US-20260128380-A1 - Composite Electrode Plate and Battery Cell

US20260128380A1US 20260128380 A1US20260128380 A1US 20260128380A1US-20260128380-A1

Abstract

The present invention provides a composite electrode plate including a current collector. The current collector has a first surface and a second surface that are opposite to each other. A positive electrode active material layer is provided on the first surface, and a negative electrode active material layer is provided on the second surface. The length of the current collector is L 1, the length of the negative electrode active material layer is L 2, and the length of the positive electrode active material layer is L 3; the width of the current collector is W 1, the width of the negative electrode active material layer is W 2, and the width of the positive electrode active material layer is W 3; wherein L 1> L 2> L 3, and/or, W 1> W 2> W 3 . The present invention also provides a battery cell.

Inventors

Haojun QI
Penghui ZHENG
Weifeng Fang
WENJUAN LIU MATTIS

Assignees

MICROVAST, INC.

Dates

Publication Date: 20260507
Application Date: 20241106

Claims (18)

1 . A composite electrode plate comprising a current collector, wherein the current collector has a length direction, a width direction, and a thickness direction; in the thickness direction, the current collector has a first surface and a second surface that are opposite to each other; a positive electrode active material layer is provided on the first surface, and a negative electrode active material layer is provided on the second surface; in the length direction, the length of the current collector is L 1 , the length of the negative electrode active material layer is L 2 , and the length of the positive electrode active material layer is L 3 ; in the width direction, the width of the current collector is W 1 , the width of the negative electrode active material layer is W 2 , and the width of the positive electrode active material layer is W 3 ; wherein L 1 >L 2 >L 3 , and/or W 1 >W 2 >W 3 .
2 . The composite electrode plate as claimed in claim 1 , wherein the first surface comprises a positive electrode active area and a positive electrode blank area, the positive electrode active material layer is arranged within the positive electrode active area, and the positive electrode blank area is arranged around the periphery of the positive electrode active material layer.
3 . The composite electrode plate as claimed in claim 2 , wherein the positive electrode blank area comprises a first blank area and a second blank area the first blank area is located on opposite sides of the positive electrode active area in the width direction, and the second blank arca is located on opposite sides of the positive electrode active area in the length direction; in the width direction, the dimension of the first blank area is K 1 ; in the length direction, the dimension of the second blank area is K 2 ; wherein K 1 >0 mm, K 2 >0 mm.
4 . The composite electrode plate as claimed in claim 3 , wherein 5 mm>K 1 >0 mm, 5 mm>K 2 >0 mm.
5 . The composite electrode plate as claimed in claim 2 , wherein the second surface comprises a negative electrode active area and a negative electrode blank area, the negative electrode active material layer is arranged within the negative electrode active area, and the negative electrode blank area is arranged around the periphery of the negative electrode active material layer.
6 . The composite electrode plate as claimed in claim 1 , wherein the second surface comprises a negative electrode active area and a negative electrode blank area, the negative electrode active material layer is arranged within the negative electrode active area, and the negative electrode blank area is arranged around the periphery of the negative electrode active material layer.
7 . The composite electrode plate as claimed in claim 6 , wherein the negative electrode blank area comprises a third blank area and a fourth blank area the third blank area is located on opposite sides of the negative electrode active area in the width direction, and the fourth blank area is located on opposite sides of the negative electrode active area in the length direction; in the width direction, the dimension of the third blank area is K 3 ; in the length direction, the dimension of the fourth blank area is K 4 ; wherein K 3 >0 mm, K 4 >0 mm.
8 . The composite electrode plate as claimed in claim 7 , wherein 3 mm>K 3 >0 mm, 3 mm>K 4 >0 mm.
9 . The composite electrode plate as claimed in claim 1 , wherein the current collector is a copper aluminum composite foil; or, the material of the current collector is stainless steel.
10 . The composite electrode plate as claimed in claim 1 , wherein the thickness of the current collector is H 1 , and H 1 is between 3 μm and 10 μm; and/or, the thickness of the positive electrode active material layer is H 2 , and H 2 is between 80 μm and 150 μm; and/or, the thickness of the negative electrode active material layer is H 3 , and H 3 is between 40 μm and 100 μm.
11 . A battery cell comprising multiple composite electrode plates as claimed in claim 1 , wherein the multiple composite electrode plates are sequentially stacked along the thickness direction, and an electrolyte layer is provided between adjacent composite electrode plates.
12 . The battery cell as claimed in claim 11 , wherein in the length direction, the length of the electrolyte layer is L 4 ; in the width direction, the width of the electrolyte layer is W 4 ; wherein L 4 >L 1 , W 4 >W 1 .
13 . The battery cell as claimed in claim 11 , wherein the thickness of the current collector is H 1 , the thickness of the positive electrode active material layer is H 2 , the thickness of the negative electrode active material layer is H 3 , and the thickness of the electrolyte layer is H 4 ; wherein 8>(H 1 +H 2 +H 3 )]]/H 4 >3.
14 . The battery cell as claimed in claim 11 , wherein the thickness of the electrolyte layer is H 4 , and H 4 is between 10 μm and 45 μm.
15 . A battery cell comprising multiple composite electrode plates as claimed in claim 5 , wherein the multiple composite electrode plates are sequentially stacked along the thickness direction, and an electrolyte layer is provided between adjacent composite electrode plates.
16 . The battery cell as claimed in claim 15 , wherein in the length direction, the length of the electrolyte layer is L 4 ; in the width direction, the width of the electrolyte layer is W 4 ; wherein L 4 >L 1 , W 4 >W 1 .
17 . The battery cell as claimed in claim 15 , wherein the thickness of the current collector is H 1 , the thickness of the positive electrode active material layer is H 2 , the thickness of the negative electrode active material layer is H 3 , and the thickness of the electrolyte layer is H 4 ; wherein 8>(H 1 +H 2 +H 3 )/H 4 >3.
18 . The battery cell as claimed in claim 15 , wherein the thickness of the electrolyte layer is H 4 , and H 4 is between 10 μm and 45 μm.

Description

TECHNICAL FIELD This invention relates to the field of battery technology, and in particular to a composite electrode plate and a battery cell. BACKGROUND In the research and application of all solid state batteries, bipolar stack structure is widely regarded as an important means to improve battery energy density and performance. Bipolar stacked solid-state battery cells generally include multiple composite electrode plates, each of which includes a current collector, and positive and negative electrode active material layers respectively arranged on opposite sides of the current collector; the multiple composite electrode plates are stacked in sequence, and adjacent composite electrode plates are separated by electrolyte layers (such as separators). The multiple composite electrode plates and the electrolyte layers are combined with each other through hot pressing process. SUMMARY In order to better separate adjacent composite electrode plates, the length and width dimensions of the electrolyte layer are generally larger than those of the composite electrode plate; meanwhile, due to the relatively large thickness of the composite electrode plate, an obvious step exists between the edges of the electrolyte layer and the edges of the composite electrode plate. During the hot pressing or rolling process, the edges of the electrolyte layer are prone to damage due to excessive shear force (due to the obvious step between the edges of the electrolyte layer and the edges of the composite electrode plate, the electrolyte layer experiences greater shear force at the step positions during the hot pressing or rolling process, which makes the edges of the electrolyte layer prone to damage), resulting in internal short circuiting of the battery cell. How to reduce or avoid damage to the electrolyte layer during the hot pressing or rolling process without affecting the overall performance of the battery cell has become an urgent technical problem in the field of bipolar stacked solid-state battery manufacturing. The object of the present invention is to provide a composite electrode plate, which forms a size gradient at the edge positions of the composite electrode plate by limiting the length and width dimensions of the current collector, the positive electrode active material layer, and the negative electrode active material layer. This reduces the step height formed between the edges of the electrolyte layer and the edges of the composite electrode plate, thereby reducing the shear force on the edges of the electrolyte layer during the hot pressing or rolling process, and reducing or avoiding damage to the electrolyte layer. An embodiment of the present invention provides a composite electrode plate including a current collector, wherein the current collector has a length direction, a width direction, and a thickness direction, every two of which are mutually perpendicular to each other; in the thickness direction, the current collector has a first surface and a second surface that are opposite to each other; a positive electrode active material layer is provided on the first surface, and a negative electrode active material layer is provided on the second surface; in the length direction, the length of the current collector is L1, the length of the negative electrode active material layer is L2, and the length of the positive electrode active material layer is L3; in the width direction, the width of the current collector is W1, the width of the negative electrode active material layer is W2, and the width of the positive electrode active material layer is W3; wherein L1>L2>L3, and/or W1>W2>3. In an achievable manner, the first surface includes a positive electrode active area and a positive electrode blank area, the positive electrode active material layer is arranged within the positive electrode active area, and the positive electrode blank area is arranged around the periphery of the positive electrode active material layer. In an achievable manner, the positive electrode blank area includes a first blank area and a second blank area, the first blank area is located on opposite sides of the positive electrode active area in the width direction, and the second blank area is located on opposite sides of the positive electrode active area in the length direction; in the width direction, the dimension of the first blank area is K1; in the length direction, the dimension of the second blank area is K2; wherein K1>0mm, K2>0 mm. In an achievable manner, 5 mm>K1>0 mm, 5 mm>K2>0 mm. In an achievable manner, the second surface includes a negative electrode active area and a negative electrode blank area, the negative electrode active material layer is arranged within the negative electrode active area, and the negative electrode blank area is arranged around the periphery of the negative electrode active material layer. In an achievable manner, the negative electrode blank area includes a third blank area and a fourth bl