CN217361647U - Composite current collector, pole piece and lithium battery - Google Patents
Composite current collector, pole piece and lithium battery Download PDFInfo
- Publication number
- CN217361647U CN217361647U CN202221205419.7U CN202221205419U CN217361647U CN 217361647 U CN217361647 U CN 217361647U CN 202221205419 U CN202221205419 U CN 202221205419U CN 217361647 U CN217361647 U CN 217361647U
- Authority
- CN
- China
- Prior art keywords
- current collector
- holes
- composite current
- pole piece
- layer
- 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
Links
Images
Classifications
-
- 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
Landscapes
- Secondary Cells (AREA)
- Cell Electrode Carriers And Collectors (AREA)
Abstract
The utility model provides a compound mass flow body, pole piece and lithium cell, compound mass flow body are including the first conducting layer, fire-retardant layer and the second conducting layer that stack gradually, first conducting layer has and runs through a plurality of first through-holes of first conducting layer, the second conducting layer has and runs through a plurality of second through-holes of second conducting layer, fire-retardant layer is suitable for to be solid-state and be liquid at the second temperature at first temperature, the second temperature is greater than first temperature, the second temperature is 250 ℃ -400 ℃. The composite current collector can avoid combustion or explosion caused by short circuit of the lithium battery, and the safety performance of the lithium battery is improved. Meanwhile, the structural integrity of the lithium battery adopting the composite current collector cannot be damaged due to micro short circuit, so that the lithium battery can be continuously used after the micro short circuit occurs.
Description
Technical Field
The utility model relates to a lithium cell technical field, concretely relates to compound mass flow body, pole piece and lithium cell.
Background
The lithium battery has the advantages of high energy density, no memory effect, environmental friendliness, long cycle life and the like, so that the lithium battery has a very wide application prospect, and is widely applied to the fields of new energy electric vehicles, electronic products, energy storage and the like. At present, a lithium battery is generally detected and regulated by a battery management system and a thermal management system, wherein the battery management system can prevent the battery from being overcharged and/or overdischarged, and the thermal management system can provide a proper temperature for charging and discharging the battery so as to keep the battery in a healthy state.
However, when the lithium battery is short-circuited, the battery management system and the thermal management system cannot resist flame, so that the lithium battery is burnt or exploded, and serious safety accidents are caused.
SUMMERY OF THE UTILITY MODEL
Therefore, the utility model discloses the technical problem who solves lies in how to avoid because the burning or the explosion that the lithium cell short circuit leads to provide a composite current collector, pole piece and lithium cell.
The utility model provides a composite current collector, including first conducting layer, fire-retardant layer and the second conducting layer that stacks gradually, first conducting layer has and runs through a plurality of first through-holes of first conducting layer, the second conducting layer has and runs through a plurality of second through-holes of second conducting layer, fire-retardant layer is suitable for to be solid-state and be liquid at the second temperature at first temperature, the second temperature is greater than first temperature, the second temperature is 200 ℃ -400 ℃.
Optionally, the flame retardant layer is a polymeric flame retardant layer.
Optionally, the flame retardant layer further comprises carbon nanotubes and/or carbon fibers in the polymeric flame retardant layer.
Optionally, the radius of the first through hole is 0.01 μm to 1000 μm; the radius of the second through hole is 0.01-1000 μm.
Optionally, the radii of the plurality of first through holes are the same, and the spacing distance between the central axes of adjacent first through holes is greater than or equal to 4 times of the radius of the first through hole; the radiuses of the second through holes are the same, and the spacing distance between the central axes of the adjacent second through holes is larger than or equal to 4 times of the radius of the second through holes.
Optionally, a plurality of the first through holes are arranged in an array; and the second through holes are arranged in an array.
Optionally, the thickness of the flame retardant layer is greater than that of the first conductive layer, and the thickness of the flame retardant layer is greater than that of the second conductive layer.
Optionally, the thickness of the first conductive layer is 0.015 to 5 μm; the thickness of the second conductive layer is 0.015-5 μm.
The utility model also provides a pole piece, include: the composite current collector; and an active material on the surface of the composite current collector.
The utility model also provides a lithium battery, including positive pole piece and negative pole piece, positive pole piece and/or negative pole piece adopt above-mentioned pole piece.
The utility model discloses technical scheme has following advantage:
1. the utility model provides a compound mass flow body can avoid because the burning or the explosion that the lithium cell short circuit leads to have improved the security performance of lithium cell. Specifically, when a micro short circuit occurs in the lithium battery, the local temperature in the lithium battery rises suddenly, so that active substances on the local surface of the composite current collector are damaged, and the local area of the composite current collector is exposed in the electrolyte; meanwhile, the local area of the composite current collector reaches a second temperature, so that the flame-retardant layer in the local area is converted from a solid state into a liquid state and overflows into the electrolyte through the first through hole and/or the second through hole, the ignition point is reduced, the combustion path of the lithium battery is blocked, the internal temperature of the lithium battery is gradually reduced, and the lithium battery is prevented from being combusted or exploded; after the interior of the lithium battery is cooled to the first temperature, part of the flame-retardant material located in the electrolyte is solidified, and when the lithium battery is subsequently subjected to micro short circuit, the ignition point is reduced, the combustion path of the lithium battery is blocked, and the flame-retardant effect is continuously exerted. In addition, the structural integrity of the lithium battery adopting the composite current collector is not damaged due to micro short circuit, so that the lithium battery can be continuously used after the micro short circuit occurs.
2. The utility model provides a composite current collector, fire-retardant layer is still including being located carbon nanotube and/or carbon fiber in the fire-retardant layer of polymer, carbon nanotube and/or carbon fiber have excellent electric conductivity, and the addition of carbon nanotube and/or carbon fiber has improved composite current collector's electric conductivity to be favorable to improving the circulation stability of lithium cell.
3. The utility model provides a pole piece can avoid because the burning or the explosion that the lithium cell short circuit leads to.
4. The utility model provides a lithium battery, when the inside little short circuit that takes place of lithium cell, can avoid the lithium cell to take place to burn or explode. Meanwhile, the structural integrity of the lithium battery cannot be damaged due to micro short circuit, so that the lithium battery can be continuously used after the micro short circuit occurs.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a composite current collector provided in an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a pole piece according to an embodiment of the present invention;
FIG. 3 is a schematic view of electric field lines between a positive pole piece and a negative pole piece;
FIG. 4 is a schematic diagram of lithium dendrites formed on the negative electrode tab shown in FIG. 3;
description of reference numerals:
1-a first conductive layer; 11-a first via; 11' -a first via hole; 2-a flame retardant layer; 3-a second conductive layer; 31' -a second through hole; 4-an active substance; 5-negative pole piece; 6-lithium dendrites.
Detailed Description
The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
Referring to fig. 1, the present embodiment provides a composite current collector, including a first conductive layer 1, a flame retardant layer 2, and a second conductive layer 3 stacked in sequence, where the first conductive layer 1 has a plurality of first through holes 11 penetrating through the first conductive layer 1, the second conductive layer 3 has a plurality of second through holes (not shown) penetrating through the second conductive layer 3, the flame retardant layer 2 is suitable for being in a solid state at a first temperature and being in a liquid state at a second temperature, the second temperature is higher than the first temperature, the second temperature is 200 ℃ to 400 ℃, and the first temperature is lower than 250 ℃.
The composite current collector can avoid combustion or explosion caused by short circuit of the lithium battery, and the safety performance of the lithium battery is improved. Specifically, when a micro short circuit occurs in the lithium battery, the local temperature in the lithium battery rises suddenly, so that active substances on the local surface of the composite current collector are damaged, and the local area of the composite current collector is exposed in the electrolyte; meanwhile, the local area of the composite current collector reaches a second temperature, so that the flame-retardant layer 2 in the local area is converted from a solid state into a liquid state and overflows into the electrolyte through the first through hole 11 and/or the second through hole, the ignition point is reduced, the combustion path of the lithium battery is blocked, the internal temperature of the lithium battery is gradually reduced, and the lithium battery is prevented from being combusted or exploded; after the interior of the lithium battery is cooled to the first temperature, part of the flame-retardant material located in the electrolyte is solidified, and when the lithium battery is subsequently subjected to micro short circuit, the ignition point is reduced, the combustion path of the lithium battery is blocked, and the flame-retardant effect is continuously exerted. In addition, the structural integrity of the lithium battery adopting the composite current collector is not damaged due to micro short circuit, so that the lithium battery can be continuously used after the micro short circuit occurs. The composite current collector is suitable for various battery cores such as soft-package battery cores, square-shell battery cores and cylindrical battery cores, and has high universality.
In this embodiment, the first conductive layer 1 and the second conductive layer 3 are both metal layers. When the composite current collector is a positive current collector, the material of the metal layer includes, but is not limited to, aluminum; when the composite current collector is a negative electrode current collector, the material of the metal layer includes, but is not limited to, copper.
In this embodiment, the flame retardant layer 2 is a polymeric flame retardant layer. In particular, the material of the polymeric flame retardant layer includes, but is not limited to, polyethylene terephthalate (PET), Polyetheretherketone (PEEK), melamine pyrophosphate (MPP), and epoxy. The polymer flame-retardant layer has high flexibility, and the metal layer has high ductility, so that the composite current collector has a certain buffer space, the volume expansion caused by long-term circulation of the lithium battery can be relieved to a certain extent, and the elastic volume change and the structural stability of the battery pack can be improved. Meanwhile, the density of the polymer flame-retardant layer is low, and the metal layer is provided with the through holes, so that a pole piece with light weight and even a lithium battery can be obtained conveniently, and the energy density of the battery can be improved.
As a preferred embodiment, the flame retardant layer 2 further comprises carbon nanotubes and/or carbon fibers in the polymeric flame retardant layer. The carbon nano tube and/or the carbon fiber have excellent conductivity, and the addition of the carbon nano tube and/or the carbon fiber improves the conductivity of the composite current collector, so that the improvement of the cycle stability of the lithium battery is facilitated. When the local area of the composite current collector reaches the second temperature, the polymer flame-retardant layer in the local area is converted from a solid state to a liquid state, and carbon nanotubes and/or carbon fibers wrapped in the polymer flame-retardant layer are overflowed to the electrolyte from the first through hole 11 and/or the second through hole.
In the present embodiment, the shape of the first through hole 11 and the second through hole includes, but is not limited to, a circle. The dimensions of the first through hole 11 and the second through hole will be described below by taking the example that the first through hole 11 and the second through hole are both circular through holes. In one embodiment, the first and second through holes 11 and 11 each have a radius of 0.01 μm to 1000 μm. Illustratively, the radius of the first via 11 may be 0.01 μm, 0.1 μm, 1 μm, 5 μm, 10 μm, 50 μm, 100 μm, 250 μm, 500 μm, 750 μm, or 1000 μm; the radius of the second via may be 0.01 μm, 0.1 μm, 1 μm, 5 μm, 10 μm, 50 μm, 100 μm, 250 μm, 500 μm, 750 μm, or 1000 μm. Preferably, the radius of each of the first through hole 11 and the second through hole is 0.1 μm to 1000 μm. The radii of the first through hole 11 and the second through hole may be the same or different.
Furthermore, the radiuses of the plurality of first through holes 11 are the same, and the spacing distance R between the central axes of the adjacent first through holes 11 is greater than or equal to 4 times of the radius of the first through holes 11; the radiuses of the second through holes are the same, and the spacing distance between the central axes of the adjacent second through holes is larger than or equal to 4 times of the radius of the second through holes. By performing the above definition to control the density of the first through holes 11 in the first conductive layer 1 and the density of the second through holes in the second conductive layer 3, the conductivity of the first conductive layer 1, the second conductive layer 3 and even the composite current collector is ensured. Preferably, the distance between the central axes of the adjacent first through holes 11 is greater than or equal to 4 times to 50 times of the radius of the first through holes 11, and the distance between the central axes of the adjacent second through holes is greater than or equal to 4 times to 50 times of the radius of the second through holes.
In one embodiment, a plurality of the first through holes 11 are arranged in an array; and the second through holes are arranged in an array. The arrangement of the first through holes 11 and the second through holes may be the same or different. The first through hole 11 and the second through hole may be arranged in other manners.
In the present embodiment, the thickness (D) of the flame retardant layer 2 is greater than the thickness (D) of the first conductive layer 1 1 ) The thickness (D) of the flame-retardant layer 2 is greater than the thickness (D) of the second conductive layer 3 2 ) That is, D.gtoreq.d is satisfied 1 And D is not less than D 2 (ii) a Preferably, D.gtoreq.d 1 +d 2 。
Furthermore, the total thickness of the composite current collector is more than or equal to 2 mu m and less than or equal to 25 mu m, namely d is more than or equal to 2 mu m and less than or equal to 25 mu m 1 +d 2 And the + D is less than or equal to 25 mu m, so that the composite current collector is lighter and thinner, and simultaneously keeps certain mechanical strength and has good structural stability. Illustratively, the total thickness of the composite current collector is 2 μm, 5 μm, 7 μm, 10 μm, 12 μm, 15 μm, 17 μm, 20 μm, 22 μm, or 25 μm. Preferably, the total thickness of the composite current collector is greater than or equal to 6 μm and less than or equal to 15 μm, namely, d is less than or equal to 6 μm 1 +d 2 +D≤15μm。
Further, the thickness of the first conductive layer 1 is 0.015 to 5 μm, the thickness of the second conductive layer 3 is 0.015 to 5 μm, and the thickness of the flame retardant layer 2 is 0.5 to 15 μm. Illustratively, the thickness of the first conductive layer 1 may be 0.015 μm, 0.05 μm, 0.1 μm, 0.5 μm, 0.75 μm, 1 μm, 2 μm, 3 μm, 4 μm, or 5 μm; the thickness of the second conductive layer 3 may be 0.015 μm, 0.05 μm, 0.1 μm, 0.5 μm, 0.75 μm, 1 μm, 2 μm, 3 μm, 4 μm, or 5 μm; the thickness of the flame retardant layer 2 may be 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm or 15 μm. Preferably, the thickness of the first conductive layer 1 is 0.1 to 3 μm, and the thickness of the second conductive layer 3 is 0.1 to 3 μm. The thickness of first conductive layer 1 and the thickness of second conductive layer 3 may be the same or different.
Referring to fig. 2, the present embodiment further provides a pole piece, including the composite current collector and an active material 4 located on the surface of the composite current collector, where the active material 4 covers the first conductive layer 1 and the second conductive layer 3 and is filled into the first through hole 11 and the second through hole. The pole piece has all the advantages of the composite current collector, and is not described in detail herein.
The embodiment also provides a lithium battery, which comprises a positive pole piece, a negative pole piece, a diaphragm and electrolyte, wherein the diaphragm and the electrolyte are positioned between the positive pole piece and the negative pole piece, and the positive pole piece and/or the negative pole piece adopt the pole pieces. The lithium battery has all the advantages of the pole piece, and the description is omitted.
As a preferred embodiment, referring to fig. 3, the positive electrode sheet and the negative electrode sheet are both the above-mentioned sheets, the second conductive layer in the positive electrode sheet faces the first conductive layer in the negative electrode sheet, and the second through hole 31 'in the positive electrode sheet is disposed opposite to the first through hole 11' in the negative electrode sheet.
It is understood that lithium batteries are inevitably subjected to a lithium precipitation reaction after improper use or long-term cycling to generate lithium dendrites, i.e., lithium ions migrate from the positive electrode plate to the negative electrode plate along the direction of an electric field and then deposit on the negative electrode plate. In a lithium battery adopting a conventional current collector, the electric field direction of the lithium battery is perpendicular to the negative pole piece, so that the growth direction of lithium dendrites is perpendicular to the negative pole piece, and the lithium dendrites easily pierce through a diaphragm to cause short circuit of the battery. Referring to fig. 3 to fig. 4, in the lithium battery provided in this embodiment, the direction of the electric field is bent at a side surface close to the negative electrode plate 5, which affects the growth direction of the lithium dendrite 6, so that the lithium dendrite 6 grows transversely on the surface of the negative electrode plate 5, which reduces the probability that the lithium dendrite 6 pierces the separator, that is, reduces the probability that the lithium battery is short-circuited, and improves the safety performance of the lithium battery.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications can be made without departing from the scope of the invention.
Claims (10)
1. The utility model provides a compound mass flow body which characterized in that, includes first conducting layer, fire-retardant layer and the second conducting layer that stacks gradually, first conducting layer has a plurality of first through-holes that run through first conducting layer, the second conducting layer has a plurality of second through-holes that run through the second conducting layer, fire-retardant layer is suitable for to be solid-state and be liquid at the second temperature at first temperature, the second temperature is greater than first temperature, the second temperature is 200 ℃ -400 ℃.
2. The composite current collector of claim 1, wherein the flame retardant layer is a polymeric flame retardant layer.
3. The composite current collector of claim 2, wherein the flame retardant layer further comprises carbon nanotubes and/or carbon fibers in the polymeric flame retardant layer.
4. The composite current collector of claim 1, wherein the radius of the first through hole is 0.01 μ ι η to 1000 μ ι η; the radius of the second through hole is 0.01-1000 μm.
5. The composite current collector of claim 4, wherein the radii of a number of the first through holes are the same, and the distance separating the central axes of adjacent first through holes is greater than or equal to 4 times the radius of the first through holes; the radiuses of the second through holes are the same, and the spacing distance between the central axes of the adjacent second through holes is larger than or equal to 4 times of the radius of the second through holes.
6. The composite current collector of claim 4 or 5, wherein the first plurality of vias are arranged in an array; and the second through holes are arranged in an array.
7. The composite current collector of any one of claims 1 to 3, wherein the thickness of the flame retardant layer is greater than the thickness of the first electrically conductive layer and the thickness of the flame retardant layer is greater than the thickness of the second electrically conductive layer.
8. The composite current collector of claim 1, wherein the thickness of the first conductive layer is 0.015 μ ι η to 5 μ ι η; the thickness of the second conductive layer is 0.015-5 microns.
9. A pole piece, comprising:
a composite current collector as claimed in any one of claims 1 to 8;
and the active material is positioned on the surface of the composite current collector.
10. A lithium battery, characterized in that, it includes the positive pole piece and the negative pole piece, the positive pole piece and/or the negative pole piece adopts the pole piece of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221205419.7U CN217361647U (en) | 2022-05-17 | 2022-05-17 | Composite current collector, pole piece and lithium battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221205419.7U CN217361647U (en) | 2022-05-17 | 2022-05-17 | Composite current collector, pole piece and lithium battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217361647U true CN217361647U (en) | 2022-09-02 |
Family
ID=83013467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221205419.7U Active CN217361647U (en) | 2022-05-17 | 2022-05-17 | Composite current collector, pole piece and lithium battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217361647U (en) |
-
2022
- 2022-05-17 CN CN202221205419.7U patent/CN217361647U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20200168888A1 (en) | Three-dimensional battery having current-reducing devices corresponding to electrodes | |
| KR101057869B1 (en) | Battery pack, battery manufacturing method and vehicle with battery pack | |
| US8124276B2 (en) | Battery structure, assembled battery, and vehicle mounting these thereon | |
| US20130177787A1 (en) | Current collector and nonaqueous secondary battery | |
| KR100846913B1 (en) | Winding assembly type lithium ion secondary power batteries | |
| JPH11238528A (en) | Lithium secondary battery | |
| US20130004827A1 (en) | Nonaqueous electrolyte secondary battery | |
| JP2020024922A (en) | Horizontal composite power-feeding structure | |
| CN216120659U (en) | Current collector, electrode plate, electrode assembly, single battery, battery and electric device | |
| JP2011009182A (en) | Unit cell for secondary battery equipped with conductive sheet layer and lithium ion secondary battery using the same | |
| KR20190005296A (en) | Pouch-Type Secondary Battery Having Electrode Lead with Couple Notch | |
| KR20230042267A (en) | Electrode and its manufacturing method, battery and electric device | |
| CN217361647U (en) | Composite current collector, pole piece and lithium battery | |
| KR102278443B1 (en) | Rechargeable battery | |
| AU2021101083A4 (en) | Multiaxial Electricity Supply System | |
| JP4439870B2 (en) | Nonaqueous electrolyte secondary battery | |
| KR20140072794A (en) | Non-aqueous electrolyte rechargeable battery pack | |
| KR20140145502A (en) | Secondary battery and battery pack including the same | |
| KR20180043571A (en) | Secondary battery | |
| CN108140877B (en) | Secondary battery | |
| JP4594478B2 (en) | Non-aqueous secondary battery | |
| JP6629710B2 (en) | Battery pack | |
| KR102101428B1 (en) | An electrode assembly with enhanced heat emission properties | |
| CN221427804U (en) | Lithium secondary battery | |
| US20240088535A1 (en) | Secondary battery cell |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |