A secondary battery includes a laminate in which a positive electrode, a separator, and a negative electrode are stacked in stated order. When either or both of an affixing surface X of the positive electrode and the separator and an affixing surface Y of the negative electrode and the separator are defined as a surface Z and the length of a connecting side of a positive electrode tab connected to the positive electrode or a negative electrode tab connected to the negative electrode is defined as L, resistance A per unit area of a region P, at the surface Z, that has a rectangular shape having the connecting side and a line segment a distance 0.3L from the connecting side as one pair of opposite sides is larger than resistance B per unit area of a region Q other than the region P at the surface Z.

A secondary battery includes a laminate in which a positive electrode, a separator, and a negative electrode are stacked in stated order. Resistance A per unit area of a central region P that has a similar shape to a shape of a surface Z that is either or both of an affixing surface X of the positive electrode and the separator and an affixing surface Y of the negative electrode and the separator, that has a center at the same position as a center of the surface Z, and that has an area equivalent to 10% of area of the surface Z is larger than resistance B per unit area of a region Q other than the central region P at the surface Z.

Electrochemical device for storing electrical energy in rectangular geometric cells, narrow stack geometry, according to the above claims wherein for being built from a sturdy housing (4) in the form of a straight rectangular parallelepiped and where hollow metal rods (5) run on the metal substrate (14) of the base (1) and through the through holes (16) of the base (16) and through the through holes (16) of it run hollow metal rods (5) and on each one of them, the positive electrode is inserted followed by a separating element and so on, while the other hollow metal bar (5) is inserted the negative electrode, followed by a separating element and so on forming a “stack” of electrodes (6) which would fit into the base (1) forming the central structure of the device, with the hollow metal rods (5) serving as current collectors. The rectangular narrow stack geometry electrode (6) allows to carry out the pre-metallisation stage necessary to create the SEI, and the subsequent cycle stage in the same device, without reopening it.

Embodiments described herein relate to electrochemical cells and production thereof under high pressure. In some aspects, a method of producing an electrochemical cell can include disposing a cathode material onto a cathode current collector to form a cathode, disposing an anode material onto an anode current collector to form an anode, and disposing the anode onto the cathode in an assembly jig with a separator positioned between the anode and the cathode to form an electrochemical cell, the assembly jig applying a force to the electrochemical cell such that a pressure in the cathode material is at least about 3,500 kPa. In some embodiments, the cathode material can be a first cathode material, and the method can further include disposing a second cathode material onto the first cathode material. In some embodiments, the first cathode material can include silicon. In some embodiments, the second cathode material can include graphite.

An electrochemical device includes a packaging shell having a first packaging body provided with a first dent and a first flange connected to a sidewall of the first dent, and a second packaging body provided with a second dent and a second flange connected to a sidewall of the second dent; a first electrode assembly disposed in the first dent; a second electrode assembly disposed in the second dent; and a partition plate including a partition layer and a first bonding layer located on a first surface of the partition layer. The partition plate is located between the first packaging body and the second packaging body. The flange overlaps the partition plate and extends beyond an edge of the partition plate. The partition plate fits with the first packaging body and the second packaging body to form mutually independent cavities on two sides of the partition plate.

An electrochemical device includes a packaging shell having a first packaging body provided with a first dent and a first flange connected to a sidewall of the first dent, and a second packaging body provided with a second dent and a second flange connected to a sidewall of the second dent; a first electrode assembly disposed in the first dent; a second electrode assembly disposed in the second dent; and a partition plate including a partition layer and a first bonding layer located on a first surface of the partition layer. The partition plate is located between the first packaging body and the second packaging body. The flange overlaps the partition plate and extends beyond an edge of the partition plate. The partition plate fits with the first packaging body and the second packaging body to form mutually independent cavities on two sides of the partition plate.

W1/T1 is equal to or greater than 5, assuming that the width of an electrode body in a direction perpendicular to a winding axis direction and a thickness direction of the electrode body is W1 (mm) and the thickness of the electrode body 3 is T1 (mm).

W1/T1 is equal to or greater than 5, assuming that the width of an electrode body in a direction perpendicular to a winding axis direction and a thickness direction of the electrode body is W1 (mm) and the thickness of the electrode body 3 is T1 (mm).

A secondary battery includes: a cylindrical case; an electrode assembly accommodated in the cylindrical case and including a positive electrode and a negative electrode; and a cap assembly sealing the cylindrical case. The cap assembly includes: a cap-up electrically connected to the positive electrode; a terminal plate coupled to an upper portion of the cap-up and electrically connected to the negative electrode; and a first insulating gasket between the cap-up and the terminal plate.

A secondary battery includes: a cylindrical case; an electrode assembly accommodated in the cylindrical case and including a positive electrode and a negative electrode; and a cap assembly sealing the cylindrical case. The cap assembly includes: a cap-up electrically connected to the positive electrode; a terminal plate coupled to an upper portion of the cap-up and electrically connected to the negative electrode; and a first insulating gasket between the cap-up and the terminal plate.