ELECTRODE ASSEMBLY, BATTERY CELL, BATTERY, AND ELECTRIC DEVICE
An electrode assembly, a battery cell, a battery, and an electric device are provided. The electrode assembly includes a first electrode plate, a second electrode plate, and a separator disposed between the first electrode plate and the second electrode plate. The first electrode plate, the separator, and the second electrode plate are wound in a winding direction to form a wound structure, where at least one of the first electrode plate and the second electrode plate includes: a current collector substrate; an active substance layer, disposed on at least one surface on a side, adjacent to the separator, of the current collector substrate; and a tab set, connected to a side edge of the current collector substrate that extends in the winding direction, where the tab set includes a plurality of tabs spaced apart in the winding direction.
1 . An electrode assembly, characterized by comprising a first electrode plate, a second electrode plate, and a separator disposed between the first electrode plate and the second electrode plate, wherein the first electrode plate, the separator, and the second electrode plate are wound in a winding direction to form a wound structure, wherein
at least one of the first electrode plate and the second electrode plate comprises:
a current collector substrate;
an active substance layer, disposed on at least one surface on a side, adjacent to the separator, of the current collector substrate; and
a tab set, connected to a side edge of the current collector substrate that extends in the winding direction, wherein the tab set comprises a plurality of tabs spaced apart in the winding direction.
2 . The electrode assembly according to claim 1 , characterized in that a distance L from an initial coverage position of the active substance layer on the current collector substrate in the winding direction to a first tab in the tab set in the winding direction satisfies:
L
=
K
1
×
C
×
p
×
f
W
1
×
ρ
3
)
;
wherein C is a specific heat capacity of the current collector substrate, p is a density of the current collector substrate, t is a thickness of the current collector substrate, W 1 is a width of the current collector substrate, ρ is a resistivity of the current collector substrate, and K 1 is a first ratio parameter.
3 . The electrode assembly according to claim 1 , characterized in that the first ratio parameter K 1 is less than or equal to
2000
mm
7
3
·
(
°
C
.
·
Ω
J
)
1
3
,
the specific heat capacity C of the current collector substrate is measured in J/(g·° C.), the density p of the current collector substrate is measured in g/mm 3 , the thickness t of the current collector substrate is measured in mm, the width W 1 of the current collector substrate is measured in mm, and the resistivity ρ of the current collector substrate is measured in Ω·mm.
4 . The electrode assembly according to claim 1 , characterized in that the first ratio parameter K 1 is less than or equal to
1600
mm
7
3
·
(
°
C
.
·
Ω
J
)
1
3
.
5 . The electrode assembly according to claim 1 , characterized in that the wound structure is a cylindrical wound structure and a width W 2 of the tab satisfies:
W
2
=
K
2
*
π
*
D
1
;
wherein D 1 is a circumferential diameter of an electrode plate layer in the cylindrical wound structure that corresponds to the first tab in the tab set in the winding direction, and K 2 is a second ratio parameter.
6 . The electrode assembly according to claim 1 , characterized in that the second ratio parameter K 2 is less than or equal to ¼.
7 . The electrode assembly according to a claim 1 , characterized in that the second ratio parameter K 2 is less than or equal to ⅙.
8 . The electrode assembly according to claim 1 , characterized in that the wound structure is a cylindrical wound structure, and the electrode assembly further comprises:
a current collection plate, located on a side of the cylindrical wound structure connected to the tab set, and fixedly connected to a flattened tab set through welding;
wherein a height h of the tab satisfies:
h
=
(
K
3
*
(
d
1
*
t
2
)
)
/
t
1
;
wherein d 1 is a radial distance between tabs respectively connected to electrode plates on adjacent layers in the cylindrical wound structure, t 1 is a thickness of the tab, t 2 is a thickness of a welding region of the current collection plate, and K 3 is a third ratio parameter.
9 . The electrode assembly according to claim 1 , characterized in that the third ratio parameter K 3 is greater than or equal to 0.25.
10 . The electrode assembly according to claim 1 , characterized in that the third ratio parameter K 3 is greater than or equal to 0.28.
11 . The electrode assembly according to claim 1 , characterized in that the wound structure is a cylindrical wound structure, and a distance d 2 between top ends of adjacent tabs in the tab set satisfies:
d
2
=
(
K
4
*
(
W
2
*
h
)
)
/
(
D
0
-
2
*
h
)
;
wherein W 2 is the width of the tab, h is the height of the tab, D 0 is a circumferential diameter of the outermost electrode plate layer of the cylindrical wound structure, and K 4 is a fourth ratio parameter.
12 . The electrode assembly according to claim 1 , characterized in that the fourth ratio parameter K 4 is less than or equal to 4.
13 . The electrode assembly according to claim 1 , characterized in that the fourth ratio parameter K 4 is less than or equal to 3.2.
14 . The electrode assembly according to claim 1 , characterized by further comprising
the current collection plate, located on a side of the wound structure connected to the tab set, and fixedly connected to the flattened tab set through welding;
wherein a distance S between a root portion of the tab and a side edge of the separator that is adjacent to a side of the tab satisfies:
S
=
K
5
*
t
2
;
wherein t 2 is the thickness of the welding region of the current collection plate, and K 5 is a fifth ratio parameter.
15 . The electrode assembly according to claim 1 , characterized in that the fifth ratio parameter K 5 is greater than or equal to 1.5.
16 . The electrode assembly according to claim 1 , characterized in that the fifth ratio parameter K 5 is greater than or equal to 3.
17 . The electrode assembly according to claim 1 , characterized in that the first electrode plate and the second electrode plate both comprise the tab set, and the tab set comprised in the first electrode plate and the tab set comprised in the second electrode plate are separately located at different ends of the wound structure in a direction perpendicular to the winding direction.
18 . A battery cell, characterized by comprising the electrode assembly according to claim 1 .
19 . A battery, characterized by comprising the battery cell according to claim 1 .
20 . An electric device, characterized by comprising the battery according to claim 1 .