WO2024026618A1 - 电化学装置和电子装置 - Google Patents

电化学装置和电子装置 Download PDF

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Publication number
WO2024026618A1
WO2024026618A1 PCT/CN2022/109437 CN2022109437W WO2024026618A1 WO 2024026618 A1 WO2024026618 A1 WO 2024026618A1 CN 2022109437 W CN2022109437 W CN 2022109437W WO 2024026618 A1 WO2024026618 A1 WO 2024026618A1
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WO
WIPO (PCT)
Prior art keywords
recess
conductive plate
area
electrochemical device
distance
Prior art date
Application number
PCT/CN2022/109437
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English (en)
French (fr)
Inventor
闫东阳
Original Assignee
宁德新能源科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to PCT/CN2022/109437 priority Critical patent/WO2024026618A1/zh
Priority to CN202280011270.5A priority patent/CN116802828A/zh
Publication of WO2024026618A1 publication Critical patent/WO2024026618A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/536—Electrode connections inside a battery casing characterised by the method of fixing the leads to the electrodes, e.g. by welding

Definitions

  • the present application relates to the field of energy storage technology, and in particular, to an electrochemical device and an electronic device having the electrochemical device.
  • Electrochemical devices such as secondary batteries
  • electronic products such as electronic mobile devices, power tools, and electric vehicles, and people have increasingly higher requirements for the service life of electrochemical devices.
  • An electrochemical device typically includes an electrode assembly and a conductive plate electrically connected to the electrode assembly.
  • protrusions such as solder marks
  • An electrochemical device When subjected to mechanical abuse (such as external extrusion, collision), protrusions (such as solder marks) on the surface of the conductive plate may pierce the isolation film and cause a short circuit, thereby reducing the service life of the electrochemical device.
  • the present application proposes an electrochemical device capable of improving service life.
  • the present application also provides an electronic device having the electrochemical device.
  • a first aspect of the present application provides an electrochemical device, including an electrode assembly and a first conductive plate.
  • the electrode assembly includes a first pole piece.
  • the first pole piece includes a first current collector and a first conductive material layer.
  • the first current collector includes a first surface, and a first conductive material layer is disposed on the first surface.
  • the first conductive material layer is provided with a first opening.
  • the first surface includes a first area configured as an area of the first surface exposed by the first opening.
  • the first conductive plate is connected to the first area.
  • the first pole piece Viewed from the first direction, the first pole piece includes a first end edge and a second end edge that are oppositely arranged in the second direction, and the first pole piece is provided with a first recess at the first end edge.
  • the first recess is separated from the first region. Viewed from the second direction, the first recess overlaps the first area. Viewed from the first direction, the first conductive plate covers a part of the first area, the first conductive plate covers a part of the first conductive material layer, and the first conductive plate covers a part of the first recess.
  • the first direction is perpendicular to the first area, and the second direction is perpendicular to the first direction.
  • the thicker position of the first pole piece with the first conductive plate is where the first pole pieces with double-sided coatings on both sides of the first area are located when viewed from the first direction. position (hereinafter referred to as: the first position), or the overlapping area between the first opening and the first recess and the first conductive plate (hereinafter referred to as: the second position), which is beneficial to reducing the size of the electrochemical device
  • the total thickness in the first direction improves space utilization.
  • the above-mentioned thicker position of the first pole piece can bear part of the external force. , reduce the possibility of protrusions piercing the isolation film and causing short circuit, and extend the service life of the electrochemical device.
  • the first recess can also provide a buffer space for the first conductive plate, reducing the possibility of the first conductive plate being folded and broken along with the first pole piece. , further extending the service life of the electrochemical device.
  • the first recess viewed from the first direction, includes a first recess side and a second recess side that are oppositely arranged in the third direction and a third recess side connecting the first recess side and the second recess side. .
  • the first recess side, the second recess side and the third recess side are surrounded by a first recess.
  • the third direction is perpendicular to both the first direction and the second direction.
  • the first recess of the above structure can provide a larger buffer space for the first conductive plate during mechanical abuse, further extending the service life of the electrochemical device.
  • the first end side includes a first connecting side connected to the first recess side. Both the third recessed portion edge and the first connecting edge extend along the third direction.
  • the distance from the first connecting side to the third recess side is the first distance L 1
  • the distance from the third recess side to the first area is the second distance L 2
  • the first distance L 1 is greater than the second distance L2 .
  • the first distance L 1 is larger, it is beneficial to increase the area of the first recess, so that the first recess can provide a larger buffer space for the first conductive plate during mechanical abuse.
  • 1mm ⁇ L 1 ⁇ 6mm, 0.3mm ⁇ L 2 ⁇ 4mm 1mm ⁇ L 1 ⁇ 6mm, 0.3mm ⁇ L 2 ⁇ 4mm.
  • the first recess can provide a larger buffer space for the first conductive plate during mechanical abuse, while also reducing the impact on the capacity of the electrochemical device.
  • the first conductive material layer located between the first opening and the first recess can effectively play a padding role and at the same time reduce the impact on the capacity of the electrochemical device.
  • the first recess further includes a fourth recess side and a fifth recess side.
  • the fourth recess side connects the first recess side and the third recess side
  • the fifth recess side connects the second recess side and the third recess side.
  • the fourth concave portion is curved on one side
  • the fifth concave portion is curved on one side.
  • the area of the first conductive material layer that acts as a cushion between the first opening and the first recess can be increased, which is beneficial to the part of the first conductive material layer that can withstand external forces when mechanical abuse occurs.
  • the thickness of the first conductive plate is smaller than the thickness of the first conductive material layer. Therefore, the thicker position of the first pole piece with the first conductive plate is the first position. Therefore, when mechanical abuse occurs, if the external force acting position overlaps with the protrusion on the surface of the first conductive plate, the first position can bear part of the external force first, and when viewed from the first direction, the first position has a greater resistance than the second position. The area is conducive to bearing larger external forces when the machine is abused, further extending the service life of the electrochemical device.
  • the distance from the first conductive plate to the side of the first recess is the third distance L 3
  • the distance from the first conductive plate to the side of the second recess is the third distance L 3
  • the fourth distance L 4 and the third distance L 3 are not equal to the fourth distance L 4 .
  • the first pole piece further includes a second conductive material layer.
  • the first current collector also includes a second surface opposite to the first surface, and the second conductive material layer is disposed on the second surface.
  • the second conductive material layer is provided with a second opening.
  • the second surface includes a second area configured as an area of the second surface exposed by the second opening. The first area and the second area overlap in the first direction. Viewed from the second direction, the second area overlaps the first recess. Therefore, the heat generated at the first conductive plate when the electrochemical device is charged can not only be dissipated through the first area exposed on the first conductive plate, but can also be conducted to the second area through the overlap of the first area and the second area. And it is dissipated by the second area, which reduces the possibility of local overheating of the first conductive plate.
  • the second region is separated from the first recess in the second direction. Therefore, part of the second conductive material layer existing between the second opening and the first recess can also play a role in raising the height in the first direction. When an external force acts on the back of the electrochemical device, this part of the second conductive material layer can also bear part of the external force, reducing the possibility of the protrusions on the surface of the first conductive plate piercing the isolation film and causing a short circuit, and prolonging the use of the electrochemical device. life.
  • the first area viewed from the first direction, includes a first side and a second side that are oppositely arranged in the third direction.
  • the first side and the first recessed portion side are located on the first side of the first conductive plate, and the second side and the second recessed portion side are located on the second side of the first conductive plate opposite to the first side.
  • the second area includes a third side and a fourth side that are oppositely arranged in the third direction.
  • the first side and the third side are located on the first side of the first conductive plate, and the second side and the fourth side are located on the second side of the first conductive plate.
  • the first pole piece has a thickness transition at a position corresponding to the first side and the third side, and/or the first pole piece has a thickness transition at a position corresponding to the second side and the fourth side.
  • the above-mentioned thickness transition is beneficial to reducing the possibility of wrinkles and other damage to the first current collector during rolling, thereby reducing the possibility of poor appearance or poor internal interface of the electrochemical device.
  • the above-mentioned thickness transition can also reduce the possibility of tearing of the first current collector when it is impacted or squeezed by an external force. Therefore, the service life of the electrochemical device is extended.
  • the second area when viewed from the first direction, completely covers the first area. Therefore, when viewed from the first direction, the protrusion of the first conductive plate can completely fall within the scope of the second area, which reduces the possibility that the conductive material falls off and causes a short circuit when the protrusion falls on the second conductive material layer, and extends shorten the service life of electrochemical devices.
  • the second area is connected to the first recess. Therefore, there is no second conductive material layer between the second region and the first recess, reducing the amount of conductive material (in some embodiments, it is covered by the second layer, and this part of the conductive material is difficult to play a capacity role). Moreover, the possibility of the conductive material falling off and causing a short circuit when the protrusions on the surface of the first conductive plate land on this part of the second conductive material layer is reduced, thereby extending the service life of the electrochemical device.
  • the electrochemical device further includes a first layer including a first insulating material.
  • the first layer bonds the first area.
  • the first conductive plate is disposed between the first area and the first layer. The first layer can reduce the risk that the protrusions on the surface of the first conductive plate penetrate the isolation film and cause a short circuit.
  • the first layer when viewed from the first direction, completely covers the first opening and the first recess, and the first layer extends beyond the first end edge in the second direction. In this way, the first layer can also cover the burrs generated at the first end edge of the first current collector during the cutting process, thereby reducing the possibility that the burrs may penetrate the isolation film and cause a short circuit.
  • the first conductive plate is welded to the first region, so that there is a higher connection strength between the first conductive plate and the first region.
  • the electrode assembly has a wound structure, and the first pole piece is a positive pole piece.
  • the present application also provides an electronic device, including the above electrochemical device.
  • the electronic device is powered by the above electrochemical device, and the electrochemical device has a high service life.
  • Figure 1 is a schematic diagram of the overall structure of an electrochemical device according to an embodiment of the present application.
  • FIG. 2A is a cross-sectional view along II-II of the electrochemical device shown in FIG. 1 .
  • FIG. 2B is an enlarged view of the electrode assembly of the electrochemical device of FIG. 2A at position A.
  • FIG. 3 is a front view of the first pole piece of the electrode assembly shown in FIG. 2A in some embodiments.
  • FIG. 4 is a back view of the first pole piece shown in FIG. 3 .
  • FIG. 5 is a front view of the first pole piece shown in FIG. 3 with the first layer removed.
  • FIG. 6 is a front view of the first pole piece shown in FIG. 3 in other embodiments.
  • FIG. 7A is a front view of the first pole piece shown in FIG. 3 in other embodiments.
  • FIG. 7B is a front view of the first pole piece shown in FIG. 3 in other embodiments.
  • FIG. 8 is a front view of the first pole piece shown in FIG. 3 in other embodiments.
  • FIG. 9 is a front view of the first pole piece shown in FIG. 3 in other embodiments.
  • FIG. 10A is a cross-sectional view along X-X of the first pole piece shown in FIG. 3 in some embodiments.
  • FIG. 10B is a cross-sectional view along X-X of the first pole piece shown in FIG. 3 in other embodiments.
  • FIG. 11 is a cross-sectional view along XI-XI of the first pole piece shown in FIG. 3 .
  • FIG. 12 is a cross-sectional view along XII-XII of the first pole piece shown in FIG. 3 .
  • FIG. 13 is a front view of the first pole piece shown in FIG. 3 in other embodiments.
  • FIG. 14 is a front view of the first pole piece shown in FIG. 3 in other embodiments.
  • Figure 15 is a back view of the first pole piece in the electrochemical device provided by another embodiment of the present application.
  • FIG. 16 is a cross-sectional view along XVI-XVI of the first pole piece shown in FIG. 15 .
  • FIG. 17 is a schematic diagram of the overall structure of an electronic device according to an embodiment of the present application.
  • the first wall 111 The first wall 111
  • the second set of fluids 220 is the second set of fluids 220
  • spatially relative terms such as “on,” etc., may be used herein for convenience to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device or device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the diagram is turned over, features described as “above” or “on” other features or features would then be oriented “below” or “beneath” the other features or features. Thus, the exemplary term “upper” may include both upper and lower directions. It will be understood that, although the terms first, second, third, etc.
  • an embodiment of the present application provides an electrochemical device 100 , including a housing 10 , an electrode assembly 20 , a first conductive plate 30 and a second conductive plate 40 .
  • the electrode assembly 20 is located within the housing 10 .
  • the first conductive plate 30 and the second conductive plate 40 are both electrically connected to the electrode assembly 20 and extend out of the housing 10 from the inside.
  • the casing 10 may be a packaging bag sealed with a packaging film (such as aluminum-plastic film), that is, the electrochemical device 100 may be a soft-pack battery.
  • the electrochemical device 100 is not limited to soft-pack batteries, and may also be steel-shell batteries or aluminum-shell batteries.
  • FIG. 2A shows that the number of electrode assemblies 20 is one. In other embodiments, the number of electrode assemblies 20 may also be multiple.
  • the plurality of electrode assemblies 20 are located in the housing 10 and are electrically connected in parallel or in series.
  • the electrode assembly 20 may be in a rolled structure.
  • the electrode assembly 20 includes a first pole piece 21 , a second pole piece 22 and an isolation film 23 .
  • the isolation film 23 is disposed between the first pole piece 21 and the second pole piece 22 .
  • the first pole piece 21 , the isolation film 23 and the second pole piece 22 are sequentially stacked and wound to form the electrode assembly 20 .
  • the electrode assembly 20 has a winding central axis C perpendicular to the paper surface.
  • the winding direction D is the direction of counterclockwise rotation around the winding center axis C as shown in FIG. 2A . In other embodiments, the winding direction D may also be a clockwise rotation direction.
  • a three-dimensional coordinate system is established based on the mutually perpendicular first direction D 1 , the second direction D 2 and the third direction D 3 .
  • the first direction D 1 is a direction perpendicular to a surface of the first conductive plate 30 .
  • the second direction D 2 is the direction in which the first conductive plate 30 protrudes from the electrode assembly 20 , and in some embodiments is also the direction of the winding central axis C.
  • the third direction D 3 is the direction from the first conductive plate 30 to the second conductive plate 40 .
  • the electrode assembly 20 may also be a laminate structure.
  • the first pole piece 21 includes a first current collector 210 , a first conductive material layer 211 and a second conductive material layer 212 .
  • the first current collector 210 includes a first surface 210a and a second surface 210b that are oppositely arranged.
  • the first conductive material layer 211 is provided on the first surface 210a
  • the second conductive material layer 212 is provided on the second surface 210b.
  • the second pole piece 22 includes a second current collector 220 , a third conductive material layer 221 and a fourth conductive material layer 222 .
  • the second current collector 220 includes a third surface 220a and a fourth surface 220b that are oppositely arranged.
  • the third conductive material layer 221 is provided on the third surface 220a, and the fourth conductive material layer 222 is provided on the fourth surface 220b.
  • the second conductive material layer 212 and the fourth conductive material layer 222 face each other across the isolation film 23 .
  • the first surface 210a of the first current collector 210 is further away from the winding central axis C than the second surface 210b, and the second current collector 220 has a
  • the third surface 220a is further away from the winding center axis C than the fourth surface 220b.
  • the first surface 210a of the first current collector 210 can also be closer to the winding central axis C, and the third surface 220a of the second current collector 220 can also be closer to the fourth surface. 220b is closer to the winding center axis C.
  • the thickness of the first current collector 210 may range from 3 ⁇ m to 20 ⁇ m
  • the thickness of the first material layer 211 may range from 30 ⁇ m to 300 ⁇ m
  • the thickness of the second conductive material layer 212 may range from 30 ⁇ m to 300 ⁇ m. The range can be 30 ⁇ m to 300 ⁇ m.
  • the first pole piece 21 may be a positive pole piece or a negative pole piece.
  • the first current collector 210 may be a positive current collector or a negative current collector, and the first conductive material layer 211 and the second conductive material layer 212 may each be a positive active material layer or a negative active material layer.
  • the second pole piece 22 may be a negative pole piece or a positive pole piece.
  • the second current collector 220 may be a negative electrode current collector or a positive electrode current collector, and the third conductive material layer 221 and the fourth conductive material layer 222 may each be a negative electrode active material layer or a positive electrode active material layer.
  • the first pole piece 21 is a positive pole piece
  • the second pole piece 22 is a negative pole piece.
  • the positive electrode current collector can be aluminum foil or nickel foil, and the negative electrode current collector can be at least one of copper foil, nickel foil or carbon-based current collector.
  • the cathode active material layer contains a cathode active material including a compound that reversibly intercalates and deintercalates lithium ions (ie, a lithiated intercalation compound).
  • the cathode active material may include lithium transition metal complex oxide.
  • the lithium transition metal composite oxide contains lithium and at least one element selected from cobalt, manganese and nickel.
  • the cathode active material is selected from lithium cobalt oxide (LiCoO 2 ), lithium nickel manganese cobalt ternary material (NCM), lithium manganate (LiMn 2 O 4 ), lithium nickel manganate (LiNi 0.5 Mn 1.5 O 4 ) or at least one of lithium iron phosphate (LiFePO 4 ).
  • the negative active material layer contains a negative active material, and a negative active material known in the art that can perform reversible deintercalation of active ions is used, which is not limited in this application.
  • a negative active material known in the art that can perform reversible deintercalation of active ions is used, which is not limited in this application.
  • it may include but is not limited to one of graphite, soft carbon, hard carbon, carbon fiber, mesophase carbon microspheres, silicon-based materials, tin-based materials, lithium titanate or other metals that can form an alloy with lithium, or Various combinations.
  • the graphite can be selected from one or a combination of artificial graphite, natural graphite and modified graphite;
  • the silicon-based material can be selected from one or more of elemental silicon, silicon oxide compounds, silicon carbon composites, silicon alloys or Various combinations;
  • tin-based materials can be selected from one or a combination of elemental tin, tin oxide compounds, tin alloys, etc.
  • the isolation film 23 includes at least one of polyethylene, polypropylene, polyvinylidene fluoride, polyethylene terephthalate, polyimide or aramid.
  • polyethylene includes at least one selected from high-density polyethylene, low-density polyethylene, or ultra-high molecular weight polyethylene.
  • polyethylene and polypropylene have a good effect on improving short circuits and can improve the stability of electrochemical devices through the shutdown effect.
  • the first conductive material layer 211 includes a first opening 2110 .
  • the first surface 210a of the first current collector 210 includes a first region 2100.
  • the first area 2100 is configured as an area where the first surface 210a is exposed from the first opening 2110. That is, the first area 2100 is exposed at the first opening 2110.
  • the first direction D 1 is also a direction perpendicular to the first area 2100 .
  • laser cleaning can be used to clean the first opening 2110 in the first conductive material layer 211 to expose the first area 2100; foam glue can also be applied to the first area 2100 in advance to coat the active material.
  • heating is performed to cause the foam glue to fall off, thereby exposing the first region 2100; or the active material on the first region 2100 can be directly scraped off with a scraper, thereby exposing the first region 2100.
  • a scraper after laser cleaning or scraping off by a scraper, a small amount of active material may remain on the surface of the first region 2100, which is not limited by this application.
  • the first region 2100 and the first opening 2110 may both be rectangular.
  • the first area 2100 includes a first side 2101 and a second side 2102 that are oppositely arranged in the third direction D3 , and a fifth side 2103 and a sixth side 2104 that are oppositely arranged in the second direction D2 .
  • the fifth side 2103 is connected between the first side 2101 and the second side 2102
  • the sixth side 2104 is connected between the first side 2101 and the second side 2102.
  • first side 2101 and the second side 2102 may both extend along the second direction D 2
  • the fifth side 2103 and the sixth side 2104 may both extend along the third direction D 3
  • the first side 2101 , the second side 2102, the fifth side 2103 and the sixth side 2104 may all be straight lines.
  • at least one of the first side 2101, the second side 2102, the fifth side 2103, and the sixth side 2104 may also include a concave and convex shape, This application is not limited.
  • the first opening 2110 is a three-dimensional structure, but when viewed from the first direction D 1 , the first opening 2110 includes a plurality of edges connected in sequence (not marked in the figure). Viewed from the first direction D 1 , the first side 2101 , the second side 2102 , the fifth side 2103 and the sixth side 2104 of the first area 2100 respectively coincide with the plurality of sides of the first opening 2110 .
  • the first conductive plate 30 connects the first area 2100 .
  • the first side 30A of the first conductive plate 30 is defined as a position located on one side of the first conductive plate 30 in the third direction D 3 when viewed from the first direction D 1
  • the second side 30A of the first conductive plate 30 is defined as 30B is a position opposite to the first side 30A and located on the other side of the first conductive plate 30 in the third direction D3 when viewed from the first direction D1 .
  • the third side 30C of the first conductive plate 30 is located on one side of the first conductive plate 30 in the second direction D2 when viewed from the first direction D1
  • the fourth side 30D of the first conductive plate 30 (in the second direction D2 1) is a position opposite to the third side 30C and located on the other side of the first conductive plate 30 in the second direction D2 when viewed from the first direction D1 .
  • the first side 30A of the first conductive plate 30 may refer to the left side of the first conductive plate 30
  • the second side 30B of the first conductive plate 30 may refer to the first side.
  • the third side 30C of the first conductive plate 30 may refer to the lower side of the first conductive plate 30
  • the fourth side 30D of the first conductive plate 30 may refer to the lower side of the first conductive plate 30 . upper side.
  • the third side 30C of the first conductive plate 30 is located inside the housing 10
  • the fourth side 30D is located outside the housing 10 .
  • the first side 2101 is located on the first side 30A of the first conductive plate 30
  • the second side 2102 is located between the first conductive plate 30 and the first side 30A.
  • Second side 30B Second side 30B.
  • the first conductive plate 30 covers part of the fifth side 2103 , and the first conductive plate 30 overlaps part of the fifth side 2103 .
  • the first region 2100 can be provided in the region of the first pole piece 21 except for the winding head and the winding tail.
  • the first conductive plate 30 is welded to the first region 2100, so that there is a high connection strength between the first conductive plate 30 and the first region 2100.
  • at least one protrusion 30 a may be formed at the welding point between the first conductive plate 30 and the first region 2100 .
  • a plurality of protrusions 30a arranged in a matrix may be formed at the welding point between the first conductive plate 30 and the first region 2100, and the protrusions 30a protrude from the first region 2100 toward the first conductive plate 30.
  • at least one protrusion 30b is formed correspondingly on the surface of the first conductive plate 30 away from the first region 2100 .
  • the second surface 210b of the first current collector 210 is correspondingly formed with at least one depression 210c.
  • the protrusions 30a and 30b and the recess 210c may be formed during the welding process (which may be called welding marks), but this application is not limiting.
  • at least one depression 30c may be formed at the welding point between the first conductive plate 30 and the first region 2100 .
  • a plurality of recesses 30c arranged in a matrix may be formed at the welding point between the first conductive plate 30 and the first region 2100 .
  • the recess 30c is recessed from the first region 2100 toward the first conductive plate 30 .
  • the depressions 30c and 30d and the protrusions 210d may be formed during the welding process (which may be called welding marks), but are not limited by this application.
  • the first conductive plate 30 may also be connected to the first region 2100 through conductive glue or other methods.
  • the thickness of the first conductive plate 30 may range from 10 ⁇ m to 150 ⁇ m
  • the thickness of the second conductive plate 40 may range from 10 ⁇ m to 150 ⁇ m.
  • the first pole piece 21 includes a first end edge 213 and a second end edge 214 that are oppositely arranged in the second direction D 2 .
  • the second direction D2 the second end side 214, the sixth side 2104, the fifth side 2103 and the first end side 213 are arranged in sequence.
  • the second end side 214, the sixth side 2104, the fifth side 2103 and the first end side 213 are arranged in sequence in the second direction D2, which refers to the sequence of a certain virtual straight line set along the second direction D2 . Passing through the second end side 214, the sixth side 2104, the fifth side 2103 and the first end side 213.
  • the first end side 213 and the second end side 214 may both extend along the third direction D3 .
  • the first pole piece 21 is provided with a first recess 2130 at the first end edge 213 .
  • the first recess 2130 may be formed by laser cutting or die cutting.
  • the first opening 2110 is separated from the first recess 2130 , so that a portion of the first conductive material layer 211 exists between the first opening 2110 and the first recess 2130 .
  • the first opening 2110 may be separated from the second end edge 214 .
  • the first area 2100 overlaps the first recess 2130.
  • overlap means that the two are at least partially covered in a certain direction.
  • the first recess 2130 covers part of the first region 2100 ; and as shown in FIG. 6 , in other embodiments, when viewed from the second direction D2 Observed from D2 , the first recess 2130 completely covers the first area 2100, and the first area 2100 also completely covers the first recess 2130 in the second direction D2 (that is, the two overlap).
  • the first conductive plate 30 covers a part of the first area 2100 , and the first conductive plate 30 also covers a part of the first conductive material layer 211 (that is, it covers the position between the first opening 2110 and the first recess 2130 The first conductive plate 30 also covers a portion of the first recess 2130.
  • the first conductive plate 30 includes a first connection area 31 , a second connection area 32 and a third connection area 33 that are connected in sequence in the second direction D 2 .
  • the first connection area 31 covers a part of the first area 2100, and the solder mark may be formed on the first connection area 31; the second connection area 32 covers a part of the first conductive material layer 211; the third connection area 33 covers a part of the first recess 2130.
  • the third connection area 33 extends beyond the first end edge 213 in the second direction D 2 and further extends out of the housing 10 .
  • the first connection area 31 is the position where the current flows when the electrochemical device 100 is charging. The heat generated at the first connection area 31 when the electrochemical device 100 is charging can be exposed to the first area 2100 of the first connection area 31 Distribute. Referring to FIGS.
  • the portion of the first conductive material layer 211 existing between the first opening 2110 and the first recess 2130 can play a role of raising the height in the first direction D 1 .
  • the existence of the conductive material layer 211 reduces the height difference with the solder mark (such as the protrusion 30b) in the first direction D 1 , and even this part of the first conductive material layer 211 can be higher than the solder mark in the first direction D 1 . Therefore, when mechanical abuse occurs, if the position where the external force is applied overlaps with the soldering mark of the first conductive plate 30, especially when the external force is applied on the front side of the electrochemical device 100 (ie, the side of the housing 10 facing the first area 2100 as shown in FIG.
  • the part of the first conductive material layer 211 that acts as a pad can withstand part of the external force, reducing the possibility that the solder print pierces the isolation film 23 and contacts the second pole piece 22 for short circuit, and prolongs the electrochemical process. The service life of the device 100.
  • the first recess 2130 includes a first recess side 2131 , a second recess side 2132 and a third recess side 2133 .
  • the first recess side 2131 and the second recess side 2132 are arranged opposite to each other in the third direction D3 .
  • the first recess side 2131 and the second recess side 2132 may both extend along the second direction D2
  • the third recess side 2133 may extend along the third direction D3 .
  • the first recessed portion side 2131 when the first recessed portion side 2131 extends along the second direction D2 , the first recessed portion side 2131 can be parallel to the second direction D2 , or can also be arranged obliquely with respect to the second direction D2 (that is, the first recessed portion side The angle between 2131 and the second direction D2 is ⁇ 90°), but the entire first recess side 2131 is not parallel to the third direction D3 .
  • the second concave edge 2132 extends along the second direction D2 in the same way.
  • the third recess side 2133 connects the first recess side 2131 and the second recess side 2132 .
  • the first recess side 2131 , the second recess side 2132 and the third recess side 2133 surround the first recess 2130 .
  • the first opening 2110 is separated from the third recess side 2133 of the first recess 2130 .
  • the first side 2101 and the first recess side 2131 are both located on the first side 30A of the first conductive plate 30
  • the second side 2102 and the second recess side 2132 are both located on the first side 30A of the first conductive plate 30 .
  • Two sides 30B, and the first conductive plate 30 covers part of the third recess side 2133.
  • the first recess 2130 when viewed from the first direction D 1 , may be substantially rectangular, and the first recess side 2131 , the second recess side 2132 and the third recess side 2133 are all straight lines. Viewed from the first direction D 1 , the virtual dividing line between the first connecting area 31 and the second connecting area 32 overlaps the fifth side 2103 , and the virtual dividing line between the second connecting area 32 and the third connecting area 33 overlaps with the fifth side 2103 .
  • the third recess sides 2133 overlap.
  • the first end side 213 includes a first connecting side 213 a connecting the first concave side 2131 and a second connecting side 213 b connecting the second concave side 2132 .
  • the first connecting side 213a and the second connecting side 213b may both extend along the third direction D3 .
  • the first connection edge 213 a is located on the first side 30A of the first conductive plate 30
  • the second connection edge 213 b is located on the second side 30B of the first conductive plate 30 .
  • the shape of the first recess 2130 can also be changed.
  • the first recess 2130 when viewed from the first direction D 1 , the first recess 2130 may also be substantially U-shaped.
  • the first recess 2130 includes a first recess side 2131, a second recess side 2132, a third recess side 2133, a fourth recess side 2134 and a fifth recess side 2135.
  • the first recess side 2131 and the second recess side 2132 are arranged opposite to each other in the third direction D3 .
  • the first recess side 2131 and the second recess side 2132 may both extend along the second direction D2
  • the third recess side 2133 may extend along the third direction D3
  • the fourth recess side 2134 connects the first recess side 2131 and the third recess side 2133, and the fourth recess side 2134 is curved.
  • the fifth recess side 2135 connects the second recess side 2132 and the third recess side 2133, and the fifth recess side 2135 is curved.
  • the first recess side 2131 , the second recess side 2132 , the third recess side 2133 , the fourth recess side 2134 and the fifth recess side 2135 surround the first recess 2130 .
  • the first recess side 2131 , the second recess side 2132 and the third recess side 2133 are all straight lines, and the fourth recess side 2134 and the fifth recess side 2135 are all protrudingly disposed away from the first recess 2130 of arc.
  • the third recess side 2133 may also be arc-shaped.
  • the area of the first conductive material layer 211 that acts as a cushion between the first opening 2110 and the first recessed portion 2130 is increased, which is beneficial in case of mechanical abuse. This part of the first conductive material layer 211 can withstand external force.
  • the first concave side 2131 can be curved, and the second concave side 2132 can also be curved.
  • the first concave portion edge 2131 is an arc-shaped protruding away from the first concave portion 2130 .
  • the second concave portion edge 2132 is also an arc-shaped projecting away from the first concave portion 2130 .
  • smooth transitions can also be made between the first recess side 2131 and the third recess side 2133, and between the second recess side 2132 and the third recess side 2133.
  • the first recess 2130 may also be substantially V-shaped when viewed from the first direction D 1 .
  • the first recess 2130 only includes a first recess side 2131 and a second recess side 2132.
  • the first recess side 2131 and the second recess side 2132 may both extend away from the second direction D2 .
  • the first recess side 2131 is directly connected to the second recess side 2132, and the first recess side 2131 and the second recess side 2132 surround the first recess 2130.
  • both the first recess side 2131 and the second recess side 2132 are straight lines.
  • the second surface 210b of the first current collector 210 includes a second region 2100'.
  • the second conductive material layer 212 includes a second opening 2120 .
  • the second area 2100' is configured as an area where the second surface 210b is exposed from the second opening 2120. That is, the second area 2100' is exposed at the second opening 2120. Viewed from the first direction D1 , the first area 2100 and the second area 2100' overlap. Therefore, the heat generated at the first conductive plate 30 when the electrochemical device 100 is charged can be dissipated not only through the first area 2100 exposed in the first connection area 31, but also through the first area 2100 and the second area 2100'.
  • the overlap is conducted to the second area 2100' and dissipated by the second area 2100', thereby reducing the possibility of local overheating of the first conductive plate 30. Viewed from the second direction D2 , the second area 2100' overlaps the first recess 2130.
  • the second region 2100' and the first recess 2130 may meet. Therefore, when viewed from the first direction D 1 , there is no second conductive material layer 212 between the second region 2100 ′ and the first recess 2130 . Therefore, the first pole piece 21 located between the first opening 2110 and the first recess 2130 is a single-sided coating area.
  • the second area 2100 ′ and the second opening 2120 may both be rectangular.
  • the second area 2100' includes a third side 2105 and a fourth side 2106 that are oppositely arranged in the third direction D3 , and a seventh side 2107 and an eighth side 2108 that are oppositely arranged in the second direction D2 .
  • the seventh side 2107 is connected between the third side 2105 and the fourth side 2106
  • the eighth side 2108 is connected between the third side 2105 and the fourth side 2106.
  • the third side 2105 and the fourth side 2106 may both extend along the second direction D2
  • the seventh side 2107 and the eighth side 2108 may both extend along the third direction D3 . As shown in FIGS.
  • the first side 2101 and the third side 2105 are located on the first side 30A of the first conductive plate 30
  • the second side 2102 and the fourth side 2106 are located on the first side 30A of the first conductive plate 30 .
  • Second side 30B of conductive plate 30 Viewed from the first direction D 1 , the first conductive plate 30 covers the seventh side 2107 .
  • the sixth side 2104 and the eighth side 2108 may overlap; in other embodiments, as shown in FIG. 9 , the sixth side 2104 and the eighth side 2108 may also be in the second direction D 2 staggered from each other.
  • sixth side 2104 overlaps eighth side 2108.
  • the second area 2100' is connected to the first recess 2130, so the fifth side 2103 and the seventh side 2107 are staggered from each other in the second direction D2 , and the seventh side 2107 is closer to the first end than the fifth side 2103. Side 213. Viewed from the first direction D 1 , the seventh side 2107 overlaps the third recess side 2133 . Therefore, in the second direction D2 , the second end side 214, the eighth side 2108, the fifth side 2103, the seventh side 2107 (the third recess side 2133) and the first end side 213 are arranged in sequence.
  • the second opening 2120 is a three-dimensional structure, but when viewed from the first direction D 1 , the second opening 2120 includes a plurality of edges connected in sequence (not marked in the figure). Viewed from the first direction D 1 , the third side 2105 , the fourth side 2106 , the seventh side 2107 and the eighth side 2108 of the second area 2100 ′ respectively coincide with the plurality of sides of the second opening 2120 .
  • the thicker position of the first pole piece 21 with the first conductive plate 30 should be from the first direction.
  • D 1 the overlapping area between the first conductive material layer 211, the first current collector 210 and the second conductive material layer 212 and the first conductive plate 30 (including the first conductive plate 30, the first conductive material layer 211, The sum of the thicknesses of the first current collector 210 and the second conductive material layer 212).
  • the thicker position of the first pole piece 21 with the first conductive plate 30 should be at the third position when viewed from the first direction D 1 .
  • the position of the first pole piece 21 with double-sided coating film located on both sides of the first area 2100 in the three directions D 3 (hereinafter referred to as: the first position P 1 , the thickness T 1 of the first position P 1 includes the first The sum of the thicknesses of the conductive material layer 211, the first current collector 210 and the second conductive material layer 212), or the overlapping area between the first opening 2110 and the first recess 2130 and the first conductive plate 30 (hereinafter It is called: second position P 2 , and the thickness T 2 of the second position P 2 includes the sum of the thicknesses of the first conductive plate 30 , the first conductive material layer 211 and the first current collector 210 ).
  • the first recess 2130 in this application, it is beneficial to reduce the total thickness of the electrochemical device 100 in the first direction D 1 and improve space utilization. Moreover, when mechanical abuse occurs, if the position where the external force is applied overlaps with the soldering mark of the first conductive plate 30, especially when the external force is applied on the front of the electrochemical device 100, the first position P with the larger thickness in the first pole piece 21 will 1 or the second position P 2 can withstand part of the external force, reducing the possibility that the solder mark (such as the protrusion 30b) penetrates the isolation film 23 and contacts the second pole piece 22 for short circuit, thereby extending the service life of the electrochemical device 100.
  • the solder mark such as the protrusion 30b
  • first pole piece 21 may be wrinkled under the action of external force, causing the first end edge 213 or the second end edge 214 of the first pole piece 21 to be folded toward the middle of the first pole piece 21 .
  • the first recess 2130 can provide a buffer space for the third connection area 33 of the first conductive plate 30, reducing the possibility of the first conductive plate 30 being folded and broken along with the first pole piece 21, and further extending the length of the electrochemical device. 100 lifespan.
  • the first recess 2130 of the above structure can be used for mechanical abuse during mechanical abuse.
  • the first conductive plate 30 provides a larger buffer space.
  • the second pole piece 22 can also adopt a similar design to the first pole piece 21 , for example, a third area (such as a blank area) is provided on the second current collector 220 of the second pole piece 22 to connect to the second current collector 220 .
  • the second conductive plate 40 is provided with a second recess at the end edge of the second pole piece 22, so that the third conductive material layer 221 corresponding to the third area of the blank area is separated from the first recess 2130 in the second direction D2. set up. In this way, the space utilization of the electrochemical device 100 can be further improved and the service life can be extended.
  • the thickness of the first conductive plate 30 is less than the thickness of the first conductive material layer 211 . Therefore, after the first conductive plate 30 is connected to the first region 2100, the thicker positions of the first pole piece 21 with the first conductive plate 30 are located on both sides of the first region 2100 in the third direction D3 . The position where the first pole piece 21 with the double-sided coating film is located is the first position P 1 .
  • the first position P1 can bear part of the external force first, and the first position P1 has a higher ratio when viewed from the first direction D1 .
  • the second position P2 has a larger area, which is conducive to withstanding larger external forces during mechanical abuse and further prolongs the service life of the electrochemical device 100 .
  • the electrochemical device 100 further includes a first layer 50 including an insulating material.
  • the first layer 50 bonds the first area 2100.
  • the first conductive plate 30 is provided between the first area 2100 and the first layer 50 .
  • the first layer 50 is used to cover the solder marks (such as the protrusions 30 b ) of the first conductive plate 30 , thereby reducing the risk of the solder marks penetrating the isolation film 23 and causing a short circuit.
  • the first layer 50 can be single-sided tape or double-sided tape, and the specific material can be selected from polypropylene, polyethylene, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, and polymethyl methacrylate. or at least one of polyethylene glycol.
  • the first layer 50 may also be a ceramic coating. In the first direction D 1 , the thickness of the first layer 50 may range from 3 ⁇ m to 30 ⁇ m.
  • the first layer 50 completely covers the first opening 2110 and the first recess 2130 , and simultaneously covers the first conductive material located between the first opening 2110 and the first recess 2130 Layer 211. Furthermore, the first layer 50 extends beyond the first end edge 213 in the second direction D2 . Specifically, viewed from the first direction D 1 , the first layer 50 includes a first edge 51 and a second edge 52 that are oppositely arranged in the second direction D 2 , and also includes a third edge 51 that is oppositely arranged in the third direction D 3 . Edge 53 and fourth edge 54. The first edge 51 and the second edge 52 may both extend along the third direction D3 .
  • the third edge 53 and the fourth edge 54 may both extend along the third direction D3 .
  • the third edge 53 is connected between the first edge 51 and the second edge 52
  • the fourth edge 54 is connected between the first edge 51 and the second edge 52 .
  • the first edge 51 extends beyond the first end edge 213 in the second direction D2 .
  • the second edge 52 may be located between the sixth side 2104 and the second end side 214 .
  • the third edge 53 is located on the first side 30A of the first conductive plate 30 , and in the third direction D 3 , the first edge 2101 is located between the third edge 53 and the first conductive plate 30 .
  • the fourth edge 54 may be located on the second side 30B of the first conductive plate 30 , and in the third direction D 3 , the second edge 2102 is located between the fourth edge 54 and the first conductive plate 30 .
  • the first layer 50 can also cover the burrs generated at the first end edge 213 of the first current collector 210 during the cutting process, thereby reducing the possibility of the burrs piercing the isolation film 23 and contacting the second pole piece 22 for a short circuit. sex. Viewed from the first direction D 1 , the first layer 50 may also cover part of the first conductive material layer 211 . In order to facilitate distinction, the first conductive material layer 211 covered by the first layer 50 and other first conductive material layers 211 in FIG.
  • first conductive material layer 211 covered by the first layer 50 and other first conductive material layers 211 are made of different active materials, and there is no clear boundary between them. It can be understood that when the curved fourth recessed portion side 2134 and the fifth recessed portion side 2135 are provided as shown in FIG. 7A , the area of the first conductive material layer 211 that serves as a cushion between the first opening 2110 and the first recessed portion 2130 increases. , which is also conducive to increasing the contact area between the first layer 50 and the first conductive material layer 211 and improving the connection strength of the first layer 50 on the first pole piece 21 .
  • the electrochemical device 100 further includes a second layer 60 including an insulating material.
  • the second layer 60 bonds the second area 2100'.
  • the second layer 60 is used to cover the solder print (such as the protrusion 210d), thereby reducing the risk of the solder print penetrating the isolation film 23 and causing a short circuit.
  • the second layer 60 may be single-sided tape, double-sided tape, or ceramic coating.
  • the distance from the first connection side 213 a to the third recess side 2133 is the first distance L 1
  • the distance from the third recess side 2133 to the third recess side is L 1
  • the distance of a region 2100 is the second distance L 2
  • L 2 is also the size of the portion of the first conductive material layer 211 located between the first opening 2110 and the first recess 2130 in the second direction D 2 .
  • the first distance L 1 is greater than the second distance L 2 (L 1 >L 2 ).
  • the first distance L 1 is larger, it is beneficial to increase the area of the first recess 2130 , so that the first recess 2130 can provide a larger buffer space for the first conductive plate 30 during mechanical abuse.
  • the part of the first conductive material layer 211 located between the first opening 2110 and the first recess 2130 is covered by the first layer 50, and the material in this part of the first conductive material layer 211 is difficult to exert its capacity during the charging and discharging process. effect.
  • sufficient space needs to be reserved in the first region 2100 in the second direction D2 to connect the first conductive plate 30 .
  • the first distance L 1 may also be smaller than the second distance L 2 .
  • the first conductive material layer 211 located between the first opening 2110 and the first recess 2130 can effectively function as a pad.
  • the first recess 2130 is generally V-shaped when viewed from the first direction D 1 , at this time, the first distance L 1 is in the second direction D 2 , and the first connecting edge 213 a to the second The distance between the intersection points of one recess side 2131 and the second recess side 2132.
  • the second distance L 2 is the distance from the intersection of the first recess side 2131 and the second recess side 2132 to the first region 2100 in the second direction D 2 .
  • the first distance L 1 ranges from 1 mm to 6 mm (1 mm ⁇ L 1 ⁇ 6 mm), and the second distance L 2 ranges from 0.3 mm to 4mm (0.3mm ⁇ L 2 ⁇ 4mm), and 0.1 ⁇ L 2 /L 1 ⁇ 1.
  • the first recess 2130 can provide a larger buffer space for the first conductive plate 30 during mechanical abuse.
  • the present application can reduce the impact on the capacity of the electrochemical device 100.
  • the ratio of the second distance L 2 to the first distance L 1 ranges from 0.1 to 1. That is, 0.1 ⁇ L 2 /L 1 ⁇ 1.
  • the ratio of the first distance L 1 to the first distance L 1 is large (the area of the first recess 2130 is large) or the distance between the first opening 2110 and the first recess 2130 is reduced.
  • the size of the portion of the first conductive material layer 211 in the second direction D2 is smaller. Therefore, the present application can reduce the impact on the capacity of the electrochemical device 100, and can also enable this part of the first conductive material layer 211 to effectively function as a pad.
  • the first conductive plate 30 when viewed from the first direction D 1 , covers the middle position of the first recess 2130 in the third direction D 3 . Therefore, in the third direction D 3 , the distance from the first conductive plate 30 to the first recess side 2131 is the third distance L 3 , the distance from the first conductive plate 30 to the second recess side 2132 is the fourth distance L 4 , and the distance from the first conductive plate 30 to the second recess side 2132 is the fourth distance L 4 .
  • the third distance L 3 is approximately equal to the fourth distance L 4 . For example, the difference between the third distance L 3 and the fourth distance L 4 does not exceed ⁇ 1.5 mm.
  • the third distance L 3 ranges from 1 mm to 8 mm
  • the fourth distance L 4 ranges from 1 mm to 8 mm. In this way, while the first recess 2130 provides sufficient buffer space for the first conductive plate 30, it also reduces the impact on the capacity of the electrochemical device 100 when the third distance L 3 or the fourth distance L 4 is too large.
  • the fourth distance L 4 is the maximum distance from the first conductive plate 30 to the second concave edge 2131 in the second direction D 2 .
  • the third distance L 3 is in the second direction D 2 , from the first conductive plate 30 to the edge of the first recess.
  • the fourth distance L 4 is the maximum distance from the first conductive plate 30 to the second recess side 2132 in the second direction D 2 .
  • the first conductive plate 30 when viewed from the first direction D 1 , may also deviate from the middle position of the first recess 2130 in the third direction D 3 , such that the third distance L 3 is not equal to the fourth distance L 4 .
  • the third distance L 3 may be smaller than the fourth distance L 4 .
  • the first conductive plate 30 when viewed from the first direction D 1 , covers the middle position of the first area 2100 in the third direction D 3 . Therefore, in the third direction D 3 , the distance from the first side 2101 to the first conductive plate 30 is the fifth distance L 5 , the distance from the second side 2102 to the first conductive plate 30 is the sixth distance L 6 , and the fifth distance L 5 is approximately equal to the sixth distance L 6 . For example, the difference between the fifth distance L 5 and the sixth distance L 6 does not exceed ⁇ 1.5 mm.
  • the fifth distance L 5 and the sixth distance L 6 are actually the size of the first area 2100 exposed on the first connection area 31 of the first conductive plate 30 in the third direction D 3 .
  • the fifth distance L 5 ranges from 1 mm to 10 mm
  • the sixth distance L 6 ranges from 1 mm to 10 mm.
  • the fifth distance L 5 is also It may be less than or greater than the sixth distance L 6 . This is beneficial to reducing the process requirements when connecting the first conductive plate 30 on the first region 2100 .
  • the fourth distance L 4 when the first recess 2130 only covers part of the first area 2100 in the second direction D 2 , the fourth distance L 4 is smaller than the sixth distance L 6 . As shown in FIG. 6 , in other embodiments, when the first recess 2130 and the first area 2100 completely overlap in the second direction D 2 , the fourth distance L 4 may also be substantially equal to the sixth distance L 6 . For example, the difference between the fourth distance L 4 and the sixth distance L 6 does not exceed ⁇ 1.5 mm.
  • the first distance L 1 to the sixth distance L 6 can be measured by direct measurement method respectively.
  • the test steps include: disassembling the electrochemical device 100 and taking the first pole piece 21 as a test sample; using a caliper or other suitable method.
  • the measuring tool directly measures the values of the first distance L 1 to the sixth distance L 6 , or collects an image of the first pole piece 21 and performs the measurement in the image.
  • the first area 2100 and the second area 2100 ′ may be staggered in the third direction D 3 .
  • the first side 2101 and the third side 2105 are staggered in the third direction D 3
  • the second side 2102 and the fourth side 2106 are in the third direction D 3 Staggered photos.
  • the first side 2101 and the third side 2105 are staggered, so that the first pole piece 21 has a thickness transition at the positions corresponding to the first side 2101 and the third side 2105 .
  • the second side 2102 and the fourth side 2106 are staggered, so that the first pole piece 21 has a thickness transition at the positions corresponding to the second side 2102 and the fourth side 2106.
  • the above thickness transition is beneficial to reducing the possibility of wrinkles and other damage caused by the sudden increase in pressure on the first current collector 210 when the pole piece is rolled, thereby reducing the possibility of poor appearance or poor internal interface of the electrochemical device 100 .
  • the above-mentioned thickness transition can also reduce the possibility of tearing of the first current collector 210 when it is impacted or squeezed by an external force. Therefore, the service life of the electrochemical device 100 is extended.
  • the second area 2100 ′ when viewed from the first direction D 1 , completely covers the first area 2100 . That is, when viewed from the first direction D 1 , the area of the second area 2100 ′ is larger than the area of the first area 2100 , so that in the first direction D 1 , the projection of the first area 2100 is completely within the projection of the second area 2100 ′. .
  • the solder mark (the depression 210 c as shown in FIG. 10A or the protrusion 210 d as shown in FIG. 10B ) can completely fall within the scope of the second area 2100 ′, which reduces the risk of the solder mark falling.
  • the possibility of the conductive material falling off and causing a short circuit in the second conductive material layer 212 prolongs the service life of the electrochemical device 100 .
  • the first area 2100 and the second area 2100 ′ may also completely overlap.
  • the first side 2101 coincides with the third side 2105
  • the second side 2102 coincides with the fourth side 2106
  • the fifth side 2103 coincides with the seventh side 2107
  • the sixth side 2104 coincides with the The eight sides overlap.
  • the area of the first region 2100 is equal to the area of the second region 2100'.
  • FIG. 15 and 16 another embodiment of the present application further provides an electrochemical device (not shown).
  • the difference from the above-mentioned electrochemical device 100 is that in the first pole piece 21, the second region 2100' is arranged separated from the first recess 2130 in the second direction D2 , so that the second opening 2120 is separated from the first recess 2130. There is a portion of the second conductive material layer 212 therebetween. Therefore, when viewed from the first direction D 1 , the first pole piece 21 located between the first opening 2110 and the first recess 2130 is a double-sided coating area.
  • the thickness T 2 of the second position P 2 at this time includes the sum of the thicknesses of the first conductive plate 30 , the first conductive material layer 211 , the first current collector 210 and the second conductive material layer 212 .
  • the part of the second conductive material layer 212 existing between the second opening 2120 and the first recess 2130 can also play a role in raising the height in the first direction D 1 .
  • this part of the second conductive material layer 212 can also bear part of the external force, reducing The possibility of small soldering marks (such as depressions 210c or protrusions 210d) piercing the isolation film 23 and contacting the second pole piece 22 for a short circuit prolongs the service life of the electrochemical device.
  • the electrochemical device of the present application includes all devices that can undergo electrochemical reactions.
  • electrochemical devices include all types of primary cells, secondary cells, fuel cells, solar cells, and capacitors (such as supercapacitors).
  • the electrochemical device may be a lithium secondary battery, including lithium metal secondary batteries, lithium ion secondary batteries, lithium polymer secondary batteries and lithium ion polymer secondary batteries.
  • an embodiment of the present application further provides an electronic device 1 .
  • the electronic device 1 includes an electrochemical device (such as the electrochemical device 100 ).
  • the electronic device 1 is powered by the above-mentioned electrochemical device 100, and the electrochemical device 100 has a relatively long service life.
  • the electrochemical device 100 of the present application is applicable to electronic devices 1 in various fields.
  • the electronic device 1 of the present application may be, but is not limited to, a notebook computer, a pen input computer, a mobile computer, an e-book player, a portable telephone, a portable fax machine, a portable copier, a portable printer, a head-mounted Stereo headphones, video recorders, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles , bicycles, lighting equipment, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.
  • the present application will be described in detail below through specific examples and comparative examples. Among them, the present application will be described by taking the electrochemical device as a battery, the first pole piece as the positive electrode, and the first conductive plate as the positive conductive plate as an example, and combined with specific test methods.
  • a first opening 2110 is cleaned in the first conductive material layer 211 using a laser cleaning method, so that the first region 2100 is exposed in the first opening 2110 .
  • a first recess 2130 is formed on the first end edge 213 of the first pole piece 21 , and the first opening 2110 is separated from the first recess 2130 when viewed from the first direction D 1 .
  • the first conductive plate 30 is then welded on the first area 2100 .
  • the second pole piece 22, isolation membrane 23, electrolyte, etc. can adopt conventional designs.
  • the first pole piece 21 , the separator 23 and the second pole piece 22 are laminated and rolled, placed in a case, injected with electrolyte and packaged to form a battery.
  • the first pole piece 21 is a cathode pole piece.
  • Embodiments 1-9 lies in the value of the first distance L 1 , the value of the second distance L 2 , or the ratio of the second distance L 2 to the first distance L 1 .
  • Embodiment 1-9 The difference from Embodiment 1-9 is that the first recess 2130 is not provided on the first pole piece 21 .
  • the specific steps of the blunt puncture test include: 1) Charge the battery to 100°C under the environmental conditions of 25 ⁇ 5°C. % SOC (State of Charge, state of charge); 2) Use a triangular rod extruder (model: DKBF-3KH, manufacturer: Dae Kyung) to squeeze the front of the battery through a semicircular head nail with a diameter of 6mm and correspond to the first A soldering position of the conductive plate 30, and then gradually increase the pressure to 1300N at a speed of 300N/min; 3) Observe whether the battery fails.
  • Example 1 have 6 0.3 0.05 14/20
  • Example 2 have 5 0.5 0.1 20/20
  • Example 3 have 4 1.2 0.3 20/20
  • Example 4 have 1 0.5 0.5 20/20
  • Example 5 have 4 3 0.75 20/20
  • Example 6 have 4 4 1 20/20
  • Example 7 have 3 3 1 20/20
  • Example 8 have 2 2 1 20/20
  • Example 9 have 1.5 1.8 1.2 17/20 Comparative ratio none none none none 6/20
  • Dent pass rate X/20 means that among the 20 samples tested, the number that passed the Dent test is X.
  • Examples 1-9 are provided with the first recess 2130 on the first pole piece 21 .
  • the part of the first conductive material layer 211 existing between the first opening 2110 and the first recess 2130 can play a role of raising the height in the first direction D1 .
  • This part of the first conductive material layer 211 can be used during the blunt puncture test. Bear some external forces.
  • the diameter of the semicircular head nail is larger (larger than the width of the first conductive plate 30 in the third direction D 3 ), so the first pole pieces with double-sided coatings located on both sides of the first area 2100 during the blunt penetration test
  • the location of 21 can also bear part of the external force.
  • the proportion of the second distance L 2 in Embodiment 1 is small so that L 2 /L 1 is small.
  • the size of the first conductive material layer 211 in the second direction D2 is smaller, and the size of the part of the first conductive material layer 211 that can effectively play the role of padding is reduced, so the pass rate of the battery during the blunt test is reduced; the first conductive material layer 211 of Example 9 A small distance L 1 makes L 2 /L 1 larger, so the area of the first recess 2130 that can provide a buffer space for the first conductive plate 30 is reduced, so the pass rate of the battery during the blunt test is reduced.

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Abstract

电化学装置(100)包括电极组件(20)和第一导电板(30)，电极组件(20)包括第一极片(21)，第一极片(21)包括第一集流体(210)和第一导电材料层(211)，第一集流体(210)包括第一表面(210a)，第一导电材料层(211)设于第一表面(210a)，第一导电材料层(211)设有第一开口(2110)，第一表面(210a)包括第一区域(2100)，第一区域(2100)配置为第一开口(2110)显露出的第一表面(210a)的区域，第一导电板(30)连接于第一区域(2100)；从第一方向观察，第一极片(21)包括第一端边(213)和第二端边(214)，第一端边(213)设有第一凹部(2130)；从第一方向观察，第一凹部(2130)与第一区域(2100)相分离设置，第一凹部(2130)与第一区域(2100)在第二方向上重叠；从第一方向观察，第一导电板(30)覆盖第一区域(2100)的一部分、第一导电材料层(211)的一部分以及第一凹部(2130)的一部分。

Description

电化学装置和电子装置 技术领域
本申请涉及储能技术领域，尤其涉及一种电化学装置以及具有该电化学装置的电子装置。
背景技术
电化学装置(如二次电池)在电子移动设备、电动工具及电动汽车等电子产品中有着广泛使用，人们对电化学装置的使用寿命要求也越来越高。
电化学装置通常包括电极组件和电连接于电极组件的导电板。当受到机械滥用(如外力挤压、碰撞)时，导电板表面的凸起(如焊印)可能会刺穿隔离膜并发生短路，从而降低电化学装置的使用寿命。
发明内容
因此，本申请提出一种能够改善使用寿命的电化学装置。
另，本申请还提供一种具有该电化学装置的电子装置。
本申请第一方面提供一种电化学装置，包括电极组件和第一导电板。电极组件包括第一极片。第一极片包括第一集流体和第一导电材料层。第一集流体包括第一表面，第一导电材料层设于第一表面。第一导电材料层设有第一开口。第一表面包括第一区域，第一区域配置为第一开口显露出的第一表面的区域。第一导电板连接于第一区域。从第一方向观察，第一极片包括在第二方向上相对设置的第一端边和第二端边，第一极片于第一端边处设有第一凹部。从第一方向观察，第一凹部与第一区域相分离设置。从第二方向观察，第一凹部与第一区域重叠。从第一方向观察，第一导电板覆盖第一区域的一部分，第一导电板覆盖第一导电材料层的一部分，第一导电板覆盖第一凹部的一部分。第一方向垂直于第一区域，第二方向垂直于第一方向。
本申请设置第一凹部后，带有第一导电板的第一极片中厚度较大的位置为从第一方向观察时，第一区域两侧的具有双面涂膜的第一极片所在的位置(以下称为：第一位置)，或者，为第一开口与第一凹部之间与第一导电板的重叠区域(以下称为：第二位置)，这有利于减小电化学装置在第一方向上的总厚度，提高空间利用率。而且在发生机械滥用(如外力撞击、挤压)时，若外力作用位置与第一导电板表面的凸起(如焊印)重叠，第一极片中上述厚度较大的位置能够承担部分外力，减小凸起刺穿隔离膜导致短路的可能性，延长电化学装置的使用寿命。另外，若第一极片在外力作用下发生褶皱或翻折，第一凹部也能够为第一导电板提供缓冲空间，降低第一导电板随着第一极片翻折并发生断裂的可能性，进一步延长电化学装置的使用寿命。
在一些可能的实现方式中，从第一方向观察，第一凹部包括在第三方向上相对设置的第一凹部边和第二凹部边以及连接第一凹部边和第二凹部边的第三凹部边。第一凹部边、第二凹部边和第三凹部边围设成第一凹部。第三方向与第一方向和第二方向均垂直。上述结构的第一凹部能够在机械滥用时为第一导电板提供较大的缓冲空间，进一步延长电化学装置的使用寿命。
在一些可能的实现方式中，从第一方向观察，第一端边包括连接第一凹部边的第一连接边。第三凹部边和第一连接边均沿第三方向延伸。在第二方向上，第一连接边至第三凹部边的距离为第一距离L 1，第三凹部边至第一区域的距离为第二距离L 2，第一距离L 1大于第二距离L 2。第一距离L 1较大时，有利于提高第一凹部的面积，使得机械滥用时第一凹部能够为第一导电板提供较大的缓冲空间。当第 二距离L 2较小时(位于第一开口与第一凹部之间的第一导电材料层在一些实施例中被第一层覆盖，难以发挥容量作用，因此第二距离减小时难以发挥容量作用的活性材料减少)，在第一极片沿第二方向尺寸一定的条件下，在第二方向上其它可发挥容量作用的活性材料增加，从而减小了对电化学装置容量的影响。
在一些可能的实现方式中，1mm≤L 1≤6mm，0.3mm≤L 2≤4mm。通过设置第一距离L 1的范围，使得机械滥用时第一凹部能够为第一导电板提供较大的缓冲空间的同时，也减小了对电化学装置容量的影响。通过设置第二距离L 2的范围，使得位于第一开口与第一凹部之间的第一导电材料层能够有效起到垫高作用的同时，也减小了对电化学装置容量的影响。
在一些可能的实现方式中，0.1≤L 2/L 1<1。通过设置第二距离L 2与第一距离L 1比值的下限值，减小了对电化学装置容量的影响，也使得该部分第一导电材料层能够有效起到垫高作用。
在一些可能的实现方式中，从第一方向观察，第一凹部还包括第四凹部边和第五凹部边。第四凹部边连接第一凹部边和第三凹部边，第五凹部边连接第二凹部边和第三凹部边。第四凹部边弯曲设置，第五凹部边弯曲设置。因此，第一凹部边和第三凹部边之间、第二凹部边和第三凹部边之间可平滑过渡，这有利于减少上述过渡的位置于切割第一凹部的过程中产生的毛刺，从而减小上述毛刺刺穿隔离膜导致短路的可能性，延长电化学装置的使用寿命。而且可使得第一开口与第一凹部之间起垫高作用的第一导电材料层面积增大，这有利于机械滥用时该部分第一导电材料层能够承担外力。
在一些可能的实现方式中，在第一方向上，第一导电板的厚度小于第一导电材料层的厚度。因此，带有第一导电板的第一极片中厚度较大的位置为第一位置。因此在发生机械滥用时，若外力作用位置与第一导电板表面的凸起重叠，则第一位置能够优先承担部分外力，且从第一方向观察时第一位置具有比第二位置更大的面积，有利于在机械滥用时承担较大的外力，进一步延长电化学装置的使用寿命。
在一些可能的实现方式中，从第一方向观察，在第三方向上，第一导电板至第一凹部边的距离为第三距离L 3，第一导电板至第二凹部边的距离为第四距离L 4，第三距离L 3不等于第四距离L 4。
在一些可能的实现方式中，第一极片还包括第二导电材料层。第一集流体还包括与第一表面相对设置的第二表面，第二导电材料层设于第二表面。第二导电材料层设有第二开口。第二表面包括第二区域，第二区域配置为第二开口显露出的第二表面的区域。第一区域与第二区域在第一方向上重叠。从第二方向观察，第二区域与第一凹部重叠。从而，电化学装置充电时第一导电板处产生的热量除了可经露出于第一导电板的第一区域进行散发外，还可经第一区域和第二区域的重叠处传导至第二区域并由第二区域进行散发，减少了第一导电板局部过热的可能性。
在一些可能的实现方式中，第二区域在第二方向上与第一凹部相分离设置。因此第二开口与第一凹部之间存在的部分第二导电材料层也可在第一方向上起到垫高作用。当外力作用于电化学装置的背面时，该部分第二导电材料层也可承担部分外力，减小第一导电板表面的凸起刺穿隔离膜导致短路的可能性，延长电化学装置的使用寿命。
在一些可能的实现方式中，从第一方向观察，第一区域包括在第三方向上相对设置的第一边和第二边。第一边和第一凹部边位于第一导电板的第一侧，第二边和第二凹部边位于第一导电板与第一侧相对的第二侧。从第一方向观察，第二区域包括在第三方向上相对设置的第三边和第四边。第一边和第三边位于第一导电板的第一侧，第二边和第四边位于第一导电板的第二侧。从第一方向观察，第一边和第三边相错开，和/或，第二边和第四边相错开。因此，第一极片在第一边和第三边对应的位置具有厚度过渡，和/或，第一极片在第二边和第四边对应的位置具有厚度过渡。上述厚度过渡有利于减小辊压时第一集流体发生褶皱等损伤的可能性，从而减小电化学装置发生外观不良或内部界面不良的可能性。再者，在受到外力碰撞或挤压时，上述厚度过渡也可减小第一集流体发生撕裂的可能性。因此， 延长了电化学装置的使用寿命。
在一些可能的实现方式中，从第一方向观察，第二区域完全覆盖第一区域。因此，从第一方向观察，第一导电板的凸起可完全落在第二区域的范围内，减小了上述凸起落于第二导电材料层时导电材料脱落并导致短路的可能性，延长了电化学装置的使用寿命。
在一些可能的实现方式中，第二区域与第一凹部相接。因此第二区域与第一凹部之间不存在第二导电材料层，减少了导电材料(在一些实施例中被第二层覆盖，该部分导电材料难以发挥容量作用)的用量。而且，减少了第一导电板表面的凸部落于该部分第二导电材料层时导电材料脱落并导致短路的可能性，延长了电化学装置的使用寿命。
在一些可能的实现方式中，电化学装置还包括包含第一绝缘材料的第一层。第一层粘接第一区域。第一导电板设于第一区域和第一层之间。第一层能够减小第一导电板表面的凸起刺穿隔离膜而产生短路的风险。
在一些可能的实现方式中，从第一方向观察，第一层完全覆盖第一开口和第一凹部，第一层在第二方向上延伸超出第一端边。如此，第一层还可覆盖第一集流体在裁切过程中于第一端边处产生的毛刺，减小上述毛刺刺穿隔离膜导致短路的可能性。
在一些可能的实现方式中，第一导电板焊接于第一区域，从而使第一导电板与第一区域之间具有较高的连接强度。
在一些可能的实现方式中，电极组件为卷绕结构，第一极片为正极极片。
本申请还提供一种电子装置，包括上述电化学装置。电子装置通过上述电化学装置供电，且电化学装置具有较高的使用寿命。
附图说明
图1为本申请一实施方式提供的电化学装置的整体结构示意图。
图2A为图1所示的电化学装置沿II-II的剖视图。
图2B为图2A的电化学装置的电极组件于A处的放大图。
图3为图2A所示的电极组件的第一极片于一些实施例中的主视图。
图4为图3所示的第一极片的背视图。
图5为图3所示的第一极片去掉第一层后的主视图。
图6为图3所示的第一极片另一些实施例中的主视图。
图7A为图3所示的第一极片另一些实施例中的主视图。
图7B为图3所示的第一极片另一些实施例中的主视图。
图8为图3所示的第一极片另一些实施例中的主视图。
图9为图3所示的第一极片另一些实施例中的主视图。
图10A为图3所示的第一极片于一些实施例中沿X-X的剖视图。
图10B为图3所示的第一极片于另一些实施例中沿X-X的剖视图。
图11为图3所示的第一极片沿XI-XI的剖视图。
图12为图3所示的第一极片沿XII-XII的剖视图。
图13为图3所示的第一极片另一些实施例中的主视图。
图14为图3所示的第一极片另一些实施例中的主视图。
图15为本申请另一实施方式提供的电化学装置中第一极片的背视图。
图16为图15所示的第一极片沿XVI-XVI的剖视图。
图17为本申请一实施方式提供的电子装置的整体结构示意图。
主要元件符号说明
电子装置               1
壳体                   10
电极组件               20
第一极片               21
第二极片               22
隔离膜                 23
第一导电板             30
凸起                   30a、30b、210d
凹陷                   30c、210c
第一侧                 30A
第二侧                 30B
第三侧                 30C
第四侧                 30D
第一连接区             31
第二连接区             32
第三连接区             33
第二导电板             40
第一层                 50
第一边缘               51
第二边缘               52
第三边缘               53
第四边缘               54
第二层                 60
电化学装置             100
第一壁                 111
第二壁                 112
第一集流体             210
第一表面               210a
第二表面               210b
第一导电材料层         211
第二导电材料层         212
第一端边               213
第一连接边             213a
第二连接边             213b
第二端边               214
第二集流体             220
第三表面               220a
第四表面               220b
第三导电材料层         221
第四导电材料层         222
第一区域               2100
第二区域               2100’
第一边                 2101
第二边                 2102
第五边                 2103
第六边                 2104
第三边                 2105
第四边                 2106
第七边                 2107
第八边                 2108
第一开口               2110
第二开口               2120
第一凹部               2130
第一凹部边             2131
第二凹部边             2132
第三凹部边             2133
第四凹部边             2134
第五凹部边             2135
卷绕中心轴             C
卷绕方向               D
第一方向               D 1
第二方向               D 2
第三方向               D 3
第一位置               P 1
第二位置               P 2
厚度                   T 1、T 2
第一距离               L 1
第二距离               L 2
第三距离               L 3
第四距离               L 4
第五距离               L 5
第六距离               L 6
如下具体实施方式将结合上述附图进一步说明本申请。
具体实施方式
下面对本申请实施例中的技术方案进行清楚、详细地描述，显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。除非另有定义，本文所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同。在本申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请。
下文，将详细地描述本申请的实施方式。但是，本申请可体现为许多不同的形式，并且不应解释为限于本文阐释的示例性实施方式。而是，提供这些示例性实施方式，从而使本申请透彻的和详细的向本领域技术人员传达。
另外，为了简洁和清楚，在附图中，各种组件、层的尺寸或厚度可被放大。遍及全文，相同的数值指相同的要素。如本文所使用，术语“及/或”、“以及/或者”包括一个或多个相关列举项目的任何和所有组合。另外，应当理解，当要素A被称为“连接”要素B时，要素A可直接连接至要素B，或可能存在中间要素C并且要素A和要素B可彼此间接连接。
进一步，当描述本申请的实施方式时使用“可”指“本申请的一个或多个实施方式”。
本文使用的专业术语是为了描述具体实施方式的目的并且不旨在限制本申请。如本文所使用，单数形式旨在也包括复数形式，除非上下文另外明确指出。应进一步理解，术语“包括”，当在本说明书中使用时，指存在叙述的特征、数值、步骤、操作、要素和/或组分，但是不排除存在或增加一个或多个其他特征、数值、步骤、操作、要素、组分和/或其组合。
空间相关术语，比如“上”等可在本文用于方便描述，以描述如图中阐释的一个要素或特征与另一要素(多个要素)或特征(多个特征)的关系。应理解，除了图中描述的方向之外，空间相关术语旨在包括设备或装置在使用或操作中的不同方向。例如，如果将图中的设备翻转，则描述为在其他要素或特征“上方”或“上”的要素将定向在其他要素或特征的“下方”或“下面”。因此，示例性术语“上”可包括上面和下面的方向。应理解，尽管术语第一、第二、第三等可在本文用于描述各种要素、组分、区域、层和/或部分，但是这些要素、组分、区域、层和/或部分不应受这些术语的限制。这些术语用于区分一个要素、组分、区域、层或部分与另一要素、组分、区域、层或部分。因此，下面讨论的第一要素、 组分、区域、层或部分可称为第二要素、组分、区域、层或部分，而不背离示例性实施方式的教导。
在本申请中，参数数值之间的大于、小于或不等于设计关系，需要排除测量设备的合理误差。
请参阅图1和图2A，本申请一实施方式提供一种电化学装置100，包括壳体10、电极组件20、第一导电板30和第二导电板40。电极组件20位于壳体10内。第一导电板30和第二导电板40均电连接于电极组件20，且由壳体10的内部伸出壳体10。壳体10可以是采用封装膜(如铝塑膜)封装得到的包装袋，即电化学装置100可以为软包电池。在另一些实施例中，电化学装置100并不限于软包电池，还可以为钢壳电池或铝壳电池等。图2A示出电极组件20的数量为一个。在其它实施例中，电极组件20的数量也可以为多个，多个电极组件20位于壳体10内，且通过并联或者串联的方式电连接。
如图2A所示，电极组件20可以为卷绕结构。电极组件20包括第一极片21、第二极片22和隔离膜23，隔离膜23设置于第一极片21和第二极片22之间。第一极片21、隔离膜23和第二极片22依次层叠卷绕以形成电极组件20。其中，如图2A所示，电极组件20具有垂直于纸面的卷绕中心轴C。卷绕方向D为图2A所示绕着卷绕中心轴C进行逆时针转动的方向。在另一些实施例中，卷绕方向D也可以为顺时针转动的方向。在本申请中，根据相互垂直的第一方向D 1、第二方向D 2和第三方向D 3建立三维坐标系。第一方向D 1为垂直于第一导电板30一表面的方向。第二方向D 2为第一导电板30凸出于电极组件20的方向，在一些实施例中也为卷绕中心轴C方向。第三方向D 3为自第一导电板30至第二导电板40的方向。在另一些实施例中，电极组件20还可以为叠片结构。
如图2A和图2B所示，第一极片21包括第一集流体210、第一导电材料层211和第二导电材料层212。第一集流体210包括相对设置的第一表面210a和第二表面210b，第一导电材料层211设于第一表面210a，第二导电材料层212设于第二表面210b。如图2A所示，第二极片22包括第二集流体220、第三导电材料层221和第四导电材料层222。第二集流体220包括相对设置的第三表面220a和第四表面220b，第三导电材料层221设于第三表面220a，第四导电材料层222设于第四表面220b。第二导电材料层212和第四导电材料层222隔着隔离膜23相面对。在一些实施例中，如图2A所示，经层叠卷绕后，第一集流体210的第一表面210a相较于第二表面210b更远离卷绕中心轴C，第二集流体220的第三表面220a相较于第四表面220b更远离卷绕中心轴C。可以理解，在其它实施例中，第一集流体210的第一表面210a也可以相较于更靠近卷绕中心轴C，第二集流体220的第三表面220a也可以相较于第四表面220b更靠近朝向卷绕中心轴C。在一些实施例中，在第一方向D 1上，第一集流体210的厚度范围可以为3μm至20μm，第一材料层211的厚度范围可以为30μm至300μm，第二导电材料层212的厚度范围可以为30μm至300μm。
第一极片21可以是正极极片或负极极片。对应地，第一集流体210可以是正极集流体或负极集流体，第一导电材料层211和第二导电材料层212可以均是正极活性材料层或负极活性材料层。第二极片22可以是负极极片或正极极片。对应地，第二集流体220可以是负极集流体或正极集流体，第三导电材料层221和第四导电材料层222可以均是负极活性材料层或正极活性材料层。在一些实施例中，第一极片21为正极极片，第二极片22为负极极片。正极集流体可以采用铝箔或镍箔，负极集流体可以采用铜箔、镍箔或碳基集流体中的至少一种。
正极活性材料层包含正极活性材料，正极活性材料包括可逆地嵌入和脱嵌锂离子的化合物(即，锂化插层化合物)。在一些实施例中，正极活性材料可以包括锂过渡金属复合氧化物。该锂过渡金属复合氧化物含有锂以及从钴、锰和镍中选择的至少一种元素。在一些实施例中，正极活性材料选自钴酸锂(LiCoO 2)、锂镍锰钴三元材料(NCM)、锰酸锂(LiMn 2O 4)、镍锰酸锂(LiNi 0.5Mn 1.5O 4)或磷酸铁锂(LiFePO 4)中的至少一种。
负极活性材料层包含负极活性材料，采用本领域已知的能够进行活性离子可逆脱嵌的负极活性材料，本申请不做限制。例如，可以是包括但不限于石墨、软碳、硬碳、碳纤维、中间相碳微球、硅基材料、锡基材料、钛酸锂或其他能与锂形成合金的金属等中的一种或多种的组合。其中，石墨可选自人造石墨、天然石墨以及改性石墨中的一种或多种的组合；硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅合金中的一种或多种的组合；锡基材料可选自单质锡、锡氧化合物、锡合金等中的一种或多种的组合。
隔离膜23包括聚乙烯、聚丙烯、聚偏氟乙烯、聚对苯二甲酸乙二醇酯、聚酰亚胺或芳纶中的至少一种。例如，聚乙烯包括选自高密度聚乙烯、低密度聚乙烯或超高分子量聚乙烯中的至少一种。其中聚乙烯和聚丙烯，它们对改善短路具有良好的作用，并可以通过关断效应改善电化学装置的稳定性。
请一并参照图3和图5，第一导电材料层211包括第一开口2110。第一集流体210的第一表面210a包括第一区域2100。第一区域2100配置为第一表面210a从第一开口2110显露出的区域。即，第一区域2100露出于第一开口2110。此时第一方向D 1也为垂直于第一区域2100的方向。本申请中，可以采用激光清洗方式在第一导电材料层211中清洗处出第一开口2110，使得第一区域2100露出；也可以预先在第一区域2100上贴发泡胶，涂覆活性材料后进行加热以使得发泡胶脱落，从而使第一区域2100露出；或者可以直接用刮刀刮除第一区域2100上的活性材料，从而使第一区域2100露出。然而可以理解，经激光清洗或者刮刀刮除后，第一区域2100表面也可残留有少数活性材料，本申请并不作限制。
在一些实施例中，从第一方向D 1观察，第一区域2100与第一开口2110可均为矩形。具体地，第一区域2100包括在第三方向D 3上相对设置的第一边2101和第二边2102、以及在第二方向D 2上相对设置的第五边2103和第六边2104。第五边2103连接于第一边2101和第二边2102之间，第六边2104连接于第一边2101和第二边2102之间。在一些实施例中，第一边2101和第二边2102可均沿着第二方向D 2延伸，第五边2103和第六边2104可均沿着第三方向D 3延伸，第一边2101、第二边2102、第五边2103和第六边2104可均为直线形。在另一些实施例中，当采用激光清洗等方式形成第一区域2100时，第一边2101、第二边2102、第五边2103和第六边2104中的至少一者也可以包括凹凸形状，本申请并不作限制。可以理解，第一开口2110是三维结构，然而第一开口2110从第一方向D 1观察时包括依次连接的多条边(图未标出)。从第一方向D 1观察，第一区域2100的第一边2101、第二边2102、第五边2103和第六边2104分别与第一开口2110的多条边重合。
从第一方向D 1观察，第一导电板30连接第一区域2100。其中，定义第一导电板30的第一侧30A为从第一方向D 1观察时，在第三方向D 3上位于第一导电板30一侧的位置，第一导电板30的第二侧30B为与第一侧30A相对且从第一方向D 1观察时，在第三方向D 3上位于第一导电板30另一侧的位置。第一导电板30的第三侧30C为从第一方向D 1观察时，在第二方向D 2上位于第一导电板30一侧的位置，第一导电板30的第四侧30D(在图1中示出)为与第三侧30C相对且从第一方向D 1观察时，在第二方向D 2上位于第一导电板30另一侧的位置。例如，如图3和图5所示，第一导电板30的第一侧30A指的可以是第一导电板30的左侧，第一导电板30的第二侧30B指的可以是第一导电板30的右侧，第一导电板30的第三侧30C指的可以是第一导电板30的下侧，第一导电板30的第四侧30D指的可以是第一导电板30的上侧。第一导电板30的第三侧30C位于壳体10内，第四侧30D位于壳体10外。从第一方向D 1观察，在第三方向D 3上，第一边2101位于第一导电板30的第一侧30A，第二边2102位于第一导电板30与第一侧30A相对设置的第二侧30B。从第一方向D 1观察，第一导电板30覆盖部分第五边2103，第一导电板30与部分第五边2103 重叠。为了满足电化学装置100大电流充电的需求，第一区域2100可设于第一极片21除卷绕头部与卷绕尾部之外的区域。
在一些实施例中，第一导电板30焊接于第一区域2100，从而使第一导电板30与第一区域2100之间具有较高的连接强度。请参阅图10A，在一些实施例中，第一导电板30与第一区域2100的焊接处可能会形成至少一凸起30a。如，第一导电板30与第一区域2100的焊接处可形成多个呈矩阵排列的凸起30a，且凸起30a自第一区域2100向第一导电板30突出。同时，第一导电板30背离第一区域2100的表面对应形成至少一凸起30b。第一集流体210的第二表面210b对应形成至少一凹陷210c。凸起30a和30b、凹陷210c可在焊接过程中形成(此时可称为焊印)，但本申请并不作限制。请参阅图10B，在另一些实施例中，第一导电板30与第一区域2100的焊接处也可能会形成至少一凹陷30c。如，第一导电板30与第一区域2100的焊接处可形成多个呈矩阵排列的凹陷30c。凹陷30c自第一区域2100向第一导电板30凹进。同时，第一导电板30背离第一区域2100的表面对应形成至少一凹陷30d，第一集流体210的第二表面210b对应形成至少一凸起210d。凹陷30c和30d、凸起210d可在焊接过程中形成(此时可称为焊印)，但本申请并不作限制。在其它实施例中，第一导电板30也可通过导电胶或其它方式连接于第一区域2100。在第一方向D 1上，第一导电板30的厚度范围可以为10μm至150μm，第二导电板40的厚度范围可以为10μm至150μm。
如图3和图5所示，从第一方向D 1观察，第一极片21包括在第二方向D 2上相对设置的第一端边213和第二端边214。在第二方向D 2上，第二端边214、第六边2104、第五边2103和第一端边213依次设置。其中，在第二方向D 2上第二端边214、第六边2104、第五边2103和第一端边213依次设置，指的是在沿第二方向D 2设置的某一虚拟直线先后经过第二端边214、第六边2104、第五边2103和第一端边213。第一端边213和第二端边214可均沿着第三方向D 3延伸。第一极片21于第一端边213处设有第一凹部2130。其中，第一凹部2130可通过激光切割或模切方式切割形成。从第一方向D 1观察，第一开口2110与第一凹部2130相分离设置，使得第一开口2110与第一凹部2130之间存在部分第一导电材料层211。从第一方向D 1观察，第一开口2110可与第二端边214相分离设置。从第二方向D 2观察，第一区域2100与第一凹部2130重叠。此处，重叠指的是两者在某个方向上至少是部分覆盖的。例如，如图3至图5所示，从第二方向D 2观察，第一凹部2130覆盖部分第一区域2100；又如，如图6所示，在另一些实施例中，从第二方向D 2观察，第一凹部2130完全覆盖第一区域2100，第一区域2100在第二方向D 2上也完全覆盖第一凹部2130(即二者重合)。从第一方向D 1观察，第一导电板30覆盖第一区域2100的一部分，第一导电板30还覆盖第一导电材料层211的一部分(即覆盖位于第一开口2110与第一凹部2130之间的部分第一导电材料层211)，第一导电板30还覆盖第一凹部2130的一部分。具体地，第一导电板30包括在第二方向D 2上依次连接的第一连接区31、第二连接区32和第三连接区33。从第一方向D 1观察，第一连接区31覆盖第一区域2100的一部分，焊印可形成于第一连接区31；第二连接区32覆盖第一导电材料层211的一部分；第三连接区33覆盖第一凹部2130的一部分。第三连接区33在第二方向D 2上延伸至超出第一端边213，并进一步伸出壳体10。其中，第一连接区31即为电化学装置100充电时电流流经的位置，电化学装置100充电时第一连接区31处产生的热量可经露出于第一连接区31的第一区域2100进行散发。请参阅图11和图12，可以理解，第一开口2110与第一凹部2130之间存在的部分第一导电材料层211可在第一方向D 1上起到垫高的作用，该部分第一导电材料层211的存在减小了与焊印(如凸起30b)在第一方向D 1上的高度差，甚至该部分第一导电材料层211在第一方向D 1上可高于焊印。因此 在发生机械滥用时，若外力作用位置与第一导电板30的焊印重叠，尤其当外力作用于电化学装置100的正面(即如图2A所示的壳体10朝向第一区域2100的第一壁111)时，起垫高作用的该部分第一导电材料层211可承担部分外力，减小焊印刺穿隔离膜23并与第二极片22接触短路的可能性，延长电化学装置100的使用寿命。
如图3和图5所示，在一些实施例中，第一凹部2130包括第一凹部边2131、第二凹部边2132和第三凹部边2133。第一凹部边2131和第二凹部边2132在第三方向D 3上相对设置。第一凹部边2131和第二凹部边2132可均沿着第二方向D 2延伸，第三凹部边2133可沿着第三方向D 3延伸。其中，当第一凹部边2131沿着第二方向D 2延伸时，第一凹部边2131可与第二方向D 2平行，也可相较于第二方向D 2倾斜设置(即第一凹部边2131与第二方向D 2的夹角＜90°)，但第一凹部边2131整体并不与第三方向D 3平行。第二凹部边2132沿着第二方向D 2延伸同理。第三凹部边2133连接第一凹部边2131和第二凹部边2132。第一凹部边2131、第二凹部边2132和第三凹部边2133围设形成第一凹部2130。从第一方向D 1观察，第一开口2110与第一凹部2130的第三凹部边2133相分离设置。从第一方向D 1观察，第一边2101和第一凹部边2131均位于第一导电板30的第一侧30A，第二边2102和第二凹部边2132均位于第一导电板30的第二侧30B，且第一导电板30覆盖部分第三凹部边2133。在一些具体地实施例中，从第一方向D 1观察，第一凹部2130可大致为矩形，第一凹部边2131、第二凹部边2132和第三凹部边2133均为直线。从第一方向D 1观察，第一连接区31和第二连接区32之间的虚拟分界线与第五边2103重叠，第二连接区32和第三连接区33之间的虚拟分界线与第三凹部边2133重叠。
进一步地，从第一方向D 1观察，第一端边213包括连接第一凹部边2131的第一连接边213a和连接第二凹部边2132的第二连接边213b。第一连接边213a和第二连接边213b可均沿着第三方向D 3延伸。从第一方向D 1观察，第一连接边213a位于第一导电板30的第一侧30A，第二连接边213b位于第一导电板30的第二侧30B。
如图7A所示，在另一些实施例中，第一凹部2130的形状还可以变更。例如，从第一方向D 1观察，第一凹部2130还可以大致为U形。此时，第一凹部2130包括第一凹部边2131、第二凹部边2132、第三凹部边2133、第四凹部边2134和第五凹部边2135。第一凹部边2131和第二凹部边2132在第三方向D 3上相对设置。第一凹部边2131和第二凹部边2132可均沿着第二方向D 2延伸，第三凹部边2133可沿着第三方向D 3延伸。第四凹部边2134连接第一凹部边2131和第三凹部边2133，第四凹部边2134弯曲设置。第五凹部边2135连接第二凹部边2132和第三凹部边2133，第五凹部边2135弯曲设置。第一凹部边2131、第二凹部边2132、第三凹部边2133、第四凹部边2134和第五凹部边2135围设形成第一凹部2130。在一些具体地实施例中，第一凹部边2131、第二凹部边2132和第三凹部边2133均为直线，第四凹部边2134和第五凹部边2135均为远离第一凹部2130凸出设置的弧形。在另一些实施例中，第三凹部边2133也可以为弧形。通过设置弯曲的第四凹部边2134和第五凹部边2135，使得第一凹部边2131和第三凹部边2133之间、第二凹部边2132和第三凹部边2133之间平滑过渡。这有利于减少上述过渡的位置于切割第一凹部2130的过程中产生的毛刺，从而减小上述毛刺刺穿隔离膜23并与第二极片22接触短路的可能性，延长电化学装置100的使用寿命。而且通过设置弯曲的第四凹部边2134和第五凹部边2135，使得第一开口2110与第一凹部2130之间起垫高作用的第一导电材料层211面积增大，这有利于机械滥用时该部分第一导电材料层211能够承担外力。
如图7B所示，在另一些实施例中，第一凹部边2131可以弯曲设置，第二凹部边2132也可以弯曲设置。在一些具体地实施例中，第一凹部边2131为远离第一凹部2130凸出设置的弧形。 第二凹部边2132也为远离第一凹部2130凸出设置的弧形。此时，同样可使得第一凹部边2131和第三凹部边2133之间、第二凹部边2132和第三凹部边2133之间平滑过渡。这有利于减少上述过渡的位置于切割第一凹部2130的过程中产生的毛刺，从而减小上述毛刺刺穿隔离膜23并与第二极片22接触短路的可能性，延长电化学装置100的使用寿命。
如图8所示，在另一些实施例中，从第一方向D 1观察，第一凹部2130还可以大致为V形。此时，第一凹部2130仅包括第一凹部边2131和第二凹部边2132。第一凹部边2131和第二凹部边2132可均偏离第二方向D 2延伸。第一凹部边2131直接连接第二凹部边2132，第一凹部边2131和第二凹部边2132围设形成第一凹部2130。在一些具体地实施例中，第一凹部边2131和第二凹部边2132均为直线。
请参阅图4，在一些实施例中，第一集流体210的第二表面210b包括第二区域2100’。第二导电材料层212包括第二开口2120。第二区域2100’配置为第二表面210b从第二开口2120显露出的区域。即，第二区域2100’露出于第二开口2120。从第一方向D 1观察，第一区域2100和第二区域2100’重叠。从而，电化学装置100充电时第一导电板30处产生的热量除了可经露出于第一连接区31的第一区域2100进行散发外，还可经第一区域2100和第二区域2100’的重叠处传导至第二区域2100’并由第二区域2100’进行散发，减少了第一导电板30局部过热的可能性。从第二方向D 2观察，第二区域2100’与第一凹部2130重叠。
在一些实施例中，第二区域2100’与第一凹部2130可相接。因此，从第一方向D 1观察，第二区域2100’与第一凹部2130之间不存在第二导电材料层212。因此，位于第一开口2110与第一凹部2130之间的第一极片21为单面涂膜区。
在一些实施例中，从第一方向D 1观察，第二区域2100’与第二开口2120可均为矩形。第二区域2100’包括在第三方向D 3上相对设置的第三边2105和第四边2106、以及在第二方向D 2上相对设置的第七边2107和第八边2108。第七边2107连接于第三边2105和第四边2106之间，第八边2108连接于第三边2105和第四边2106之间。第三边2105和第四边2106可均沿着第二方向D 2延伸，第七边2107和第八边2108可均沿着第三方向D 3延伸。如图3至图5所示，从第一方向D 1观察，第一边2101和第三边2105位于第一导电板30的第一侧30A，第二边2102和第四边2106位于第一导电板30的第二侧30B。从第一方向D 1观察，第一导电板30覆盖第七边2107。从第一方向D 1观察，第六边2104与第八边2108可以重叠；在另一些实施例中，如图9所示，第六边2104与第八边2108也可以在第二方向D 2上相互错开。在一些实施例中，如图3至图5所示，第六边2104与第八边2108重叠。而第二区域2100’与第一凹部2130相接，因此第五边2103和第七边2107在第二方向D 2上相互错开，第七边2107相较于第五边2103更靠近第一端边213。从第一方向D 1观察，第七边2107与第三凹部边2133重叠。因此在第二方向D 2上，第二端边214、第八边2108、第五边2103、第七边2107(第三凹部边2133)和第一端边213依次设置。由于第二区域2100’与第一凹部2130之间不存在第二导电材料层212，因此减少了导电材料的用量。而且，减少了焊印(如图10A所示的凹陷210c或图10B所示的凸起210d)超出第五边2103并落于该部分第二导电材料层212时导电材料脱落并导致短路的可能性，延长了电化学装置100的使用寿命。可以理解，第二开口2120是三维结构，然而第二开口2120从第一方向D 1观察时包括依次连接的多条边(图未标出)。从第一方向D 1观察，第二区域2100’的第三边2105、第四边2106、第七边2107和第八边2108分别与第二开口2120的多条边重合。
可以理解，若未设置第一凹部2130，在第一区域2100上连接第一导电板30后，带有第一导电板30的第一极片21中厚度较大的位置应为从第一方向D 1观察时，第一导电材料层211、 第一集流体210和第二导电材料层212三者与第一导电板30的重叠区域(包括第一导电板30、第一导电材料层211、第一集流体210和第二导电材料层212四者的厚度之和)。
如图10A至图12所示，本申请设置第一凹部2130后，带有第一导电板30的第一极片21中厚度较大的位置应为从第一方向D 1观察时，在第三方向D 3上位于第一区域2100两侧的具有双面涂膜的第一极片21所在的位置(以下称为：第一位置P 1，第一位置P 1的厚度T 1包括第一导电材料层211、第一集流体210和第二导电材料层212三者的厚度之和)，或者，为第一开口2110与第一凹部2130之间与第一导电板30的重叠区域(以下称为：第二位置P 2，第二位置P 2的厚度T 2包括第一导电板30、第一导电材料层211和第一集流体210三者的厚度之和)。
因此本申请通过设置第一凹部2130，有利于减小电化学装置100在第一方向D 1上的总厚度，提高空间利用率。而且在发生机械滥用时，若外力作用位置与第一导电板30的焊印重叠，尤其当外力作用于电化学装置100的正面时，第一极片21中上述厚度较大的第一位置P 1或第二位置P 2能够承担部分外力，减小焊印(如凸起30b)刺穿隔离膜23并与第二极片22接触短路的可能性，延长电化学装置100的使用寿命。另外，第一极片21可能会在外力作用下发生褶皱，使得第一极片21的第一端边213或第二端边214朝向第一极片21中部翻折。此时第一凹部2130能够为第一导电板30的第三连接区33提供缓冲空间，降低第一导电板30随着第一极片21翻折并发生断裂的可能性，进一步延长电化学装置100的使用寿命。尤其如图3、图7A和图7B所示当第一凹部2130包括第一凹部边2131、第二凹部边2132和第三凹部边2133时，上述结构的第一凹部2130能够在机械滥用时为第一导电板30提供较大的缓冲空间。
在一些实施例中，第二极片22也可采用与第一极片21相似的设计，如在第二极片22的第二集流体220上设置第三区域(如空白区)以连接第二导电板40，在第二极片22的端边处设置第二凹部，并使得第三导电材料层221对应于空白区的第三区域在第二方向D 2上与第一凹部2130相分离设置。如此，可进一步提高电化学装置100的空间利用率、延长使用寿命。
如图10A至图12所示，在一些实施例中，在第一方向D 1上，第一导电板30的厚度小于第一导电材料层211的厚度。因此在第一区域2100上连接第一导电板30后，带有第一导电板30的第一极片21中厚度较大的位置为在第三方向D 3上位于第一区域2100两侧的具有双面涂膜的第一极片21所在的位置，即第一位置P 1。因此在发生机械滥用时，若外力作用位置与第一导电板30的焊印重叠，则第一位置P 1能够优先承担部分外力，且从第一方向D 1观察时第一位置P 1具有比第二位置P 2更大的面积，这有利于在机械滥用时承担较大的外力，进一步延长电化学装置100的使用寿命。
如图3、图10A至图12所示，在一些实施例中，电化学装置100还包括包含绝缘材料的第一层50。第一层50粘接第一区域2100。第一导电板30设于第一区域2100和第一层50之间。第一层50用于覆盖第一导电板30的焊印(如凸起30b)，从而减小上述焊印刺穿隔离膜23而产生短路的风险。其中，第一层50可以为单面胶或双面胶，具体材质可以选自聚丙烯、聚乙烯、聚偏二氟乙烯、偏二氟乙烯-六氟丙烯共聚物、聚甲基丙烯酸甲酯或聚乙二醇中至少一种。在其它实施例中，第一层50也可以为陶瓷涂层。在第一方向D 1上，第一层50的厚度范围可以为3μm至30μm。
在一些实施例中，从第一方向D 1观察，第一层50完全覆盖第一开口2110和第一凹部2130，且同时覆盖位于第一开口2110和第一凹部2130之间的第一导电材料层211。而且，第一层50在第二方向D 2上延伸超出第一端边213。具体地，从第一方向D 1观察，第一层50包括在第二方向D 2上相对设置的第一边缘51和第二边缘52，还包括在第三方向D 3上相对设置的第三边缘 53和第四边缘54。第一边缘51和第二边缘52可均沿第三方向D 3延伸。第三边缘53和第四边缘54可均沿第三方向D 3延伸。第三边缘53连接于第一边缘51和第二边缘52之间，第四边缘54连接于第一边缘51和第二边缘52之间。第一边缘51在第二方向D 2上延伸超出第一端边213。从第一方向D 1观察，第二边缘52可位于第六边2104与第二端边214之间。第三边缘53位于第一导电板30的第一侧30A，且在第三方向D 3上，第一边2101位于第三边缘53和第一导电板30之间。第四边缘54可位于第一导电板30的第二侧30B，且在第三方向D 3上，第二边2102位于第四边缘54和第一导电板30之间。如此，第一层50还可覆盖第一集流体210在裁切过程中于第一端边213处产生的毛刺，减小上述毛刺刺穿隔离膜23并与第二极片22接触短路的可能性。从第一方向D 1观察，第一层50也可覆盖部分第一导电材料层211。为了便于区分，图3中被第一层50覆盖的第一导电材料层211与其它第一导电材料层211采用不同的填充方式示出。然而可以理解，这并不意味着被第一层50覆盖的第一导电材料层211与其它第一导电材料层211采用不同的活性材料制得，两者之间并无明显界限。可以理解，如图7A所示当设置弯曲的第四凹部边2134和第五凹部边2135时，第一开口2110与第一凹部2130之间起垫高作用的第一导电材料层211面积增大，这也有利于增大第一层50与第一导电材料层211之间的接触面积，提高第一层50于第一极片21上的连接强度。
如图5、图10A至图12所示，电化学装置100还包括包含绝缘材料的第二层60。第二层60粘接第二区域2100’。第二层60用于覆盖焊印(如凸起210d)，从而减小上述焊印刺穿隔离膜23而产生短路的风险。在一些实施例中，第二层60可以为单面胶、双面胶或陶瓷涂层。
如图3和图5所示，在一些实施例中，在第二方向D 2上，第一连接边213a至第三凹部边2133的距离为第一距离L 1，第三凹部边2133至第一区域2100的距离为第二距离L 2，L 2也为位于第一开口2110与第一凹部2130之间的部分第一导电材料层211在第二方向D 2上的尺寸。第一距离L 1大于第二距离L 2(L 1>L 2)。其中，第一距离L 1较大时，有利于提高第一凹部2130的面积，使得机械滥用时第一凹部2130能够为第一导电板30提供较大的缓冲空间。而且可以理解，位于第一开口2110与第一凹部2130之间的部分第一导电材料层211被第一层50覆盖，该部分第一导电材料层211内的材料在充放电过程中难以发挥容量作用。同时，第一区域2100在第二方向D 2上需预留出足够的空间以连接第一导电板30。因此在第一极片21沿第二方向D 2尺寸一定的条件下，当第二距离L 2较小时(被第一层50覆盖的难以发挥容量作用的活性材料减少)，在第六边2104至第二端边214之间的距离可增加(即第六边2104至第二端边214之间未被第一层50覆盖、可发挥容量作用的活性材料增加)，从而减小了对电化学装置100容量的影响。在另一些实施例中，第一距离L 1也可以小于第二距离L 2。此时由于第二距离L 2较大，使得位于第一开口2110与第一凹部2130之间的第一导电材料层211能够有效起到垫高作用。
可以理解，如图8所示，若从第一方向D 1观察第一凹部2130大致为V形，此时，第一距离L 1为在第二方向D 2上，第一连接边213a至第一凹部边2131和第二凹部边2132的交点的距离。第二距离L 2为在第二方向D 2上，第一凹部边2131和第二凹部边2132的交点至第一区域2100的距离。
当满足第一距离L 1大于第二距离L 2时，在一些实施例中，第一距离L 1的范围为1mm至6mm(1mm≤L 1≤6mm)，第二距离L 2的范围为0.3mm至4mm(0.3mm≤L 2≤4mm)，且0.1≤L 2/L 1<1。通过设置第一距离L 1的范围，使得机械滥用时第一凹部2130能够为第一导电板30提供较大的缓冲空间的同时，相较于第一距离L 1较大时(即第一凹部2130的面积增大，第一凹部2130内被移除的第一导电材料层211面积也增大)的情况，本申请可减小对电化学装置100容量的影响。 通过设置第二距离L 2的范围，使得位于第一开口2110与第一凹部2130之间的第一导电材料层211能够有效起到垫高作用的同时，相较于第二距离L 2较大时的情况，本申请可减小对电化学装置100容量的影响。在一些实施例中，第二距离L 2与第一距离L 1的比值的范围为0.1至1。即，0.1≤L 2/L 1<1。通过设置第二距离L 2与第一距离L 1比值的下限值，减小了第一距离L 1占比较大(第一凹部2130的面积较大)或第一开口2110与第一凹部2130之间的部分第一导电材料层211在第二方向D 2上的尺寸较小的可能性。因此，本申请可减小对电化学装置100容量的影响，也可使得该部分第一导电材料层211能够有效起到垫高作用。
如图3和图5所示，在一些实施例中，从第一方向D 1观察，第一导电板30在第三方向D 3上覆盖第一凹部2130的中间位置。因此在第三方向D 3上，第一导电板30至第一凹部边2131的距离为第三距离L 3，第一导电板30至第二凹部边2132的距离为第四距离L 4，第三距离L 3大致等于第四距离L 4。例如，第三距离L 3与第四距离L 4的差值不超过±1.5mm。在一些具体地实施例中，第三距离L 3的范围为1mm至8mm，第四距离L 4的范围为1mm至8mm。如此，在使得第一凹部2130为第一导电板30提供足够的缓冲空间的同时，也减小了第三距离L 3或第四距离L 4过大时对电化学装置100容量的影响。
可以理解，如图7B所示，若第一凹部边2131和第二凹部边2132的延伸方向并非严格平行于第二方向D 2时，第三距离L 3为在第二方向D 2上，第一导电板30至第一凹部边2131的最大距离，第四距离L 4为在第二方向D 2上，第一导电板30至第二凹部边2132的最大距离。如图8所示，若从第一方向D 1观察第一凹部2130大致为V形，此时，第三距离L 3为在第二方向D 2上，第一导电板30至第一凹部边2131的最大距离。第四距离L 4为在第二方向D 2上，第一导电板30至第二凹部边2132的最大距离。
如图13所示，在另一些实施例中，从第一方向D 1观察，第一导电板30在第三方向D 3上也可以偏离第一凹部2130的中间位置，使得第三距离L 3不等于第四距离L 4。在一些具体的实施例中，第三距离L 3可小于第四距离L 4。
如图3和图5所示，在一些实施例中，从第一方向D 1观察，第一导电板30在第三方向D 3上覆盖第一区域2100的中间位置。因此在第三方向D 3上，第一边2101至第一导电板30的距离为第五距离L 5，第二边2102至第一导电板30的距离为第六距离L 6，第五距离L 5大致等于第六距离L 6。例如，第五距离L 5与第六距离L 6的差值不超过±1.5mm。第五距离L 5与第六距离L 6实际上为在第三方向D 3上露出于第一导电板30的第一连接区31的第一区域2100的尺寸。在一些具体地实施例中，第五距离L 5的范围为1mm至10mm，第六距离L 6的范围为1mm至10mm。如此，在使得电化学装置100充电时第一连接区31处产生的热量可经露出于第一连接区31的第一区域2100进行散发、减少了第一导电板30局部过热的可能性的同时，也减小了第五距离L 5或第六距离L 6过大时对电化学装置100容量的影响。
如图13所示，在另一些实施例中，当从第一方向D 1观察，第一导电板30在第三方向D 3上偏离第一区域2100的中间位置时，第五距离L 5也可以小于或大于第六距离L 6。这有利于降低在第一区域2100上连接第一导电板30时的工艺要求。
如图3和图5所示，在一些实施例中，当第一凹部2130在第二方向D 2上仅覆盖部分第一区域2100时，第四距离L 4小于第六距离L 6。如图6所示，在另一些实施例中，当第一凹部2130和第一区域2100在第二方向D 2上完全重合时，第四距离L 4也可以大致等于第六距离L 6。例如，第四距离L 4与第六距离L 6的差值不超过±1.5mm。
其中，第一距离L 1至第六距离L 6可分别采用直接测量法测得，测试步骤包括：将电化学装 置100进行拆解，取第一极片21作为测试样品；采用卡尺或其它合适的量具直接测量第一距离L 1至第六距离L 6的数值，或者采集第一极片21的图像，在图像中进行测量。
如图3至图5所示，在一些实施例中，从第一方向D 1观察，第一区域2100和第二区域2100’可以在第三方向D 3上相错开。在一些具体的实施例中，从第一方向D 1观察，第一边2101和第三边2105在第三方向D 3上相错开，第二边2102和第四边2106在第三方向D 3上相错开。第一边2101和第三边2105相错开，使得第一极片21在第一边2101和第三边2105对应的位置具有厚度过渡。同理，第二边2102和第四边2106相错开，使得第一极片21在第二边2102和第四边2106对应的位置具有厚度过渡。上述厚度过渡有利于减小极片辊压时第一集流体210受压突然增大而发生褶皱等损伤的可能性，从而减小电化学装置100发生外观不良或内部界面不良的可能性。再者，在受到外力碰撞或挤压时，上述厚度过渡也可减小第一集流体210发生撕裂的可能性。因此，延长了电化学装置100的使用寿命。
进一步地，在一些实施例中，从第一方向D 1观察，第二区域2100’完全覆盖第一区域2100。即，从第一方向D 1观察，第二区域2100’的面积大于第一区域2100的面积，使得在第一方向D 1上，第一区域2100的投影完全位于第二区域2100’的投影内。如此，从第一方向D 1观察，焊印(如图10A所示的凹陷210c或图10B所示的凸起210d)可完全落在第二区域2100’的范围内，减小了焊印落于第二导电材料层212时导电材料脱落并导致短路的可能性，延长了电化学装置100的使用寿命。
请参阅图14，在另一些实施例中，从第一方向D 1观察，第一区域2100和第二区域2100’也可以完全重合。具体地，从第一方向D 1观察，第一边2101与第三边2105重合，第二边2102与第四边2106重合，第五边2103与第七边2107重合，第六边2104与第八边2108重合。此时从第一方向D 1观察，第一区域2100的面积与第二区域2100’的面积相等。
请参阅图15和图16，本申请另一实施方式还提供一种电化学装置(图未标出)。与上述电化学装置100不同之处在于，在第一极片21中，第二区域2100’在第二方向D 2上与第一凹部2130相分离设置，使得第二开口2120与第一凹部2130之间存在部分第二导电材料层212。因此，从第一方向D 1观察，位于第一开口2110与第一凹部2130之间的第一极片21为双面涂膜区。
如图16所示，此时第二位置P 2的厚度T 2包括第一导电板30、第一导电材料层211、第一集流体210和第二导电材料层212四者的厚度之和。此时在第二位置P 2处，第二开口2120与第一凹部2130之间存在的部分第二导电材料层212也可在第一方向D 1上起到垫高作用。当外力作用于电化学装置100的背面(即如图2A所示的壳体10朝向第二区域2100’的第二壁112)时，该部分第二导电材料层212也可承担部分外力，减小焊印(如凹陷210c或凸起210d)刺穿隔离膜23并与第二极片22接触短路的可能性，延长电化学装置的使用寿命。
其中，本申请的电化学装置(如电化学装置100)包括所有能够发生电化学反应的装置。具体的，电化学装置包括所有种类的原电池、二次电池、燃料电池、太阳能电池和电容器(例如超级电容器)。可选地，电化学装置可以为锂二次电池，包括锂金属二次电池、锂离子二次电池、锂聚合物二次电池和锂离子聚合物二次电池。
请参阅图17，本申请一实施方式还提供一种电子装置1，电子装置1包括电化学装置(如电化学装置100)。电子装置1通过上述电化学装置100供电，且电化学装置100具有较高的使用寿命。其中，本申请的电化学装置100适用于各种领域的电子装置1。在一实施方式中，本申请的电子装置1可以是，但不限于笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、 手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。
以下通过具体实施例和对比例对本申请作详细说明。其中，以电化学装置为电池、第一极片为正极、第一导电板为正极导电板为例并结合具体测试方法对本申请进行说明。
实施例1-9
参阅图3，在经过冷压工序后的第一极片21上，采用激光清洗方式在第一导电材料层211中清洗出第一开口2110，使得第一区域2100露出于第一开口2110。在第一极片21的第一端边213上开设第一凹部2130，从第一方向D 1观察时第一开口2110与第一凹部2130相分离设置。然后在第一区域2100上焊接第一导电板30。第二极片22、隔离膜23和电解液等可采用常规设计。将第一极片21、隔离膜23和第二极片22进行层叠卷绕，置于壳体后注入电解液并进行封装，从而制作为电池，第一极片21为阴极极片。
实施例1-9的不同之处在于、第一距离L 1的值、第二距离L 2的值、或第二距离L 2与第一距离L 1的比值。
对比例
与实施例1-9不同之处在于，第一极片21上不设置第一凹部2130。
对各实施例和对比例的电池各取20个分别进行钝刺测试(又称Dent测试)，钝刺测试的具体步骤包括：1)在25±5℃的环境条件下，将电池充电至100％SOC(State of Charge，荷电状态)；2)采用三角棒挤压机(型号：DKBF-3KH，厂商：Dae Kyung)，通过直径为6mm的半圆头钉挤压在电池正面且对应于第一导电板30的焊印位置，然后以300N/min的速度逐渐增加压力至1300N；3)观察电池是否失效。其中，Dent通过率的计算公式为：Dent通过率＝通过Dent测试的电池数量/测试的电池数量。结果记录于表1中。
表1
  第一凹部 L 1/mm L 2/mm L 2/L 1 Dent通过率
实施例1 有 6 0.3 0.05 14/20
实施例2 有 5 0.5 0.1 20/20
实施例3 有 4 1.2 0.3 20/20
实施例4 有 1 0.5 0.5 20/20
实施例5 有 4 3 0.75 20/20
实施例6 有 4 4 1 20/20
实施例7 有 3 3 1 20/20
实施例8 有 2 2 1 20/20
实施例9 有 1.5 1.8 1.2 17/20
对比例 无 无 无 无 6/20
注：Dent通过率X/20表示测试的20个样品中，通过Dent测试的个数为X个。
从表1数据可知，相较于对比例，实施例1-9在第一极片21上设置第一凹部2130。第一开口2110与第一凹部2130之间存在的部分第一导电材料层211可在第一方向D 1上起到垫高的作用，该部分第一导电材料层211在钝刺测试过程中可承担部分外力。同时，半圆头钉直径较大(大于第一导电板30在第三方向D 3上的宽度)，因此钝刺测试过程中位于第一区域2100两侧的具有双面涂膜的第一极片21所在的位置也可承担部分外力。因此，减少了焊印刺穿隔离膜23并与 第二极片22接触短路的可能性，使得实施例1-9的电池在钝刺测试过程中通过率较高。再者，实施例1-9中，实施例1的第二距离L 2占比较小使得L 2/L 1较小，因此第一开口2110与第一凹部2130之间的部分第一导电材料层211在第二方向D 2上的尺寸较小，能够有效起到垫高作用的该部分第一导电材料层211尺寸减小，因此电池在钝刺测试过程中通过率降低；实施例9的第一距离L 1占比较小使得L 2/L 1较大，因此能够为第一导电板30提供缓冲空间的第一凹部2130的面积减小，因此电池在钝刺测试过程中通过率降低。
最后应说明的是，以上实施例仅用以说明本申请的技术方案而非限制，尽管参照较佳实施例对本申请进行了详细说明，本领域的普通技术人员应当理解，可以对本申请的技术方案进行修改或等同替换，而不脱离本申请技术方案的精神和范围。

Claims (18)

  1. 一种电化学装置，包括电极组件和第一导电板，所述电极组件包括第一极片，所述第一极片包括第一集流体和第一导电材料层，所述第一集流体包括第一表面，所述第一导电材料层设于所述第一表面，其中，
    所述第一导电材料层设有第一开口，所述第一表面包括第一区域，所述第一区域配置为所述第一开口显露出的所述第一表面的区域，所述第一导电板连接于所述第一区域；
    从第一方向观察，所述第一极片包括在第二方向上相对设置的第一端边和第二端边，所述第一极片于所述第一端边处设有第一凹部；从所述第一方向观察，所述第一凹部与所述第一区域相分离设置，从所述第二方向观察，所述第一凹部与所述第一区域重叠；从所述第一方向观察，所述第一导电板覆盖所述第一区域的一部分，所述第一导电板覆盖所述第一导电材料层的一部分，所述第一导电板覆盖所述第一凹部的一部分；所述第一方向垂直于所述第一区域，所述第二方向垂直于所述第一方向。
  2. 如权利要求1所述的电化学装置，其中，从所述第一方向观察，所述第一凹部包括在第三方向上相对设置的第一凹部边和第二凹部边以及连接所述第一凹部边和所述第二凹部边的第三凹部边，所述第一凹部边、所述第二凹部边和所述第三凹部边围设成所述第一凹部，所述第三方向与所述第一方向和所述第二方向均垂直。
  3. 如权利要求2所述的电化学装置，其中，从所述第一方向观察，所述第一端边包括连接所述第一凹部边的第一连接边，所述第三凹部边和所述第一连接边均沿所述第三方向延伸，在所述第二方向上，所述第一连接边至所述第三凹部边的距离为第一距离L 1，所述第三凹部边至所述第一区域的距离为第二距离L 2，所述第一距离L 1大于所述第二距离L 2。
  4. 如权利要求3所述的电化学装置，其中，1mm≤L 1≤6mm，0.3mm≤L 2≤4mm。
  5. 如权利要求4所述的电化学装置，其中，0.1≤L 2/L 1<1。
  6. 如权利要求2所述的电化学装置，其中，从所述第一方向观察，所述第一凹部还包括第四凹部边和第五凹部边，所述第四凹部边连接所述第一凹部边和所述第三凹部边，所述第五凹部边连接所述第二凹部边和所述第三凹部边，所述第四凹部边弯曲设置，所述第五凹部边弯曲设置。
  7. 如权利要求1所述的电化学装置，其中，在所述第一方向上，所述第一导电板的厚度小于所述第一导电材料层的厚度。
  8. 如权利要求2所述的电化学装置，其中，从所述第一方向观察，在所述第三方向上，所述第一导电板至所述第一凹部边的距离为第三距离L 3，所述第一导电板至所述第二凹部边的距离为第四距离L 4，所述第三距离L 3不等于所述第四距离L 4。
  9. 如权利要求2所述的电化学装置，其中，所述第一极片还包括第二导电材料层，所述第一集流体还包括与所述第一表面相对设置的第二表面，所述第二导电材料层设于所述第二表面；所述第二导电材料层设有第二开口，所述第二表面包括第二区域，所述第二区域配置为所述第二开口显露出的所述第二表面的区域；所述第一区域与所述第二区域在所述第一方向上重叠，从所述第二方向观察，所述第二区域与所述第一凹部重叠。
  10. 如权利要求9所述的电化学装置，其中，所述第二区域在所述第二方向上与所述第一凹部相分离设置。
  11. 如权利要求10所述的电化学装置，其中，从所述第一方向观察，所述第一区域包括在所述第三方向上相对设置的第一边和第二边，所述第一边和所述第一凹部边位于所述第一导电板的第一侧， 所述第二边和所述第二凹部边位于所述第一导电板与所述第一侧相对的第二侧；从所述第一方向观察，所述第二区域包括在所述第三方向上相对设置的第三边和第四边，所述第一边和所述第三边位于所述第一导电板的所述第一侧，所述第二边和所述第四边位于所述第一导电板的所述第二侧；从所述第一方向观察，所述第一边和所述第三边相错开，和/或，所述第二边和所述第四边相错开。
  12. 如权利要求11所述的电化学装置，其中，从所述第一方向观察，所述第二区域完全覆盖所述第一区域。
  13. 如权利要求9所述的电化学装置，其中，所述第二区域与所述第一凹部相接。
  14. 如权利要求1所述的电化学装置，其中，所述电化学装置还包括包含第一绝缘材料的第一层，所述第一层粘接所述第一区域，所述第一导电板设于所述第一区域和所述第一层之间。
  15. 如权利要求14所述的电化学装置，其中，从所述第一方向观察，所述第一层完全覆盖所述第一开口和所述第一凹部，所述第一层在所述第二方向上延伸超出所述第一端边。
  16. 如权利要求1所述的电化学装置，其中，所述第一导电板焊接于所述第一区域。
  17. 如权利要求1所述的电化学装置，其中，所述电极组件为卷绕结构，所述第一极片为正极极片。
  18. 一种电子装置，包括如权利要求1至17中任一项所述的电化学装置。
PCT/CN2022/109437 2022-08-01 2022-08-01 电化学装置和电子装置 WO2024026618A1 (zh)

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Publication number Priority date Publication date Assignee Title
JP2015118772A (ja) * 2013-12-17 2015-06-25 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． リチウムイオン二次電池およびリチウムイオン二次電池の製造方法
CN114094044A (zh) * 2021-11-18 2022-02-25 珠海冠宇电池股份有限公司 极片和电池
CN216928675U (zh) * 2022-03-29 2022-07-08 珠海冠宇电池股份有限公司 一种电池
CN114766066A (zh) * 2021-03-17 2022-07-19 宁德新能源科技有限公司 极片及其制备方法、电池、电子装置

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JP2015118772A (ja) * 2013-12-17 2015-06-25 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． リチウムイオン二次電池およびリチウムイオン二次電池の製造方法
CN114766066A (zh) * 2021-03-17 2022-07-19 宁德新能源科技有限公司 极片及其制备方法、电池、电子装置
CN114094044A (zh) * 2021-11-18 2022-02-25 珠海冠宇电池股份有限公司 极片和电池
CN216928675U (zh) * 2022-03-29 2022-07-08 珠海冠宇电池股份有限公司 一种电池

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