CN114824441A - Battery core, battery module and battery pack - Google Patents
Battery core, battery module and battery pack Download PDFInfo
- Publication number
- CN114824441A CN114824441A CN202210501600.0A CN202210501600A CN114824441A CN 114824441 A CN114824441 A CN 114824441A CN 202210501600 A CN202210501600 A CN 202210501600A CN 114824441 A CN114824441 A CN 114824441A
- Authority
- CN
- China
- Prior art keywords
- active material
- positive
- current collector
- insulating support
- battery
- 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.)
- Pending
Links
- 239000007774 positive electrode material Substances 0.000 claims abstract description 87
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 84
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 42
- 238000004804 winding Methods 0.000 claims abstract description 16
- 238000010030 laminating Methods 0.000 claims abstract description 5
- 239000002131 composite material Substances 0.000 claims description 27
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 12
- 239000011889 copper foil Substances 0.000 claims description 12
- 239000007773 negative electrode material Substances 0.000 claims description 10
- 239000002245 particle Substances 0.000 claims description 9
- HFCVPDYCRZVZDF-UHFFFAOYSA-N [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O Chemical compound [Li+].[Co+2].[Ni+2].[O-][Mn]([O-])(=O)=O HFCVPDYCRZVZDF-UHFFFAOYSA-N 0.000 claims description 4
- 229920000620 organic polymer Polymers 0.000 claims description 3
- 229920000642 polymer Polymers 0.000 claims description 3
- 239000002861 polymer material Substances 0.000 claims description 3
- 239000003792 electrolyte Substances 0.000 abstract description 7
- 238000012360 testing method Methods 0.000 description 21
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 9
- 229910052782 aluminium Inorganic materials 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- 239000011888 foil Substances 0.000 description 7
- 238000000034 method Methods 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000007600 charging Methods 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000013329 compounding Methods 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 229910003002 lithium salt Inorganic materials 0.000 description 3
- 159000000002 lithium salts Chemical class 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 229920000742 Cotton Polymers 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 229910001416 lithium ion Inorganic materials 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 239000002210 silicon-based material Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- 229910015015 LiAsF 6 Inorganic materials 0.000 description 1
- 229910013063 LiBF 4 Inorganic materials 0.000 description 1
- 229910013684 LiClO 4 Inorganic materials 0.000 description 1
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- 229910012513 LiSbF 6 Inorganic materials 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 229910000572 Lithium Nickel Cobalt Manganese Oxide (NCM) Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- HMDDXIMCDZRSNE-UHFFFAOYSA-N [C].[Si] Chemical compound [C].[Si] HMDDXIMCDZRSNE-UHFFFAOYSA-N 0.000 description 1
- FBDMTTNVIIVBKI-UHFFFAOYSA-N [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] Chemical compound [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] FBDMTTNVIIVBKI-UHFFFAOYSA-N 0.000 description 1
- 238000001467 acupuncture Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 239000002041 carbon nanotube Substances 0.000 description 1
- 229910021393 carbon nanotube Inorganic materials 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 238000010280 constant potential charging Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910021389 graphene Inorganic materials 0.000 description 1
- 239000007770 graphite material Substances 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 238000011900 installation process Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 239000002931 mesocarbon microbead Substances 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910021382 natural graphite Inorganic materials 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 229910021384 soft carbon Inorganic materials 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000011366 tin-based material Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium 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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
Abstract
The invention discloses a battery cell, a battery module and a battery pack, and relates to the technical field of battery cells; the battery comprises a shell, a winding core and electrolyte, wherein the winding core and the electrolyte are arranged in the shell, and the winding core is formed by laminating or winding a positive plate, an isolating film and a negative plate which are arranged in a stacked mode; the positive plate comprises a positive current collector and a nickel-containing positive active material coated on the positive current collector, the positive current collector comprises an insulating support layer and a conductive layer at one side of the insulating support layer, the thickness of the insulating support layer is A, the unit is um, the surface density of the positive active material is G, and the unit is mg/1540.25mm 2 The weight percentage of nickel element in the positive active material is I, and the unit is percent; the thickness A of the insulating supporting layer, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material meet 0.01-100A/(G)I) Less than or equal to 5. The battery cell has the advantages of high energy density and high safety performance.
Description
Technical Field
The invention relates to the technical field of battery cells, in particular to a battery cell, a battery module and a battery pack.
Background
The current positive current collector used by the pole piece of the lithium ion cell is an aluminum foil, and the negative current collector is a copper foil. Copper foil and aluminum foil have excellent conductivity, but when the battery cell is damaged by needling, extrusion and the like, the interior of the battery cell is easy to be short-circuited, so that thermal runaway of the battery cell is caused.
In view of this, the invention is particularly proposed.
Disclosure of Invention
The invention aims to provide a battery cell, a battery module and a battery pack, which are high in energy density and high in safety performance.
Embodiments of the invention may be implemented as follows:
in a first aspect, the present invention provides a battery cell, including:
the winding core is formed by laminating or winding a positive plate, an isolating film and a negative plate which are arranged in a stacked mode; the positive plate comprises a positive current collector and a nickel-containing positive active material coated on the positive current collector, the positive current collector comprises an insulating support layer and a conductive layer composite current collector at one side of the insulating support layer, the thickness of the insulating support layer is A, the unit is um, the surface density of the positive active material is G, and the unit is mg/1540.25mm 2 The weight percentage of nickel element in the positive active material is I, and the unit is percent;
the thickness A of the insulating supporting layer, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material meet 0.01-100A/(G I) -5.
In an alternative embodiment, the thickness a of the insulating support layer, the areal density G of the positive electrode active material, and the weight percentage I of nickel elements in the positive electrode active material satisfy 0.09 ≦ 100 a/(G ≦ I) 2.
In an alternative embodiment, the thickness a of the insulating support layer is in the range of 1-30 um; preferably, the thickness a of the insulating support layer is in the range of 3-15 um.
In an alternative embodiment, the positive electrode active material has an areal density G in the range of 50 to 115mg/1540.25mm 2 (ii) a Preferably, the area density G of the positive electrode active material is in the range of 50-95 mg/1540.25mm 2 。
In an optional embodiment, the weight percentage I of the nickel element in the positive active material is in a range of 30-60%; preferably, the weight percentage I of the nickel element in the positive active material is 30-45%.
In an alternative embodiment, the active particles of the positive electrode active material are lithium nickel cobalt manganese oxide.
In an alternative embodiment, the negative electrode sheet is a copper foil;
or the negative plate comprises a negative current collector and a negative active material coated on the negative current collector, the negative current collector is a composite current collector comprising an insulating support layer and a conducting layer at least arranged on one side of the insulating support layer, the insulating support layer is an organic polymer material layer or a ceramic-doped polymer layer, and the conducting layer is a copper foil layer.
In an alternative embodiment, the composite current collector includes two conductive layers, and the two conductive layers have the same thickness and are respectively disposed on two sides of the insulating support layer.
In a second aspect, the present invention provides a battery module including the battery cell of any one of the foregoing embodiments.
In a third aspect, the present invention provides a battery pack, comprising the battery cell of any one of the foregoing embodiments; alternatively, the battery module of the foregoing embodiment is included.
The embodiment of the invention has at least the following advantages or beneficial effects:
the embodiment of the invention provides a battery cell, which comprises a shell, a winding core and electrolyte, wherein the winding core and the electrolyte are arranged in the shell, and the winding core is formed by laminating or winding a positive plate, an isolating film and a negative plate which are arranged in a stacked mode; the positive plate comprises a positive current collector and a nickel-containing positive active material coated on the positive current collector, the positive current collector comprises an insulating support layer and a conductive layer at least arranged on one side of the insulating support layer, the thickness of the insulating support layer is A, the unit is um, the surface density of the positive active material is G, the unit is mg/1540.25mm 2 The weight percentage of nickel element in the positive active material is I, and the unit is percent; the thickness A of the insulating supporting layer, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material meet 0.01-100A/(G I) -5.
On one hand, the positive current collector of the battery core is a composite current collector which is a composite structure obtained by compounding an insulating support layer and a conducting layer, the weight of the current collector can be reduced, the weight energy density of the battery core is improved, meanwhile, burrs generated by the conducting layer when the current collector is needled are small, the short-circuit resistance is large, the generated heat is small, thermal runaway is not easy to occur, the problem of thermal runaway of the battery core under the condition of internal short circuit can be relieved to a certain extent, and the safety performance of the battery core can be improved; on the other hand, the thermal runaway risk degree of the battery core is in positive correlation with the surface density of the positive electrode active material and the proportion of the nickel element in the positive electrode material, namely, the higher the content of the nickel element is, the worse the stability of the positive electrode active material is, and the more easily the safety accident occurs. However, the degree of the thermal runaway risk of the battery cell is inversely related to the thickness of the insulating layer in the composite base material, so that the energy density of the battery cell can be maximized on the premise of ensuring the safety of the battery cell by limiting the relationship among the thickness a of the insulating support layer, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material.
The embodiment of the invention also provides a battery module and a battery pack, which both comprise the battery core. Therefore, the battery module also has the advantages of high energy density and high safety performance.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
Fig. 1 is a schematic structural diagram of a composite current collector of a battery cell according to an embodiment of the present invention.
Icon: 10-a composite current collector; 111-an insulating support layer; 112-conductive layer.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or the orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements 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," "third," and the like are used solely to distinguish one from another, and are not to be construed as indicating or implying relative importance.
Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are required to be absolutely horizontal or pendant, but rather may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the related art, the positive current collector used for the pole piece of the lithium ion cell is an aluminum foil, and the negative current collector is a copper foil. Copper foil and aluminum foil have excellent conductivity, but when the battery cell is damaged by needling, extrusion and the like, the interior of the battery cell is easy to be short-circuited, so that thermal runaway of the battery cell is caused.
In view of this, the embodiment of the present invention provides an electrical core in which a composite current collector is used as a positive plate, and a relationship among a thickness a of an insulating support layer, an area density G of a positive active material, and a weight percentage I of a nickel element in the positive active material is defined, so that the energy density of the electrical core can be effectively improved while the safety of the electrical core is ensured. The structure and performance of the cell will be described in detail below.
Fig. 1 is a schematic structural diagram of a composite current collector 10 of a battery cell according to an embodiment of the present invention. The battery cell provided by the embodiment comprises a shell, a winding core and electrolyte. The shell is an aluminum shell, the winding core and electrolyte are arranged in the shell, the winding core is formed by laminating a positive plate, an isolation film (made of PE and/or PP materials) and a negative plate which are arranged in a stacking mode or winding, the positive plate is connected with a positive tab, the negative plate is connected with a negative tab, a positive post and a negative post are arranged on the shell, the positive tab is electrically connected with the positive post (for example, welding), and the negative post is electrically connected with the negative tab (for example, welding) so as to guarantee normal operation of charge and discharge of the battery core.
Meanwhile, in the embodiment of the present invention, both the positive electrode tab and the negative electrode tab have the composite structure shown in fig. 1. The positive plate comprises a positive current collector and a positive active material coated on the positive current collector, active particles of the positive active material can be selected from nickel-containing positive materials, for example, the active particles of the positive active material can be selected from nickel-cobalt lithium manganate (ternary lithium), the negative plate comprises a negative current collector and a negative active material coated on the negative current collector, and the negative active material can be selected from graphite, graphene, titanium-based materials, tin-based materials, silicon-based materials or nitride materials. Of course, in other embodiments, only the positive electrode current collector of the positive electrode tab may be set as the composite current collector, and only the negative electrode tab may be set as the copper foil layer, which is not limited in this embodiment.
Also, in the embodiment of the present invention, the composite current collector 10, whether it is a positive electrode tab or a negative electrode tab, includes an insulating support layer 111 and two conductive layers 112 respectively disposed on both sides of the insulating support layer 111. In other embodiments, only one conductive layer 112 may be disposed on the insulating support layer 111, and thus, this embodiment is not described again.
Meanwhile, the thicknesses of the insulating support layers 111 of the positive plate and the negative plate can be selected to be the same or different, in the embodiment of the present invention, the thicknesses of the insulating support layers can be set to be the same, and both are a, and the unit is um, and the micrometer is adopted to measure the thicknesses. The thicknesses of the two conductive layers 112 of the positive electrode tab and the negative electrode tab can be set to be the same or different, and the two conductive layers can be set to be the same and can also be measured by a micrometer according to an embodiment of the present invention. The thickness of the positive active material layer obtained by rolling after the positive active material is coated on the positive current collector can be between 40 and 120 micrometers, and the thickness of the negative active material layer obtained by rolling after the negative active material is coated on the negative current collector can be between 70 and 160 micrometers, and can be measured by a micrometer. And no matter whether the thicknesses of the insulating support layer 111 and the conductive layer 112 of the positive and negative electrode plates are the same or not, in the embodiment of the invention, the surface density of the positive electrode active material is G, and the unit is mg/1540.25mm 2 The weight percentage of nickel element in the positive electrode active material is I, and the unit is%. The thickness A of the insulating support layer 111, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material satisfy 0.01-100A/(G I) -5.
On one hand, the positive current collector of the battery cell is a composite current collector 10, the composite current collector 10 is a composite structure obtained by compounding an insulating support layer 111 and a conductive layer 112, the weight of the current collector can be reduced, the weight energy density of the battery cell is improved, burrs generated by the conductive layer 112 when the current collector is needled are small, the short-circuit resistance is large, the generated heat is small, thermal runaway is not easy to occur, the problem of thermal runaway of the battery cell under the condition of internal short circuit can be relieved to a certain extent, and the safety performance of the battery cell can be improved; on the other hand, the thermal runaway risk degree of the battery core is in positive correlation with the surface density of the positive electrode active material and the proportion of the nickel element in the positive electrode material, namely, the higher the content of the nickel element is, the worse the stability of the positive electrode active material is, and the more easily the safety accident occurs. However, the degree of the thermal runaway risk of the battery cell is inversely related to the thickness of the insulating layer in the composite substrate, so that the energy density of the battery cell can be maximized on the premise of ensuring the safety of the battery cell by limiting the relationship among the thickness a of the insulating support layer 111, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material.
It should be noted that in other embodiments of the present invention, the cell type may be a square aluminum case, a soft bag, a lamination, a cylinder, and the materials of the insulating support layer 111 of the positive and negative current collectors may be all selected from organic polymer materials (such as PET materials) or ceramic-doped polymers. The conductive layer 112 of the positive current collector may be selected to be an aluminum foil layer. The conductive layer 112 of the negative electrode collector may be selected to be a copper foil layer. Meanwhile, the positive electrode active material layer and the negative electrode active material layer are both prepared by mixing active particles (the active particles of the positive electrode active material are nickel cobalt lithium manganate, and the active particles of the negative electrode active material are graphite), a conductive agent (such as carbon black, carbon nanotubes and the like), a binder (such as styrene butadiene rubber, PVDF and the like) and other auxiliaries.
It should be further noted that, in the embodiment of the present invention, a square aluminum-shell battery cell is selected; the test method of the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material adopts an IPC element analysis method to test, and the test equipment can be selected to be IPC-OES. Specifically, when the surface density test is carried out, a battery core pole piece with a specified area can be taken at normal temperature, a punching machine is adopted to punch a round hole on the pole piece, and the area of the round hole is 1540.25mm 2 Then, the mass m1 was weighed by an electronic balance, the current collector was punched in the same manner, the mass m2 was weighed by an electronic balance, and the areal density was obtained by the formula (m1-m 2)/1540.25.
Optionally, in the present embodiment, the thickness a of the insulating support layer 111, the areal density G of the positive electrode active material, and the weight percentage I of the nickel element in the positive electrode active material satisfy 0.09 ≤ 100 × a/(G × I) ≤ 2. The selection relation among the thickness A of the insulating support layer 111, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material is controlled within the range, so that the energy density can be maximized while the safety of the battery cell is ensured.
Further optionally, the thickness a of the insulating support layer 111 ranges from 1-30 um; preferably, the thickness a of the insulating support layer 111 ranges from 3 to 15 um. The thickness of the insulating supporting layer 111 is controlled within the range, so that the thickness of the conducting layer 112 can be set to be 0.03-3um, the thickness of the conducting layer 112 is relatively thin, burrs generated by the conducting layer 112 when the conducting layer is needled are small, short-circuit resistance is large, generated heat is small, thermal runaway cannot occur easily, the thermal runaway problem of the electric core under the condition of internal short circuit can be relieved to a certain degree, and the safety performance of the electric core can be improved.
The surface density G of the positive electrode active material is 50-115 mg/1540.25mm 2 (ii) a Preferably, the area density G of the positive electrode active material is in the range of 50-95 mg/1540.25mm 2 . By controlling the area density G of the positive electrode active material within this range, the energy density of the cell can be increased while ensuring the safety of the cell.
The weight percentage I of the nickel element in the positive active material is 30-60%; preferably, the weight percentage I of the nickel element in the positive electrode active material is in a range of 30-45%. The weight percentage I of the nickel element in the positive electrode active material is controlled within this range, and can be matched with the surface density G of the positive electrode active material and the thickness a of the insulating support layer 111, so that the energy density can be maximized while the safety of the battery cell is ensured.
The embodiment of the invention also provides a battery module which comprises a plurality of battery cores which are connected in series or in parallel. The thickness A of the insulating support layer 111 of each cell, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material all meet 0.09-100A/(G I) -2. Therefore, the battery module also has the advantages of high energy density and high safety performance.
The embodiment of the invention also provides a battery pack which comprises a plurality of battery modules. A plurality of battery modules are arranged in series or in parallel to form a battery pack. The thickness A of the insulating support layer 111 of each cell, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material all meet 0.09-100A/(G I) -2. Therefore, the battery module also has the advantages of high energy density and high safety performance. Of course, in other embodiments of the present invention, the battery pack may also be directly assembled by a plurality of the battery cells described above to form a module-free battery pack, so as to ensure energy density.
The following describes the battery cell, the battery module, and the battery pack provided by the embodiment of the present invention in detail with reference to specific embodiments:
examples 1 to 20
Examples 1-20 each provide 20 cells (cells 1-20), and the relationship among the thickness a of the insulating support layer 111, the areal density G of the positive electrode active material, and the weight percentage I of the nickel element in the positive electrode active material for the 20 cells is shown in table 1. Meanwhile, the insulating support layers 111 of the positive current collector and the negative current collector of the 20 kinds of cells are made of PET, the conductive layer 112 of the positive current collector is made of aluminum foil, and the conductive layer of the negative current collector is made of copper foil. The active particles of the positive active material are nickel cobalt lithium manganate. The active particles of the negative active material are graphite materials including, but not limited to, natural graphite, artificial graphite, various coated/modified natural or artificial graphites, such as graphite, soft carbon, hard carbon, carbon fiber, mesocarbon microbeads, silicon-based materials, and silicon-carbon materials. The separator film material of the 20 cells may be selected from polyethylene film, polypropylene film, polyvinylidene fluoride film and multilayer composite film thereof. The electrolyte solution generally uses a lithium salt solution dissolved in an organic solvent. The lithium salt is, for example, LiClO 4 、LiPF 6 、LiBF 4 、LiAsF 6 、LiSbF 6 Etc. inorganic lithium salt, or LiCF 3 SO 3 、LiCF 3 CO 2 、Li 2 C 2 F 4 (SO 3 ) 2 、LiN(CF 3 SO 2 ) 2 、LiC(CF 3 SO 2 ) 3 、LiCnF 2n+1 SO 3 (n is more than or equal to 2) and the like.
TABLE 1 parameters for examples 1-20 cells
As can be seen from the data in table 1, the thickness a of the insulating support layer 111, the surface density G of the positive electrode active material, and the weight percentage I of nickel element in the positive electrode active material of 20 cells provided in examples 1 to 20 of the present invention all satisfy 0.09 ≦ 100 × a/(G × I) ≦ 2.
Comparative examples 1 to 4
Comparative examples 1-4 provide 4 cells (cells 21-24) with specific parameters for the 4 cells shown in table 2.
TABLE 2 parameters of comparative examples 1-4 cells
Experimental example 1
The 20 cells provided in examples 1 to 20 and the 4 cells provided in comparative examples 1 to 4 were subjected to a needling test according to the procedure in the national standard GBT 31485. During testing, the battery cell is placed in a constant current of 1.0C and charged to 4.3V, then constant voltage charging is carried out until the current is reduced to 0.05C, a high-temperature-resistant steel needle with the diameter of 1mm penetrates through the battery cell from the direction perpendicular to the pole piece of the battery cell at the speed of 2mm/s, the penetrating position is close to the geometric center of the needling surface, the steel needle stays in the battery cell, one hour is observed, and the experimental result is shown in table 3.
TABLE 3 acupuncture test data of cells
As can be seen from the data tested in table 3, in examples 1 to 20 of the present invention, compared with comparative examples 1 to 4, by controlling the relationship between A, G and I within this range, the energy density of the battery cell can be sufficiently improved on the premise of ensuring the safety performance of the battery cell, and the needling test has no smoke, no fire, no explosion, high safety performance, and is beneficial to preventing the thermal diffusion of the battery cell, and the safety performance is higher.
Experimental example 2
The 20 cells provided in examples 1 to 20 of the present invention were subjected to energy density tests under the same conditions as the 4 cells provided in comparative examples 1 to 4. Wherein the discharge energy of 1C is represented by E1 in Wh; the mass of the cell is expressed in m in kg, and the gravimetric energy density of the cell is expressed in W in Wh/kg. And, the test condition of E1 was that in a 25 ℃ incubator, the voltage was charged at a constant current of 1C rate to 4.3V, then charged at a constant voltage of 4.3V to a current of 0.05C, and then discharged at a constant current of 1C rate to a voltage of 2.8V, to obtain discharge energy E1. The weight test condition of the battery cell is that the mass m of each battery cell can be obtained by an electronic scale in an environment of 25 ℃. The weight energy density of the cell was calculated by the formula p ═ E1/m, and the specific results are shown in table 4.
TABLE 4 test data of cells
As can be seen from the data in table 5, examples 1 to 20 of the present invention enable the energy density of the cell to approach 252Wh/kg in advance of ensuring the safety of the cell as compared with comparative examples 1 to 4, and can improve the energy density of the cell while ensuring the safety of the cell.
Experimental example 3
Temperature rise and voltage tests were performed on 20 cells provided in examples 1 to 20 of the present invention under the same conditions as on 4 cells provided in comparative examples 1 to 4. Wherein the charging strategy is: at the ambient temperature of 25 +/-5 ℃, the outside of the battery cell is wrapped by heat-insulating cotton made of 10mm thick glass cotton, the battery cell is charged to 4.3V by a current constant current of 1C, and then is placed for 30 minutes, meanwhile, the temperature rise test record conditions are that the temperature of the battery cell is monitored by adopting a multi-channel temperature measuring instrument at the ambient temperature of 25 +/-5 ℃ in the charging process, one section of a temperature sensing line is connected with the multi-channel temperature measuring instrument, the other end of the temperature sensing line is attached to the central point position of the large surface of the battery cell, and the temperature of the battery cell is recorded at intervals of 1 s. The conditions of the voltage test recording are that voltage of positive and negative poles of the battery cell is monitored by using voltage test equipment in the charging process, the test end of the voltage test equipment is connected with the poles of the battery cell in the test process, voltage data is recorded every 1s, and the test results are shown in table 5.
TABLE 5 test data of cells
As can be seen from the data in table 5, in comparison with the number 21-24 battery cells provided in the prior art, the number 1-20 battery cells provided in this embodiment have relatively low temperature rise, relatively stable voltage, less thermal runaway, and higher safety performance under the same test conditions.
The following describes the installation process, operation principle and beneficial effects of the battery pack provided by the embodiment of the present invention in detail:
this battery package accessible is directly integrated to the battery package box with a plurality of electric cores in, also can be earlier with a plurality of electric core equipment to be the battery module, is the battery package with a plurality of battery module equipment again. When the battery core is manufactured, the positive plate, the negative plate and the diaphragm can be wound to obtain the pole core, the pole core is arranged in the shell, the positive lug connected with the positive plate is welded with the positive post on the shell, the negative lug connected with the negative plate is welded with the negative post on the shell, and finally the electrolyte is injected into the sealed shell. In the process of selecting the positive plate and the negative plate, the positive plate is obtained by coating a positive active material on a positive current collector, the negative plate is obtained by coating a negative active material on a negative current collector, the positive current collector and the negative current collector are both composite current collectors 10, the composite current collectors 10 are obtained by coating conductive layers 112 on two sides of an insulating support layer 111, the conductive layer 112 of the positive current collector is an aluminum foil, the conductive layer 112 of the negative current collector is a copper foil, and the thickness A of the insulating support layer 111, the surface density G of the positive active material and the weight percentage I of nickel elements in the positive active material meet the condition that the weight percentage of A/(G I) is not less than 0.01 and not more than 100 and not more than 5.
In the above process, on one hand, the positive current collector of the battery cell is the composite current collector 10, and the composite current collector 10 is a composite structure obtained by compounding the insulating support layer 111 and the conductive layer 112, so that the weight of the current collector can be reduced, the weight energy density of the battery cell can be improved, burrs generated by the conductive layer 112 when the current collector is needled are small, the short-circuit resistance is large, the generated heat is small, the thermal runaway is not easy to occur, the thermal runaway problem of the battery cell under the condition of internal short circuit can be relieved to a certain extent, and the safety performance of the battery cell can be improved; on the other hand, the thermal runaway risk degree of the battery core is in positive correlation with the surface density of the positive electrode active material and the proportion of the nickel element in the positive electrode material, namely, the higher the content of the nickel element is, the worse the stability of the positive electrode active material is, and the more easily the safety accident occurs. However, the degree of the thermal runaway risk of the battery cell is inversely related to the thickness of the insulating layer in the composite substrate, so that the energy density of the battery cell can be maximized on the premise of ensuring the safety of the battery cell by limiting the relationship among the thickness a of the insulating support layer 111, the surface density G of the positive electrode active material and the weight percentage I of the nickel element in the positive electrode active material.
In summary, the embodiments of the present invention provide an electric core, a battery module, and a battery pack with high energy density and high safety performance.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A battery cell, comprising:
the winding core is formed by laminating or winding a positive plate, an isolating film and a negative plate which are arranged in a stacked mode; the positive plate comprises a positive current collector and a nickel-containing positive active material coated on the positive current collector, the positive current collector comprises an insulating support layer and a composite current collector at least arranged on a conducting layer on one side of the insulating support layer, the thickness of the insulating support layer is A, the unit is um, the surface density of the positive active material is G, and the unit is mg/1540.25mm 2 The weight percentage of nickel element in the positive active material is I, and the unit is;
the thickness A of the insulating supporting layer, the surface density G of the positive electrode active material and the weight percentage I of nickel elements in the positive electrode active material meet 0.01-100A/(G I) -5.
2. The cell of claim 1, wherein:
the thickness A of the insulating support layer, the surface density G of the positive electrode active material and the weight percentage I of nickel elements in the positive electrode active material meet 0.09-100A/(G I) -2.
3. The cell of claim 1, wherein:
the thickness A of the insulating support layer ranges from 1 um to 30 um; preferably, the thickness a of the insulating support layer is in the range of 3-15 um.
4. The cell of claim 1, wherein:
the surface density G of the positive electrode active material ranges from 50 to 115mg/1540.25mm 2 (ii) a Preferably, the surface density G of the positive electrode active material ranges from 50 to 95mg/1540.25mm 2 。
5. The electrical core of claim 1, wherein:
the weight percentage I of the nickel element in the positive active material is 30-60%; preferably, the weight percentage I of the nickel element in the positive active material is in a range of 30-45%.
6. The cell of claim 1, wherein:
the active particles of the positive active material are nickel cobalt lithium manganate.
7. The electrical core of any of claims 1 to 6, wherein:
the negative plate is a copper foil;
or, the negative plate comprises a negative current collector and a negative active material coated on the negative current collector, the negative current collector comprises an insulating support layer and a composite current collector at least arranged on a conducting layer on one side of the insulating support layer, the insulating support layer is an organic polymer material layer or a ceramic-doped polymer layer, and the conducting layer is a copper foil layer.
8. The cell of any of claims 1 to 6, wherein:
the composite current collector comprises two conductive layers, wherein the thickness of the two conductive layers is the same, and the conductive layers are respectively arranged on two sides of the insulating supporting layer.
9. A battery module, characterized by comprising the battery cell of any one of claims 1 to 8.
10. A battery pack comprising the cell of any one of claims 1 to 8; alternatively, the battery module according to claim 9 is included.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210501600.0A CN114824441A (en) | 2022-05-09 | 2022-05-09 | Battery core, battery module and battery pack |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210501600.0A CN114824441A (en) | 2022-05-09 | 2022-05-09 | Battery core, battery module and battery pack |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114824441A true CN114824441A (en) | 2022-07-29 |
Family
ID=82512830
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210501600.0A Pending CN114824441A (en) | 2022-05-09 | 2022-05-09 | Battery core, battery module and battery pack |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114824441A (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104993121A (en) * | 2015-05-21 | 2015-10-21 | 中信国安盟固利电源技术有限公司 | Nickel and manganese blended lithium ion battery positive material and preparation method thereof |
| CN106159169A (en) * | 2016-07-11 | 2016-11-23 | 湖南立方新能源科技有限责任公司 | A kind of lithium ion battery and preparation method thereof |
| CN109585781A (en) * | 2018-12-29 | 2019-04-05 | 深圳市比克动力电池有限公司 | A kind of lithium ion battery negative electrode and the lithium ion battery using the pole piece |
| CN110265627A (en) * | 2018-09-28 | 2019-09-20 | 宁德时代新能源科技股份有限公司 | Positive electrode plate and lithium ion secondary battery |
| CN110943215A (en) * | 2019-05-31 | 2020-03-31 | 宁德时代新能源科技股份有限公司 | Lithium ion secondary battery |
| CN112216878A (en) * | 2019-07-10 | 2021-01-12 | 比亚迪股份有限公司 | Lithium ion battery repeating unit, lithium ion battery, using method of lithium ion battery, battery module and automobile |
| CN113748546A (en) * | 2020-04-17 | 2021-12-03 | 宁德时代新能源科技股份有限公司 | Negative pole piece, secondary battery and device thereof |
| US20220037667A1 (en) * | 2019-04-15 | 2022-02-03 | Contemporary Amperex Technology Co., Limited | Positive electrode plate, electrochemical apparatus, and apparatus |
| US20220037669A1 (en) * | 2019-04-15 | 2022-02-03 | Contemporary Amperex Technology Co., Limited | Electrode plate, electrochemical device, and apparatus |
-
2022
- 2022-05-09 CN CN202210501600.0A patent/CN114824441A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104993121A (en) * | 2015-05-21 | 2015-10-21 | 中信国安盟固利电源技术有限公司 | Nickel and manganese blended lithium ion battery positive material and preparation method thereof |
| CN106159169A (en) * | 2016-07-11 | 2016-11-23 | 湖南立方新能源科技有限责任公司 | A kind of lithium ion battery and preparation method thereof |
| CN110265627A (en) * | 2018-09-28 | 2019-09-20 | 宁德时代新能源科技股份有限公司 | Positive electrode plate and lithium ion secondary battery |
| CN109585781A (en) * | 2018-12-29 | 2019-04-05 | 深圳市比克动力电池有限公司 | A kind of lithium ion battery negative electrode and the lithium ion battery using the pole piece |
| US20220037667A1 (en) * | 2019-04-15 | 2022-02-03 | Contemporary Amperex Technology Co., Limited | Positive electrode plate, electrochemical apparatus, and apparatus |
| US20220037669A1 (en) * | 2019-04-15 | 2022-02-03 | Contemporary Amperex Technology Co., Limited | Electrode plate, electrochemical device, and apparatus |
| CN110943215A (en) * | 2019-05-31 | 2020-03-31 | 宁德时代新能源科技股份有限公司 | Lithium ion secondary battery |
| CN112216878A (en) * | 2019-07-10 | 2021-01-12 | 比亚迪股份有限公司 | Lithium ion battery repeating unit, lithium ion battery, using method of lithium ion battery, battery module and automobile |
| CN113748546A (en) * | 2020-04-17 | 2021-12-03 | 宁德时代新能源科技股份有限公司 | Negative pole piece, secondary battery and device thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11476469B2 (en) | Negative current collector, negative electrode plate, electrochemical device, and apparatus | |
| US20220052346A1 (en) | Positive current collector, positive electrode plate, secondary battery, and apparatus | |
| US11804604B2 (en) | Positive electrode piece in a battery, electrochemical device and apparatus | |
| EP3944365B1 (en) | Lithium metal battery and preparation method therefor, and apparatus comprising lithium metal battery and negative electrode plate | |
| EP3930053B1 (en) | Positive pole piece, electrochemical device and device | |
| US20220052349A1 (en) | Positive current collector, positive electrode plate, battery, and apparatus | |
| US11621425B2 (en) | Positive electrode current collector, positive electrode piece, electrochemical device and apparatus | |
| EP4160756A1 (en) | Electrode sheet, secondary battery, battery module, battery pack and electric device | |
| US11705556B2 (en) | Positive electrode current collector and positive electrode plate, battery, battery module, battery pack, and apparatus containing such positive electrode current collector | |
| US20220123322A1 (en) | Positive current collector, positive plate, electrochemical device and apparatus | |
| US20220393291A1 (en) | Battery module, battery pack, electrical apparatus, and manufacturing method and manufacturing device of battery module | |
| US20220140345A1 (en) | Positive electrode plate, and lithium-ion battery and apparatus related thereto | |
| WO2024114403A1 (en) | Positive electrode plate for battery, and battery, apparatus and preparation method | |
| US20230361403A1 (en) | Battery cell, battery module, battery pack, and electrical apparatus | |
| CN114824288B (en) | Electric core, battery module and battery package | |
| CN114883633A (en) | Battery core, battery module and battery pack | |
| CN114864952A (en) | Battery core, battery module and battery pack | |
| CN114824441A (en) | Battery core, battery module and battery pack | |
| KR20140072794A (en) | Non-aqueous electrolyte rechargeable battery pack | |
| CN114883576B (en) | Electric core, battery module and battery package | |
| CN114824287B (en) | Electric core, battery module and battery package | |
| CN114883562B (en) | Electric core, battery module and battery package | |
| CN114824506A (en) | Battery core, battery module and battery pack | |
| CN114883664A (en) | Battery core, battery module and battery pack | |
| CN115000647A (en) | Battery cell structure and lithium ion battery |
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 |