CN114566769A - Electrochemical device, battery module, and electric device - Google Patents
Electrochemical device, battery module, and electric device Download PDFInfo
- Publication number
- CN114566769A CN114566769A CN202210188280.8A CN202210188280A CN114566769A CN 114566769 A CN114566769 A CN 114566769A CN 202210188280 A CN202210188280 A CN 202210188280A CN 114566769 A CN114566769 A CN 114566769A
- Authority
- CN
- China
- Prior art keywords
- tab
- electrochemical device
- width
- battery module
- electrode assembly
- 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.)
- Granted
Links
- 238000005452 bending Methods 0.000 claims abstract description 14
- 239000003292 glue Substances 0.000 claims description 17
- 230000003064 anti-oxidating effect Effects 0.000 claims 1
- 239000000463 material Substances 0.000 description 8
- 238000003466 welding Methods 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 238000004806 packaging method and process Methods 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 239000013543 active substance Substances 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 102100037651 AP-2 complex subunit sigma Human genes 0.000 description 3
- 101000806914 Homo sapiens AP-2 complex subunit sigma Proteins 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 238000009434 installation Methods 0.000 description 3
- 229910052744 lithium Inorganic materials 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000012546 transfer Methods 0.000 description 3
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 229910001416 lithium ion Inorganic materials 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 239000002985 plastic film Substances 0.000 description 2
- 229920006255 plastic film Polymers 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000007773 negative electrode material Substances 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
Images
Classifications
-
- 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
- H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
- H01M50/204—Racks, modules or packs for multiple batteries or multiple cells
-
- 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
- H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
- H01M50/244—Secondary casings; Racks; Suspension devices; Carrying devices; Holders characterised by their mounting method
-
- 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
- H01M50/502—Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside a battery casing
- H01M50/503—Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside a battery casing characterised by the shape of the interconnectors
-
- 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
- H01M50/528—Fixed electrical connections, i.e. not intended for disconnection
-
- 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
Abstract
The application discloses electrochemical device, battery module and consumer. The electrochemical device comprises a shell, an electrode assembly and a tab, wherein the electrode assembly is contained in the shell, the tab comprises a first part and a second part, the first part is contained in the shell, one end of the first part is connected to the electrode assembly, the other end of the first part is connected to the second part, the second part extends out of the shell, the second part is used for being electrically communicated with the outside, the width of the second part is smaller than that of the first part along a first direction, and the bending resistance of the second part is 20N-300N. The bending resistance of the second part is limited within the numerical range, so that the second part has better flexibility and better mechanical strength, the tab can be prevented from being torn when being impacted or pulled by the outside, and the yield of the electrochemical device is improved.
Description
Technical Field
The present application relates to the field of battery technologies, and in particular, to an electrochemical device, a battery module, and an electric device.
Background
The tab is used as a metal conductor leading out the positive electrode and the negative electrode from the electrochemical device and is a contact point of the positive electrode and the negative electrode during charging and discharging. The existing tab is usually reserved with a certain length so as to be capable of communicating with the outside world in the processes of shipment transportation of the electrochemical device, tab punching test and vibration and impact test of the electrochemical device at the later stage. However, the tabs are easily bent by external impact during shipment and transportation of the electrochemical device, and then easily broken.
Disclosure of Invention
An object of the present application is to provide an electrochemical device in which the tab is easily broken.
An electrochemical device includes a case, an electrode assembly, and tabs. The electrode assembly is received in the case. The tab includes a first portion and a second portion. One end of the first portion is connected to the electrode assembly, and the other end of the first portion is connected to the second portion, which protrudes outside the case, for electrical conduction with the outside. The width of the second portion is smaller than the width of the first portion along the first direction. And the second portion has a bending resistance of 20N-300N. Wherein the first direction, the thickness direction of the electrode assembly, and the protruding direction of the second portion are perpendicular to each other two by two. The bending strength of the second part is limited within the numerical range, so that the second part has better flexibility and better mechanical strength, the situation that the tab fails due to bending when being impacted by the outside can be improved, and the yield of the electrochemical device is improved.
In some optional embodiments, a thickness direction of the electrode assembly is referred to as a second direction, and a ratio of a width of the second portion in the first direction to a thickness of the second portion in the second direction is 0.5 to 20. The width-thickness ratio of the second part is limited within the numerical range, so that the second part is approximately linear, the contact area of the second part and the external impact is reduced, and the situation that the second part is easy to break when being subjected to the external impact is improved.
In some optional embodiments, a ratio of a width of the first portion in the first direction to a thickness of the first portion in the second direction is 10-500. The width-thickness ratio of the first part is limited within the numerical range, and the thickness of the first part of the tab metal strip is reduced during installation under the condition that the current carrying capacity of the first part is not changed, so that the energy density of the electrochemical device is improved.
In some optional embodiments, the extending direction of the second portion is referred to as a third direction, and the tab further includes a third portion connected between the other end of the first portion and the second portion along the third direction. The third portion may be a transition portion between the first portion and the second portion of the tab to facilitate the manufacturing process of the tab.
In some optional embodiments, along the third direction, a width of the third portion along the first direction gradually decreases. So set up for the first portion and the second part of utmost point ear can evenly pass through, further reduce the manufacturing degree of difficulty of utmost point ear.
In some optional embodiments, the tab further comprises a tab glue, the tab glue being connected between the housing and the third portion. The relative movement of the third part at each position after the pole lug glue is coated can be prevented, so that the situation of generating gaps and bubbles between pole lug metal strips is improved.
In some optional embodiments, the surface of the second portion is formed with an oxidation resistant layer, so that the second portion of the tab has good oxidation resistance, thereby improving the connection stability of the second portion with the outside.
Another object of the present application is to provide a battery module, which improves the situation of easily generating debris during the welding process of the tab and the electrical connection sheet.
The application also provides a battery module, which comprises a battery frame, an electric connecting sheet and the electrochemical device, wherein the electric connecting sheet is fixed on the battery frame, the electric connecting sheet is provided with a binding post, the electrochemical device is contained in the battery frame, and the second part of the tab is wound and fixed on the binding post. Through the mode, the welding assembly process can be omitted, and the risk that chips generated when the tabs and the connecting sheets are welded are easy to be embedded into the gap between the electrochemical device and the battery frame to cause the housing of the electrochemical device to be punctured is improved.
In some optional embodiments, the battery module further includes a nut. The nut is fixed on the binding post in a threaded manner, and the second part is clamped between the nut and the binding post.
Another object of the present application is to provide an electric device including a load and the battery module as described above, the load being electrically connected to the battery module.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and it is obvious for a person skilled in the art to obtain other drawings based on the drawings without any creative effort.
Fig. 1 is a schematic diagram of an electrical device according to an embodiment of the present disclosure;
fig. 2 is a sectional view of a battery module in the electric device shown in fig. 1;
fig. 3 is a schematic view illustrating the structure of an electrochemical device included in the battery module shown in fig. 2;
fig. 4 is a schematic structural view of another electrochemical device in the battery module shown in fig. 2;
fig. 5 is a schematic structural diagram of a battery frame in the electric device shown in fig. 2.
Detailed Description
In order to facilitate an understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is referred to as being "fixed to" or "affixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present. The terms "vertical," "horizontal," "left," "right," "inner," "outer," and the like as used herein are for purposes of description only.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
The battery module 1 disclosed in the embodiment of the present application is suitable for various electric devices using the battery module 1, so that the risk of the electrochemical device 30 in the battery module 1 being punctured can be reduced, and the mechanical safety performance of the battery module 1 can be improved.
Referring to an example shown in fig. 1, fig. 1 is a schematic view of an electric device according to an embodiment of the present disclosure, where the electric device includes a battery module 1 and a load 2, the battery module 1 is electrically connected to the load 2, and the battery module 1 is used for providing electric energy for the load 2. In some application scenarios, the electric device may include a power mechanism formed by the battery module 1 and the driving motor, and other types of power mechanisms such as an engine, and the electric device may provide driving force for the load 2 of the electric device by using electric energy and other energy sources (e.g., mechanical energy), for example, the electric device may be a vehicle, a ship, a small airplane, and the like. In other application scenarios, the electric device may only include a power mechanism consisting of a battery pack and a driving motor, and the electric energy is used to provide all driving force for the load 2 of the electric device. For example, the electric device may be a pure electric vehicle, a hybrid electric vehicle, an extended range vehicle, an electric tricycle, or a two-wheeled electric vehicle.
Referring to the example shown in fig. 2, fig. 2 is a cross-sectional view of a battery module 1 according to an embodiment of the present disclosure, where the battery module 1 includes a battery frame 10, an electrical connection sheet 20, and an electrochemical device 30, the electrochemical device 30 is accommodated in the battery frame 10, the electrical connection sheet 20 is fixed to the battery frame 10, and the electrochemical device 30 is electrically connected to the electrical connection sheet 20 to form a positive electrode or a negative electrode of the battery module 1.
In order to be able to describe the orientations clearly in the following, the directions are defined by using the coordinate system in fig. 2. Wherein the coordinate axis X represents a first direction parallel to the plane of the electrode assembly 32, and in some embodiments, the width direction of the tabs of the electrochemical device 30. In some embodiments of the present application, there is also a relative arrangement direction of the third side plate 123 and the fourth side plate 124 of the battery frame 10. The coordinate axis Y represents a second direction perpendicular to the plane of the electrode assembly, and in some embodiments, the thickness direction of the electrode assembly 32. In some embodiments of the present application, the arrangement direction of each electrochemical device 30 in the battery module 1 is also. Which is the relative arrangement direction of the first side plate 121 and the second side plate 122 of the battery frame 10. The coordinate axis Z represents a third direction parallel to the plane of the electrode assembly, and in some embodiments, the extending direction of the tabs of the electrochemical device. In some embodiments of the present application, the relative arrangement direction of the first and second support plates 111 and 112 of the battery frame 10. Any two of the third direction Z, the second direction Y and the first direction X are vertical to each other.
Based on the above orientation definitions, the following description will explain specific configurations of the battery frame 10, the electrical connection sheet 20, and the electrochemical device 30, with reference to the illustrated embodiments. And the terms "upper", "lower", "top", "bottom", and the like used below represent orientation or positional relationships, all with respect to the third direction Z. It should be noted that the technical features mentioned in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.
With the above-described cell frame 10, the cell frame 10 serves to accommodate all the electrochemical devices 30 in the battery module 1 while the power supply tab 20 is mounted. The cell frame 10 serves as a mounting support structure for the respective electrochemical devices 30 and protects the respective electrochemical devices 30. Referring to fig. 5 in conjunction with fig. 2, the battery frame 10 is substantially rectangular. The battery frame 10 includes a support plate 11 and side plates 12, and the side plates 12 are attached to the periphery of the support plate 11, so that the battery frame 10 has a cavity for receiving the electrochemical device 30. It is understood that the shape of the battery frame 10 is not limited to a rectangular parallelepiped shape, and may be, for example, a circular shape or other regular shapes, and the specific shape may be provided according to the shape of the electrochemical device 30.
Specifically, the support plate 11 includes a first support plate 111 and a second support plate 112, the first support plate 111 may serve as a bottom plate for supporting the electrochemical device 30, and the second support plate 112 may serve as a top plate for supporting the electrical connection sheet 20. The side plates 12 include a first side plate 121, a second side plate 122, a third side plate 123 and a fourth side plate 124, the first side plate 121, the second side plate 122, the third side plate 123 and the fourth side plate 124 are sequentially connected end to form a middle frame structure, one side of the middle frame structure along the second direction Y is connected to the first supporting plate 111, the other side of the middle frame structure along the second direction Y is connected to the second supporting plate 112, and the cavity 10a of the battery frame 10 is formed by enclosing. The first side plate 121 and the second side plate 122 are disposed opposite to each other along the second direction Y, and the third side plate 123 and the fourth side plate 124 are disposed opposite to each other along the first direction X.
As for the above-described electrical connection sheet 20, the electrical connection sheet 20 is used to electrically connect different electrochemical devices 30 to achieve series, parallel, or series-parallel connection of the electrochemical devices 30 in the battery module 1. As shown in fig. 2, the electrical connection sheet 20 is substantially rectangular plate-shaped, the electrical connection sheet 20 is fixed to the top plate 112 and extends along the first direction X, the electrical connection sheet 20 is provided with a binding post 21, and the binding post 21 is used for electrically connecting the electrochemical device 30. Wherein the terminal posts 21 protrude from the surface facing the cavity of the battery frame 10. It should be understood that the structural configuration of the electrical connection sheet 20 is not limited thereto, for example, the electrical connection sheet 20 may also be a continuous bending structure or other irregular shapes, and may specifically vary according to the space reserved after the arrangement of other components of the battery module 1. In addition, the connection manner of the electrical connection sheet 20 and the top plate 112 of the battery frame 10 may be various, and is not particularly limited in the embodiment of the present application, for example, the electrical connection sheet 20 may be connected by bonding, screwing, snapping, or integrally connecting, etc.
Alternatively, the electrical connection pads 20 may be made of a conductive material, for example, the electrical connection pads 20 may be conductive copper bars. The electrical connection sheet 20 may also be made of a non-metallic material coated with a conductive coating.
As for the electrochemical device 30 described above, the electrochemical device 30 is a component for generating electric power in the battery module 1. As shown in fig. 3, the electrochemical device 30 is substantially rectangular parallelepiped and includes a case 31, an electrode assembly 32, and tabs 33, the case 31 is fixed to the bottom plate 111 of the battery frame 10, the electrode assembly 32 is accommodated in the case 31, the tabs 33 are connected to the electrode assembly 32, the tabs 33 extend out of the case 31 in the third direction Z, and the portions of the tabs 33 extending out of the case 31 are electrically connected to the electrical connection sheet 20 to electrically communicate with the load 2 of the electric device. It is understood that the fixing manner of the electrochemical device 30 to the battery frame 10 may be various, and the embodiment of the present application is not limited in particular, for example, the casing 31 may be fixed to the bottom plate of the battery frame 10 by using a bolt, a stopper, or other structural members, or one or more of glue, double-sided tape, or a snap structure may be provided on the bottom plate of the battery frame 10 to fix the casing 31 to the bottom plate of the battery frame 10. Of course, the case 31 is not limited to being fixed to the bottom plate of the battery frame 10.
It should be noted that the electrochemical device 30 in the embodiment of the present application includes all devices in which electrochemical reactions are reacted. Illustratively, the electrochemical device 30 includes, but is not limited to, all kinds of primary battery, secondary battery, fuel cell, solar cell, and capacitor (e.g., supercapacitor) electrochemical devices. The electrochemical device 30 may be selected from lithium secondary batteries including, but not limited to, lithium metal secondary batteries, lithium ion secondary batteries, lithium polymer secondary batteries, and lithium ion polymer secondary batteries.
The housing 31 may be a soft package housing 31, for example, the housing 31 may be made of an aluminum-plastic film, and the soft package housing 31 is made of polymers such as an aluminum-plastic film, and has the characteristics of light weight, small thickness, high installation performance, and the like. It is understood that the housing 31 of the electrochemical device is not limited thereto, and for example, the housing 31 may be a hard housing 31 made of aluminum alloy or stainless steel, and may be set according to the structural use requirement of the battery module 1.
The electrode assembly 32 is a component of the electrochemical device 30 for realizing the charge and discharge functions, the electrode assembly 32 can include a positive electrode piece, a negative electrode piece and an isolating membrane separating the positive electrode piece and the negative electrode piece, the positive electrode piece includes a positive electrode current collector and a positive electrode active substance layer coated on the surface of the positive electrode current collector, the positive electrode current collector can be an aluminum foil, and the positive electrode active substance layer can include a ternary material, lithium manganate or lithium iron phosphate. The negative pole piece comprises a negative pole current collector and a negative pole active substance layer coated on the surface of the negative pole current collector, the negative pole current collector can be a copper foil, and the negative pole active substance layer can comprise graphite or silicon. The members of the electrochemical device in the present application are not limited to, for example, the material for the positive electrode active material and the material for the negative electrode active material. Specifically, the electrode assembly 32 may be a wound electrode assembly, i.e., one positive electrode sheet and one negative electrode sheet, and the positive electrode sheet and the negative electrode sheet are both in a band structure. The positive electrode sheet, the separator and the negative electrode sheet are sequentially laminated and wound two or more times to form the wound electrode assembly, which may be flat. Alternatively, the electrode assembly 32 may be a laminated electrode assembly, and specifically, the positive electrode tab is provided in plurality, the negative electrode tab is provided in plurality, the positive electrode tab and the negative electrode tab are alternately laminated in the thickness direction of the electrode assembly 32, and the separator separates the positive electrode tab and the negative electrode tab.
The tab 33 is a metal conductor for leading out the positive electrode and the negative electrode in the electrochemical device 30, the tab 33 includes a first portion 331, a second portion 332 and a tab glue 334, the tab glue 334 is hot-pressed and compounded on the second portion 332, and the tab glue 334 is clamped between the casing 31 and the tab and isolates the inside of the casing 31 from the external environment. The first portion 331 is integrally connected to the second portion 332, and the first portion 331 is a portion where a tab is received in the case 31 of the electrochemical device 30 and connected to the electrode assembly 32. The second portion 332 is a portion where the tab protrudes outside the electrochemical device 30 and is connected to the electrical connection sheet 20. Wherein, the part of the second part 332 of the tab extending out of the housing 31 is wound and fixed on the post 21 of the electrical connection sheet 20.
In the embodiment of the present application, on one hand, since the tab and the terminal post 21 are fixed by winding connection, the assembly process of welding can be omitted, and the situation that debris is easily generated when the tab and the electrical connection sheet 20 are welded is improved, that is, the risk of puncturing the casing 31 of the electrochemical device 30 caused by the debris being embedded into the gap between the electrochemical device 30 and the battery frame 10 is reduced. On the other hand, the winding force applied to the terminal 21 by the tab increases the friction between the tab and the terminal 21, thereby enhancing the connection stability at the joint of the tab and the terminal 21. On the other hand, the tab can be sufficiently attached to the outer peripheral surface of the terminal 21, that is, the contact area between the tab and the terminal 21 is increased, so that the current carrying capacity of the joint of the tab and the terminal 21 is improved.
Wherein the thickness of the first portion 331 in the second direction Y is greater than the thickness of the second portion 332 in the second direction Y. The width w1 of the first portion 331 along the first direction X and the width w2 of the second portion 332 along the first direction X satisfy: w1 > w2 in mm. The calculation formula of the current carrying capacity of the tab 33 shows that the current carrying capacity of the tab 33 is independent of the length of the tab 33 and only dependent on the width and the thickness of the tab 33, so that the current carrying capacities of the first portion 331 and the second portion 332 of the tab can be approximately converged by changing the thickness and the width of the tab 33, the impedance of the tab is further reduced, and the aging of the tab material caused by the heat radiation accumulation generated by the increase of the impedance is improved. The electrochemical device 30 can improve the situation that electrolyte leakage is easy to occur at the packaging position caused by the reduction of the packaging strength of the tab glue 334 and the tab.
The formula of the current carrying capacity of the tab is as follows:
wherein: i is the current carrying capacity of the tab 33;
b is the width of the tab 33 in millimeters;
t is the thickness of the tab 33 in microns;
Po-resistance ratio;
α - -temperature coefficient of resistance;
h- - -heat dissipation coefficient;
t temperature difference between the pole piece temperature and the normal temperature.
Further, a ratio of a width w1 of the first portion 331 along the first direction X to a thickness t1 of the first portion 331 along the second direction Y satisfies: w1/t1 is more than 10 and less than or equal to 500, namely, the first part 331 of the tab is wider and thinner, and the thickness required for installation is reduced under the condition of ensuring that the current carrying capacity of the first part 331 is not changed, so that the energy density of the electrochemical device 30 is improved, and the welding difficulty of the first part 331 and a current collector of a pole piece is reduced due to the fact that the surface area of the first part 331 is increased. Alternatively, the cross-sectional shape of the first portion 331 may be wedge-shaped or waisted, viewed in the third direction Z.
Further, a ratio of the width w2 of the second portion 332 in the first direction X to the thickness t2 of the second portion 332 in the second direction Y satisfies: 0.5 & lt w2/t2 is not more than 20, namely the second part 332 of the tab is narrower and thicker, so that the second part 332 is easy to bend under the condition of ensuring that the current carrying capacity of the second part 332 is not changed, and the assembly difficulty of the second part 332 and the binding post 21 of the electric connecting sheet 20 is further reduced. Alternatively, the cross-sectional shape of the second portion 332 may be rectangular, square, circular, oval or prismatic, viewed in the third direction Z.
Referring to the experimental results in table 1, the tab is evaluated by a three-point bending resistance test method, and the bending resistance f of the second portion 332 of the tab can satisfy: f is more than or equal to 20N and less than 300N. When the bending resistance of the second portion of the tab is less than 20N, for example, 10N, the rate of deformation and fracture of the tab is large. When the bending resistance of the second portion of the tab is greater than 300N, for example, the bending resistance of the second portion of the tab is 400N, the rate of deformation and fracture of the tab at this time is further increased, and the connection failure rate of the second portion of the tab to the module is also further increased. Illustratively, the bending resistance of the second portion 332 of the tab may be 20N, 100N, 200N, or 300N. The bending resistance of the second part of the tab is limited within the range, and besides the deformation and fracture ratio of the tab is reduced, the minimum overcurrent ratio of the second part of the tab is increased, so that the improvement of the electrical performance of the second part of the tab is facilitated. It should be noted that the bending resistance in the embodiment of the present application is a force applied between two support points of the tab until the tab starts to deform.
Further, the surface of the second part of the tab is provided with the oxidation resistant layer, so that the second part of the tab has good oxidation resistance, and the connection stability between the second part and the outside is further improved. For example, the oxidation resistant layer includes at least one of chromium, tin, copper, nickel, aluminum, or a copper-plated nickel alloy.
Further, the first portion 331 of the tab has a first electrical conductivity σ 1, the second portion 332 of the tab has a second electrical conductivity σ 2, and the second electrical conductivity σ 2 and the first electrical conductivity σ 1 satisfy: sigma 2/sigma 1 is more than or equal to 1. The cross section area of the electrode lug and the conductivity sigma/maximum allowable charge and discharge current of the product are more than 20 percent.
In order to improve the connection stability between the electrochemical device 30 and the electrical connection sheet 20, the outer circumferential surface of the terminal 21 is provided with a thread (not shown), optionally, the battery module 1 further includes a nut (not shown), the nut is screwed and fixed with the terminal 21, and the second portion 332 of the electrochemical device 30 is clamped between the terminal 21 and the nut. Further, the outer peripheral surface of the post 21 is annularly provided with a groove (not shown), the shape of the groove is matched with the shape of the second portion 332, and the second portion 332 can be fixed in the groove under the action of the nut. On one hand, the acting force generated when the nut is screwed on the post 21 can be reduced, so that the second portion 332 is not easy to extend, and the resistance of the second portion 332 is further reduced. On the other hand, the surfaces of the second portion 332 are fitted with the grooves, so that the contact area between the second portion 332 and the electrical connection sheet 20 is further increased, and the resistance between the second portion 332 and the electrical connection sheet 20 is smaller and the connection is more reliable.
Optionally, the tab further comprises a third portion 333, the third portion 333 being a transition portion between the first portion 331 and the second portion 332 of the tab. In the third direction Z, a sectional area of the third portion 333 near an end of the first portion 331 gradually decreases to a sectional area of the third portion 333 near an end of the second portion 332. Specifically, the tab glue 334 is disposed on the third portion 333, and the third portion 333 may be encapsulated in the case 31 by the tab glue 334. Further, the width t3 at any position of the third portion 333 along the first direction X satisfies: 0.01: (w1-w2) < t3 < 3
(w1-w 2). Illustratively, 2mm < t3 < 20mm, so that relative movement is not easily generated at each position of the third portion 333 after the tab glue 334 is coated, thereby improving the situation of generating gaps and bubbles between the tabs and improving the sealing performance of the electrochemical device 30. It is understood that the connection position of the tab glue 334 is not limited thereto, and the coating position of the tab glue 334 can be adjusted according to the actual use situation, so that the amount of the tab glue 334 required for encapsulating the tab with the housing 31 is less, and the manufacturing cost of the electrochemical device 30 is more easily saved.
The tab 33 includes a positive tab and a negative tab, the positive tab and the positive current collector of the positive plate can be fixed by transfer welding, and optionally, the material of the positive tab can be an aluminum material. The negative electrode tab 33 and the negative electrode current collector of the negative plate can be welded and fixed through transfer welding, and the material of the negative electrode tab can be copper, nickel or copper nickel-plated material. The arrangement of the positive electrode tab and the negative electrode tab can be various. For example, as shown in fig. 2, the positive and negative electrode tabs are located on the same side of the electrode assembly 32, and the connection lengths of the positive and negative electrode tabs to the terminal posts 21 of the electrical connection sheet 20 are substantially the same, so as to save the manufacturing cost of the battery module 1. Of course, the positive and negative tabs may also extend from opposite sides of the electrode assembly 32.
Alternatively, the tab 33 of each electrochemical device 30 is wound around the terminal post 21 fixed to the electrical connection sheet 20. With continued reference to the example shown in fig. 2, the positive tab 33 of one electrochemical device 30 and the negative tab 33 of another electrochemical device 30 adjacent thereto are wound around the same terminal 21 fixed to the electrical connection sheet 20, i.e., are connected in series between the electrochemical devices 30. It can be understood that, unlike the previous embodiment, the tabs 33 of the electrochemical devices 30 having the same polarity are wound around the same terminal 21 of the electrical connection sheet 20, i.e., the electrochemical devices 30 are connected in parallel, which is advantageous in that the welding process of the tabs 33 of the electrochemical devices 30 to the electrical connection sheet 20 can be reduced, thereby reducing the difficulty in assembling the battery module 1.
For ease of understanding, the assembly process of the battery module 1 is given below: firstly, the tab and the tab glue are hot-pressed and compounded to form an independent structural part. And secondly, fixing the current collector empty foil area on the electrode assembly and the electrode lug through transfer welding, and adjusting the position of the electrode lug to enable the electrode lug to be arranged at the packaging opening of the shell for hot-pressing packaging to form the electrochemical device. And finally, stacking a plurality of electrochemical devices along the second direction Y, wherein the orientations of the electrochemical devices are the same, and adding a battery frame and other structural members to assemble the battery module.
In addition, some examples using the present application scheme and comparative examples not using the present application scheme for comparison of effects are given below.
Comparative example 1
The thickness and the width of the first part and the second part of the tab are the same, the width of the tab is taken as 20mm, the thickness of the tab is taken as 0.2 mm, and the connection goodness and the leakage failure ratio of the packaging of the electrochemical device are tested.
Comparative example 2
The thickness and the width of the first part and the second part of the tab are the same, the width of the tab is taken as 2mm, the thickness of the tab is taken as 0.3 mm, and the connection goodness and the leakage failure ratio of the packaging of the electrochemical device are tested.
Example 1
The thickness and the width of the first part and the second part of the tab are different, the width of the first part of the tab is 0.5 mm, and the thickness of the first part of the tab is 0.5 mm. And (3) measuring the width of the second part of the tab as 20mm and the width of the second part of the tab as 0.2 mm, and testing the connection goodness and leakage failure ratio of the package of the electrochemical device.
Example 2
The thickness and the width of the first part and the second part of the tab are different, the width of the first part of the tab is 1 mm, and the thickness of the first part of the tab is 0.5 mm. And (3) measuring the width of the second part of the tab as 10 mm and the width of the second part of the tab as 0.2 mm, and testing the connection goodness and leakage failure ratio of the package of the electrochemical device.
The results of the experiment are shown in table 2 below:
from the experimental data of the table it can be seen that:
in comparative example 2, the smaller the thickness and width of the tab metal strip, the lower the leakage failure rate of the electrochemical device, and accordingly, the lower the connection goodness of the tab, compared to comparative example 1, while the other structure of the electrochemical device was maintained.
Example 1 compared to comparative example 1, the thickness and width of the first portion of the tab were maintained constant, the thickness and width of the second portion of the metal strip of the tab were decreased, the leakage failure rate of the electrochemical device was greatly reduced, and the connection goodness of the tab was improved. In the present application, the connection goodness of the tab refers to the connection success rate of the tab with the connected component, such as a terminal post. The pole ear is connected with the binding post, and when the current is conducted to the binding post, the pole ear is considered to be successfully connected with the binding post.
In example 2, the width of the first portion of the tab was reduced and the thickness was unchanged, and the width of the second portion of the tab was increased and the thickness was increased, as compared to example 1. The width of the second part of the tab is reduced and the thickness is unchanged, the leakage failure rate of the electrochemical device is further reduced, the tab connection optimal rate is kept unchanged, and the minimum overcurrent ratio of the tab is increased.
The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application or are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.
Claims (10)
1. An electrochemical device comprising a case, an electrode assembly accommodated in the case, and a tab including a first portion accommodated in the case, one end of the first portion being connected to the electrode assembly, the other end of the first portion being connected to the second portion, the second portion protruding outside the case, and a second portion for electrically communicating with the outside, wherein, in a first direction, a width of the second portion is smaller than a width of the first portion, and a bending resistance of the second portion is 20N-300N, wherein the first direction, a thickness direction of the electrode assembly, and a protruding direction of the second portion are perpendicular to each other two by two.
2. The electrochemical device according to claim 1, wherein a thickness direction of the electrode assembly is referred to as a second direction, and a ratio of a width of the second portion in the first direction to a thickness of the second portion in the second direction is 0.5 to 20.
3. The electrochemical device of claim 2, wherein a ratio of a width of said first portion in said first direction to a thickness of said first portion in said second direction is 10-500.
4. The electrochemical device as claimed in any one of claims 1 to 3, wherein the second portion extends in a third direction, and the tab further comprises a third portion connected between the other end of the first portion and the second portion in the third direction.
5. The electrochemical device according to claim 4, wherein along the third direction, a width of the third portion along the first direction is gradually reduced.
6. The electrochemical device of claim 5 wherein said tab further comprises a tab glue, said tab glue coupled between said housing and said third portion.
7. An electrochemical device according to any of claims 1 to 3, wherein the surface of the second portion is formed with an anti-oxidation layer.
8. A battery module comprising a battery frame, an electrical connection sheet secured to the battery frame, the electrical connection sheet being provided with a terminal post, and an electrochemical device as claimed in any one of claims 1 to 7, the electrochemical device being accommodated in the battery frame, the second portion of the tab being wound around and secured to the terminal post.
9. The battery module according to claim 8, further comprising a nut threadedly secured to the terminal post;
the second portion is clamped between the nut and the terminal.
10. An electric device, characterized by comprising a load and the battery module according to claim 8 or 9, the load being electrically connected to the battery module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210188280.8A CN114566769B (en) | 2022-02-28 | 2022-02-28 | Electrochemical device, battery module, and electricity using device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210188280.8A CN114566769B (en) | 2022-02-28 | 2022-02-28 | Electrochemical device, battery module, and electricity using device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114566769A true CN114566769A (en) | 2022-05-31 |
| CN114566769B CN114566769B (en) | 2024-01-19 |
Family
ID=81716533
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210188280.8A Active CN114566769B (en) | 2022-02-28 | 2022-02-28 | Electrochemical device, battery module, and electricity using device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114566769B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003173766A (en) * | 2001-12-04 | 2003-06-20 | Japan Storage Battery Co Ltd | Storage lead battery |
| JP2018133306A (en) * | 2017-02-17 | 2018-08-23 | リチウム エナジー アンド パワー ゲゼルシャフト ミット ベシュレンクテル ハフッング ウント コンパニー コマンディトゲゼルシャフトＬｉｔｈｉｕｍ Ｅｎｅｒｇｙ ａｎｄ Ｐｏｗｅｒ ＧｍｂＨ ＆ Ｃｏ． ＫＧ | Power storage element |
| CN208225978U (en) * | 2018-05-09 | 2018-12-11 | 合肥国轩高科动力能源有限公司 | A kind of lithium battery pole piece structure of anti-lug bending |
| JP2020077527A (en) * | 2018-11-08 | 2020-05-21 | 積水化学工業株式会社 | Storage battery module |
| CN210926142U (en) * | 2019-12-05 | 2020-07-03 | 恒大新能源技术(深圳)有限公司 | Battery with a battery cell |
| CN211017230U (en) * | 2019-12-02 | 2020-07-14 | 宁德时代新能源科技股份有限公司 | Battery cell pole piece and battery cell |
| CN213816367U (en) * | 2020-12-08 | 2021-07-27 | 惠州亿纬创能电池有限公司 | Prevent short circuit utmost point ear and electric core |
-
2022
- 2022-02-28 CN CN202210188280.8A patent/CN114566769B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003173766A (en) * | 2001-12-04 | 2003-06-20 | Japan Storage Battery Co Ltd | Storage lead battery |
| JP2018133306A (en) * | 2017-02-17 | 2018-08-23 | リチウム エナジー アンド パワー ゲゼルシャフト ミット ベシュレンクテル ハフッング ウント コンパニー コマンディトゲゼルシャフトＬｉｔｈｉｕｍ Ｅｎｅｒｇｙ ａｎｄ Ｐｏｗｅｒ ＧｍｂＨ ＆ Ｃｏ． ＫＧ | Power storage element |
| CN208225978U (en) * | 2018-05-09 | 2018-12-11 | 合肥国轩高科动力能源有限公司 | A kind of lithium battery pole piece structure of anti-lug bending |
| JP2020077527A (en) * | 2018-11-08 | 2020-05-21 | 積水化学工業株式会社 | Storage battery module |
| CN211017230U (en) * | 2019-12-02 | 2020-07-14 | 宁德时代新能源科技股份有限公司 | Battery cell pole piece and battery cell |
| CN210926142U (en) * | 2019-12-05 | 2020-07-03 | 恒大新能源技术(深圳)有限公司 | Battery with a battery cell |
| CN213816367U (en) * | 2020-12-08 | 2021-07-27 | 惠州亿纬创能电池有限公司 | Prevent short circuit utmost point ear and electric core |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114566769B (en) | 2024-01-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111048728B (en) | Secondary battery, battery module, and device using secondary battery as power supply | |
| US8623537B2 (en) | Rechargeable battery and battery module | |
| EP2988344B1 (en) | Battery module having novel structure and battery pack comprising same | |
| US8808908B2 (en) | Battery module of novel structure | |
| US9203065B2 (en) | Battery module | |
| US8771863B2 (en) | Battery module and manufacturing method of battery module | |
| EP2846377B1 (en) | Battery assembly having single electrode terminal joint part | |
| EP2779269B1 (en) | Battery cell having a novel structure | |
| EP3678208B1 (en) | Battery module, battery pack, and vehicle | |
| EP3349269B1 (en) | Battery module, and battery pack and vehicle comprising the same | |
| KR20130105596A (en) | Power storage module | |
| JPWO2014002950A1 (en) | Battery pack | |
| EP3675213B1 (en) | A battery pack | |
| US11929510B2 (en) | Secondary battery and manufacturing method thereof, battery module, and apparatus | |
| EP3706192A1 (en) | Battery module and battery pack | |
| KR20220084357A (en) | Secondary batteries, battery modules, and devices using batteries as power | |
| EP2978061B1 (en) | Pouch-type secondary battery and secondary battery module comprising same | |
| KR20120088122A (en) | Battery Cell of Improved Connection Reliability and Battery Module Employed with the Same | |
| KR101051485B1 (en) | Thin battery of novel structure and battery module consisting of | |
| CN114566769B (en) | Electrochemical device, battery module, and electricity using device | |
| KR20080010735A (en) | Safety member for secondary battery having steps-formed end portion at bottom of both sides | |
| KR20220012037A (en) | Battery module having a simple connection structure between cell lead and voltage sensing member and battery pack including the same | |
| CN218827495U (en) | Battery pack | |
| CN115566328B (en) | Electrochemical device and power utilization device | |
| CN218182268U (en) | Battery and battery pack |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |