer containing a cathode active material, and the anode sheet includes an anode film layer containing an anode active material; and the secondary battery meets a following function relationship: 0.22?3?(A1/A2)?(B2?B1)/(B1+B2)?1.55, the parameters are referred to the description; and an electrical device including the secondary battery. The secondary battery in the present application has both good cycle life and excellent fast charging capacity.

Provided is an electrode alloy powder that is useful to obtain a nickel-metal hydride storage battery having a high battery capacity and a reduced self-discharge. The alloy powder is: a mixture including particles of a first hydrogen storage alloy having an AB.sub.5-type crystal structure, and particles of at least one second hydrogen storage alloy selected from the group consisting of a hydrogen storage alloy a having an AB.sub.2-type crystal structure and a hydrogen storage alloy b having an AB.sub.3-type crystal structure, wherein an amount of the first hydrogen storage alloy included in the mixture is greater than 50 mass %.

A secondary zinc-manganese dioxide secondary cell is disclosed. The cell includes a zinc gel anode, high manganese content cathode in either prismatic or jelly roll form. An aqueous based continuous reel to reel process for formulation and fabrication of the anode and cathode is provided. The cell is contained in a box assembly.

Electrochemical cells are provided. An example electrochemical cell may include a container, an electrolyte; an anode; a cathode; a current collector, and a separator disposed between the anode and the cathode. In some embodiments, the anode and the cathode may define an interfacial area y and the separator defines a thickness x, wherein a relation between the interfacial area y and the separator thickness x is defined between 26.532x.sup.?0.15?y?284.5x.sup.?0.675.

The present application relates to a secondary battery, which includes: a cathode sheet, an anode sheet, and an electrolyte; the cathode sheet includes a cathode film layer containing a cathode active material, and the anode sheet includes an anode film layer containing an anode active material; and the secondary battery meets a following function relationship: 0.22?3?(A1/A2)?(B2?B1)/(B1+B2)?1.55, the parameters are referred to the description; and an electrical device including the secondary battery. The secondary battery in the present application has both good cycle life and excellent fast charging capacity.

A secondary zinc-manganese dioxide secondary cell is disclosed. The cell includes a zinc gel anode, high manganese content cathode in either prismatic or jelly roll form. An aqueous based continuous reel to reel process for formulation and fabrication of the anode and cathode is provided. The cell is contained in a box assembly.

An electrode body, which includes a positive electrode plate and a negative electrode plate, is contained in a battery case, which is composed of a rectangular casing and a sealing plate. A first positive-electrode tab group, which is composed of a plurality of positive electrode tabs, and a second positive-electrode tab group, which is composed of a plurality of positive electrode tabs, are disposed between the sealing plate and the electrode body. The first positive-electrode tab group and the second positive-electrode tab group are disposed so as to be displaced from each other in the longitudinal direction of the sealing plate. The first positive-electrode tab group and the second positive-electrode tab group are connected to different positions on a positive-electrode current collector.

A non-aqueous electrolyte secondary battery includes battery element formed by laminating and winding positive electrode and negative electrode via separator. Positive electrode includes a positive electrode current-collector-exposed portion, in which the positive electrode current collector is exposed over a length dimension of not less than one turn of the winding of battery element in the outermost circumference and an intermediate layer portion of the winding. The negative electrode in a part facing the positive electrode current collector exposed in the intermediate layer portion includes the negative electrode active material layer laminated on the negative electrode current collector. Negative electrode can be provided with a slit at an exposed side with respect to both exposed ends of the positive electrode current-collector-exposed portion.

An energy storage device includes: a core; and a wound body including, layered and wound around the core: a positive electrode, a negative electrode, and two separators, one of which is interposed between the positive electrode and the negative electrode and each having a first surface and a second surface. The first surface has thermal bonding properties superior to thermal bonding properties of the second surface, and at least one of the two separators is bonded to the core via the first surface thereof.