WO2024093571A1 - 电池及用电设备 - Google Patents

电池及用电设备 Download PDF

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Publication number
WO2024093571A1
WO2024093571A1 PCT/CN2023/120464 CN2023120464W WO2024093571A1 WO 2024093571 A1 WO2024093571 A1 WO 2024093571A1 CN 2023120464 W CN2023120464 W CN 2023120464W WO 2024093571 A1 WO2024093571 A1 WO 2024093571A1
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WO
WIPO (PCT)
Prior art keywords
region
pole
pole piece
area
battery
Prior art date
Application number
PCT/CN2023/120464
Other languages
English (en)
French (fr)
Inventor
陈梅锋
Original Assignee
宁德新能源科技有限公司
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Publication of WO2024093571A1 publication Critical patent/WO2024093571A1/zh

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Classifications

    • 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
    • H01M10/04—Construction or manufacture in general
    • 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
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/103—Primary casings; Jackets or wrappings characterised by their shape or physical structure prismatic or rectangular
    • 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
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of energy storage technology, and in particular to a battery and electrical equipment.
  • the production process of battery pole pieces usually includes coating and cold pressing steps.
  • cold pressing can make the pole pieces compacted, which plays a very important role in improving the energy density and electrical performance of the battery.
  • the active material layer area and the empty foil area that forms the pole ear have different degrees of extension during the cold pressing process, after the pole piece is cold pressed, in order to reduce the risk of deformation or warping of the pole ear, it is usually necessary to stretch and extend the empty foil area.
  • this stretching and extension operation can easily cause the pole piece to break, affecting the cold pressing processing efficiency.
  • the existing technology usually adopts a thicker current collector or reduces the compaction density of the pole piece. This measure not only has a poor effect on improving the breakage phenomenon, but also causes a loss of energy density.
  • An embodiment of the present application provides a battery, including a pole piece and a pole ear, the pole piece including a current collector and an active material layer disposed on the current collector, the pole ear connected to the current collector, and extending from the pole piece along the width direction of the pole piece.
  • the pole ear includes a first region and a second region, the first region is located between the second region and the active material layer, the thickness of the first region is t1, the thickness of the second region is t2, and 0.5% ⁇ (t1-t2)/t1 ⁇ 5%.
  • the pole ear is arranged into a first region and a second region along the width direction of the pole piece, the first region is located between the second region and the active material layer, the second region is pressed and rolled before cold pressing to pre-extend it, and the thickness t1 of the first region and the thickness t2 of the second region satisfy 0.5% ⁇ (t1-t2)/t1 ⁇ 5%, the thickness of the first region and the second region cannot differ too much, if the difference is too large, due to the stress concentration at the boundary, it is easy to break the belt, if the difference is too small, less than 0.5%, the second region cannot achieve the extension effect, and the pole ear is prone to warping and folding.
  • the thickness t1 of the first region and the thickness t2 of the second region satisfy 0.5% ⁇ (t1-t2)/t1 ⁇ 5%, which can reduce the phenomenon of pole piece breaking after cold pressing, improve the processing rate, and then use thinner current collectors and/or higher compaction density, and improve the energy density of the battery.
  • 0.5% ⁇ (t1-t2)/t1 ⁇ 3% which can further reduce the phenomenon of tape breakage of the electrode after cold pressing.
  • 0.5% ⁇ (t1-t2)/t1 ⁇ 1.5% which can further reduce the phenomenon of tape breakage of the electrode after cold pressing.
  • the current collector area covered by the active material layer has better ductility after cold pressing, and the second area has better ductility after pre-pressing and rolling. Since the first area is adjacent to the active material layer, it is not possible to make the first area also rolled in the process, so the ductility is poor.
  • the first area is between the active material layer and the second area, and the pole piece will be arched in the second area, causing the pole piece to warp or bend, so the area of the first area is generally reduced as much as possible to make the area of the second area as large as possible.
  • the projected area of the pole ear is S1
  • the projected area of the second area is S2, 60% ⁇ S2/S1 ⁇ 95%, which is conducive to reducing the warping or bending of the pole ear, and improving the winding quality, battery cell flatness and energy density.
  • 80% ⁇ S2/S1 ⁇ 95% which can further reduce the occurrence of undesirable phenomena such as warping and bending of the tabs after cold pressing, and improve the winding quality and the flatness and energy density of the battery cell.
  • the pole ear further includes a third region, which is disposed between the first region and the active material layer and connects the first region and the active material layer.
  • a first insulating layer is disposed on the third region, which is located between the first region and the active material layer. The first insulating layer can play an insulating role when the pole pieces are wound or stacked to form an electrode assembly, thereby reducing the risk of short circuit between the pole ear and another pole ear/pole piece with opposite polarity due to burrs piercing the diaphragm.
  • first dividing line at the junction of the first region and the second region, and the minimum distance between the first dividing line and the first insulating layer is d1, 0.1mm ⁇ d1 ⁇ 1mm, so that the first region has a certain width along the width direction of the pole piece, and the first region can serve as a transition area between the pre-rolled and stretched second region and the active material layer, thereby improving the structural strength of the connection area between the first pole ear and the active material layer, reducing the risk of bending or breaking of the first pole ear at the connection with the active material layer, and improving the shock resistance of the battery.
  • the first insulating layer satisfies at least one of the following a, b, and c: a.
  • the thickness of the first insulating layer is less than the thickness of the active material layer; b.
  • the length of the electrode ear is W1
  • the length of the first insulating layer is W2, W2/W1 ⁇ 0.5, W2 ⁇ 1mm; c.
  • the first insulating layer includes an inorganic substance, and the material of the inorganic substance includes at least one of aluminum oxide, magnesium oxide and titanium oxide.
  • the tab is a positive electrode tab.
  • An embodiment of the present application further provides an electrical device, comprising the battery described in any of the aforementioned embodiments.
  • the battery can reduce the phenomenon of pole piece breaking after cold pressing by arranging the pole ear into the first area and the second area, and pre-extending it by pressing and rolling in the second area, thereby enabling the use of thinner current collectors and/or higher compaction density designs, thereby improving the energy density of the battery.
  • FIG. 1 is a schematic diagram of the three-dimensional structure of a battery in one embodiment of the present application.
  • FIG. 2 is a schematic diagram of a battery before packaging in an embodiment of the present application.
  • FIG. 3 is a view of the electrode assembly along the III-III cross section in FIG. 2 .
  • FIG. 4 is a schematic diagram of a structure in which a first pole tab is connected to a first pole piece in an embodiment of the present application.
  • FIG. 5 is a view of a V-V section in FIG. 4 .
  • FIG. 6 is a schematic structural diagram of an extended embodiment of the structure shown in FIG. 4 .
  • FIG. 7 is a view of a section VII-VII in FIG. 6 .
  • FIG. 8 is a schematic structural diagram of an extended embodiment of the structure shown in FIG. 4 .
  • FIG. 9 is a view of a cross section taken along line IX-IX in FIG. 8 .
  • FIG. 10 is a schematic structural diagram of an extended embodiment of the structure shown in FIG. 4 .
  • FIG. 11 is a view of a cross section taken along line XI-XI in FIG. 10 .
  • FIG. 12 is a schematic structural diagram of an extended embodiment of the structure shown in FIG. 4 .
  • FIG. 13 is a schematic diagram of the structure in which the second pole tab is connected to the second pole piece in one embodiment of the present application.
  • FIG. 14 is a view of a section XIV-XIV in FIG. 13 .
  • FIG. 15 is a schematic diagram of the structure of an electrical device in an embodiment of the present application.
  • the production process of battery pole pieces usually includes coating and cold pressing steps.
  • cold pressing can compact the pole pieces, which plays a very important role in improving the energy density and electrical performance of the battery.
  • the active material layer area and the empty foil area that forms the pole ear have different degrees of extension during the cold pressing process, after the pole piece is cold pressed, in order to reduce the risk of deformation or warping of the pole ear, it is usually necessary to stretch and extend the empty foil area.
  • this stretching and extension operation can easily cause the pole piece to break, affecting the cold pressing processing efficiency.
  • the existing technology usually adopts a thicker current collector or reduces the compaction density of the pole piece. This measure not only has a poor effect on improving the breakage phenomenon, but also causes a loss of energy density.
  • An embodiment of the present application provides a battery, including a pole piece and a pole ear, the pole piece including a current collector and an active material layer disposed on the current collector, the pole ear connected to the current collector, and extending from the pole piece along the width direction of the pole piece.
  • the pole ear includes a first region and a second region, the first region is located between the second region and the active material layer, the thickness of the first region is t1, the thickness of the second region is t2, and 0.5% ⁇ (t1-t2)/t1 ⁇ 5%.
  • the pole ear is arranged into a first region and a second region along the width direction of the pole piece, the first region is located between the second region and the active material layer, and the second region is pre-extended by rolling, and the thickness t1 of the first region and the thickness t2 of the second region satisfy 0.5% ⁇ (t1-t2)/t1 ⁇ 5%.
  • the thickness of the first region and the second region cannot differ too much. If the difference is too large, the band is easily broken due to stress concentration at the boundary. If the difference is too small, less than 0.5%, the second region cannot achieve the extension effect, and the pole ear It is easy to bend and bend.
  • the thickness t1 of the first area and the thickness t2 of the second area meet 0.5% ⁇ (t1-t2)/t1 ⁇ 5%, which can reduce the phenomenon of the pole piece breaking after cold pressing.
  • the thickness of the first area and the second area cannot differ too much. If the difference is too large, the stress concentration at the boundary will cause the pole piece to break easily. If the difference is too small, the second area will not achieve the extension effect, and the pole piece will be easy to bend and bend.
  • an embodiment of the present application provides a battery 100, including a shell 10, an electrode assembly 20, a first pole ear 30 and a second pole ear 40, the electrode assembly 20 is arranged inside the shell 10, and the first pole ear 30 and the second pole ear 40 are both connected to the electrode assembly 20 and extend out of the shell 10.
  • the housing 10 includes a first portion 11 and a second portion 12 that are connected to each other.
  • an internal space that can accommodate the electrode assembly 20 can be formed.
  • the housing 10 includes a main body 13 and an edge seal 14, the edge seal 14 is connected to the main body 13 and extends from the main body 13, the electrode assembly 20 is disposed inside the main body 13, and the first pole tab 30 and the second pole tab 40 extend from the edge seal 14.
  • the edge seal 14 includes a top edge seal 141 and a side edge seal 142 connected to each other, and the first pole tab 30 and the second pole tab 40 extend from the top edge seal 141.
  • first electrode tab 30 and the second electrode tab 40 are located on the same side of the main body 13. In other embodiments, the first electrode tab 30 and the second electrode tab 40 may also be located at opposite ends of the main body 13 (not shown).
  • the electrode assembly 20 includes a first pole piece 21, a second pole piece 22 and a diaphragm 23, wherein the diaphragm 23 is disposed between the first pole piece 21 and the second pole piece 22, and the first pole piece 21, the diaphragm 23 and the second pole piece 22 are wound to form the electrode assembly 20, the first pole piece 30 is connected to the first pole piece 21, and the second pole piece 40 is connected to the second pole piece 22.
  • the first pole piece 21, the diaphragm 23 and the second pole piece 22 are stacked to form the electrode assembly 20 (not shown).
  • first pole tab 30 and the second pole tab 40 is a positive pole tab
  • the other of the first pole tab 30 and the second pole tab 40 is a negative pole tab
  • the first pole tab 30 is a positive pole tab
  • the second pole tab 40 is a negative pole tab
  • the first pole sheet 21 is a positive pole sheet
  • the second pole sheet 22 is a negative pole sheet.
  • the material of the first pole tab 30 includes aluminum.
  • the material of the second pole tab 40 includes any one of copper, nickel, or a nickel alloy.
  • the first pole piece 21 includes a first current collector 211 and a first active material layer 212 arranged on the surface of the first current collector 211, the first pole ear 30 is connected to the first current collector 211, and the first pole ear 30 extends from the first pole piece 21 along a first direction Z, wherein the first direction Z is the width direction of the first pole piece 21.
  • the first electrode tab 30 and the first current collector 211 are an integrally formed structure, and the first electrode tab 30 is cut from the first current collector 211.
  • the material of the first current collector 211 includes aluminum.
  • the area on the first pole piece 21 where the first active material layer 212 is provided is also called the coating area
  • the area on the first pole piece 21 where the first current collector 211 is exposed and the area on the first pole tab 30 where the first current collector 211 is exposed are also called the coating area.
  • the area of fluid 211 is also called the empty foil area.
  • the first current collector 211 on the first pole piece 21 needs to be cold pressed before forming the first pole lug 30.
  • the cold pressing process part of the particles of the first active material layer 212 are pressed and embedded in the first current collector 211, resulting in a decrease in the structural strength and ductility of the first current collector 211.
  • the empty foil area is stretched after cold pressing, it is very easy to cause the first current collector 211 to break, affecting the processing rate.
  • the first pole piece 21 provided in the present application is pressed and rolled on at least part of the empty foil area before cold pressing to pre-stretch it, and after the first current collector 211 is cut to form the first pole lug 30, the pre-pressed and stretched empty foil area constitutes at least part of the first pole lug 30.
  • the first electrode tab 30 includes a first region 31 and a second region 32 .
  • the first region 31 is located between the second region 32 and the first active material layer 212 .
  • the first region 31 connects the second region 32 and the first electrode sheet 21 .
  • the first electrode tab 30 has a first dividing line 34 , which is located at the junction of the first region 31 and the second region 32 .
  • the first region 31 and the second region 32 are located on both sides of the first dividing line 34 .
  • the first boundary line 34 is formed by pre-pressing and stretching the first pole piece 21, and the pre-pressed and stretched empty foil area constitutes the second area 32.
  • the first boundary line 34 is an indentation.
  • the thickness of the first region 31 is t1
  • the thickness of the second region 32 is t2, 0.5% ⁇ (t1-t2)/t1 ⁇ 5%
  • the second direction X is the thickness direction of the first pole piece 21.
  • the thickness t1 of the first area 31 that has not been pre-rolled and stretched and the thickness t2 of the second area 32 that has been pre-rolled and stretched meet 0.5% ⁇ (t1-t2)/t1 ⁇ 5%.
  • the thickness of the first area 31 and the second area 32 cannot differ too much. If the difference is too large, the band is easily broken due to stress concentration at the boundary. If the difference is too small, less than 0.5%, the second area 32 cannot achieve the extension effect, and the first pole ear 30 is prone to warping and folding.
  • the thickness t1 of the first area 31 and the thickness t2 of the second area 32 meet 0.5% ⁇ (t1-t2)/t1 ⁇ 5%.
  • the first pole piece 21 provided by the present application can reduce the phenomenon of band breaking.
  • the first pole piece 21 of the present application can also adopt a design of a thinner first current collector 211 and a first active material layer 212 with a higher compaction density while ensuring that the frequency of breaking is not increased, thereby improving the energy density of the battery 100 .
  • 0.5% ⁇ (t1-t2)/t1 ⁇ 3% which can further reduce the phenomenon of broken bands in the first pole piece 21, and thus enable the use of thinner current collectors and/or higher compaction density designs, thereby improving the energy density of the battery.
  • the value of (t1-t2)/t1 is any one of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% and 5%.
  • the projected area of the first pole ear 30 is S1
  • the projected area of the second region 32 is S2, and 60% ⁇ S2/S1 ⁇ 95%. Since the first region 31 has poor ductility, and the second region 32 has good ductility after pre-pressing and rolling, if the area of the second region 32 is too small, it is easy to warp or bend during the winding process of the first pole sheet 21. Therefore, along the thickness direction of the first pole ear 30, the projected area S1 of the first pole ear 30 and the projected area S2 of the second region 32 meet 60% ⁇ S2/S1 ⁇ 95%, which is conducive to reducing the warping and bending of the first pole ear 30 and improving the flatness and energy density of the battery cell.
  • 80% ⁇ S2/S1 ⁇ 95% which can further reduce the warping and bending of the first electrode tab 30 and improve the flatness and energy density of the battery cell.
  • the value of S2/S1 is any one of 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% and 100%.
  • the first electrode tab 30 further includes a third region 33 .
  • the third region 33 is located between the first region 31 and the first active material layer 212 .
  • the third region 33 connects the first region 31 and the first active material layer 212 .
  • the first electrode tab 30 further has a second boundary line 35 , which is located at the junction of the first region 31 and the third region 33 .
  • the first region 31 and the third region 33 are located on both sides of the second boundary line 35 .
  • the battery 100 further includes a first insulating layer 50, which is disposed on the surface of the third region 33 and is connected to the first active material layer 212.
  • the first insulating layer 50 can play an insulating and protective role, reduce the risk of short circuit between the first pole tab 30 and the second pole tab 40, and improve the safety performance of the battery 100.
  • the burrs on the edge of the first pole tab 30 are very easy to pierce the separator 23 and thus be electrically connected to the second pole tab 40, resulting in a short circuit of the battery 100.
  • the first insulating layer 50 can cover the burrs on the edge of the first pole tab 30, thereby reducing the risk of short circuit of the battery 100.
  • the first active material layer 212 completely covers the first current collector 211 of the first electrode sheet 21, and the first insulating layer 50 is connected to the first active material layer 212, which can reduce the exposed area of the empty foil area, further reduce the risk of short circuit between the first electrode tab 30 and the second electrode tab 40, and improve the safety performance of the battery 100.
  • a fourth region 213 is provided on the first pole piece 21, the fourth region 213 exposes the first current collector 211, and the fourth region 213 is located between the first active material layer 212 and the first pole tab 30, and connects the first active material layer 212 and the first pole tab 30. In one embodiment, the fourth region 213 is located between the first active material layer 212 and the third region 33, and connects the first active material layer 212 and the third region 33.
  • the battery 100 further includes a second insulating layer 60, which is disposed on the surface of the fourth region 213 and connects the first insulating layer 50 and the first active material layer 212.
  • the second insulating layer 60 can play an insulating role, reduce the risk of short circuit between the first electrode 21 and the second electrode 22, and improve Safety performance of the battery 100.
  • the burrs on the edge of the first pole piece 21 are very likely to pierce the diaphragm 23 and thus be electrically connected to the second pole piece 22, causing the battery 100 to short-circuit.
  • the second insulating layer 60 can cover the burrs on the edge of the first pole piece 21, thereby reducing the risk of the battery 100 short-circuiting.
  • the first insulating layer 50 and the second insulating layer 60 are made of the same material, and the first insulating layer 50 and the second insulating layer 60 are formed at one time, which can simplify the preparation process of the battery 100 , shorten the preparation cycle of the battery 100 , and save costs.
  • the following further describes the case where the surfaces of the third region 33 and the fourth region 213 are both provided with the first insulating layer 50 .
  • the junction of the first region 31 and the second region 32 also has a first dividing line 34, and the minimum distance between the first dividing line 34 and the first insulating layer 50 is d1, 0.1mm ⁇ d1 ⁇ 1mm, so that the first region 31 has a certain width along the first direction Z.
  • the first region 31 can serve as a transition area between the pre-rolled and stretched second region 32 and the first pole ear 30, thereby improving the structural strength of the connection area between the first pole ear 30 and the first pole sheet 21, reducing the risk of bending or breaking of the first pole ear 30 along the connection with the first pole sheet 21, and improving the seismic resistance of the battery 100.
  • 0.4 mm ⁇ d1 ⁇ 1 mm which can further ensure the structural strength of the connection area between the first pole ear 30 and the first pole piece 21, reduce the risk of bending or breaking of the first pole ear 30 along the connection with the first pole piece 21, and improve the shock resistance of the battery 100.
  • the value of d1 is any one of 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm and 1 mm.
  • the thickness of the first insulating layer 50 is t3, the thickness of the first active material layer 212 is t4, and t3 ⁇ t4. In one embodiment, 50 ⁇ m ⁇ t4 ⁇ 150 ⁇ m.
  • t3 t4 (not shown). In other embodiments, t3>t4 (not shown).
  • the length of the first insulating layer 50 is W2, W2 ⁇ 1 mm, and the length range of the first insulating layer 50 along the first direction Z can ensure the protection effect of the first insulating layer 50 and reduce the risk of short circuit of the battery 100. In one embodiment, W2 ⁇ 2 mm.
  • the length of the first pole tab 30 is W1, W2/W1 ⁇ 0.5, and the dimensional relationship between the first pole tab 30 and the first insulating layer 50 along the first direction Z is beneficial to improving the current conduction ability and heat dissipation ability of the first pole tab 30, thereby improving the charging and discharging speed and heat dissipation efficiency of the battery 100.
  • the first insulating layer 50 includes an inorganic substance.
  • the material of the inorganic substance includes but is not limited to at least one of aluminum oxide, magnesium oxide and titanium oxide.
  • the weight of the first active material layer 212 is G1, 100 g/m ⁇ 2 ⁇ G1 ⁇ 300 g/m ⁇ 2.
  • the weight G1 of the first active material layer 212 refers to the weight of the first active material layer 212 coated per square meter on a single side surface of the first current collector 211.
  • the compaction density of the first active material layer 212 is D1, 2.2 g/cm ⁇ 3 ⁇ D1 ⁇ 4.2 g/cm ⁇ 3.
  • the compaction density D1 of the first active material layer 212 refers to the weight of the first active material layer 212 per unit volume after the first electrode 21 is cold pressed.
  • first tabs 30 there are multiple first tabs 30, which are arranged along a direction perpendicular to the first tab.
  • a plurality of first pole tabs 30 are arranged at intervals. Providing a plurality of first pole tabs 30 can not only improve the charging and discharging speed of the battery 100, but also improve the heat dissipation capacity of the battery 100.
  • the number of the first pole tabs 30 is two.
  • the second pole piece 22 includes a second current collector 221 and a second active material layer 222 disposed on the surface of the second current collector 221 .
  • the second pole tab 40 is connected to the second current collector 221 , and the second pole tab 40 extends out of the second pole piece 22 along the first direction Z.
  • the second electrode tab 40 and the second current collector 221 are integrally formed, and the second electrode tab 40 is cut from the second current collector 221.
  • the material of the second current collector 221 includes any one of copper, nickel, or a nickel alloy.
  • the second pole tab 40 and the second current collector 221 have higher material structure strength and stronger ability to resist deformation.
  • a pre-rolling operation is performed on the blank foil area on the second electrode 22, which can reduce the phenomenon of tape breakage of the second electrode 22 after cold-pressing.
  • the pre-rolling operation on the blank foil area on the second electrode 22 is the same as any one of the embodiments of the pre-rolling operation on the blank foil area on the first electrode 21, and the present application will not repeat it.
  • the preparation process of the first pole piece 21 is as follows:
  • step 2) coating the slurry in step 1) on a portion of the surface of the first current collector 211, and leaving a portion of the surface of the first current collector 211 exposed;
  • step 3 drying the slurry on the surface of the first current collector 211 in step 2) to obtain the first pole piece 21;
  • step 3 The blank foil area on the surface of the first pole piece 21 obtained in step 3) is pre-rolled and stretched, and then the coated area of the first pole piece 21 is roll-pressed to obtain the first pole piece 21.
  • the preparation process of the first electrode tab 30 is as follows: the empty foil area of the first electrode sheet 21 is cut to obtain the first electrode tab 30 extending from the first electrode sheet 21 .
  • first pole piece 21 preparation process and technology of the first pole piece 21 are only used as examples, and the present application does not specifically limit the composition and proportion of each material in the first pole piece 21 .
  • first pole pieces 21 are selected for comparative test and embodiment test. In each group of comparative test, the sample size of the first pole pieces 21 is 10, and in each group of embodiment test, the sample size of the first pole pieces 21 is 10.
  • the average value of the band break frequency of each first pole piece 21 after stretching and extension of the empty foil area and cold pressing of the pole piece in multiple groups of comparative examples, and the average value of the energy density of the battery 100 including each first pole piece 21 are obtained.
  • the first pole piece 21 is not pre-calendered. After the first pole piece 21 is cold-pressed, the empty foil area is stretched and extended.
  • the coating weight of the first active material layer 212 is 150 g/m ⁇ 2, and the compaction density of the first active material layer 212 is 3.85 g/cm ⁇ 3.
  • the first pole piece 21 is pre-rolled and then cold-pressed. After cold-pressing, the empty foil area is not further stretched.
  • Embodiment 1 is a diagrammatic representation of Embodiment 1:
  • the first pole piece 21 is pre-rolled and then cold-pressed. After cold-pressing, the empty foil area is not further stretched.
  • the thickness test method of the first area 31 and the second area 32 is: select any three positions in the first area 31, measure the thickness of each position with a vernier caliper, and then take the arithmetic mean, which is the thickness of the first area 31.
  • the thickness test of the second area 32 is the same method.
  • Embodiment 2 is a diagrammatic representation of Embodiment 1:
  • Embodiment 3 is a diagrammatic representation of Embodiment 3
  • Embodiment 4 is a diagrammatic representation of Embodiment 4:
  • Embodiment 5 is a diagrammatic representation of Embodiment 5:
  • Embodiment 6 is a diagrammatic representation of Embodiment 6
  • Embodiment 7 is a diagrammatic representation of Embodiment 7:
  • Example 6 The only difference from Example 6 is that the compaction density of the first active material layer 212 is 3.90 g/cm ⁇ 3.
  • Embodiment 8 is a diagrammatic representation of Embodiment 8
  • Example 6 The only difference from Example 6 is that the compaction density of the first active material layer 212 is 4.00 g/cm ⁇ 3.
  • Embodiment 9 is a diagrammatic representation of Embodiment 9:
  • Example 6 The only difference from Example 6 is that the compaction density of the first active material layer 212 is 4.10 g/cm ⁇ 3.
  • Embodiment 10 is a diagrammatic representation of Embodiment 10:
  • Example 6 The only difference from Example 6 is that the compaction density of the first active material layer 212 is 4.20 g/cm ⁇ 3.
  • Embodiment 11 is a diagrammatic representation of Embodiment 11:
  • Example 6 The only difference from Example 6 is that the minimum distance d1 between the first boundary line 34 and the first insulating layer 50 is 0.1 mm, and the ratio of the area S2 of the second region 32 (pre-calendering region) to the area S1 of the first electrode tab 30 is 95%.
  • Embodiment 12 is a diagrammatic representation of Embodiment 12
  • Example 6 The only difference from Example 6 is that the minimum distance d1 between the first boundary line 34 and the first insulating layer 50 is 0.3 mm, and the ratio of the area S2 of the second region 32 (pre-calendering region) to the area S1 of the first electrode tab 30 is 93%.
  • Embodiment 13 is a diagrammatic representation of Embodiment 13:
  • Example 6 The only difference from Example 6 is that the minimum distance d1 between the first boundary line 34 and the first insulating layer 50 is 0.7 mm, and the ratio of the area S2 of the second region 32 (pre-calendering region) to the area S1 of the first electrode tab 30 is 85%.
  • Embodiment 14 is a diagrammatic representation of Embodiment 14:
  • Example 6 The only difference from Example 6 is that the minimum distance d1 between the first boundary line 34 and the first insulating layer 50 is 1.0 mm, and the ratio of the area S2 of the second region 32 (pre-calendering region) to the area S1 of the first electrode tab 30 is 80%.
  • Embodiment 15 is a diagrammatic representation of Embodiment 15:
  • Example 6 The only difference from Example 6 is that the minimum distance d1 between the first boundary line 34 and the first insulating layer 50 is 1.2 mm, and the ratio of the area S2 of the second region 32 (pre-calendering region) to the area S1 of the first electrode tab 30 is 75%.
  • Embodiment 16 is a diagrammatic representation of Embodiment 16:
  • Example 6 The only difference from Example 6 is that the minimum distance d1 between the first boundary line 34 and the first insulating layer 50 is 1.5 mm, and the ratio of the area S2 of the second region 32 (pre-calendering region) to the area S1 of the first electrode tab 30 is 60%.
  • Embodiment 17 is a diagrammatic representation of Embodiment 17:
  • Example 6 The only difference from Example 6 is that the minimum distance d1 between the first boundary line 34 and the first insulating layer 50 is 1.6 mm, and the ratio of the area S2 of the second region 32 (pre-calendering region) to the area S1 of the first electrode tab 30 is 55%.
  • the first pole piece 21 of the present application is pre-rolled for the empty foil area before cold pressing, which can improve the situation of the first pole piece 21 being broken.
  • the first pole piece 21 can withstand a greater compaction strength, thereby increasing the compaction density of the first active material layer 212 and improving the energy density of the battery 100 .
  • the pole ear is arranged into a first region 31 and a second region 32 along the width direction of the pole piece, the first region 31 connects the second region 32 and the pole piece, and the second region 32 is pressed before cold pressing to pre-extend it, and the thickness t1 of the first region 31 and the thickness t2 of the second region 32 satisfy 0.5% ⁇ (t1-t2)/t1 ⁇ 5%, which can reduce the phenomenon of broken bands of the pole piece after cold pressing, and thus can adopt a thinner current collector and/or a higher compaction density design to improve the energy density of the battery 100.
  • an embodiment of the present application further provides an electric device 200 , comprising the battery 100 described in any of the aforementioned embodiments, and the battery 100 can provide electrical energy to the electric device 200 .
  • the power-consuming device 200 includes electronic devices such as drones, mobile phones, watches, tablet computers, and laptop computers.
  • the first pole piece 21 of the battery 100 is pre-rolled and stretched on the empty foil area before cold pressing, which improves the problem of broken strips of the first pole piece 21, and then adopts a thinner current collector and/or a higher compaction density design, thereby improving the energy density of the battery 100 and reducing the impact of the low energy density of the battery 100 on the electrical equipment 200.

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Abstract

本申请公开一种电池及用电设备，电池包括极片和极耳，极片包括集流体和设于集流体上的活性物质层，极耳连接于集流体，沿极片的宽度方向，极耳伸出于极片。沿极片的宽度方向，极耳包括第一区域和第二区域，第一区域位于第二区域和活性物质层之间，第一区域的厚度为t1，第二区域的厚度为t2，0.5％≤(t1-t2)/t1≤5％。

Description

电池及用电设备 技术领域
本申请涉及储能技术领域，特别涉及一种电池及用电设备。
背景技术
目前，在电池极片的生产过程中，通常包括涂料及冷压工序。其中通过冷压能使极片被压实，对电池能量密度以及电性能的提升具有非常重要的作用。由于活性物质层区域和形成极耳的空箔区在冷压过程中的延展程度不同，在极片经过冷压后，为了减少极耳出现变形或翘曲的风险，通常需要对空箔区进行拉伸延展，但是该拉伸延展操作极易导致极片出现断带现象，影响冷压加工优率。为了减少极片出现断带的风险，现有技术通常采用更厚的集流体或降低极片的压实密度，该措施不仅对改善断带现象的效果不佳，而且会造成能量密度的损失。
发明内容
鉴于上述状况，有必要提供一种电池，减少极片出现断带的风险，提升电池能量密度。
本申请的实施例提供一种电池，包括极片和极耳，极片包括集流体和设于集流体上的活性物质层，极耳连接于集流体，沿极片的宽度方向，极耳伸出于极片。沿极片的宽度方向，极耳包括第一区域和第二区域，第一区域位于第二区域和活性物质层之间，第一区域的厚度为t1，第二区域的厚度为t2，0.5％≤(t1-t2)/t1≤5％。
上述的电池中，沿极片的宽度方向将极耳设置成第一区域和第二区域，第一区域位于第二区域和活性物质层之间，在冷压前将第二区域进行压轧使其预先延展，且第一区域的厚度t1和第二区域的厚度t2满足0.5％≤(t1-t2)/t1≤5％，第一区域和第二区域的厚度不能相差太大，若相差太大，由于分界处应力集中，容易断带，若相差太小，小于0.5％，则第二区域达不到延伸效果，极耳容易发生翘曲、打折。因此第一区域的厚度t1和第二区域的厚度t2满足0.5％≤(t1-t2)/t1≤5％，能够减少极片在冷压后出现断带的现象，提高加工优率，进而能使用更薄的集流体和/或更高的压实密度，提高电池的能量密度。
在本申请的一些实施例中，0.5％≤(t1-t2)/t1≤3％，能够进一步减少极片在冷压后出现断带的现象。
在本申请的一些实施例中，0.5％≤(t1-t2)/t1≤1.5％，能够进一步减少极片在冷压后出现断带的现象。
在本申请的一些实施例中，由于极片在制备过程中，会经冷压工序，因此冷压后，被活性物质层覆盖的集流体区域延展性较好，第二区域经过预压延后延展性较好，由于第一区域紧挨着活性物质层，工艺上没法使得第一区域也被压延，所以延展性较差，在极片卷绕过程中，第一区域介于活性物质层和第二区域之间，极片在第二区域会发生拱起，引起极片翘曲或者打折，故一般会尽量减小第一区域的面积，使得第二区域的面积尽可能大。因此沿极耳的厚度方向上，极耳的投影的面积为S1，第二区域的投影的面积为S2，60％≤S2/S1≤95％，有利于减少极耳翘曲或打折，提升卷绕的优率、电芯平整度及能量密度。
在本申请的一些实施例中，80％≤S2/S1≤95％，能够进一步减少极耳在冷压后出现翘曲、打折等不良现象，提高卷绕的优率及电芯的平整度和能量密度。
在本申请的一些实施例中，极耳还包括第三区域，第三区域设于第一区域和活性物质层之间，并连接第一区域和活性物质层。第三区域上设置有第一绝缘层，第一绝缘层位于第一区域和活性物质层之间，第一绝缘层能够在极片卷绕或层叠形成电极组件时起到绝缘作用，减少该极耳与另一极性相反的极耳/极片因毛刺刺穿隔膜而发生短路的风险。
在本申请的一些实施例中，第一区域和第二区域交界处还具有第一分界线,第一分界线与第一绝缘层之间的最小距离为d1,0.1mm≤d1≤1mm，使得第一区域沿极片宽度方向上具有一定的宽度，第一区域可以作为预先压轧延展的第二区域与活性材料层的过渡区域，提高第一极耳与活性材料层之间的连接区域的结构强度，减少第一极耳沿与活性材料层的连接处发生弯折或断裂的风险，提高电池的抗震性能。
在本申请的一些实施例中，第一绝缘层满足以下a、b、c中的至少之一：a、第一绝缘层的厚度小于活性物质层的厚度；b、沿极片的宽度方向上，极耳的长度为W1，第一绝缘层的长度为W2,W2/W1≤0.5，W2≥1mm；c、第一绝缘层包括无机物，无机物的材质包括氧化铝、氧化镁和氧化钛中的至少一种。
在本申请的一些实施例中，极耳的数量为多个。
在本申请的一些实施例中，极耳为正极极耳。
本申请的实施例还提供一种用电设备，包括前述任一实施例所述的电池。
上述的用电设备中，电池通过将极耳设置成第一区域和第二区域，并在第二区域进行压轧使其预先延展，能够减少极片在冷压后出现断带的现象，进而能采用更薄的集流体和/或更高的压实密度设计，使电池的能量密度得到提升。
附图说明
图1是本申请的一个实施例中电池的立体结构示意图。
图2是本申请的一个实施例中电池在封装前的状态示意图。
图3是图2中电极组件沿III-III截面的视图。
图4是本申请的一个实施例中第一极耳连接于第一极片的结构示意图。
图5是图4中V-V截面的视图。
图6是图4所示结构的扩展实施例的结构示意图。
图7是图6中VII-VII截面的视图。
图8是图4所示结构的扩展实施例的结构示意图。
图9是图8中IX-IX截面的视图。
图10是图4所示结构的扩展实施例的结构示意图。
图11是图10中XI-XI截面的视图。
图12是图4所示结构的扩展实施例的结构示意图。
图13是本申请的一个实施例中第二极耳连接于第二极片的结构示意图。
图14是图13中XIV-XIV截面的视图。
图15是本申请的一个实施例中用电设备的结构示意图。
主要元件符号说明
电池                                   100
壳体                                   10
第一部分                               11
第二部分                               12
主体部                                 13
封边部                                 14
顶封边                                 141
侧封边                                 142
电极组件                               20
第一极片                               21
第一集流体                             211
第一活性物质层                         212
第四区域                               213
第二极片                               22
第二集流体                             221
第二活性物质层                         222
隔膜                                   23
第一极耳                               30
第一区域                               31
第二区域                               32
第三区域                               33
第一分界线                             34
第二极耳                               40
第一绝缘层                           50
第二绝缘层                              60
用电设备                                200
第一方向                                Z
第二方向                                X
第三方向                                Y
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
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行描述，显然，所描述的实施例仅是本申请一部分实施例，而不是全部的实施例。
需要说明的是，当一个元件被认为是“连接”另一个元件，它可以是直接连接到另一个元件或者可能同时存在居中设置的元件。当一个元件被认为是“设置在”另一个元件，它可以是直接设置在另一个元件上或者可能同时存在居中设置的元件。
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。本文中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。
目前，在电池极片的生产过程中，通常包括涂料及冷压工序。其中冷压能使极片被压实，对电池能量密度和电性能的提升具有非常重要的作用。由于活性物质层区域和形成极耳的空箔区在冷压过程中的延展程度不同，在极片经过冷压后，为了减少极耳出现变形或翘曲的风险，通常需要对空箔区进行拉伸延展，但是该拉伸延展操作极易导致极片出现断带现象，影响冷压加工优率。为了减少极片出现断带的风险，现有技术通常采用更厚的集流体或降低极片的压实密度，该措施不仅对改善断带现象的效果不佳，而且会造成能量密度的损失。
本申请的实施例提供一种电池，包括极片和极耳，极片包括集流体和设于集流体上的活性物质层，极耳连接于集流体，沿极片的宽度方向，极耳伸出于极片。沿极片的宽度方向，极耳包括第一区域和第二区域，第一区域位于第二区域和活性物质层之间，第一区域的厚度为t1，第二区域的厚度为t2，0.5％≤(t1-t2)/t1≤5％。
上述的电池中，沿极片的宽度方向将极耳设置成第一区域和第二区域，第一区域位于第二区域和活性物质层之间，在第二区域进行压轧使其预先延展，且第一区域的厚度t1和第二区域的厚度t2满足0.5％≤(t1-t2)/t1≤5％，第一区域和第二区域的厚度不能相差太大，若相差太大，由于分界处应力集中，容易断带，若相差太小，小于0.5％，则第二区域达不到延伸效果，极耳 容易发生翘曲、打折。因此第一区域的厚度t1和第二区域的厚度t2满足0.5％≤(t1-t2)/t1≤5％，能够减少极片在冷压后出现断带的现象，第一区域和第二区域的厚度不能相差太大，若相差太大，由于分界处应力集中，容易断带，若相差太小，则第二区域达不到延伸效果，极耳容易发生翘曲、打折。
下面结合附图，对本申请的实施例作进一步的说明。
如图1、图2和图3所示，本申请的实施方式提供一种电池100，包括壳体10、电极组件20、第一极耳30和第二极耳40，电极组件20设于壳体10内部，第一极耳30和第二极耳40均连接于电极组件20并伸出于壳体10。
在一实施例中，壳体10包括相互连接的第一部分11和第二部分12，第一部分11和第二部分12相向连接后，可形成能够容纳电极组件20的内部空间。
在一实施例中，壳体10包括主体部13和封边部14，封边部14连接于主体部13并自主体部13延伸，电极组件20设于主体部13内部，第一极耳30和第二极耳40从封边部14伸出。在一实施例中，封边部14包括相互连接的顶封边141和侧封边142，第一极耳30和第二极耳40从顶封边141伸出。
在一实施例中，第一极耳30和第二极耳40位于主体部13的同一侧。在其他实施例中，第一极耳30和第二极耳40也可以分别位于主体部13相对的两端(图未示)。
电极组件20包括第一极片21、第二极片22和隔膜23，隔膜23设于第一极片21和第二极片22之间，第一极片21、隔膜23和第二极片22卷绕设置形成电极组件20，第一极耳30连接于第一极片21，第二极耳40连接于第二极片22。在其他实施例中，第一极片21、隔膜23和第二极片22层叠设置形成电极组件20(图未示)。
第一极耳30和第二极耳40中的其中一个为正极极耳，第一极耳30和第二极耳40中的另一个为负极极耳。在一实施例中，第一极耳30为正极极耳，第二极耳40为负极极耳，第一极片21为正极片，第二极片22为负极片。在一实施例中，第一极耳30的材质包括铝。在一实施例中，第二极耳40的材质包括铜、镍或镍合金中的任一种。
如图4和图5所示，第一极片21包括第一集流体211和设于第一集流体211表面的第一活性物质层212，第一极耳30连接于第一集流体211，并且，沿第一方向Z，第一极耳30伸出于第一极片21，其中，第一方向Z为第一极片21的宽度方向。
本申请的实施例中，第一极耳30与第一集流体211为一体成型结构，第一极耳30由第一集流体211裁切而成。在一实施例中，第一集流体211的材质包括铝。
需要说明的是，第一极片21上设有第一活性物质层212的区域又叫涂覆区，第一极片21上露出第一集流体211的区域和第一极耳30上露出第一集 流体211的区域又叫空箔区。
为了提高第一活性物质层212的压实密度以提高电池100的能量密度，在第一极片21上的第一集流体211在形成第一极耳30前，需要对第一极片21进行冷压，由于在冷压过程中，第一活性物质层212的部分颗粒被压嵌入第一集流体211，导致第一集流体211的结构强度及延展能力下降，待冷压后再对空箔区进行拉伸时，极易造成第一集流体211断带，影响加工优率。本申请提供的第一极片21在冷压前对至少部分空箔区进行压轧以使其预先延展拉伸，并且，在将第一集流体211进行裁切形成第一极耳30后，进行预先压轧延展的空箔区构成第一极耳30的至少部分。
第一极耳30包括第一区域31和第二区域32，第一区域31位于第二区域32和第一活性物质层212之间，第一区域31连接第二区域32和第一极片21。
第一极耳30具有第一分界线34，第一分界线34位于第一区域31和第二区域32的交界处，沿第一方向Z，第一区域31和第二区域32分别位于第一分界线34的两侧。
本申请中，第一分界线34由针对第一极片21的预先压轧延展而形成，进行预先压轧延展的空箔区构成第二区域32。在一实施例中，第一分界线34为压痕。
沿垂直于第一方向Z的第二方向X上，第一区域31的厚度为t1，第二区域32的厚度为t2，0.5％≤(t1-t2)/t1≤5％，其中，第二方向X为第一极片21的厚度方向。
本申请的电池100中，在冷压第一极片21前，将部分空箔区进行压轧使其预先延展拉伸，且未被预先压轧延展的第一区域31的厚度t1和被预先压轧延展的第二区域32的厚度t2满足0.5％≤(t1-t2)/t1≤5％。第一区域31和第二区域32的厚度不能相差太大，若相差太大，由于分界处应力集中，容易断带，若相差太小，小于0.5％，则第二区域32达不到延伸效果，第一极耳30容易发生翘曲、打折。将本申请的第一极片21冷压后，第一区域31的厚度t1和第二区域32的厚度t2满足0.5％≤(t1-t2)/t1≤5％，与在冷压后再对空箔区进行拉伸延展的其他第一极片21相比，本申请提供的第一极片21能够减少出现断带的现象。并且，本申请的第一极片21，在保证断带频次不增大的情况下，还能采用厚度更薄的第一集流体211及压实密度更高的第一活性物质层212的设计，提高电池100的能量密度。
在一实施例中，0.5％≤(t1-t2)/t1≤3％，能够进一步减少第一极片21出现断带的现象，进而能采用更薄的集流体和/或更高的压实密度设计，使电池的能量密度得到提升。
在一实施例中，0.5％≤(t1-t2)/t1≤1.5％，能够进一步减少第一极片21出现断带的现象。在一实施例中，(t1-t2)/t1的值为0.5％、1％、1.5％、2％、2.5％、3％、3.5％、4％、4.5％和5％中的任一个。
在一实施例中，沿第二方向X上，第一极耳30的投影的面积为S1，第二区域32的投影的面积为S2，60％≤S2/S1≤95％。由于第一区域31延展性较差，第二区域32经过预压延后延展性较好，第二区域32若面积太小，则在第一极片21卷绕过程中容易翘曲或打折，因此沿第一极耳30的厚度方向上，第一极耳30的投影的面积S1与第二区域32的投影的面积S2满足60％≤S2/S1≤95％，有利于减少第一极耳30的翘曲、打折，提升电芯的平整度和能量密度。
在一实施例中，80％≤S2/S1≤95％，能够进一步减少有利于减少第一极耳30的翘曲、打折，提升电芯的平整度和能量密度。
在一实施例中，S2/S1的值为60％、65％、70％、75％、80％、85％、90％、95％和100％中的任一个。
如图6和图7所示，在一实施例中，第一极耳30还包括第三区域33，第三区域33位于第一区域31和第一活性物质层212之间，第三区域33连接第一区域31和第一活性物质层212。
在一实施例中，第一极耳30还具有第二分界线35，第二分界线35位于第一区域31和第三区域33的交界处，沿第一方向Z，第一区域31和第三区域33分别位于第二分界线35的两侧。
电池100还包括第一绝缘层50，第一绝缘层50设于第三区域33的表面，第一绝缘层50连接于第一活性物质层212。当第一极片21、第二极片22和隔膜23卷绕或层叠形成电极组件20时，第一绝缘层50能够起到绝缘防护作用，减少第一极耳30与第二极耳40发生短路的风险，提高电池100的安全性能。相较于未设置第一绝缘层50的电池100，第一极耳30边缘的毛刺极易刺穿隔膜23从而与第二极耳40发生电性连接，导致电池100短路，本申请的一实施例中，通过设置第一绝缘层50，能够使第一绝缘层50将第一极耳30边缘的毛刺包覆，继而减少电池100发生短路的风险。
在一实施例中，第一活性物质层212将第一极片21的第一集流体211完全覆盖，第一绝缘层50连接于第一活性物质层212，能够减少空箔区裸露的面积，进一步减少第一极耳30与第二极耳40发生短路的风险，提高电池100的安全性能。
如图8和图9所示，在一实施例中，第一极片21上设有第四区域213，第四区域213显露出第一集流体211，第四区域213位于第一活性物质层212和第一极耳30之间，并连接第一活性物质层212和第一极耳30。在一实施例中，第四区域213位于第一活性物质层212和第三区域33之间，并连接第一活性物质层212和第三区域33。
电池100还包括第二绝缘层60，第二绝缘层60设于第四区域213的表面，第二绝缘层60连接第一绝缘层50和第一活性物质层212。当第一极片21、第二极片22和隔膜23卷绕或层叠形成电极组件20时，第二绝缘层60能够起到绝缘作用，减少第一极片21与第二极片22发生短路的风险，提高 电池100的安全性能。相较于未设置第二绝缘层60的电池100，第一极片21边缘的毛刺极易刺穿隔膜23从而与第二极片22发生电性连接，导致电池100短路，本申请的一实施例中，通过设置第二绝缘层60，能够使第二绝缘层60将第一极片21边缘的毛刺包覆，继而减少电池100发生短路的风险。
如图10和图11所示，在一实施例中，第一绝缘层50和第二绝缘层60的材质相同，第一绝缘层50和第二绝缘层60一次成型，能够简化电池100的制备工艺，缩短电池100的制备周期，节约成本。
为了便于理解及描述，作为实例性的，下面以第三区域33和第四区域213的表面均设有第一绝缘层50为例作进一步的说明。
在一实施例中，沿第一方向Z上，第一区域31和第二区域32交界处还具有第一分界线34，第一分界线34与第一绝缘层50之间的最小距离为d1，0.1mm≤d1≤1mm，使得第一区域31沿第一方向Z上具有一定的宽度，第一区域31可以作为预先压轧延展的第二区域32与第一极耳30的过渡区域，提高第一极耳30与第一极片21之间的连接区域的结构强度，减少第一极耳30沿与第一极片21的连接处发生弯折或断裂的风险，提高电池100的抗震性能。
在一实施例中，0.4mm≤d1≤1mm，能够进一步保证第一极耳30与第一极片21之间的连接区域的结构强度，减少第一极耳30沿与第一极片21的连接处发生弯折或断裂的风险，提高电池100的抗震性能。
在一实施例中，d1的值为0.1mm、0.2mm、0.3mm、0.4mm、0.5mm、0.6mm、0.7mm、0.8mm、0.9mm和1mm中的任一个。
在一实施例中，沿第二方向X上，第一绝缘层50的厚度为t3，第一活性物质层212的厚度为t4，t3＜t4。在一实施例中，50μm≤t4≤150μm。
在其他实施例中，t3＝t4(图未示)。在其他实施例中，t3＞t4(图未示)。
在一实施例中，沿第一方向Z上，第一绝缘层50的长度为W2，W2≥1mm，第一绝缘层50沿第一方向Z上的长度范围能够保证第一绝缘层50的防护效果，减小电池100发生短路的风险。在一实施例中，W2≥2mm。
在一实施例中，沿第一方向Z上，第一极耳30的长度为W1，W2/W1≤0.5，第一极耳30与第一绝缘层50沿第一方向Z上的尺寸关系有利于提高第一极耳30导通电流的能力及散热能力，提高电池100的充放电速度及散热效率。
在一实施例中，第一绝缘层50包括无机物。在一实施例中，无机物的材质包括但不限于氧化铝、氧化镁和氧化钛中的至少一种。
在一实施例中，第一活性物质层212的重量为G1，100g/m^2≤G1≤300g/m^2。其中，第一活性物质层212的重量G1是指，第一集流体211的单侧表面上，每平方米范围内涂覆的第一活性物质层212的重量。
在一实施例中，第一活性物质层212的压实密度为D1，2.2g/cm^3≤D1≤4.2g/cm^3。其中，第一活性物质层212的压实密度D1是指，第一极片21经过冷压后，单位体积的第一活性物质层212的重量。
如图12所示，在一实施例中，第一极耳30的数量为多个，沿垂直于第 一方向Z和第二方向X的第三方向Y，多个第一极耳30间隔设置。设置多个第一极耳30，不仅能够提高电池100的充放电速度，还能够提高电池100的散热能力。可选的，第一极耳30的数量为两个。
如图13和图14所示，第二极片22包括第二集流体221和设于第二集流体221表面的第二活性物质层222，第二极耳40连接于第二集流体221，并且，沿第一方向Z，第二极耳40伸出于第二极片22。
在一实施例中，第二极耳40与第二集流体221为一体成型结构，第二极耳40由第二集流体221裁切而成。在一实施例中，第二集流体221的材质包括铜、镍或镍合金中的任一种。
相较于第一极耳30及第一集流体211，第二极耳40和第二集流体221的材质结构强度较高，抵抗变形的能力较强。在一实施例中，第二极片22在冷压后，无需针对空箔区进行拉伸延展。在一实施例中，第二极片22在冷压前，无需针对空箔区进行预压延操作。
在一实施例中，第二极片22在冷压前，针对第二极片22上留白的空箔区进行预压延操作，能够在冷压后，减少第二极片22发生断带的现象。在一实施例中，第二极片22上针对空箔区的预压延操作与前述针对第一极片21上空箔区的预压延操作中的任意一个实施例相同，本申请不再赘述。
在一实施例中，第一极片21的制备流程为：
1)将96％的钴酸锂、1.5％导电碳、2.5％粘结剂及适量溶剂(如去离子水、N-甲基吡咯烷酮)混合均匀，制成固含量约75％的浆料；
2)将步骤1)中的浆料涂覆在第一集流体211的部分表面，并使第一集流体211的部分表面留白裸露；
3)将步骤2)中第一集流体211表面的浆料烘干，得到第一极片21；
4)将步骤3)中得到的第一极片21的表面留白的空箔区进行预先压轧延展，然后对第一极片21的涂覆区域进行辊压，得到第一极片21。
在一实施例中，第一极耳30的制备流程为：将前述的第一极片21的空箔区进行裁切，得到伸出于第一极片21的第一极耳30。
需要说明的是，前述第一极片21的制备流程及工艺仅作为示例，本申请对第一极片21中各个材料的成分及比例不做具体的限定。
为了验证本申请的第一极片21在冷压前预先压延对减少断带，及采用更薄集流体和/或更高压实密度的极片对电池100能量密度的影响，进行了多组对比测试，具体信息如下：
选取多组第一极片21分别进行对比例测试及实施例测试。每组对比例测试中，第一极片21的样本量为10个，每组实施例测试中，第一极片21的样本量为10个。
获取多组对比例中每一第一极片21在针对空箔区拉伸延展以及极片冷压后的断带频率的平均值，及包含每一第一极片21的电池100的能量密度的平均值。
对比例测试及实施例测试的其他具体信息如下：
对比例1：
第一极片21未进行预压延，在第一极片21冷压后对空箔区进行拉伸延展，第一活性物质层212的涂覆重量为150g/m^2，第一活性物质层212的压实密度为3.85g/cm^3。
对比例2：
对第一极片21进行预压延，然后对第一极片21进行冷压，在冷压后不进针对空箔区进行拉伸延展，第一活性物质层212的涂覆重量为150g/m^2，第一活性物质层212的压实密度为3.85g/cm^3，第一区域31的厚度t1与第二区域32的厚度t2的关系为：(t1-t2)/t1＝10％，第一分界线34与第一绝缘层50之间的最小距离d1为0.5mm，第二区域32(预压延区域)的面积S2与第一极耳30的面积S1的比值为90％。
对比例3：
与对比例2的区别仅在于，第一区域31的厚度t1与第二区域32的厚度t2的关系为(t1-t2)/t1＝7％。
实施例1：
对第一极片21进行预压延，然后对第一极片21进行冷压，在冷压后不进针对空箔区进行拉伸延展，第一活性物质层212的涂覆重量为150g/m^2，第一活性物质层212的压实密度为3.85g/cm^3，第一区域31的厚度t1与第二区域32的厚度t2的关系为：(t1-t2)/t1＝5％，第一分界线34与第一绝缘层50之间的最小距离d1为0.5mm，第二区域32(预压延区域)的面积S2与第一极耳30的面积S1的比值为90％。
第一区域31与第二区域32的厚度测试方法为：在第一区域31选取任意3个位置，用游标卡尺测量每个位置的厚度，然后再取算术平均值，即第一区域31的厚度。第二区域32的厚度测试也是同样的方法。
实施例2：
与实施例1的区别仅在于，第一区域31的厚度t1与第二区域32的厚度t2的关系为(t1-t2)/t1＝3.5％。
实施例3：
与实施例1的区别仅在于，第一区域31的厚度t1与第二区域32的厚度t2的关系为(t1-t2)/t1＝3.0％。
实施例4：
与实施例1的区别仅在于，第一区域31的厚度t1与第二区域32的厚度t2的关系为(t1-t2)/t1＝2.5％。
实施例5：
与实施例1的区别仅在于，第一区域31的厚度t1与第二区域32的厚度t2的关系为(t1-t2)/t1＝1.5％。
实施例6：
与实施例1的区别仅在于，第一区域31的厚度t1与第二区域32的厚度t2的关系为(t1-t2)/t1＝0.5％。
实施例7：
与实施例6的区别仅在于，第一活性物质层212的压实密度为3.90g/cm^3。
实施例8：
与实施例6的区别仅在于，第一活性物质层212的压实密度为4.00g/cm^3。
实施例9：
与实施例6的区别仅在于，第一活性物质层212的压实密度为4.10g/cm^3。
实施例10：
与实施例6的区别仅在于，第一活性物质层212的压实密度为4.20g/cm^3。
实施例11：
与实施例6的区别仅在于，第一分界线34与第一绝缘层50之间的最小距离d1为0.1mm，第二区域32(预压延区域)的面积S2与第一极耳30的面积S1的比值为95％。
实施例12：
与实施例6的区别仅在于，第一分界线34与第一绝缘层50之间的最小距离d1为0.3mm，第二区域32(预压延区域)的面积S2与第一极耳30的面积S1的比值为93％。
实施例13：
与实施例6的区别仅在于，第一分界线34与第一绝缘层50之间的最小距离d1为0.7mm，第二区域32(预压延区域)的面积S2与第一极耳30的面积S1的比值为85％。
实施例14：
与实施例6的区别仅在于，第一分界线34与第一绝缘层50之间的最小距离d1为1.0mm，第二区域32(预压延区域)的面积S2与第一极耳30的面积S1的比值为80％。
实施例15：
与实施例6的区别仅在于，第一分界线34与第一绝缘层50之间的最小距离d1为1.2mm，第二区域32(预压延区域)的面积S2与第一极耳30的面积S1的比值为75％。
实施例16：
与实施例6的区别仅在于，第一分界线34与第一绝缘层50之间的最小距离d1为1.5mm，第二区域32(预压延区域)的面积S2与第一极耳30的面积S1的比值为60％。
实施例17：
与实施例6的区别仅在于，第一分界线34与第一绝缘层50之间的最小距离d1为1.6mm，第二区域32(预压延区域)的面积S2与第一极耳30的面积S1的比值为55％。
针对前述的多组对比例及实施例，获取每一第一极片21在单位长度上的断带次数，及对所有的第一极片21进行追踪，获取包含每一第一极片21的电池100的能量密度，获取部分实施例中第一极耳30出现翻折的频次。统计成表格，如下：
表格1
表格2
表格3

由表格1可知，相较于在冷压前未进行预压延的第一极片21，本申请的第一极片21在冷压前针对空箔区进行预压延，能够改善第一极片21出现断带的情况。
由表格2可知，采用本申请实施例的第一极片21，可以承受更大的压实强度，提高了第一活性物质层212的压实密度，提高电池100的能量密度。
由表格3可知，采用本申请实施例的第一极片21，能够减少第一极耳30出现翻折的频率，提高电池100的良率。
综上所述，本申请的电池100中，沿极片的宽度方向将极耳设置成第一区域31和第二区域32，第一区域31连接第二区域32和极片，在冷压前将第二区域32进行压轧使其预先延展，且第一区域31的厚度t1和第二区域32的厚度t2满足0.5％≤(t1-t2)/t1≤5％，能够减少极片在冷压后出现断带的现象，进而能采用更薄的集流体和/或更高的压实密度设计，提高电池100的能量密度。
如图15所示，本申请的实施方式还提供一种用电设备200，包括前述任一项实施例所述的电池100，电池100可为用电设备200提供电能。
在一实施例中，用电设备200包括无人机、手机、手表、平板电脑和笔记本电脑等电子设备。
上述的用电设备200中，电池100的第一极片21在冷压前，针对空箔区进行预先压轧延展的操作，改善了第一极片21断带的问题，进而采用更薄的集流体和/或更高的压实密度设计，提高了电池100的能量密度，减少电池100能量密度低对用电设备200的影响。
另外，本领域技术人员还可在本申请精神内做其它变化，当然，这些依据本申请精神所做的变化，都应包含在本申请所公开的范围。

Claims (11)

  1. 一种电池，其特征在于，包括：
    极片，所述极片包括集流体和设于所述集流体上的活性物质层；
    极耳，连接于所述集流体，沿所述极片的宽度方向，所述极耳伸出于所述极片；
    沿所述极片的宽度方向，所述极耳包括第一区域和第二区域，且所述第一区域位于所述第二区域和所述活性物质层之间，所述第一区域的厚度为t1，所述第二区域的厚度为t2，0.5％≤(t1-t2)/t1≤5％。
  2. 如权利要求1所述的电池，其特征在于，0.5％≤(t1-t2)/t1≤3％。
  3. 如权利要求1所述的电池，其特征在于，0.5％≤(t1-t2)/t1≤1.5％。
  4. 如权利要求1所述的电池，其特征在于，沿所述极耳的厚度方向上，所述极耳的投影的面积为S1，所述第二区域的投影的面积为S2，60％≤S2/S1≤95％。
  5. 如权利要求4所述的电池，其特征在于，80％≤S2/S1≤95％。
  6. 如权利要求1所述的电池，其特征在于，沿所述极片的宽度方向，所述极耳还包括第三区域，所述第三区域位于所述第一区域和所述活性物质层之间，并连接所述第一区域和所述活性物质层，所述第三区域上设置有第一绝缘层，所述第一绝缘层位于所述第一区域和所述活性物质层之间。
  7. 如权利要求6所述的电池，其特征在于，所述第一区域和所述第二区域交界处还具有第一分界线，所述第一分界线与所述第一绝缘层之间的最小距离为d1,0.1mm≤d1≤1mm。
  8. 如权利要求6所述的电池，其特征在于，所述第一绝缘层满足以下a、b、c中的至少之一：
    a、所述第一绝缘层的厚度小于所述活性物质层的厚度；
    b、沿所述极片的宽度方向上，所述极耳的长度为W1，所述第一绝缘层的长度为W2,W2/W1≤0.5，W2≥1mm；
    c、所述第一绝缘层包括无机物，所述无机物的材质包括氧化铝、氧化镁和氧化钛中的至少一种。
  9. 如权利要求1所述的电池，其特征在于，所述极耳的数量为多个。
  10. 如权利要求1所述的电池，其特征在于，所述极耳为正极极耳。
  11. 一种用电设备，其特征在于，包括如权利要求1-10任一项所述的电池。
PCT/CN2023/120464 2022-11-04 2023-09-21 电池及用电设备 WO2024093571A1 (zh)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000348756A (ja) * 1999-06-03 2000-12-15 Hitachi Ltd 二次電池および二次電池の設計方法
CN112216842A (zh) * 2019-07-12 2021-01-12 宁德新能源科技有限公司 复合集流体及包括所述复合集流体的电极极片和电芯
CN113097662A (zh) * 2021-03-31 2021-07-09 珠海冠宇电池股份有限公司 电池极片及其制备方法、锂离子电池
CN114204038A (zh) * 2021-12-07 2022-03-18 远景动力技术(江苏)有限公司 集流体及其应用
CN216793731U (zh) * 2021-11-04 2022-06-21 孚能科技(赣州)股份有限公司 一种锂离子电池极片、电池极片预制件和锂离子二次电池
CN115764179A (zh) * 2022-11-04 2023-03-07 宁德新能源科技有限公司 电池及用电设备

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000348756A (ja) * 1999-06-03 2000-12-15 Hitachi Ltd 二次電池および二次電池の設計方法
CN112216842A (zh) * 2019-07-12 2021-01-12 宁德新能源科技有限公司 复合集流体及包括所述复合集流体的电极极片和电芯
CN113097662A (zh) * 2021-03-31 2021-07-09 珠海冠宇电池股份有限公司 电池极片及其制备方法、锂离子电池
CN216793731U (zh) * 2021-11-04 2022-06-21 孚能科技(赣州)股份有限公司 一种锂离子电池极片、电池极片预制件和锂离子二次电池
CN114204038A (zh) * 2021-12-07 2022-03-18 远景动力技术(江苏)有限公司 集流体及其应用
CN115764179A (zh) * 2022-11-04 2023-03-07 宁德新能源科技有限公司 电池及用电设备

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