Electrode assembly, battery cell, battery, and method and apparatus for manufacturing electrode assembly
An electrode assembly includes a positive electrode plate and a negative electrode plate wound or stacked to form a bend region, and a barrier layer provided at the bend region. At least part of the barrier layer is located between the positive electrode plate and the negative electrode plate that are adjacent to each other, and is configured to prevent at least part of ions deintercalated from the positive electrode plate from being intercalated into the negative electrode plate in the bend region. A ratio of a thickness of the barrier layer to a porosity of the barrier layer is larger than or equal to 3.5 microns and smaller than or equal to 2000 microns.
1 . An electrode assembly comprising:
a positive electrode plate and a negative electrode plate wound or stacked to form a bend region; and
a barrier layer provided at the bend region, at least part of the barrier layer being located between the positive electrode plate and the negative electrode plate that are adjacent to each other, and being configured to prevent at least part of ions deintercalated from the positive electrode plate from being intercalated into the negative electrode plate in the bend region;
wherein a ratio of a thickness of the barrier layer to a porosity of the barrier layer is larger than or equal to 3.5 microns and smaller than or equal to 2000 microns, a value of the porosity of the barrier layer is greater than 0% and less than or equal to 100%, the barrier layer is made of polyethylene phthalate, polyvinylidene fluoride, polyurethane, sodium polyacrylate, styrene butadiene rubber, polyetherimide, carboxymethyl cellulose, or acrylate, and the barrier layer comprises two ends in a direction perpendicular to a bending direction, and one or two of the two ends of the barrier layer extend beyond a positive electrode active material layer of the positive electrode plate.
2 . The electrode assembly according to claim 1 , further comprising:
a separator isolating the positive electrode plate from the negative electrode plate that are adjacent to each other;
wherein the barrier layer is attached to at least one of:
one or two surfaces of the positive electrode plate,
one or two surfaces of the negative electrode plate, or
one or two surfaces of the separator.
3 . The electrode assembly according to claim 2 , wherein the porosity of the barrier layer is less than a porosity of the separator.
4 . The electrode assembly according to claim 1 , further comprising:
a separator isolating the positive electrode plate from the negative electrode plate that are adjacent to each other;
wherein the barrier layer is independently provided:
between the positive electrode plate and the separator that are adjacent to each other in the bend region, or
between the negative electrode plate and the separator that are adjacent to each other in the bend region.
5 . The electrode assembly according to claim 1 , wherein:
the positive electrode plate and the negative electrode plate are compacted and wound to form a winding structure; and
the barrier layer is provided between the positive electrode plate and the negative electrode plate that are adjacent to each other on at least an innermost side of the bend region.
6 . The electrode assembly according to claim 5 , wherein an innermost electrode plate in the bend region is the negative electrode plate.
7 . The electrode assembly according to claim 1 , wherein the barrier layer is one of a plurality of discontinuous barrier layers spaced apart from each other in a bending direction or in a direction perpendicular to the bending direction.
8 . The electrode assembly according to claim 1 , wherein the thickness of the barrier layer is 2 to 200 microns.
9 . The electrode assembly according to claim 1 , wherein the barrier layer is provided with at least one through hole.
10 . The electrode assembly according to claim 9 , wherein the porosity of the barrier layer is 10% to 70%.
11 . The electrode assembly according to claim 1 , further comprising:
a separator isolating the positive electrode plate from the negative electrode plate that are adjacent to each other;
wherein the barrier layer is attached to one or two surfaces of the separator.
12 . The electrode assembly according to claim 1 , wherein two ends, in a direction perpendicular to a bending direction, of a negative electrode active material layer of the negative electrode plate extend beyond corresponding ends of a positive electrode active material layer of the positive electrode plate.
13 . The electrode assembly according to claim 1 , wherein a negative electrode active material layer of the negative electrode plate extends beyond one or two of the two ends of the barrier layer.
14 . The electrode assembly according to claim 1 , wherein the barrier layer is disposed opposite a largest-curvature portion of the negative electrode plate.
15 . The electrode assembly according to claim 1 , wherein two ends, extending in the bending direction, of the barrier layer are located in the bend region.
16 . The electrode assembly according to claim 1 , wherein:
the positive electrode plate and the negative electrode plate further form a flat region connected to the bend region;
one end, extending in the bending direction, of the barrier layer is located in the flat region; and
another end, extending in the bending direction, of the barrier layer is located in the bend region or in the flat region.
17 . A battery cell, comprising:
a housing having an accommodating cavity and an opening;
a cover plate configured to close the opening of the housing; and
the electrode assembly according to claim 1 accommodated in the accommodating cavity.
18 . A battery, comprising:
a box body; and
the battery cell according to claim 17 received in the box body.
19 . An electrode assembly comprising:
a positive electrode plate and a negative electrode plate wound or stacked to form a bend region; and
a barrier layer provided at the bend region, at least part of the barrier layer being located between the positive electrode plate and the negative electrode plate that are adjacent to each other, and being configured to prevent at least part of ions deintercalated from the positive electrode plate from being intercalated into the negative electrode plate in the bend region;
wherein a ratio of a thickness of the barrier layer to a porosity of the barrier layer is larger than or equal to 3.5 microns and smaller than or equal to 2000 microns, a value of the porosity of the barrier layer is greater than 0 and less than or equal to 1, the barrier layer comprises inorganic oxide.