WO2019178771A1 - 电芯 - Google Patents

电芯 Download PDF

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Publication number
WO2019178771A1
WO2019178771A1 PCT/CN2018/079839 CN2018079839W WO2019178771A1 WO 2019178771 A1 WO2019178771 A1 WO 2019178771A1 CN 2018079839 W CN2018079839 W CN 2018079839W WO 2019178771 A1 WO2019178771 A1 WO 2019178771A1
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WO
WIPO (PCT)
Prior art keywords
region
width
battery cell
foil
active layer
Prior art date
Application number
PCT/CN2018/079839
Other languages
English (en)
French (fr)
Inventor
殷进超
陈轩
明帮生
牛翱翔
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.)
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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/CN2018/079839 priority Critical patent/WO2019178771A1/zh
Publication of WO2019178771A1 publication Critical patent/WO2019178771A1/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
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the application relates to a battery cell.
  • the battery In order to pass safety tests, such as heavy impact and needling, the battery usually lengthens the length of the empty copper foil and the empty aluminum foil at the head or the tail of the pole piece, so that the inner or outer ring of the battery core forms a vest during winding.
  • the design of the cell is due to the presence of empty copper foil and empty aluminum foil in the inner or outer ring, the empty copper foil and the empty aluminum foil are relatively smooth, and the area is not coated with active material, so that the vest and the diaphragm
  • the adhesive strength is not strong, and since the width of the empty copper foil and the empty aluminum foil and the diaphragm between them are substantially equal; when the battery core is dropped, the empty copper foil and the empty aluminum foil are easily exceeded during the falling process due to the weak binding force of the vest. Contact with the edge of the diaphragm, causing the battery to be shorted.
  • an object of the present application is to provide an electrode assembly that solves the problem of short-circuit contact between a cathode current collector and an anode current collector when a cell is dropped due to weak vesting force of the vest.
  • the application provides a battery core, comprising: a first pole piece comprising a first active layer and a first current collector, the first active layer being disposed on the surface of the first current collector; and the surface of the first current collector being free of the first active layer
  • the first photo foil region and the first film region having the first active layer have a width smaller than a width of the first film region.
  • the first membrane regions are of equal width.
  • a second pole piece is further included, the second pole piece includes a second active layer and a second current collector, the second active layer is disposed on the surface of the second current collector, and the surface of the second current collector is free of the second active layer. a second photo foil region and a second film region having a second active layer.
  • the width of the second current collector is equal.
  • the width of the second light foil zone is less than the width of the second film zone.
  • the first light foil area is disposed at the tail of the first pole piece, and the second light foil area is disposed at the tail of the second pole piece.
  • the first light foil zone or the second light foil zone occupies half a turn to one turn of the outermost circle of the cell.
  • the battery core further includes a tab, the first light foil area is disposed on the first pole piece head, the second light foil area is disposed on the second pole piece head, and the pole of the battery core is disposed on the first light foil The area and the second light foil area.
  • the first light foil area is disposed in the middle of the first pole piece, and the second light foil area is disposed in the middle of the second pole piece.
  • the opposite side surfaces of the first light foil region have no first active layer or only one side of the opposite side surfaces has no first active layer; the opposite sides of the second light foil region have no second active Only one of the layers or opposite side surfaces has no second active layer.
  • connection line between the first optical foil region and the first diaphragm region is parallel to the width direction of the first diaphragm region.
  • the angle between the connecting line between the first optical foil region and the first diaphragm region and the width direction of the first diaphragm region is an acute angle.
  • the connecting line between the first optical foil region and the first diaphragm region is curved.
  • the curved configuration is a shape that is recessed inward or a shape that protrudes outward.
  • the first current collector surface further has a third light foil region without the first active layer and a third diaphragm region having the first active layer
  • the second current collector surface further has a fourth active layer free a photo foil region and a fourth film region having a second active layer
  • the third photo foil region and the fourth photo foil region are both located at the innermost circumference of the cell, and the tabs of the cell are disposed on the third photo foil region and the fourth photo foil region.
  • the third diaphragm region and the fourth diaphragm region are both located at the innermost circumference of the battery core, and the tabs of the battery core are disposed on the first optical foil region and the second optical foil region.
  • the width of the third optical foil region is smaller than the width of the third diaphragm region, and the width of the fourth optical foil region is smaller than the width of the fourth diaphragm region.
  • a diaphragm is further provided, the diaphragm being disposed between the first pole piece and the second pole piece, and the width of the first light foil zone and the width of the second light foil zone are both smaller than the width of the diaphragm.
  • the difference between the width of the first light foil region and the width of the second light foil region and the width of the separator is 2 mm to 45 mm, respectively.
  • the width of the first light foil region is smaller than that of the first diaphragm The width of the zone, so that when the cell is dropped, the first foil area does not exceed the first diaphragm area and contacts the light foil area of the other current collectors, thereby avoiding the risk of shorting the cells.
  • FIG. 1 is a side cross-sectional view of a first embodiment of a battery cell of the present application.
  • FIG 2 is a top plan view of a first embodiment of a first pole piece of the present application.
  • FIG 3 is a side elevational view of a first embodiment of a first pole piece of the present application.
  • FIG. 4 is a top plan view of a second embodiment of the first pole piece of the present application.
  • Figure 5 is a side elevational view of a second embodiment of the first pole piece of the present application.
  • Figure 6 is a top plan view of a second pole piece of the present application.
  • Figure 7 is a side elevational view of the second pole piece of the present application.
  • Figure 8 is a schematic cross-sectional view of a second embodiment of the battery cell of the present application.
  • Figure 9 is a schematic cross-sectional view of a third embodiment of the battery cell of the present application.
  • Figure 10 is a top plan view of a third embodiment of a first pole piece or a second pole piece of the present application.
  • Figure 11 is a side elevational view of a third embodiment of a first pole piece or a second pole piece of the present application.
  • Figure 12 is a side elevational view of a fourth embodiment of a first pole piece or a second pole piece of the present application.
  • Figure 13 is a top plan view of a fifth embodiment of a first pole piece or a second pole piece of the present application.
  • Figure 14 is a top plan view of a sixth embodiment of the first pole piece of the present application.
  • Figure 15 is a schematic cross-sectional view showing a fourth embodiment of the battery cell of the present application.
  • Figure 16 is a schematic cross-sectional view showing a fifth embodiment of the battery cell of the present application.
  • 17 is a top plan view of a battery cell of the present application.
  • the present application provides a battery cell including: a first pole piece 1 including a first active layer 11 and a first current collector 13, the first active layer 11 being disposed on the first a surface of the current collector 13; a first light foil region 10 having no first active layer 11 and a first film region 12 having a first active layer 11 on the surface of the first current collector 13, the width of the first light foil region 10 being less than The width of the first diaphragm region 12.
  • the “width” refers to the dimension in the direction indicated by the arrow W in FIGS. 1 and 3.
  • the first optical foil region 10 having no first active layer 11 and the first diaphragm region 12 having the first active layer 11 are present on the surface of the first current collector 13, the first optical foil region 10
  • the width is smaller than the width of the first diaphragm region 12, so that when the battery cell is dropped, the first optical foil region 10 does not exceed the first diaphragm region 12 and contacts the light foil region of the other current collector, thereby avoiding the short circuit of the battery core. risk.
  • the first pole piece 1 may be a cathode pole piece
  • the second pole piece 2 may be an anode pole piece
  • the first current collector 13 may be a copper foil
  • the second current collector 23 may be an aluminum foil.
  • the polarities of the first pole piece 1 and the second pole piece 2 may be interchanged, and the first current collector 13 and the second current collector 23 may be other suitable materials.
  • the first membrane regions 12 are of equal width. That is, the widths of the first membrane regions 12 are uniform, and the entire first membrane region 12 is uniform in width. In other embodiments, the width of the first diaphragm region 12 can be varied as appropriate.
  • the battery cell further includes a second pole piece 2, the second pole piece 2 includes a second active layer 21 and a second current collector 23, and the second active layer 21 is disposed in the second
  • the surface of the current collector 23 has a second photo foil region 20 having no second active layer 21 and a second film region 22 having a second active layer 21 on the surface of the second current collector 23.
  • the structure of the second pole piece 2 may be identical to that of the first pole piece 1, for example, the width of the second light foil zone 20 is smaller than the width of the second diaphragm zone 22. Of course, the structure of the second pole piece 2 can also be different from the structure of the first pole piece 1.
  • the second current collectors 23 have the same width, which is different from the structure of the first pole piece 1. That is, on the second current collector 23, the widths of the second optical foil region 20 and the second diaphragm region 22 are equal, and at this time, the second current collector 23 may be an anode current collector. With such a configuration, the number of optical foil regions with reduced width in the battery core can be reduced, the complexity of the manufacturing process of the battery core can be reduced, and cost can be saved.
  • the first optical foil region 10 is disposed at the tail of the first pole piece 1, and the second optical foil region 20 is disposed at the tail of the second pole piece 2.
  • the tail of the pole piece means the end of the pole piece that is finally wound or laminated, usually located at the outermost circumference of the wound cell.
  • “Outer circle” means the outermost side of the cell. That is, in the embodiments illustrated in the above figures, the vest structure composed of the first optical foil region 10, the second optical foil region 20 and the diaphragm 3 is located at the outermost circumference 4 of the cell. Generally speaking, the outermost ring of the cell is the most prone to the contact between the cathode and the anode current collector when the cell is dropped.
  • the improved vest structure is arranged on the outermost ring of the cell to effectively improve the cell. Safety performance and drop performance.
  • the vest structure is arranged on the outermost ring of the battery core.
  • the first optical foil zone 10 and the second optical foil zone 20 occupy one turn of the outermost ring 4 of the cell.
  • the first optical foil zone 10 and the second optical foil zone 20 occupy a half turn of the outermost ring 4 of the cell. It should be understood that in other embodiments, the first optical foil region 10 and the second optical foil region 20 may occupy any number of half of the outermost ring of the cell to one turn, depending on the specific needs of the cell production. .
  • the battery cell further includes a tab 6 disposed on the head of the first pole piece 1 and the second photo foil region 20 disposed on the head of the second pole piece 2,
  • the tabs 6 of the cells are disposed on the first optical foil region 10 and the second optical foil region 20.
  • the head of the pole piece means the end of the pole piece that is wound or laminated first, usually at the innermost ring 5 of the wound cell. "The innermost circle” means the most central part of the cell. It should be understood that the first optical foil zone 10 and the second optical foil zone 20 are also current collectors that have been modified as described above.
  • the first light foil region 10 is disposed in the middle of the first pole piece 1, and the second light foil region 20 is disposed in the middle of the second pole piece 2.
  • “Middle” refers to the position between the head and the tail of the pole piece.
  • the opposite side surfaces of the first light foil region 10 are free of the first active layer 11 or only one of the opposite side surfaces has no first active layer 11;
  • the opposite side surfaces of the foil region 20 have no second active layer 21 or only one of the opposite side surfaces has no second active layer 21. That is, both the first light foil region 10 and the second light foil region 20 may be double-sided light or single-sided light.
  • the connecting line 14 between the first optical foil region 10 and the first diaphragm region 12 is parallel to the width direction W of the first diaphragm region 12. That is, the junction between the first photo foil region 10 and the first diaphragm region 12 forms a right angle.
  • the connecting line 14 can also be referred to as a contour that transitions from the first optical foil region 10 to the first diaphragm region 12.
  • the angle between the connecting line 4 between the first optical foil region 10 and the first diaphragm region 12 and the width direction W of the first diaphragm region is an acute angle. That is, the connecting line 14 at this time may be a straight line segment (not shown) that extends obliquely from the outer edge of the first diaphragm region 12 to the outer edge of the first optical foil region 10.
  • the connecting line 14 between the first optical foil region 10 and the first diaphragm region 12 is curved.
  • the curved configuration is a shape that is recessed inward (as shown in FIG. 13) or a shape that protrudes outward (as shown in FIG. 14). It should be understood that the concave and convex portions herein are relative to the pole pieces 1, 2.
  • a third photo foil region 30 having no first active layer 11 and a third diaphragm region 32 having a first active layer 11 are present on the surface of the first current collector 13, and the second current collector
  • a fourth photo foil region 40 having no second active layer 21 and a fourth film region 42 having a second active layer 21 on the surface of the surface 23 are also present.
  • the width of the third optical foil region 30 is smaller than the width of the third diaphragm region 32
  • the width of the fourth optical foil region 40 is smaller than the width of the fourth diaphragm region 42.
  • the width is set such that the third optical foil zone 30 and the fourth optical foil zone 40 also have similar advantages as the first optical foil zone 10 and the second optical foil zone 20.
  • the third optical foil region 30 and the fourth optical foil region 40 are both located in the innermost ring 5 of the cell, and the tabs 6 of the cell are disposed in the third optical foil region 30 and Four light foil areas 40.
  • the third optical foil region 30 and the fourth optical foil region 40 are both disposed in the electrical
  • the innermost ring 5 of the core thereby simultaneously forming a vest structure, that is, an outer vest and an inner vest, at the outermost ring 4 and the innermost ring 5 of the cell.
  • the battery core prevents contact short-circuiting at the innermost ring 5 and the outermost ring 4 of the battery cell by providing a double-improved vest structure.
  • the third diaphragm region 32 and the fourth diaphragm region 42 are both located in the innermost ring 5 of the cell, the tabs 6 of the cell being disposed in the first optical foil region 10 and the second On the photo foil area 20. That is, in this embodiment, the tabs 6 normally disposed at the innermost ring 5 of the cell are transferred to the first and second foil regions 10 and 20 of the outermost ring 4, and are located at the innermost The current collector of the ring 5 is coated with the pole piece active material, thereby increasing the energy density of the cell and effectively preventing the current collector from contacting the short circuit.
  • the battery cell further includes a diaphragm 3 disposed between the first pole piece 1 and the second pole piece 2, and the width of the first light foil region 10 and the width of the second light foil region 20 are both smaller than the diaphragm 3.
  • the width of the first optical foil region 10 and the width of the second optical foil region 20 are both smaller than the width of the diaphragm 3, the first optical foil region 10 and the second optical foil region 20 do not exceed the diaphragm when the cell is dropped. 3 edge contact, thereby reducing the probability of shorting of empty copper foil and empty aluminum foil.
  • the difference between the width of the first optical foil region 10 and the width of the second optical foil region 20 and the width of the diaphragm 3, respectively, G, H is 2 mm to 45 mm. That is, the difference G between the width of the first optical foil region 10 and the width of the separator 3 is 2 mm to 45 mm, and the difference H between the width of the second optical foil region 20 and the width of the separator 3 is 2 mm to 45 mm.
  • the width of the first optical foil region 10 may be greater than the width of the second optical foil region 20.
  • the drop performance can be improved on the basis of improving the safety performance of the battery core.

Abstract

本申请提供一种电芯，包括：第一极片，包括第一活性层和第一集流体，第一活性层设置于第一集流体表面；第一集流体表面存在无第一活性层的第一光箔区和有第一活性层的第一膜片区，第一光箔区的宽度小于第一膜片区的宽度。本申请的目的在于提供一种电极组件，解决由于马甲束缚力弱导致的电芯跌落时阴极集流体与阳极集流体接触短路问题。

Description

电芯 技术领域
本申请涉及一种电芯。
背景技术
电芯为了通过安全测试，比如重物冲击和针刺，通常会在极片头部或尾部加长空铜箔和空铝箔的长度，以便卷绕时电芯内圈或外圈形成马甲，以此提升测试通过率；此种设计电芯由于内圈或外圈存在空铜箔和空铝箔，空铜箔和空铝箔由于比较光滑，再加上此区域没有涂覆活性物质使得马甲与隔膜之间粘接力不强，而且由于空铜箔和空铝箔与它们之间的隔膜的宽度基本相等；在电芯跌落时，由于马甲束缚力弱，空铜箔与空铝箔很容易在跌落过程中超出隔膜边缘而接触，导致电芯短路。
发明内容
针对现有技术中存在的问题，本申请的目的在于提供一种电极组件，解决由于马甲束缚力弱导致的电芯跌落时阴极集流体与阳极集流体接触短路问题。
本申请提供一种电芯，包括：第一极片，包括第一活性层和第一集流体，第一活性层设置于第一集流体表面；第一集流体表面存在无第一活性层的第一光箔区和有第一活性层的第一膜片区，第一光箔区的宽度小于第一膜片区的宽度。
根据本申请，第一膜片区宽度相等。
根据本申请，还包括第二极片，第二极片包括第二活性层和第二集流体，第二活性层设置于第二集流体表面，第二集流体表面存在无第二活性层的第二光箔区和有第二活性层的第二膜片区。
根据本申请，第二集流体的宽度相等。
根据本申请，第二光箔区的宽度小于第二膜片区的宽度。
根据本申请，第一光箔区设置于第一极片尾部，第二光箔区设置于第二极片尾部。
根据本申请，第一光箔区或第二光箔区占据电芯的最外圈的半圈至一圈。
根据本申请，电芯还包括极耳，第一光箔区设置于第一极片头部，第二光箔区设置于第二极片头部，电芯的极耳设置在第一光箔区和第二光箔区上。
根据本申请，第一光箔区设置于第一极片中部，第二光箔区设置于第二极片中部
根据本申请，第一光箔区的相对两侧表面均无第一活性层或者相对两侧表面中只有一侧无第一活性层；第二光箔区的相对两侧表面均无第二活性层或者相对两侧表面中只有一侧无第二活性层。
根据本申请，第一光箔区与第一膜片区之间的连接线与第一膜片区宽度方向平行。
根据本申请，第一光箔区与第一膜片区之间的连接线与第一膜片区宽度方向的夹角为锐角。
根据本申请，第一光箔区与第一膜片区之间连接线为弧形。
根据本申请，弧形构造为向内凹陷的形状或者向外凸出的形状。
根据本申请，第一集流体表面还存在无第一活性层的第三光箔区和有第一活性层的第三膜片区，第二集流体表面还存在无第二活性层的第四光箔区和有第二活性层的第四膜片区。
根据本申请，第三光箔区和第四光箔区均位于电芯的最内圈，电芯的极耳设置在第三光箔区和第四光箔区上。
根据本申请，第三膜片区和第四膜片区均位于电芯的最内圈，电芯的极耳设置在第一光箔区和第二光箔区上。
根据本申请，第三光箔区的宽度小于第三膜片区的宽度，第四光箔区的宽度小于第四膜片区的宽度。
根据本申请，还包括隔膜，隔膜设置在第一极片和第二极片之间，并且第一光箔区的宽度和第二光箔区的宽度均小于隔膜的宽度。
根据本申请，第一光箔区的宽度和第二光箔区的宽度分别与隔膜的宽度之差为2mm至45mm。
本申请的有益技术效果在于：
本申请的电芯中，由于第一集流体表面存在无第一活性层的第一光箔区和有第一活性层的第一膜片区，第一光箔区的宽度小于第一膜片区的宽度，所以在电芯跌落时，第一光箔区不会超出第一膜片区而接触其他集流体的光箔区，从而避免了电芯短路的风险。
附图说明
图1是本申请的电芯的第一实施例的侧视截面示意图。
图2是本申请的第一极片的第一实施例的俯视示意图。
图3是本申请的第一极片的第一实施例的侧视示意图。
图4是本申请的第一极片的第二实施例的俯视示意图。
图5是本申请的第一极片的第二实施例的侧视示意图。
图6是本申请的第二极片的俯视示意图。
图7是本申请的第二极片的侧视示意图。
图8是本申请的电芯的第二实施例的截面示意图。
图9是本申请的电芯的第三实施例的截面示意图。
图10是本申请的第一极片或第二极片的第三实施例的俯视示意图。
图11是本申请的第一极片或第二极片的第三实施例的侧视示意图。
图12是本申请的第一极片或第二极片的第四实施例的侧视示意图。
图13是本申请的第一极片或第二极片的第五实施例的俯视示意图。
图14是本申请的第一极片的第六实施例的俯视示意图。
图15是本申请的电芯的第四实施例的截面示意图。
图16是本申请的电芯的第五实施例的截面示意图。
图17是本申请的电芯的俯视示意图。
具体实施方式
现参照附图对本申请的实施例进行详细说明，但该说明仅是示例性的， 不用于限制本申请的保护范围。
参照图1至图5，在一个实施例中，本申请提供一种电芯，包括：第一极片1，包括第一活性层11和第一集流体13，第一活性层11设置于第一集流体13表面；第一集流体13表面存在无第一活性层11的第一光箔区10和有第一活性层11的第一膜片区12，第一光箔区10的宽度小于第一膜片区12的宽度。所述的“宽度”指图1和图3中箭头W所指方向上的尺寸。本申请的电芯中，由于第一集流体13表面存在无第一活性层11的第一光箔区10和有第一活性层11的第一膜片区12，第一光箔区10的宽度小于第一膜片区12的宽度，所以在电芯跌落时，第一光箔区10不会超出第一膜片区12而接触其他集流体的光箔区，从而避免了电芯短路的风险。示例性地，第一极片1可以是阴极极片，第二极片2可以是阳极极片，相应地，第一集流体13可以是铜箔，第二集流体23可以是铝箔。应当理解，在其他实施例中，第一极片1和第二极片2的极性可以互换，第一集流体13和第二集流体23可以是其他合适的材料。通过上述光箔区10、20的宽度小于膜片区12、22的结构配置，在正常产生电能的膜片区保持较宽的宽度，该宽度可以与隔膜3的宽度基本相等，而集流体区的宽度进行相应减小，从而使得电芯既保证较大的能量密度和电池容量，又能有效地避免了马甲结构可能产生的电芯短路风险。
参照图2，在一个实施例中，第一膜片区12宽度相等。也就是说，第一膜片区12各处的宽度一致，整个第一膜片区12宽度均匀。在其他实施例中，第一膜片区12宽度可以有适当变化。
参照图6和图7，在一个实施例中，电芯还包括第二极片2，第二极片2包括第二活性层21和第二集流体23，第二活性层21设置于第二集流体23表面，第二集流体23表面存在无第二活性层21的第二光箔区20和有第二活性层21的第二膜片区22。第二极片2的结构可以与第一极片1的结构完全相同，例如第二光箔区20的宽度小于第二膜片区22的宽度。当然第二极片2的结构也可以与第一极片1的结构不相同。例如，第二集流体23的宽度相等，这与第一极片1的结构不相同。也就是说，在第二集流体23上，第二光箔区20和第二膜片区22的宽度相等，此时第二集流体 23可以为阳极集流体。如此配置，可以减少电芯中宽度缩小的光箔区的数量，减少电芯制造工艺的复杂度，节约成本。
参照图1和图8，在一些实施例中，第一光箔区10设置于第一极片1尾部，第二光箔区20设置于第二极片2尾部。极片的尾部意指极片被最后卷绕或叠片处理的端部，通常位于卷绕式电芯的最外圈。“最外圈”意指电芯的最外侧。也就是说，在上述各图示出的实施例中，由第一光箔区10、第二光箔区20和隔膜3构成的马甲结构位于电芯的最外圈4。通常来讲，电芯的最外圈在电芯跌落时是最容易发生阴阳极集流体接触短路的部位，本申请中经过上述改进的马甲结构设置在电芯的最外圈可以有效提高电芯安全性能及跌落性能。同时马甲结构设置在电芯的最外圈，当电芯遭遇穿钉等冲击时，阳极集流体和阴极集流体依然能够快速形成短路，使电芯内部的电量放出，防止电池爆炸、起火，保证电芯的抗机械滥用性能。
进一步具体而言，在图1示出的实施例中，第一光箔区10和第二光箔区20占据电芯的最外圈4的一圈。在图8示出的实施例中，第一光箔区10和第二光箔区20占据电芯的最外圈4的半圈。应当理解，在其他实施例中，第一光箔区10和第二光箔区20可以占据电芯的最外圈4半圈至一圈中任意数量，这根据电芯生产的具体需求而定。
参照图9，在一个实施例中，电芯还包括极耳6，第一光箔区10设置于第一极片1头部，第二光箔区20设置于第二极片2头部，电芯的极耳6设置在第一光箔区10和第二光箔区20上。极片的头部意指极片被最先卷绕或叠片处理的端部，通常位于卷绕式电芯的最内圈5。“最内圈”意指电芯的最中心的部位。应当理解，该第一光箔区10和第二光箔区20也为经过上述宽度改进的集流体。
参照图10，在一个实施例中，第一光箔区10设置于第一极片1中部，第二光箔区20设置于第二极片2中部。“中部”是指极片的头部和尾部之间的位置。
参照图11和图12，在一个实施例中，第一光箔区10的相对两侧表面均无第一活性层11或者相对两侧表面中只有一侧无第一活性层11；第二光箔区20的相对两侧表面均无第二活性层21或者相对两侧表面中只有一 侧无第二活性层21。也就是说，第一光箔区10和第二光箔区20均可以是双面光或者单面光。
参照图4，在一个实施例中，第一光箔区10与第一膜片区12之间的连接线14与第一膜片区12宽度方向W平行。也就是说，第一光箔区10与第一膜片区12之间的连接处形成一直角。连接线14也可以称作从第一光箔区10向第一膜片区12过渡的轮廓线。在另一个实施例中，第一光箔区10与第一膜片区12之间的连接线4与第一膜片区宽度方向W的夹角为锐角。也就是说，此时连接线14可以为一条直线段(未示出)，其从第一膜片区12的外边缘倾斜延伸至第一光箔区10的外边缘。
参照图13和图14，在一些实施例中，第一光箔区10与第一膜片区12之间连接线14为弧形。具体而言，弧形构造为向内凹陷的形状(如图13所示)或者向外凸出的形状(如图14所示)。应当理解，这里的内凹与外凸是相对极片1、2而言的。
参照图13，在一个实施例中，第一集流体13表面还存在无第一活性层11的第三光箔区30和有第一活性层11的第三膜片区32，第二集流体23表面还存在无第二活性层21的第四光箔区40和有第二活性层21的第四膜片区42。具体地，第三光箔区30的宽度小于第三膜片区32的宽度，第四光箔区40的宽度小于第四膜片区42的宽度。如此设置宽度，使得第三光箔区30和第四光箔区40同样具有与第一光箔区10和第二光箔区20类似的优势。
进一步参照图15，在一个实施例中，第三光箔区30和第四光箔区40均位于电芯的最内圈5，电芯的极耳6设置在第三光箔区30和第四光箔区40上。在该实施例中，在第一光箔区10和第二光箔区20设置在电芯的最外圈4的基础上，第三光箔区30和第四光箔区40均设置在电芯的最内圈5，从而同时在电芯的最外圈4和最内圈5形成马甲结构，即外马甲和内马甲。该电芯通过设置双重改进的马甲结构，从而同时在电芯的最内圈5和最外圈4防止接触短路。
参照图16，在一实施例中，第三膜片区32和第四膜片区42均位于电芯的最内圈5，电芯的极耳6设置在第一光箔区10和第二光箔区20上。 也就是说，在该实施例中，将通常设置在电芯最内圈5的极耳6转移到最外圈4的第一光箔区10和第二光箔区20上，而位于最内圈5的集流体涂满极片活性材料，从而既增加电芯的能量密度又有效防止集流体接触短路。
参照图1，电芯还包括隔膜3，隔膜设置在第一极片1和第二极片2之间，并且第一光箔区10的宽度和第二光箔区20的宽度均小于隔膜3的宽度。所以第一光箔区10、第二光箔区20和隔膜3三者构成马甲结构，具备马甲结构抗机械滥用的功能。同时由于第一光箔区10的宽度和第二光箔区20的宽度均小于隔膜3的宽度，所以在电芯跌落时，第一光箔区10和第二光箔区20不会超出隔膜3边缘而接触，从而减小了空铜箔和空铝箔短路的概率。
进一步，参照图17，第一光箔区10的宽度和第二光箔区20的宽度分别与隔膜3的宽度之差G、H为2mm至45mm。也就是说，第一光箔区10的宽度与隔膜3的宽度之差G为2mm至45mm，第二光箔区20的宽度与隔膜3的宽度之差H为2mm至45mm。有益地，为了充分利用阳极材料，增加电芯容量，第一光箔区10的宽度可以大于第二光箔区20的宽度。
综上，包括但不限于在上述实施例中提出的电芯，在提升电芯安全性能的基础上，可以提高跌落性能。
以上仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (20)

  1. 一种电芯，包括：第一极片，包括第一活性层和第一集流体，所述第一活性层设置于所述第一集流体表面；所述第一集流体表面存在无所述第一活性层的第一光箔区和有所述第一活性层的第一膜片区，所述第一光箔区的宽度小于所述第一膜片区的宽度。
  2. 根据权利要求1所述的电芯，其中，所述第一膜片区宽度相等。
  3. 根据权利要求1所述的电芯，其中，还包括第二极片，所述第二极片包括第二活性层和第二集流体，所述第二活性层设置于所述第二集流体表面，所述第二集流体表面存在无所述第二活性层的第二光箔区和有所述第二活性层的第二膜片区。
  4. 根据权利要求3所述的电芯，其中，所述第二集流体的宽度相等。
  5. 根据权利要求3所述的电芯，其中，所述第二光箔区的宽度小于所述第二膜片区的宽度。
  6. 根据权利要求5所述的电芯，其中，所述第一光箔区设置于所述第一极片尾部，所述第二光箔区设置于所述第二极片尾部。
  7. 根据权利要求6所述的电芯，其中，所述第一光箔区或所述第二光箔区占据所述电芯的最外圈的半圈至一圈。
  8. 根据权利要求5所述的电芯，其中，所述电芯还包括极耳，所述第一光箔区设置于所述第一极片头部，所述第二光箔区设置于所述第二极片头部，所述电芯的极耳设置在所述第一光箔区和所述第二光箔区上。
  9. 根据权利要求5所述的电芯，其中，所述第一光箔区设置于所述第一极片中部，所述第二光箔区设置于所述第二极片中部
  10. 根据权利要求5所述的电芯，其中，所述第一光箔区的相对两侧表面均无所述第一活性层或者相对两侧表面中只有一侧无所述第一活性层；所述第二光箔区的相对两侧表面均无所述第二活性层或者相对两侧表面中只有一侧无所述第二活性层。
  11. 根据权利要求1所述的电芯，其中，所述第一光箔区与所述第一 膜片区之间的连接线与所述第一膜片区宽度方向平行。
  12. 根据权利要求1所述的电芯，其中，所述第一光箔区与所述第一膜片区之间的连接线与所述第一膜片区宽度方向的夹角为锐角。
  13. 根据权利要求1所述的电芯，其中，所述第一光箔区与所述第一膜片区之间连接线为弧形。
  14. 根据权利要求13所述的电芯，其中，所述弧形构造为向内凹陷的形状或者向外凸出的形状。
  15. 根据权利要求6所述的电芯，其中，所述第一集流体表面还存在无所述第一活性层的第三光箔区和有所述第一活性层的第三膜片区，所述第二集流体表面还存在无所述第二活性层的第四光箔区和有所述第二活性层的第四膜片区。
  16. 根据权利要求15所述的电芯，其中，所述第三光箔区和所述第四光箔区均位于所述电芯的最内圈，所述电芯的极耳设置在所述第三光箔区和所述第四光箔区上。
  17. 根据权利要求15所述的电芯，其中，所述第三膜片区和所述第四膜片区均位于所述电芯的最内圈，所述电芯的极耳设置在所述第一光箔区和所述第二光箔区上。
  18. 根据权利要求15所述的电芯，其中，所述第三光箔区的宽度小于所述第三膜片区的宽度，所述第四光箔区的宽度小于所述第四膜片区的宽度。
  19. 根据权利要求3所述的电芯，其中，还包括隔膜，所述隔膜设置在所述第一极片和所述第二极片之间，并且所述第一光箔区的宽度和所述第二光箔区的宽度均小于所述隔膜的宽度。
  20. 根据权利要求19所述的电芯，其中，所述第一光箔区的宽度和所述第二光箔区的宽度分别与所述隔膜的宽度之差为2mm至45mm。
PCT/CN2018/079839 2018-03-21 2018-03-21 电芯 WO2019178771A1 (zh)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101604763A (zh) * 2009-07-07 2009-12-16 广东国光电子有限公司 一种窄型锂离子电池及其制造工艺
CN206401457U (zh) * 2016-12-27 2017-08-11 宁德新能源科技有限公司 一种卷绕式电芯

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101604763A (zh) * 2009-07-07 2009-12-16 广东国光电子有限公司 一种窄型锂离子电池及其制造工艺
CN206401457U (zh) * 2016-12-27 2017-08-11 宁德新能源科技有限公司 一种卷绕式电芯

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