A positive electrode plate (11) includes a current collector (30) and a mixture layer (31) disposed on the current collector (30). The mixture layer (31) has a thin portion (32) with a thickness of less than 200 μm disposed on an inner coil half of the current collector (30) and a thick portion (33) having a larger thickness than the thin portion (32), the thick portion (33) having a yield loop height H measured by a stiffness test of 6 mm<H<15 mm.

A lithium-ion cell includes a ribbon-shaped electrode-separator assembly having an anode, a separator, and a cathode in a sequence anode/separator/cathode. The anode has a ribbon-shaped anode current collector having a first longitudinal edge, a second longitudinal edge, and two ends, wherein the anode current collector has a strip-shaped main region loaded with a layer of negative electrode material and a free edge strip extending along the first longitudinal edge that is not loaded with the electrode material. The cathode has a ribbon-shaped cathode current collector, wherein the cathode current collector has a strip-shaped main region loaded with a layer of positive electrode material and a free edge strip extending along the first longitudinal edge that is not loaded with the electrode material. The negative electrode material containing the at least one active material in a range of from 20 wt % to 90 wt %.

An exemplary embodiment of the present invention provides a spiral-wound electrode assembly including: a negative electrode and a positive electrode, each of which is configured to include a substrate, and a first composite material and a second composite material formed on opposite surfaces of the substrate; and a separator disposed between the negative electrode and the anode, wherein the first composite material of the negative electrode is disposed farther away from a center of the electrode assembly than the second composite material of the negative electrode, and the first composite material of the negative electrode is oriented with respect to a first surface of the substrate of the negative electrode.

An exemplary embodiment of the present invention provides a spiral-wound electrode assembly including: a negative electrode and a positive electrode, each of which is configured to include a substrate, and a first composite material and a second composite material formed on opposite surfaces of the substrate; and a separator disposed between the negative electrode and the anode, wherein the first composite material of the negative electrode is disposed farther away from a center of the electrode assembly than the second composite material of the negative electrode, and the first composite material of the negative electrode is oriented with respect to a first surface of the substrate of the negative electrode.

An electrochemical apparatus includes a housing, an electrode assembly disposed inside the housing, a first tab group, and a first adapting piece electrically connected to the first tab group and extending out from the housing. The electrode assembly is configured to be a winding structure including a first electrode plate. The first tab group includes M first tabs connected to the first electrode plate. A thickness direction of the electrode assembly is defined as a first direction. In the first direction, the electrode assembly includes N layers of the first electrode plate, N being greater than M. The M first tabs are each connected to the first electrode plate. A plane passing through a winding center axis of the electrode assembly and perpendicular to the first direction is defined as a winding center plane. The M first tabs are disposed on two sides of the winding center plane.

An electrochemical apparatus includes a housing, an electrode assembly disposed inside the housing, a first tab group, and a first adapting piece electrically connected to the first tab group and extending out from the housing. The electrode assembly is configured to be a winding structure including a first electrode plate. The first tab group includes M first tabs connected to the first electrode plate. A thickness direction of the electrode assembly is defined as a first direction. In the first direction, the electrode assembly includes N layers of the first electrode plate, N being greater than M. The M first tabs are each connected to the first electrode plate. A plane passing through a winding center axis of the electrode assembly and perpendicular to the first direction is defined as a winding center plane. The M first tabs are disposed on two sides of the winding center plane.

There is provided a method for producing a separator for an electricity storage device that includes a step of contacting a porous body formed from a silane-modified polyolefin-containing molded sheet with a base solution or acid solution, and a separator for an electricity storage device comprising a microporous film with a melted film rupture temperature of 180° C. to 220° C. as measured by thermomechanical analysis (TMA).

There is provided a method for producing a separator for an electricity storage device that includes a step of contacting a porous body formed from a silane-modified polyolefin-containing molded sheet with a base solution or acid solution, and a separator for an electricity storage device comprising a microporous film with a melted film rupture temperature of 180° C. to 220° C. as measured by thermomechanical analysis (TMA).

A battery includes a negative electrode active material layer, a positive electrode active material layer. The negative electrode active material layer includes a first portion and a second portion including a first surface and a first end. The first surface is connected to the first portion by using a first connection part. A thickness of the second portion decreases from the first connection part to the first end. The positive electrode active material layer includes a third portion and a fourth portion including a second surface and a second end. The first surface is at least partially opposite to the second surface, and the second surface is connected to the third portion by using a second connection part. A thickness of the fourth portion gradually decreases from the second connection part to the second end. The first connection part is located between the second connection part and the second end.

A battery including a negative electrode active material layer, a positive electrode active material layer and a separator. In a first direction, the positive electrode active material layer includes a first portion and a second portion connected to the first portion. The second portion includes a first end, and the first portion includes a first surface. The first surface is connected to the second portion through a first connection, the first end is away from the first connection and is an end of the positive electrode active material layer, and a thickness of the second portion in a second direction perpendicular to the first direction decreases from the first connection to the first end in the first direction.