CN209401784U - Secondary cell - Google Patents

Secondary cell Download PDF

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Publication number
CN209401784U
CN209401784U CN201920265229.6U CN201920265229U CN209401784U CN 209401784 U CN209401784 U CN 209401784U CN 201920265229 U CN201920265229 U CN 201920265229U CN 209401784 U CN209401784 U CN 209401784U
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CN
China
Prior art keywords
electrode assembly
insulating tape
electrode
pole piece
secondary cell
Prior art date
Legal status (The legal status 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 status listed.)
Active
Application number
CN201920265229.6U
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Chinese (zh)
Inventor
李志凌
李晖
张婷婷
周勇
何佳宁
吴维清
李白清
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Qinghai Times New Energy Technology Co Ltd
Qinghai Contemporary Amperex Technology Ltd
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Qinghai Times New Energy Technology Co Ltd
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Application filed by Qinghai Times New Energy Technology Co Ltd filed Critical Qinghai Times New Energy Technology Co Ltd
Priority to CN201920265229.6U priority Critical patent/CN209401784U/en
Application granted granted Critical
Publication of CN209401784U publication Critical patent/CN209401784U/en
Priority to PCT/CN2020/076824 priority patent/WO2020177599A1/en
Priority to JP2021550680A priority patent/JP7374204B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50Manufacturing or production processes characterised by the final manufactured product

Abstract

The utility model provides a kind of secondary cell comprising electrode assembly, shell, cap assembly and the first insulating tape.Electrode assembly includes one or more electrode units, electrode unit has anode pole piece, cathode pole piece and the diaphragm being set between anode pole piece, cathode pole piece, electrode unit be takeup type structure and be it is flat, the cathode pole piece of the outmost turns of electrode unit is located at the outside of the anode pole piece of outmost turns.Shell has the first side wall and accommodating chamber, and electrode assembly is contained in accommodating chamber, and shell is electrically connected with anode pole piece, and cap assembly is sealedly attached to shell.First insulating tape fits closely between electrode assembly and the first side wall, and with the outer surface of electrode assembly.

Description

Secondary cell
Technical field
The utility model relates to field of batteries more particularly to a kind of secondary cells.
Background technique
Secondary cell includes electrode assembly and the shell for accommodating electrode assembly, and existing shell is usually and electrode assembly Anode conducting, make shell keep higher current potential to prevent from corroding.However, will increase the short circuit of secondary cell after shell electrification Risk.For example, during assembling secondary cell, it can be in the outer surface kish foreign matter of electrode assembly;And electrode assembly Expansion and after cycling phase extruding shell during the work time, at this point, metallic foreign body is easy to puncture the diaphragm of electrode assembly, and will The cathode of electrode assembly is connected to shell, to cause short circuit, causes security risk.
Utility model content
In view of the problems in the background art, the purpose of this utility model is to provide a kind of secondary cells, can drop Low short-circuit risks improve security performance.
To achieve the goals above, the utility model provides a kind of secondary cell comprising electrode assembly, shell, top Cap assemblies and the first insulating tape.Electrode assembly includes one or more electrode units, and electrode unit has anode pole piece, cathode pole Piece and the diaphragm being set between anode pole piece, cathode pole piece, electrode unit are takeup type structure and are flat, electrode unit Outmost turns cathode pole piece be located at outmost turns anode pole piece outside.Shell has the first side wall and accommodating chamber, electrode group Part is contained in accommodating chamber, and shell is electrically connected with anode pole piece, and cap assembly is sealedly attached to shell.First insulating tape is located at electrode Between component and the first side wall, and fitted closely with the outer surface of electrode assembly.
Cathode pole piece includes negative current collector and the negative electrode active material layer coated on two surfaces of negative current collector, along flat Row exceeds negative electrode active material layer in the length direction of the wireline reel of electrode unit, the end of the first insulating tape.
Electrode assembly has two end faces being oppositely arranged along its length, and the end of the first insulating tape is without departing from end face.
First insulating tape includes matrix and adhesive layer, and matrix is pasted on the outer surface of electrode assembly by adhesive layer.
Matrix with a thickness of 10 μm~50 μm, elasticity modulus is 1Gpa~6Gpa.
Adhesive layer with a thickness of 0.5 μm~15 μm, the adhesive strength of adhesive layer is greater than 0.05N/mm2
Secondary cell further includes the protection component positioned at enclosure interior, protection component by electrode assembly and the first insulating tape with Shell separates
The outer surface of electrode assembly includes first surface and second surface, and first surface is burnishing surface and is located at electrode group The end of part through-thickness, second surface are connected to first surface and are located at the end of electrode assembly in the width direction.The One side wall is located at the outside of electrode assembly through-thickness, and the first insulating tape is between first surface and the first side wall.
The secondary cell further includes the second insulating tape, and the second insulating tape is at least partly fitted closely with second surface, And second insulating tape and the first insulating tape it is integrally formed.
The area of first insulating tape and the area ratio of first surface are 75%~95%.
Electrode unit is that multiple and through-thickness arranges, and the end of each electrode unit in the width direction has leptoprosopy, the Two surfaces include the leptoprosopy of each electrode unit.
The beneficial effects of the utility model are as follows: by the way that the outer surface of the first insulating tape and electrode assembly is fitted closely, The metallic foreign body of the outer surface attachment of electrode assembly can be reduced;Furthermore when electrode assembly expansion, the first insulating tape can be incited somebody to action The first side wall and electrode assembly separate, so that metallic foreign body be avoided to pierce through diaphragm, electrode assembly are prevented to be electrically connected with the first side wall, Short-circuit risks are reduced, insulation performance and security performance are improved.
Detailed description of the invention
Fig. 1 is the schematic diagram according to the secondary cell of the utility model.
Fig. 2 is another schematic diagram according to the secondary cell of the utility model.
Fig. 3 is the schematic diagram of the electrode assembly of Fig. 2 and an embodiment of the first insulating tape.
Fig. 4 is a cross-section diagram of Fig. 3.
Fig. 5 is the cross-section diagram that A-A makes along Fig. 4.
Fig. 6 is the schematic diagram of the electrode unit of Fig. 4.
Fig. 7 is the schematic diagram of the electrode assembly of Fig. 2 and another embodiment of the first insulating tape.
Wherein, the reference numerals are as follows:
1 electrode assembly, 22 accommodating chamber
11 electrode unit, 23 second sidewall
111 anode pole piece, 3 cap assembly
31 lamina tecti of 111c plus plate current-collecting body
32 electrode terminal of 111d positive electrode active material layer
112 cathode pole piece, 33 switching piece
4 first insulating tape of 112c negative current collector
41 matrix of 112d negative electrode active material layer
113 diaphragm, 42 adhesive layer
11a leptoprosopy 4c first edge
11b interarea 4d second edge
12 end face, 5 second insulating tape
13 first surfaces 6 protect component
14 second surface X width directions
2 shell Y thickness directions
21 the first side wall Z length directions
Specific embodiment
It is with reference to the accompanying drawings and embodiments, right in order to which the objects, technical solutions and advantages of the application are more clearly understood The application is further elaborated.It should be appreciated that specific embodiment described herein is only used to explain the application, and It is not used in restriction the application.
In the description of the present application unless specifically defined or limited otherwise, term " first ", " second ", " third " are only For descriptive purposes, it is not understood to indicate or imply relative importance;Term " multiple " is more than two (including two It is a);Unless otherwise prescribed or illustrating, term " connection " shall be understood in a broad sense, for example, " connection " may be a fixed connection, it can also To be to be detachably connected, or be integrally connected, or electrical connection or signal connect;" connection " can be directly connected, and can also lead to Intermediary is crossed to be indirectly connected.For the ordinary skill in the art, above-mentioned term can be understood as the case may be Concrete meaning in this application.
In the description of this specification, it is to be understood that the nouns of locality such as "upper", "lower" described in the embodiment of the present application are With angle shown in the drawings come what is be described, the restriction to the embodiment of the present application should not be construed as.Below by specific reality It applies example and the application is described in further detail in conjunction with attached drawing.
Referring to Figures 1 and 2, the secondary cell of the application includes electrode assembly 1, shell 2, cap assembly 3 and the first insulation Band 4.
Electrode assembly 1 includes electrode unit 11, and electrode unit 11 can be one or more;In the present embodiment, electrode list Member 11 is preferably several and through-thickness Y is arranged.Referring to fig. 4 to fig. 6, electrode unit 11 includes anode pole piece 111, cathode pole Piece 112 and the diaphragm 113 being set between anode pole piece 111, cathode pole piece 112.Electrode unit 11 can be by being helically wrapped Anode pole piece 111, cathode pole piece 112 and diaphragm 113 and formed, and electrode unit 11 presses to form flat knot through excess pressure Structure.
Anode pole piece 111 includes plus plate current-collecting body 111c and the positive-active coated on two surfaces plus plate current-collecting body 111c Material layer 111d, plus plate current-collecting body 111c can be aluminium foil, and positive electrode active material layer 111d includes LiMn2O4 or LiFePO4.Anode Collector 111c has the positive white space not covered by positive electrode active material layer 111d.Cathode pole piece 112 includes cathode collection Fluid 112c and negative electrode active material layer 112d coated on two surfaces negative current collector 112c, negative current collector 112c can be Copper foil, negative electrode active material layer 112d include graphite or silicon.Negative current collector 112c has not by negative electrode active material layer 112d The cathode white space of covering.
In the course of work of secondary cell, the lithium ion in positive electrode active material layer 111d is needed across diaphragm 113 simultaneously It is embedded into negative electrode active material layer 112d;In winding, if (i.e. electrode unit 11 is outermost with the ending of anode pole piece 111 The cathode pole piece 112 of circle is located at the inside of the anode pole piece 111 of outmost turns), then the lithium ion of the anode pole piece 111 of outmost turns It can not be embedded into cathode pole piece 112, to cause analysis lithium problem.It is therefore preferred that the electrode unit 11 of the application is outermost The cathode pole piece 112 of circle is located at the outside of the anode pole piece 111 of outmost turns.Certainly, in order to guarantee insulating properties, electrode unit 11 The diaphragm 113 of outmost turns is located at the outside of the cathode pole piece 112 of outmost turns.
Referring to Fig. 6, electrode unit 11 includes leptoprosopy 11a and interarea 11b, and interarea 11b is located at electrode unit 11 along thickness side To the both ends of Y, and interarea 11b is substantially planar.Leptoprosopy 11a is located at electrode unit 11 both ends of X and at least portion in the width direction It is divided into arc surface, two interarea 11b of leptoprosopy 11a connection.The area of interarea 11b is greater than the area of leptoprosopy 11a.Wherein, thickness side It is perpendicular to one another to Y and width direction X, and thickness direction Y and width direction X are each perpendicular to the wireline reel of electrode unit 11.In addition, Since 11 outmost turns of electrode unit are diaphragm 113, so leptoprosopy 11a and interarea 11b are the exposed surface of diaphragm 113.
Accommodating chamber 22 is formed with inside shell 2, to accommodate electrode assembly 1 and electrolyte.Accommodating chamber 22 forms open at one end Mouthful, and electrode assembly 1 can be placed into accommodating chamber 22 via the opening.Shell 2 can be by conductive metals such as aluminum or aluminum alloy Material is made.
Shell 2 can be to be prismatic, specifically, and shell 2 includes the first side wall 21, second sidewall 23 and bottom wall, the first side wall 21 are two and are respectively arranged at the two sides of 1 through-thickness Y of electrode assembly, and second sidewall 23 is two and is respectively arranged at electricity The two sides of the X in the width direction of pole component 1, two the first side walls 21 and two second sidewalls 23 link together and form approximate square The framework of shape.Bottom wall is set to the downside of the first side wall 21 and second sidewall 23 and is connected to the first side wall 21 and second sidewall 23, bottom wall, two the first side walls 21 and two second sidewalls 23 surround the accommodating chamber 22 of shell 2.Compared with second sidewall 23, the One side wall 21 has biggish area.
Referring to Fig.1, cap assembly 3 includes lamina tecti 31, electrode terminal 32 and switching piece 33.Lamina tecti 31 is connected to shell 2 and the opening of shell 2 is covered, the opening of shell 2 is sealed.Electrode terminal 32 is set to lamina tecti 31, and switching piece 33 can lead to The modes such as welding are crossed to be electrically connected with electrode terminal 32, electrode assembly 1 respectively.On length direction Z, lamina tecti 31 and shell 2 Bottom wall is located at the two sides of electrode assembly 1.
Electrode terminal 32 can be two, wherein the electrode terminal 32 of positive polarity is via a switching piece 33 and anode pole piece 111 electrical connections, the electrode terminal 32 of negative polarity are electrically connected via another switching piece 33 with cathode pole piece 112.Lamina tecti 31 can For metal plate, and lamina tecti 31 is electrically connected with the electrode terminal 32 of positive polarity, is insulated with the electrode terminal 32 of negative polarity.Shell 2 It can be tightly connected by the modes such as welding and lamina tecti 31.
In known technology, electrolyte easily corrodes shell 2, influences performance and the service life of secondary cell;And in the application In, shell 2 is electrically connected via lamina tecti 31 and the electrode terminal of positive polarity 32 with anode pole piece 111, so that shell 2 be enable to protect It holds in high potential, avoids electrochemical corrosion, improve performance and the service life of secondary cell.
During assembling secondary cell, the metallic foreign body of generation is easy to sputter and be attached to the outer surface of electrode assembly 1. During the work time, electrode assembly 1 will appear expansion, and expansion of the electrode assembly 1 on thickness direction Y is the most serious;Expansion When, electrode assembly 1 can squeeze the first side wall 21, and under the effect of the pressure, the metallic foreign body for being attached to 1 surface of electrode assembly is easy Diaphragm 113 is punctured, and the negative electrode active material layer 112d of cathode pole piece 112 and the first side wall 21 are connected, especially when secondary electricity When pond is in fully charged state, the rapid heat production of meeting inside electrode assembly 1, to cause security risk.
It is therefore preferred that the first insulating tape 4, the first insulating tape is preferably arranged in the application on the outer surface of electrode assembly 1 4 and the outer surface of electrode assembly 1 fit closely and between electrode assembly 1 and the first side wall 21.First insulating tape 4 is preferably Two, and two the first insulating tapes 4 are located at the both ends of 1 through-thickness Y of electrode assembly.
It is briefly described as follows the forming process of the secondary cell of the application:
(i) anode pole piece 111, cathode pole piece 112 and diaphragm 113 winding are integrated to prepare electrode unit 11;Volume In the first insulating tape of surface mount 4 of electrode unit 11 after molding.
(ii) multiple electrodes unit 11 is stacked together, multiple electrodes unit 11 forms electrode assembly 1;It, will when stacking The outside of electrode assembly 1 is arrived in the setting of first insulating tape 4.
(iii) the positive white space of electrode unit 11 and cathode white space are welded to two switching pieces 33, Then two switching pieces 33 are welded to two electrode terminals 32 of cap assembly 1 again.
(iv) electrode assembly 1 and the first insulating tape 4 being bonded on electrode assembly 1 are put into shell 2, then by shell The lamina tecti 31 of body 2 and cap assembly 3 welds, and realizes the sealing of shell 2.
Wherein, it when the quantity of electrode assembly 1 is more, need to only be pasted on the surface of outermost two electrode units 11 First insulating tape 4, therefore, in step (i), the surface of some electrode units 11 is without pasting the first insulating tape 4.
In known technology, when welding electrode terminal and switching piece, the metallic foreign body for welding generation is easy to be attached to The outer surface of electrode assembly.And electrode assembly expands during the work time and after cycling the phase squeeze shell, at this point, metallic foreign body It is easy to puncture the diaphragm of electrode assembly, and the cathode of electrode assembly is connected to shell, to cause short circuit, cause safety wind Danger.
And in this application, before welding switching piece 33 and electrode terminal 32, first on the outer surface of electrode assembly 1 It is bonded the first insulating tape 4;When welding switching piece 33 and electrode terminal 32, the first insulating tape 4 can protect electrode assembly 1, from And reduce the metallic foreign body for being attached directly to the outer surface of electrode assembly 1.
When electrode assembly 1 expands, the first insulating tape 4 can separate the first side wall 21 and electrode assembly 1, to avoid The metallic foreign body retained between first insulating tape 4 and shell 2 pierces through diaphragm 113, and electrode assembly 1 is prevented to be electrically connected with the first side wall 21 It connects, reduces short-circuit risks, improve insulation performance.
If there are gap between the first insulating tape 4 and the outer surface of electrode assembly 1, metallic foreign body may be remained Between the first insulating tape 4 and electrode assembly 1;When electrode assembly 1 expands, metallic foreign body is still easy to puncture diaphragm 113, very To cathode pole piece 112 is stabbed, the performance of secondary cell is influenced.And in this application, the first insulating tape 4 is outer with electrode assembly 1 Surface fits closely, so metallic foreign body hardly enters between the first insulating tape 4 and electrode assembly 1, to avoid metal Foreign matter punctures diaphragm 113 and cathode pole piece 112.
In order to guarantee that the lithium ion of anode pole piece 111 can be embedded into as much as possible in cathode pole piece 112, edge is parallel to electricity The length direction Z of the wireline reel of pole unit 11, the negative electrode active material layer 112d size of cathode pole piece 112 are typically larger than positive pole The positive electrode active material layer 111d size of piece 111.Specifically, it referring to Fig. 5, in one end of the Z along its length of electrode assembly 1, bears An end 112a of pole active material layer 112d exceeds an end 111a of positive electrode active material layer 111d;In electrode assembly Another end 112b of the other end of 1 Z along its length, negative electrode active material layer 112d exceeds positive electrode active material layer 111d Another end 111b.And in order to guarantee insulation performance, Z, the size of diaphragm 113 are typically larger than negative electrode active along its length The size of material layer 112d;Specifically, in one end of the Z along its length of electrode assembly 1, an end 113a of diaphragm 113 is super An end 112a of negative electrode active material layer 112d out;In the other end of the Z along its length of electrode assembly 1, diaphragm 113 it is another One end 113b exceeds another end 112b of negative electrode active material layer 112d.At this point, Z is complete along its length for diaphragm 113 All standing positive electrode active material layer 111d and negative electrode active material layer 112d.
Preferably, in this application, edge is parallel to the length direction Z of the wireline reel of electrode unit 11, the first insulating tape 4 End exceeds the negative electrode active material layer 112d of cathode pole piece 112.That is, electrode assembly 1 along its length Z one End, an end 4a of the first insulating tape 4 exceed an end 112a of negative electrode active material layer 112d;On 1 edge of electrode assembly The other end of length direction Z, another end 4b of the first insulating tape 4 exceed another end of negative electrode active material layer 112d 112b.At this point, negative electrode active material layer 112d can be completely covered in the first insulating tape 4, on length direction Z so as to improve exhausted Edge performance reduces the risk that negative electrode active material layer 112d and the first side wall 21 are connected to the full extent, improves security performance.
Electrode assembly 1 has two end faces 12 that Z is oppositely arranged along its length.Specifically, when electrode assembly 1 is wound into After type, two ends of diaphragm 113 are wound as multi-turn, and each end approximately forms a face, and the face that each end is formed is end face 12.There are tiny gaps on described two end faces 12, and electrolyte can enter the inside of electrode assembly 1 via the gap, So as to improve wellability.
In this application, it is preferable that Z along its length, the end of the first insulating tape 4 is without departing from end face 12, that is to say, that Z along its length, the first insulating tape 4 are located between two end faces of electrode assembly 1.If the end of the first insulating tape 4 exceeds End face 12, then the first insulating tape 4 is easy to be folded on end face 12 beyond the part of end face 12 in assembly or use process, To block the gap on end face 12, wellability is influenced, causes analysis lithium risk.
First insulating tape 4 includes matrix 41 and adhesive layer 42, and matrix 41 is pasted on the outer of electrode assembly 1 by adhesive layer 42 Surface.The material of matrix 41 can be flexible polymer, such as PMMA or PET.The material of adhesive layer 42 can be acrylate or second Acetoacetic ester.
In this application, matrix 41 is adhered directly to the outer surface of electrode assembly 1, the first insulating tape 4 via adhesive layer 42 The gapless between electrode assembly 1, so that metallic foreign body be avoided to enter between the first insulating tape 4 and electrode assembly 1.In the application In, although the first insulating tape 4 can reduce the metallic foreign body for being attached to the outer surface of electrode assembly 1, metallic foreign body is still It can be attached to the outer surface of the first insulating tape 4, therefore, the first insulating tape 4 needs to have enough thickness, golden to avoid itself Belong to foreign matter to pierce through.In addition, due to electrode assembly 1 in use can dilatancy, the first insulating tape 4 must assure that can be with The dilation of electrode assembly 1 and correspondingly elastic deformation occurs, to guarantee the cycle performance and security performance of secondary cell.
In this application, 10 μm~50 μm of the thickness of matrix 41, elasticity modulus are 1Gpa~6Gpa.
In secondary cell assembling process, the size for generating metallic foreign body by welding is uneven, when the thickness of matrix 41 is less than At 10 μm, larger-size metallic foreign body still may puncture the first insulating tape 4, lead to cathode pole piece 112 and the first side wall 21 electrical connections, cause short-circuit risks;When the thickness of matrix 41 is greater than 50 μm, the volume of the first insulating tape 4 is larger, occupies shell 2 inner space.Therefore, it is 10 μm~50 μm by limiting the thickness of matrix 41, short-circuit risks can be effectively reduced, It can also ensure that the first insulating tape 4 will not occupy 2 space of shell too much simultaneously.Preferably, 12 μm~30 μ of thickness of matrix 41 m。
When the elasticity modulus of matrix 41 is less than 1Gpa, matrix 41 is easy to be plastically deformed under the bulbs of pressure, leads Cause matrix 41 thickness become smaller, weakened, metallic foreign body may puncture the first insulating tape 4 at this time, cause cathode pole piece 112 with The first side wall 21 is electrically connected, and causes short-circuit risks.When the elasticity modulus of matrix 41 is greater than 6Gpa, matrix 41 is under the bulbs of pressure It hardly deforms, that is to say, that matrix 41 can fetter the expansion of electrode assembly 1;Under the action of binding force, electrode assembly 1 The phenomenon that electrolyte of part is extruded, causes insufficient electrolyte can not cause analysis by diaphragm 113 so as to cause lithium ion Lithium.Therefore 1Gpa is greater than by the elasticity modulus of limitation matrix 41 and is less than 6Gpa, short-circuit risks can be effectively reduced, simultaneously also It can be avoided generation analysis lithium, improve cycle performance.Preferably, the elasticity modulus of matrix 41 is 1.2Gpa~4.5Gpa.
Adhesive layer 42 with a thickness of 0.5 μm~15 μm.If the thickness of adhesive layer 42 is less than 0.5 μm, adhesive layer 42 Adhesive strength it is relatively low, be easy to cause matrix 41 to separate with electrode assembly 1, the defencive function of matrix 41 caused to fail.If viscous The thickness for connecing layer 42 is greater than 15 μm, and it is excessive to will lead to 42 the space occupied of adhesive layer, reduces the energy density of secondary cell.
When electrode assembly 1 expand when, can be generated between diaphragm 113 and adhesive layer 42 stress concentration, for avoid diaphragm 113 with Adhesive layer 42 separates, and the adhesive strength of adhesive layer 42 is preferably greater than 0.05N/mm2
Referring to Fig. 3, the outer surface of electrode assembly 1 includes two first surfaces 13 and two second surfaces 14.Two first The generally flat face in surface 13 and the both ends for being located at 1 through-thickness Y of electrode assembly, two second surfaces 14 distinguish position In the both ends of the X in the width direction of electrode assembly 1.The both ends of each second surface 14 are connected to two first surfaces 13.
In the present embodiment, the 11 through-thickness Y of multiple electrodes unit of electrode assembly 1 is arranged successively, therefore, described In all interarea 11b of multiple electrodes unit 11, an interarea 11b near a first side wall 21 exposes, near another Another interarea 11b of one the first side wall 21 exposes.The two interarea 11b exposed are then respectively two of electrode assembly 1 the One surface 13.In addition, " exposing " be relative to electrode assembly 1 generally speaking.
Due to leptoprosopy 11a at least partially arc surface, there are gaps between the leptoprosopy 11a of adjacent electrode unit 11, respectively The leptoprosopy 11a of electrode unit 11 will not be covered by other electrode units 11, and therefore, the leptoprosopy 11a of multiple electrodes unit 11 reveals Out.One second surface 14 includes the leptoprosopy 11a of each electrode unit 11 one end X in the width direction, another second surface 14 packet Include the leptoprosopy 11a of each electrode unit 11 X other end in the width direction.
In this application, two first surfaces 13 are located at the both ends of 1 through-thickness Y of electrode assembly, and two Two surfaces 14 are located at the both ends of the X in the width direction of electrode assembly 1, and first surface 13 and second surface 14 intersect with each other, institute It will form intersecting lens L with the intersection of first surface 13 and second surface 14.
Since the area of the interarea 11b of electrode unit 11 is greater than the area of leptoprosopy 11a, so when electrode unit 11 is using When expanding in the process, the interarea 11b deformation of electrode unit 11 is more serious;In other words, constant in 11 thickness of electrode unit In the case of, the size of the interarea 11b through-thickness Y protrusion of electrode unit 11 is greater than the ruler of leptoprosopy 11a through-thickness Y protrusion It is very little.Therefore, first surface 13 is easier to squeeze shell 2 compared to second surface 14.Furthermore the generally flat face of first surface 13, And second surface 14 includes multiple leptoprosopy 11b and each leptoprosopy 11b at least partially arc surface, even if first surface 13 and the The degree of two surfaces 14 deformation is identical, and first surface 13 and 2 contact area of shell are compared to second surface 14 and 2 contact surface of shell Product is bigger.Therefore, there are higher short-circuit risks compared to leptoprosopy 11a by the interarea 11b of electrode unit 11.
In order to improve energy density, the gap reserved between electrode assembly 1 and shell 2 is smaller, especially first surface 13 Gap between the first side wall 21.When electrode assembly 1 expands, first surface 13 is easy the effect by the first side wall 21 Power;And since second surface 14 is generally arcuate, between second surface 14 and second sidewall 23 and second surface 14 and first There are biggish gaps between side wall 21, so second surface 14 is not easily susceptible to 23 He of second sidewall when electrode assembly 1 expands The active force of the first side wall 21.It is therefore preferred that the first insulating tape 4 is fitted closely with first surface 13, that is to say, that first Insulating tape 4 is bonded on first surface 13.First insulating tape 4 can separate the first side wall 21 and first surface 13, to keep away Exempt from metallic foreign body and pierce through first surface 13, negative electrode active material layer 112d is prevented to be electrically connected with the first side wall 21, improves insulating properties Energy.
Referring to Fig. 4, X, the edge of the first insulating tape 4 extend to intersecting lens L in the width direction.Specifically, the first insulating tape 4 Two edges of X are respectively first edge 4c and second edge 4d in the width direction;On width direction X, first edge 4c with Intersecting lens L positioned at 13 one end of first surface is flushed, and the second edge 4d and intersecting lens L for being located at 13 other end of first surface is neat It is flat.At this point, the first insulating tape 4 can be completely separated by the first side wall 21 and cathode pole piece 112, to keep away on width direction X Exempt from the first side wall 21 to be electrically connected with cathode pole piece 112, improves insulation performance.
First surface 13 does not still have the risk punctured by metallic foreign body by the region that the first insulating tape 4 covers, because This, in order to guarantee insulation performance, the area of the first insulating tape 4 and the area ratio of first surface 13 are preferably 75%~95%. If the area ratio is greater than 95%, when being bonded the first insulating tape 4, the first insulating tape 4 is easy to appear dislocation, leads to the One insulating tape 4 exceeds end face 12, influences wellability, causes analysis lithium risk.
In order to further increase insulation performance and avoid the damage when entering shell 2 of the first insulating tape 4, secondary cell is also wrapped The protection component 6 being located inside shell 2 is included, protection component 6 can be looped around the outside of electrode assembly 1 and the first insulating tape 4, will Electrode assembly 1 separates with shell 2 and separates 1 first insulating tape 4 of electrode assembly with shell 2.Protection component 6 generally circumscribes one The cavity of rectangle, and electrode assembly 1 and the first insulating tape 4 are housed in the cavity and are surrounded by protection component 6.Specifically, It is first before electrode assembly 1 and the first insulating tape 4 being bonded on electrode assembly 1 are put into shell 2 in step (iv) To first component 6 be protected to be looped around the outside of electrode assembly 1 and the first insulating tape 4, it then will protection component 6, electrode assembly 1 and the One insulating tape 4 is put into togerther inside shell 2, finally welds shell 2 and the lamina tecti 31 of cap assembly 3, realizes the close of shell 2 Envelope.
Referring to Fig. 7, in alternate embodiments, the secondary cell further includes the second insulating tape 5, the second insulating tape 5 to Small part is fitted closely with second surface 14, and the second insulating tape 5 is connected with the first insulating tape 4.First insulating tape 4 and second is exhausted Marginal zone 5 is preferably one-piece member.If without the second insulating tape 5, when pasting the first insulating tape 4, therefore, to assure that first Edge 4c and second edge 4d are flushed with intersecting lens L, more demanding to craft precision;And by the second insulating tape 5 of setting, it can be with First edge 4c and intersecting lens L is allowed to misplace, as long as guaranteeing that intersecting lens L is covered by the first insulating tape 4 or the second insulating tape 5 Lid, to simplify the technique for sticking of insulating tape.

Claims (11)

1. a kind of secondary cell, which is characterized in that including electrode assembly (1), shell (2), cap assembly (3) and the first insulating tape (4);
Electrode assembly (1) includes one or more electrode units (11), and electrode unit (11) has anode pole piece (111), cathode Pole piece (112) and the diaphragm (113) being set between anode pole piece (111), cathode pole piece (112), electrode unit (11) are volume Wound structure and to be flat, the cathode pole piece (112) of the outmost turns of electrode unit (11) is located at the anode pole piece of outmost turns (111) outside;
Shell (2) has the first side wall (21) and accommodating chamber (22), and electrode assembly (1) is contained in accommodating chamber (22), shell (2) and Anode pole piece (111) electrical connection, cap assembly (3) are sealedly attached to shell (2);
First insulating tape (4) is located between electrode assembly (1) and the first side wall (21), and tight with the outer surface of electrode assembly (1) Closely connected conjunction.
2. secondary cell according to claim 1, which is characterized in that
Cathode pole piece (112) includes that negative current collector (112c) and the cathode coated on two surfaces negative current collector (112c) are lived Property material layer (112d);
Along the length direction (Z) for the wireline reel for being parallel to electrode unit (11), the end of the first insulating tape (4) exceeds negative electrode active Material layer (112d).
3. secondary cell according to claim 2, which is characterized in that electrode assembly (1) is opposite with (Z) along its length Two end faces (12) being arranged, the end of the first insulating tape (4) is without departing from end face (12).
4. secondary cell according to claim 1, which is characterized in that the first insulating tape (4) includes matrix (41) and bonding Layer (42), matrix (41) are pasted on the outer surface of electrode assembly (1) by adhesive layer (42).
5. secondary cell according to claim 4, which is characterized in that matrix (41) with a thickness of 10 μm~50 μm, elasticity Modulus is 1Gpa~6Gpa.
6. secondary cell according to claim 4, which is characterized in that adhesive layer (42) with a thickness of 0.5 μm~15 μm, glue The adhesive strength for connecing layer (42) is greater than 0.05N/mm2
7. secondary cell according to claim 1, which is characterized in that secondary cell further includes internal positioned at shell (2) It protects component (6), protection component (6) separates electrode assembly (1), the first insulating tape (4) and shell (2).
8. described in any item secondary cells according to claim 1~7, which is characterized in that
The outer surface of electrode assembly (1) includes first surface (13) and second surface (14), first surface (13) be burnishing surface simultaneously And it is located at the end of electrode assembly (1) through-thickness (Y), second surface (14) is connected to first surface (13) and is located at electricity The end of pole component (1) (X) in the width direction;
The first side wall (21) is located at side of electrode assembly (1) through-thickness (Y) close to first surface (13), the first insulating tape (4) between first surface (13) and the first side wall (21).
9. secondary cell according to claim 8, which is characterized in that the secondary cell further includes the second insulating tape (5), Second insulating tape (5) is at least partly fitted closely with second surface (14), and the second insulating tape (5) and the first insulating tape (4) It is integrally formed.
10. secondary cell according to claim 8, which is characterized in that the area and first surface of the first insulating tape (4) (13) area ratio is 75%~95%.
11. secondary cell according to claim 8, which is characterized in that electrode unit (11) is multiple and through-thickness (Y) arrange, each electrode unit (11) in the width direction (X) end have leptoprosopy (11a), second surface (14) includes each electrode The leptoprosopy (11a) of unit (11).
CN201920265229.6U 2019-03-01 2019-03-01 Secondary cell Active CN209401784U (en)

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JP2021550680A JP7374204B2 (en) 2019-03-01 2020-02-26 secondary battery

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110190340A (en) * 2019-03-01 2019-08-30 青海时代新能源科技有限公司 Secondary cell
WO2020177599A1 (en) * 2019-03-01 2020-09-10 青海时代新能源科技有限公司 Secondary battery
WO2021164594A1 (en) * 2020-02-21 2021-08-26 比亚迪股份有限公司 Battery sequence, battery pack and vehicle
WO2023050969A1 (en) * 2021-09-29 2023-04-06 宁德时代新能源科技股份有限公司 Battery cell, battery and electric apparatus
CN110190340B (en) * 2019-03-01 2024-04-19 青海时代新能源科技有限公司 Secondary battery

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110190340A (en) * 2019-03-01 2019-08-30 青海时代新能源科技有限公司 Secondary cell
WO2020177599A1 (en) * 2019-03-01 2020-09-10 青海时代新能源科技有限公司 Secondary battery
CN110190340B (en) * 2019-03-01 2024-04-19 青海时代新能源科技有限公司 Secondary battery
WO2021164594A1 (en) * 2020-02-21 2021-08-26 比亚迪股份有限公司 Battery sequence, battery pack and vehicle
CN113381098A (en) * 2020-02-21 2021-09-10 比亚迪股份有限公司 Battery sequence, battery package and electric motor car
WO2023050969A1 (en) * 2021-09-29 2023-04-06 宁德时代新能源科技股份有限公司 Battery cell, battery and electric apparatus

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