Pole piece, battery, battery device, and electric device

Abstract

The application belongs to the field of batteries, and specifically discloses a pole piece, a battery, a battery device and a power utilization device, wherein the pole piece comprises: a current collector; a pole lug arranged at one end of the current collector; a first heat dissipation layer arranged on the current collector at a portion close to the pole lug; and an active material layer arranged on a portion of the current collector and located on a side of the first heat dissipation layer away from the pole lug in a first direction; wherein the first heat dissipation layer comprises a first heat dissipation material and a first conductive material. The application effectively reduces the temperature rise at the pole lug, improves the heat dissipation of the pole lug, and further improves the overcurrent capacity of the pole lug, thereby being beneficial to the fast charging performance of the battery.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of batteries, and particularly relates to a tab, a battery, a battery device and a power utilization device. BACKGROUND

[0002] Increasing the energy density of batteries is an important direction for the development of battery technology, which can not only significantly improve the performance and application range of batteries, but also reduce application costs and improve market competitiveness. This is of great significance for promoting the development and application of battery technology. At the same time, the greater the energy density of the battery cell is, the greater the current density of the battery cell is at the same rate, which is easy to cause high heat generation at the tab, difficult to dissipate heat, trigger high temperature alarm, poor overcurrent capacity, and affect the fast charging performance of the battery. The prior art cannot effectively solve the above technical problems. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the related art. To this end, the present application proposes a tab, a battery, a battery device and a power utilization device. The present application effectively reduces the temperature rise at the tab, improves the heat dissipation of the tab, and further improves the overcurrent capacity of the tab, thereby facilitating the fast charging performance of the battery.

[0004] The first aspect of the present application proposes a tab. According to embodiments of the present application, the tab comprises:

[0005] a current collector;

[0006] a tab, the tab being arranged at one end of the current collector;

[0007] a first heat dissipation layer, the first heat dissipation layer being arranged on a part of the current collector close to the tab;

[0008] an active material layer, the active material layer being arranged on a part of the current collector, and along a first direction, the active material layer being located on a side of the first heat dissipation layer away from the tab;

[0009] wherein the first heat dissipation layer comprises a first heat dissipation material and a first conductive material.

[0010] According to the tab of the above embodiments of the present application, by introducing the first heat dissipation layer at the tab of the current collector, the temperature rise at the tab can be effectively reduced, the heat dissipation of the tab can be improved, and the overcurrent capacity of the tab can be further improved, thereby facilitating the fast charging performance of the battery.

[0011] In addition, the tab according to the above embodiments of the present application can also have the following additional technical features:

[0012] In some embodiments of the present application, the first heat dissipation material and the first conductive material are mixedly distributed in the first heat dissipation layer, and the mass percentage of the first conductive material is 5% to 50% based on the total mass of the first heat dissipation material and the first conductive material.

[0013] In some embodiments of the present application, the first heat dissipation layer further comprises a first binder, and the mass ratio of the sum of the mass of the first heat dissipation material and the mass of the first conductive material to the mass of the first binder is (30-50):(30-45).

[0014] In some embodiments of the present application, the width d1 of the first heat dissipation layer is 2 mm to 8 mm; and / or the thickness of the first heat dissipation layer is 50 μm to 160 μm.

[0015] In some embodiments of the present application, the first heat dissipation layer comprises a first heat dissipation material layer and a first conductive material layer, the first conductive material layer is arranged on the current collector, and the first heat dissipation material layer is arranged on the surface of the first conductive material layer away from the current collector; the first heat dissipation material layer comprises the first heat dissipation material, and the first conductive material layer comprises the first conductive material.

[0016] In some embodiments of the present application, the thickness ratio of the first conductive material layer to the first heat dissipation material layer is (10-40):(60-90).

[0017] In some embodiments of the present application, the sum of the thickness of the first conductive material layer and the thickness of the first heat dissipation material layer is 50 μm to 160 μm.

[0018] In some embodiments of the present application, the first heat dissipation material comprises at least one of hexagonal boron nitride, aluminum nitride, aluminum oxide, mica sheet, ultra-high molecular weight polyethylene fiber / epoxy resin composite material, and polyimide filled boron nitride composite material; and / or the first conductive material comprises at least one of MXene material, carbon black, carbon nanotube, graphene, metal oxide, and conductive polymer.

[0019] In some embodiments of the present application, the MXene material comprises at least one of one-dimensional transition metal carbide, nitride and carbonitride with a general formula of M n+1 X n T x ; wherein M is at least one of Ti, V, Nb, Mo, Ta, Cr, Hf, Zr, Mn, n is 1, 2 or 3; X is at least one of C and N; T x is a surface terminal group comprising at least one of -O, -OH, -F, -Cl, and x is a positive real number in the range of 1 to 3 satisfying the stoichiometric ratio.

[0020] In some embodiments of the application, the pole piece further comprises: a second heat dissipation layer, the second heat dissipation layer is arranged on the current collector, and the second heat dissipation layer is located on the side of the active material layer away from the first heat dissipation layer along the first direction; wherein the second heat dissipation layer comprises a second heat dissipation material and a second conductive material.

[0021] In some embodiments of the application, the second heat dissipation material and the second conductive material are mixedly distributed in the second heat dissipation layer, and the mass percentage of the second conductive material is 5% to 50% based on the total mass of the second heat dissipation material and the second conductive material.

[0022] In some embodiments of the application, the second heat dissipation layer further comprises a second binder, and the mass ratio of the sum of the mass of the second heat dissipation material and the second conductive material to the mass of the second binder is (30-50):(30-45).

[0023] In some embodiments of the application, the width d2 of the second heat dissipation layer is 2mm to 8mm; and / or, the thickness of the second heat dissipation layer is 50μm to 160μm.

[0024] In some embodiments of the application, the second heat dissipation layer comprises a second heat dissipation material layer and a second conductive material layer, the second conductive material layer is arranged on the current collector, and the second heat dissipation material layer is arranged on the surface of the second conductive material layer away from the current collector; the second heat dissipation material layer comprises the second heat dissipation material, and the second conductive material layer comprises the second conductive material.

[0025] In some embodiments of the application, the thickness ratio of the second conductive material layer to the second heat dissipation material layer is (10-40):(60-90).

[0026] In some embodiments of the application, the sum of the thickness of the second conductive material layer and the second heat dissipation material layer is 50μm to 160μm.

[0027] In some embodiments of the application, the second heat dissipation material comprises at least one of hexagonal boron nitride, aluminum nitride, aluminum oxide, mica sheet, ultra-high molecular weight polyethylene fiber / epoxy resin composite material, and polyimide filled boron nitride composite material; and / or, the second conductive material comprises at least one of MXene material, carbon black, carbon nanotube, graphene, metal oxide and conductive polymer.

[0028] In some embodiments of the application, the MXene material comprises a general formula of M n+1 X n T xat least one of one-dimensional transition metal carbide, nitride and carbonitride; wherein M is selected from at least one of Ti, V, Nb, Mo, Ta, Cr, Hf, Zr, Mn, n is 1, 2 or 3; X is at least one of C and N; T x is a surface terminal group, including at least one of -O, -OH, -F, -Cl, x is a positive real number in the range of 1-3 satisfying the stoichiometric ratio.

[0029] A second aspect of the present application provides a battery. According to embodiments of the present application, the battery includes a positive electrode tab, which is the tab described in the above embodiments; and / or, includes a negative electrode tab, which is the tab described in the above embodiments. In this way, the fast-charging performance and safety performance of the battery are effectively improved. It should be noted that, since the above-mentioned tab is used, the battery of the present application has all the advantages of the above-mentioned tab, which will not be described here.

[0030] In some embodiments of the present application, the width of the first heat dissipation layer of the positive electrode tab is greater than the width of the first heat dissipation layer of the negative electrode tab; and / or, the width of the second heat dissipation layer of the positive electrode tab is greater than the width of the second heat dissipation layer of the negative electrode tab.

[0031] A third aspect of the present application provides a battery device. According to embodiments of the present application, the battery device includes the tab of the first aspect or the battery of the second aspect. Since the above-mentioned tab is used, the battery device of the present application has all the advantages of the above-mentioned tab, which will not be described here.

[0032] A fourth aspect of the present application provides a power-using device. According to embodiments of the present application, the power-using device includes the tab of the first aspect or the battery of the second aspect or the battery device of the third aspect. In this way, the features and advantages described above for the battery also apply to the power-using device, which will not be described here.

[0033] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0034] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings.

[0035] Figure 1 Structure diagram of the tab of some embodiments of the present application;

[0036] Figure 2 Structure diagram of the tab of some embodiments of the present application;

[0037] Figure 3A cross-sectional schematic view of a pole piece of some embodiments of the application;

[0038] Figure 4 A cross-sectional schematic view of a pole piece of some embodiments of the application;

[0039] Figure 5 A schematic view of a battery pole piece of some embodiments of the application;

[0040] Figure 6 A schematic view of a battery pole piece of some embodiments of the application;

[0041] Figure 7 A schematic view of a battery pole piece of some embodiments of the application.

[0042] Reference signs:

[0043] 110 - tab, 111 - positive tab, 112 - negative tab, 120 - first heat dissipation layer, 121 - first conductive material layer, 122 - first heat dissipation material layer, 123 - positive first heat dissipation layer, 124 - negative first heat dissipation layer, 130 - active material layer, 131 - positive active material layer, 132 - negative active material layer, 140 - second heat dissipation layer, 141 - second conductive material layer, 142 - second heat dissipation material layer, 143 - positive second heat dissipation layer, 144 - negative second heat dissipation layer, 150 - current collector, 100 - positive pole piece, 200 - negative pole piece. DETAILED DESCRIPTION

[0044] Embodiments of the present application are described below in detail with reference to the accompanying drawings, in which examples of the embodiments are shown, wherein the same or similar notations are used to denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary, and are intended to explain the present application, and cannot be understood as limiting the present application.

[0045] In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed, and are merely for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third", and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0046] In the description of the embodiments of the present application, the term "and / or" is merely an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of existence of A, existence of A and B, and existence of B. In addition, the character " / " in this paper generally represents an "or" relationship between the front and rear associated objects.

[0047] In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more than two. The meaning of "multiple" is two or more than two. In this paper, the term "contains" or "includes" is an open expression, that is, it includes the content indicated in this application, but does not exclude other aspects.

[0048] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited. The ranges or values should be construed as having a range around the values disclosed. For ranges of values, the endpoints of the ranges are combined with the individual points to form new ranges, which are to be considered as being specifically disclosed.

[0049] The first aspect of the present application proposes a pole piece. According to the embodiments of the present application, referring to the accompanying drawings Figure 1 Figure 4 The first aspect of the present application proposes a pole piece. According to the embodiments of the present application, referring to the accompanying drawings

[0050] The principle of the pole piece proposed in the present application capable of achieving the above beneficial effects is described in detail as follows:

[0051] ​The first heat dissipation layer 120 is introduced at the tab 110 of the current collector, and the first heat dissipation layer 120 includes a first heat dissipation material and a first conductive material, which can effectively reduce the temperature rise at the tab 110, improve the heat dissipation of the tab 110, and further improve the overcurrent capacity of the tab 110, thereby facilitating the fast charging performance of the battery. The first heat dissipation material and the first conductive material have a synergistic effect at the tab 110. The first heat dissipation material not only has an insulating effect, but also can effectively avoid short circuit caused by the bending contact of the positive and negative tabs 110, and has strong heat dissipation capacity, which can effectively reduce the heat generation of the tab 110 under large current, avoid triggering the over-temperature alarm, and improve the overcurrent capacity of the tab. In the prior art, the contact impedance at the tab 110 is high, which can cause a large amount of heat when the current passes through the tab 110. The first conductive material has strong conductivity, which can effectively reduce the contact impedance at the tab 110, thereby reducing the heat generation at the tab 110.

[0052] In addition, the first heat dissipation layer 120 is arranged near the tab 110, does not hinder the movement of lithium ions, and the active material area is not occupied, and the movement of lithium ions is normal.

[0053] It should be noted that the first heat dissipation layer can be in contact with the tab, or there can be a small gap between the first heat dissipation layer and the tab, or the first heat dissipation layer can partially cover the tab. In the drawings, Figure 1 In the drawings, Figure 7 In the drawings, the X direction is the length direction or the width direction of the tab, the Y direction is the width direction or the length direction of the tab, and the Z direction is the thickness direction of the tab.

[0054] According to some specific embodiments of the present application, the first heat dissipation material and the first conductive material are mixedly distributed in the first heat dissipation layer 120, which further facilitates the synergistic effect of the first heat dissipation material and the first conductive material at the tab 110, further effectively reduces the temperature rise at the tab 110, improves the heat dissipation of the tab 110, and further improves the overcurrent capacity of the tab 110. And based on the total mass of the first heat dissipation material and the first conductive material being 100%, the mass percentage of the first conductive material is 5% to 50%, for example, it can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% or any range between any two of them, etc. By limiting the mass percentage of the first conductive material within the above range, the synergistic effect of the first heat dissipation material and the first conductive material at the tab 110 can be further facilitated, the temperature rise at the tab 110 can be further effectively reduced, the heat dissipation of the tab 110 can be improved, and the overcurrent capacity of the tab 110 can be further improved.

[0055] According to still some specific embodiments of the present application, the first heat dissipation layer 120 further comprises a first adhesive, which is used to firmly bond the first heat dissipation layer 120 to the surface of the current collector 150. Moreover, the mass ratio of the sum of the mass of the first heat dissipation material and the first conductive material to the mass of the first adhesive is (30-50):(30-45), for example, it can be 30:30, 30:35, 30:40, 30:45, 40:30, 40:35, 40:45, 50:30, 50:35, 50:40, 50:45, or any range between any two of them, etc. By limiting the mass ratio of the sum of the mass of the first heat dissipation material and the first conductive material to the mass of the first adhesive within the above range, it is further conducive to firmly bonding the first heat dissipation layer 120 to the surface of the current collector 150, avoiding the first heat dissipation layer 120 from falling off the current collector 150, while ensuring effectively reducing the temperature rise at the tab 110, improving the heat dissipation of the tab 110, and further improving the overcurrent capacity of the tab 110.

[0056] According to still some specific embodiments of the present application, the width d1 of the first heat dissipation layer 120 is 2mm-8mm, for example, it can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, or any range between any two of them, etc.; and / or, the thickness of the first heat dissipation layer 120 is 50μm-160μm, for example, it can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, or any range between any two of them, etc. By limiting the width d1 of the first heat dissipation layer 120 and / or the thickness of the first heat dissipation layer 120 within the above range, it can further effectively reduce the temperature rise at the tab 110, further improve the heat dissipation of the tab 110, and further improve the overcurrent capacity of the tab 110, thereby further facilitating the fast charging performance of the battery.

[0057] According to still some specific embodiments of the present application, referring to the accompanying drawings Figure 4 The first heat dissipation layer 120 comprises a first heat dissipation material layer 122 and a first conductive material layer 121, the first conductive material layer 121 is arranged on the current collector 150, and the first heat dissipation material layer 122 is arranged on the surface of the first conductive material layer 121 away from the current collector 150; the first heat dissipation material layer 122 comprises a first heat dissipation material, and the first conductive material layer 121 comprises a first conductive material. The first conductive material layer 121 has the effect of strong conductivity, which can effectively reduce the contact impedance at the tab 110, thereby reducing the heat generation at the tab 110. The first heat dissipation material layer 122 has the effect of effectively avoiding short circuit caused by the bending contact of the positive and negative tabs 110, and has strong heat dissipation capacity, which can effectively reduce the heat generation of the tab 110 under large current, avoid triggering the over-temperature alarm, and improve the overcurrent capacity of the tab.

[0058] According to still some specific embodiments of the present application, the thickness ratio of the first conductive material layer 121 and the first heat dissipation material layer 122 is (10~40):(60~90), for example, can be 25:60, 25:65, 25:70, 25:75, 25:80, 25:85, 25:90 or any range between any two of them, etc., by limiting the thickness ratio of the first conductive material layer 121 and the first heat dissipation material layer 122 in the above range, the temperature rise at the tab 110 can be further effectively reduced, the heat dissipation of the tab 110 is further improved, and the overcurrent capacity of the tab 110 is further improved, thereby further facilitating the fast charging performance of the battery.

[0059] According to still some specific embodiments of the present application, the sum of the thicknesses of the first conductive material layer 121 and the first heat dissipation material layer 122 is 50μm~160μm, for example, can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm or any range between any two of them, etc., by limiting the sum of the thicknesses of the first conductive material layer 121 and the first heat dissipation material layer 122 in the above range, the temperature rise at the tab 110 can be further effectively reduced, the heat dissipation of the tab 110 is further improved, and the overcurrent capacity of the tab 110 is further improved, thereby further facilitating the fast charging performance of the battery.

[0060] According to still some specific embodiments of the present application, the first conductive material layer 121 and the first heat dissipation material layer 122 respectively include a first adhesive, which functions to bond the first conductive material layer 121 to the current collector 150 and bond the first heat dissipation material layer 122 to the surface of the first conductive material layer 121.

[0061] In the embodiments of the present application, the specific type of the first heat dissipation material is not particularly limited, and those skilled in the art can select according to actual needs, as some preferred embodiments, the first heat dissipation material includes at least one of hexagonal boron nitride, aluminum nitride, aluminum oxide, mica sheet, ultra-high molecular weight polyethylene fiber / epoxy resin composite material, and polyimide filled boron nitride composite material. The first heat dissipation material of the above-mentioned type not only plays an insulating role, can effectively avoid the short circuit caused by the bending contact of the positive and negative tabs 110, but also has strong heat dissipation capacity, which can effectively reduce the heat generation of the tab 110 under large current.

[0062] In the embodiments of the present application, the specific type of the first conductive material is not particularly limited, and can be selected by those skilled in the art according to actual needs. As some preferred embodiments, the first conductive material includes at least one of MXene material, carbon black, carbon nanotube, graphene, metal oxide and conductive polymer. The first conductive material of the above-mentioned type has strong conductivity, which can effectively reduce the contact impedance at the tab 110, thereby reducing the heat generation at the tab 110.

[0063] According to still some specific embodiments of the present application, the MXene material includes at least one of one-dimensional transition metal carbide, nitride and carbonitride of a general formula of M n+1 X n T x ; wherein M is at least one of Ti, V, Nb, Mo, Ta, Cr, Hf, Zr and Mn, n is 1, 2 or 3; X is at least one of C and N; T is a surface terminal group, including at least one of -O, -OH, -F and -Cl, and x is a positive real number in a range of 1 to 3 satisfying the stoichiometric ratio. x

[0064] According to still some specific embodiments of the present application, referring to the accompanying drawings Figure 2 Figure 4 The tab further includes: a second heat dissipation layer 140, the second heat dissipation layer 140 is arranged on the current collector 150, and along the first direction, the second heat dissipation layer 140 is located on the side of the active material layer 130 away from the first heat dissipation layer 120, that is, the second heat dissipation layer 140 is arranged on the slitting side of the tab; wherein the second heat dissipation layer 140 includes a second heat dissipation material and a second conductive material. The present application introduces the second heat dissipation layer 140 on the slitting side, and the second heat dissipation layer 140 includes the second heat dissipation material and the second conductive material, wherein the second heat dissipation material not only has an insulating effect, but can further effectively avoid short circuit caused by the bending contact of the positive and negative tabs 110, and has strong heat dissipation capacity, which can further effectively reduce the heat generation of the tab under large current, avoid triggering the over-temperature alarm, and improve the over-current capacity of the tab. The second conductive material can further improve the over-current capacity of the tab as a whole. In addition, the second heat dissipation layer 140 is arranged on the slitting side, which does not hinder the movement of lithium ions, and the active material region is not occupied, and the movement of lithium ions is normal.

[0065] ​​According to some specific embodiments of this application, the second heat dissipation material and the second conductive material are mixed and distributed in the second heat dissipation layer 140. This further facilitates the synergistic effect of the second heat dissipation material and the second conductive material on the slitting side, further avoids short circuits caused by bending contact of the positive and negative electrode tabs 110, further effectively reduces the temperature rise on the slitting side, improves heat dissipation on the slitting side, and thus further improves the current carrying capacity of the electrode sheet. Furthermore, based on the total mass of the second heat dissipation material and the second conductive material being 100%, and the mass percentage of the second conductive material being 5% to 50%, for example, it can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or any range between the two, by limiting the mass percentage of the second conductive material within the above range, it is further beneficial for the second heat dissipation material and the second conductive material to work synergistically on the slitting side, further avoids short circuits caused by bending contact of the positive and negative electrode tabs 110, further effectively reduces the temperature rise on the slitting side, improves heat dissipation on the slitting side, and thus further improves the current carrying capacity of the electrode sheet.

[0066] According to some specific embodiments of this application, the second heat dissipation layer 140 further includes a second adhesive, which serves to firmly bond the second heat dissipation layer 140 to the surface of the current collector 150. Furthermore, the mass ratio of the sum of the masses of the second heat dissipation material and the second conductive material to the mass of the second adhesive is (30~50):(30~45), for example, it can be 30:30, 30:35, 30:40, 30:45, 40:30, 40:35, 40:45, 50:30, 50:35, 50:40, 50:45, or any range between the two. By limiting the mass ratio of the sum of the masses of the second heat dissipation material and the second conductive material to the mass of the second adhesive within the above range, it is further beneficial to firmly bond the second heat dissipation layer 140 to the surface of the current collector 150, preventing the second heat dissipation layer 140 from falling off the current collector 150, while ensuring effective reduction of the temperature rise on the slit side, improving the heat dissipation of the electrode, and thus improving the current carrying capacity of the electrode.

[0067] According to still some specific embodiments of the present application, the width d2 of the second heat dissipation layer 140 is 2mm-8mm, for example, can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm or any range between any two of them, etc.; and / or, the thickness of the second heat dissipation layer 140 is 50μm-160μm, for example, can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm or any range between any two of them, etc., by limiting the width d2 of the second heat dissipation layer 140 and / or the thickness of the second heat dissipation layer 140 within the above range, the short circuit caused by the bending contact of the positive and negative tabs 110 can be further avoided, the temperature rise of the slitting side is further effectively reduced, the heat dissipation of the slitting side is further improved, and the overcurrent capacity of the tab is further improved.

[0068] According to still some specific embodiments of the present application, referring to the accompanying drawings Figure 4 The second heat dissipation layer 140 includes a second heat dissipation material layer 142 and a second conductive material layer 141, the second conductive material layer 141 is arranged on the current collector 150, and the second heat dissipation material layer 142 is arranged on the surface of the second conductive material layer 141 away from the current collector 150; the second heat dissipation material layer 142 includes a second heat dissipation material, and the second conductive material layer 141 includes a second conductive material. The second heat dissipation material layer 142 can further effectively avoid the short circuit caused by the bending contact of the positive and negative tabs 110, and has strong heat dissipation capacity, which can further effectively reduce the tab heat generation under large current, avoid triggering the over-temperature alarm, and improve the overcurrent capacity of the tab. The second conductive material layer 141 has strong conductivity, which can further improve the overcurrent capacity of the tab as a whole.

[0069] According to still some specific embodiments of the present application, the thickness ratio of the second conductive material layer 141 and the second heat dissipation material layer 142 is (10-40):(60-90), for example, can be 25:60, 25:65, 25:70, 25:75, 25:80, 25:85, 25:90 or any range between any two of them, etc., by limiting the thickness ratio of the second conductive material layer 141 and the second heat dissipation material layer 142 within the above range, the short circuit caused by the bending contact of the positive and negative tabs 110 can be further avoided, the temperature rise of the slitting side is further effectively reduced, the heat dissipation of the slitting side is further improved, and the overcurrent capacity of the tab is further improved.

[0070] According to still some specific embodiments of the present application, the sum of the thicknesses of the second conductive material layer 141 and the second heat dissipation material layer 142 is 50 μm to 160 μm, for example, can be 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm or any range between any two of them, etc. By limiting the sum of the thicknesses of the second conductive material layer 141 and the second heat dissipation material layer 142 within the above range, the short circuit caused by the bending contact of the positive and negative tabs 110 can be further avoided, the temperature rise of the slitting side is further effectively reduced, the heat dissipation of the slitting side is further improved, and the overcurrent capacity of the tab is further improved.

[0071] According to still some specific embodiments of the present application, the second conductive material layer 141 and the second heat dissipation material layer 142 respectively include a second adhesive, which functions to bond the second conductive material layer 141 to the current collector 150 and bond the second heat dissipation material layer 142 to the surface of the second conductive material layer 141.

[0072] In the embodiments of the present application, the specific type of the second heat dissipation material is not particularly limited and can be selected by those skilled in the art according to actual needs. As some preferred embodiments, the second heat dissipation material includes at least one of hexagonal boron nitride, aluminum nitride, aluminum oxide, mica sheet, ultra-high molecular weight polyethylene fiber / epoxy resin composite material, and polyimide filled boron nitride composite material. The second heat dissipation material of the above type not only functions as an insulator, which can effectively avoid the short circuit caused by the bending contact of the positive and negative tabs 110, but also has strong heat dissipation capacity, which can effectively reduce the heat generation of the tab under large current.

[0073] In the embodiments of the present application, the specific type of the second conductive material is not particularly limited and can be selected by those skilled in the art according to actual needs. As some preferred embodiments, the second conductive material includes at least one of MXene material, carbon black, carbon nanotube, graphene, metal oxide and conductive polymer. The second conductive material of the above type has strong conductivity, which can further improve the overcurrent capacity of the tab as a whole.

[0074] According to still some specific embodiments of the present application, the MXene material includes at least one of one-dimensional transition metal carbide, nitride and carbonitride with a general formula of M n+1 X n T x ; wherein M is selected from at least one of Ti, V, Nb, Mo, Ta, Cr, Hf, Zr and Mn, n is 1, 2 or 3, X is at least one of C and N, and T xat least one of -O, -OH, -F, -Cl, x is a positive real number in the range of 1-3 satisfying the stoichiometric ratio.

[0075] A second aspect of the present application provides a battery. According to embodiments of the present application, the battery comprises the tab of the first aspect. Thus, the fast-charging performance and safety performance of the battery are effectively improved. It should be noted that, since the above-mentioned tab is adopted, the battery of the present application has all the advantages of the above-mentioned tab, which will not be repeated here.

[0076] According to some specific embodiments of the present application, reference is made to the accompanying drawings Figure 5 Figure 7 According to some specific embodiments of the present application, reference is made to the accompanying drawings

[0077] According to some specific embodiments of the present application, reference is made to the accompanying drawings Figure 5 , the positive tab 100 is the tab of the first aspect, and along the first direction (i.e. the X direction), the positive tab 100 comprises the positive tab lug 111, the positive first heat dissipation layer 123 and the positive active material layer 131 arranged in sequence, the first direction (i.e. the X direction) being the length direction or the width direction of the positive tab 100; and the negative tab 200 is a conventional tab, and along the first direction (i.e. the X direction), the negative tab 200 comprises the negative tab lug 112 and the negative active material layer 132 arranged in sequence.

[0078] According to some specific embodiments of the present application, reference is made to the accompanying drawings Figure 6 , the positive tab 100 is the tab of the first aspect, and along the first direction (i.e. the X direction), the positive tab 100 comprises the positive tab lug 111, the positive first heat dissipation layer 123 and the positive active material layer 131 arranged in sequence, the first direction (i.e. the X direction) being the length direction or the width direction of the positive tab 100; and the negative tab 200 is a conventional tab, and along the first direction (i.e. the X direction), the negative tab 200 comprises the negative tab lug 112 and the negative active material layer 132 arranged in sequence.

[0079] According to some specific embodiments of the present application, reference is made to the accompanying drawings Figure 7 ​The positive electrode tab 100 is the tab of the first aspect, and along the first direction (i.e., the X direction), the positive electrode tab 100 comprises the positive electrode tab 111, the positive electrode first heat dissipation layer 123, the positive electrode active material layer 131, and the positive electrode second heat dissipation layer 143 arranged in sequence, and the first direction (i.e., the X direction) is the length direction or the width direction of the positive electrode tab 100. The negative electrode tab 200 is the tab of the first aspect, and along the first direction (i.e., the X direction), the negative electrode tab 200 comprises the negative electrode tab 112, the negative electrode first heat dissipation layer 124, the negative electrode active material layer 132, and the negative electrode second heat dissipation layer 144 arranged in sequence, and the first direction (i.e., the X direction) is the length direction or the width direction of the negative electrode tab 200.

[0080] According to still another specific embodiment of the present application, the width of the first heat dissipation layer of the positive electrode tab is greater than the width of the first heat dissipation layer of the negative electrode tab; and / or, the width of the second heat dissipation layer of the positive electrode tab is greater than the width of the second heat dissipation layer of the negative electrode tab. In this way, the heat dissipation effect of the positive electrode tab can be more excellent, which is further conducive to improving the fast charging performance and safety performance of the battery.

[0081] According to still another specific embodiment of the present application, the above-mentioned battery further comprises a separator and an electrolyte arranged between the positive electrode tab and the negative electrode tab. The specific type of the above-mentioned battery is not particularly limited, including but not limited to a lithium ion battery, a sodium ion battery, a potassium ion battery, etc.

[0082] In some embodiments of the present application, the above-mentioned positive electrode tab comprises a positive electrode active material layer, which comprises a positive electrode active material, an optional positive electrode binder, and an optional positive electrode conductive agent. The specific type of the above-mentioned positive electrode active material is not particularly limited, including but not limited to one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), and lithium-containing phosphate with an olivine structure (such as lithium iron phosphate (LFP) and lithium manganese iron phosphate (LFMP)).

[0083] In some embodiments of the present application, the above-mentioned negative electrode tab comprises a negative electrode active material layer, which comprises a negative electrode active material, an optional negative electrode binder, and an optional negative electrode conductive agent. The specific type of the above-mentioned negative electrode active material is not particularly limited, and a negative electrode active material commonly known in the art for a battery can be used. As an example, the negative electrode active material can comprise at least one of the following materials: graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate, etc. The silicon-based material can comprise at least one of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can comprise at least one of elemental tin, tin oxide compound, and tin alloy.

[0084] The third aspect of the present application provides a battery device comprising the battery of the second aspect of the present application. Since the above-mentioned pole piece is adopted, the battery device of the present application has all the advantages of the above-mentioned pole piece, which will not be repeated here.

[0085] The battery device of the present application can be, but is not limited to, a battery module, a battery pack, or an integrated chassis of an automobile.

[0086] The fourth aspect of the present application provides a power consumption device comprising the battery of the second aspect of the present application. Since the above-mentioned pole piece is adopted, the power consumption device of the present application has all the advantages of the above-mentioned pole piece, which will not be repeated here.

[0087] The power consumption device of the present application can be, but is not limited to, a mobile device (such as a mobile phone, a notebook computer, a computer, etc.), an electric vehicle (such as a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.), an electric train, a ship and a satellite, an aircraft, an energy storage system, etc.

[0088] The embodiments of the present application are described in detail below. It should be noted that the embodiments described below are exemplary and are used to explain the present application only, and cannot be understood as a limitation of the present application. In addition, if not specifically stated, all reagents used in the following examples are commercially available or can be synthesized according to the methods described herein or known methods, and the reaction conditions not listed are also easily obtained by those skilled in the art.

[0089] Example 1

[0090] The present embodiment provides a lithium ion blade battery, and a preparation method thereof comprises:

[0091] (1) Preparation of the positive pole piece:

[0092] Preparation of the first heat dissipation layer slurry of the positive electrode:

[0093] Mixing the first conductive material (specifically MXene material Ti3C2T x , T x is a surface terminal group, including at least one of -O, -OH, -F, -Cl, and x is a positive real number in the range of 1-2 that satisfies the stoichiometric ratio), the first heat dissipation material (specifically hexagonal boron nitride), and the first binder (specifically PVDF) in a mass ratio of 1:39:35, and adding N-methyl pyrrolidone (NMP) for mixing and stirring to obtain the first heat dissipation layer slurry of the positive electrode.

[0094] Preparation of the second heat dissipation layer slurry of the positive electrode:

[0095] Mixing the second conductive material (specifically MXene material Ti3C2Tx x is a surface terminal group, including at least one of -O, -OH, -F, -Cl, and x is a positive real number in the range of 1-2 satisfying the stoichiometric ratio, the second heat dissipation material (specifically, hexagonal boron nitride), the second binder (specifically, PVDF) are mixed, and NMP is added for mixing and stirring to obtain the second heat dissipation layer slurry of the positive electrode.

[0096] Preparation of positive electrode slurry and positive electrode sheet:

[0097] The positive electrode active material (lithium iron phosphate), carbon black and polyvinylidene fluoride with a mass ratio of 98.5:0.5:1 are mixed, and NMP is added for mixing and stirring to obtain the positive electrode slurry.

[0098] Reference is made to the accompanying drawings Figure 7 The first heat dissipation layer slurry, the positive electrode slurry and the second heat dissipation layer slurry of the positive electrode are simultaneously coated on the surface of the positive electrode current collector aluminum foil by an extrusion coater, wherein the first heat dissipation layer slurry and the second heat dissipation layer slurry are respectively located on both sides of the active material area where the positive electrode slurry is located, to ensure that the heat dissipation layer and the active material area do not interpenetrate, and then after oven baking and roll cutting processing, the positive electrode sheet is obtained. The width of the first heat dissipation layer of the positive electrode is 5 mm, and the thickness is 110 μm. The width of the second heat dissipation layer of the positive electrode is 5 mm, and the thickness is 110 μm.

[0099] (2) Preparation of negative electrode sheet:

[0100] Preparation of first heat dissipation layer slurry of negative electrode:

[0101] The first conductive material (specifically, MXene material Ti3C2T x x is a surface terminal group, including at least one of -O, -OH, -F, -Cl, and x is a positive real number in the range of 1-2 satisfying the stoichiometric ratio, the first heat dissipation material (specifically, hexagonal boron nitride), the first binder (specifically, PVDF) are mixed, and N-methyl pyrrolidone is added for mixing and stirring to obtain the first heat dissipation layer slurry of the negative electrode.

[0102] Preparation of second heat dissipation layer slurry of negative electrode:

[0103] The second conductive material (specifically, MXene material Ti3C2T x x ​​​To surface terminal groups, including at least one of -O, -OH, -F, -Cl, x is a positive real number in the range of 1~2 to meet the stoichiometric ratio), the second heat dissipation material (specifically hexagonal boron nitride), the second binder (specifically PVDF) are mixed, and N-methyl pyrrolidone is added for mixing and stirring to obtain the second heat dissipation layer slurry of the negative electrode.

[0104] Preparation of negative electrode slurry and negative electrode tab:

[0105] The negative electrode active material (graphite), carbon black, butadiene styrene rubber SBR, CMC with a mass ratio of 97.5:1:1.5 are mixed uniformly, and water is added for mixing and stirring to obtain the negative electrode slurry.

[0106] Reference is made to the accompanying drawings Figure 7 The first heat dissipation layer slurry, the negative electrode slurry and the second heat dissipation layer slurry of the negative electrode are simultaneously coated on the surface of the negative electrode current collector copper foil by an extrusion coater, wherein the first heat dissipation layer slurry and the second heat dissipation layer slurry are located on both sides of the active area where the negative electrode slurry is coated, and the three are coated to ensure that the heat dissipation layer does not interpenetrate with the active area. After being treated by an oven baking and roll cutting equipment, a negative electrode tab is obtained. The width of the first heat dissipation layer of the negative electrode is 5 mm, and the thickness is 110 μm. The width of the second heat dissipation layer of the negative electrode is 5 mm, and the thickness is 110 μm.

[0107] (3) Assembly: The above positive electrode tab, separator and negative electrode tab are stacked in order to obtain a core; wherein the separator completely separates the positive electrode tab and the negative electrode tab, and then the stacked core is assembled into a shell and electrolyte is injected. After being treated by vacuum packaging, standing, formation, cutting and sealing processes, a lithium ion battery is obtained, and the design capacity of the battery is 152 Ah.

[0108] Examples 2~17

[0109] Examples 2~17 of the present embodiment are basically the same as the preparation method of Example 1, and the only difference is that:

[0110] In the preparation process of the positive electrode tab, the mass ratio of the first conductive material, the first heat dissipation material and the first binder is different, and the mass ratio of the second conductive material, the second heat dissipation material and the second binder is different. The specific parameters are shown in Table 1.

[0111] In the preparation process of the negative electrode tab, the mass ratio of the first conductive material, the first heat dissipation material and the first binder is different, and the mass ratio of the second conductive material, the second heat dissipation material and the second binder is different. The specific parameters are shown in Table 2.

[0112] Example 18

[0113] Example 18 of the present embodiment is basically the same as the preparation method of Example 3, and the only difference is that:

[0114] Reference Appendix Figure 5 In the process of preparing the positive electrode sheet, only the first heat dissipation layer of the positive electrode is prepared, and the second heat dissipation layer of the positive electrode is not prepared. The specific parameters are shown in Table 1.

[0115] Reference Appendix Figure 5 During the preparation of the negative electrode sheet, the first and second heat dissipation layers of the negative electrode were not prepared. The specific parameters are shown in Table 2.

[0116] Example 19

[0117] The preparation method of Example 19 is basically the same as that of Example 3, the only difference being:

[0118] During the preparation of the positive electrode sheet, the first heat dissipation layer and the second heat dissipation layer of the positive electrode are prepared, and the specific parameters are shown in Table 1.

[0119] During the preparation of the negative electrode sheet, the first and second heat dissipation layers of the negative electrode were not prepared. The specific parameters are shown in Table 2.

[0120] Example 20

[0121] The preparation methods of Example 20 and Example 3 are basically the same, with the only difference being:

[0122] Reference Appendix Figure 6 In the process of preparing the positive electrode sheet, the first heat dissipation layer and the second heat dissipation layer of the positive electrode are prepared, and the specific parameters are shown in Table 1.

[0123] Reference Appendix Figure 6 During the preparation of the negative electrode sheet, only the first heat dissipation layer of the negative electrode is prepared, and the second heat dissipation layer of the negative electrode is not prepared. The specific parameters are shown in Table 2.

[0124] Example 21

[0125] The preparation methods of Example 21 and Example 3 are basically the same, with the only difference being:

[0126] (1) Preparation of the positive electrode sheet:

[0127] Preparation of the first conductive material layer slurry for the positive electrode:

[0128] The first conductive material (specifically MXene material Ti3C2T) with a mass ratio of 40:35 x T x The first conductive material layer slurry of the positive electrode is obtained by mixing a surface terminal group (including at least one of -O, -OH, -F, and -Cl, where x is a positive real number in the range of 1 to 2 that satisfies the stoichiometric ratio) with a first binder (specifically PVDF) and adding N-methylpyrrolidone for mixing and stirring.

[0129] Preparation of the first heat dissipation material layer slurry of the positive electrode:

[0130] The first heat dissipation material (specifically, hexagonal boron nitride) and the first binder (specifically, PVDF) with a mass ratio of 40:35 were mixed, and N-methyl pyrrolidone was added for mixing and stirring to obtain the first heat dissipation material layer slurry of the positive electrode.

[0131] Preparation of the second conductive material layer slurry of the positive electrode:

[0132] The second conductive material (specifically, MXene material Ti3C2T x , T x is a surface terminal group, including at least one of -O, -OH, -F, -Cl, and x is a positive real number in the range of 1-2 that satisfies the stoichiometric ratio) and the second binder (specifically, PVDF) with a mass ratio of 40:35 were mixed, and N-methyl pyrrolidone was added for mixing and stirring to obtain the second conductive material layer slurry of the positive electrode.

[0133] Preparation of the second heat dissipation material layer slurry of the positive electrode:

[0134] The second heat dissipation material (specifically, hexagonal boron nitride) and the second binder (specifically, PVDF) with a mass ratio of 40:35 were mixed, and N-methyl pyrrolidone was added for mixing and stirring to obtain the second heat dissipation material layer slurry of the positive electrode.

[0135] Preparation of the positive electrode slurry and the positive electrode tab:

[0136] The positive electrode active material (lithium iron phosphate), carbon black, and polyvinylidene fluoride with a mass ratio of 98.5:0.5:1 were mixed, and NMP was added for mixing and stirring to obtain the positive electrode slurry.

[0137] Reference is made to the accompanying drawings Figure 4The positive electrode slurry, the first conductive material layer slurry of the positive electrode, and the second conductive material layer slurry of the positive electrode are simultaneously coated on the surface of the positive electrode current collector aluminum foil by an extrusion coater, the first conductive material layer slurry of the positive electrode and the second conductive layer slurry of the positive electrode are respectively located on both sides of the active area of the positive electrode slurry, so as to ensure that the conductive layer and the active area do not interpenetrate, and after baking, a positive electrode sheet is obtained. The positive electrode sheet is subjected to secondary coating, the first heat dissipation material layer slurry of the positive electrode and the second heat dissipation layer slurry of the positive electrode are simultaneously coated on the positive electrode sheet, the positions of the first heat dissipation material layer slurry of the positive electrode and the second heat dissipation layer slurry of the positive electrode correspond to the coating areas of the first conductive material layer slurry of the positive electrode and the second conductive layer slurry of the positive electrode respectively, and then after baking and roll cutting, the required positive electrode sheet is obtained. The width of the first conductive material layer of the positive electrode is 5 mm, and the thickness is 25 μm. The width of the first heat dissipation material layer of the positive electrode is 5 mm, and the thickness is 75 μm. The width of the second conductive material layer of the positive electrode is 5 mm, and the thickness is 25 μm. The width of the second heat dissipation material layer of the positive electrode is 5 mm, and the thickness is 75 μm.

[0138] (2) Preparation of the negative electrode sheet:

[0139] Preparation of the first conductive material layer slurry of the negative electrode:

[0140] The first conductive material (specifically MXene material Ti3C2T x , T x is a surface terminal group, at least one of -O, -OH, -F, and -Cl, and x is a positive real number in the range of 1-2 that satisfies the stoichiometric ratio) and the first binder (specifically PVDF) are mixed in a mass ratio of 40:35, and N-methyl pyrrolidone is added for mixing and stirring to obtain the first conductive material layer slurry of the negative electrode.

[0141] Preparation of the first heat dissipation material layer slurry of the negative electrode:

[0142] The first heat dissipation material (specifically hexagonal boron nitride) and the first binder (specifically PVDF) are mixed in a mass ratio of 40:35, and N-methyl pyrrolidone is added for mixing and stirring to obtain the first heat dissipation material layer slurry of the negative electrode.

[0143] Preparation of the second conductive material layer slurry of the negative electrode:

[0144] The second conductive material (specifically MXene material Ti3C2T x , T x is a surface terminal group, at least one of -O, -OH, -F, and -Cl, and x is a positive real number in the range of 1-2 that satisfies the stoichiometric ratio) and the second binder (specifically PVDF) are mixed in a mass ratio of 40:35, and N-methyl pyrrolidone is added for mixing and stirring to obtain the second conductive material layer slurry of the negative electrode.

[0145] Preparation of the second heat dissipation material layer slurry of the negative electrode:

[0146] The second heat dissipation material (specifically hexagonal boron nitride) and the second binder (specifically PVDF) with a mass ratio of 40:35 were mixed, and N-methyl pyrrolidone was added for mixing and stirring to obtain the second heat dissipation material layer slurry of the negative electrode.

[0147] The negative electrode active material (graphite), carbon black, butadiene rubber SBR, and CMC with a mass ratio of 97.5:1:1.5 were mixed, and benzyl ether was added for mixing and stirring to obtain the negative electrode slurry.

[0148] Preparation of the negative electrode slurry and the negative electrode tab:

[0149] The negative electrode active material (graphite), carbon black, butadiene rubber SBR, and CMC with a mass ratio of 97.5:1:1.5 were mixed, and water was added for mixing and stirring to obtain the negative electrode slurry.

[0150] Reference is made to the accompanying drawings Figure 4 The above negative electrode slurry, the first conductive material layer slurry of the negative electrode, and the second conductive material layer slurry of the negative electrode were simultaneously coated on the surface of the negative electrode current collector copper foil by an extrusion coater, wherein the first conductive material layer slurry of the negative electrode and the second conductive layer slurry of the negative electrode were respectively located on both sides of the active area where the negative electrode slurry was located, to ensure that the conductive layer and the active area do not interpenetrate, and after baking, a negative electrode tab was obtained. The first heat dissipation material layer slurry of the negative electrode and the second heat dissipation layer slurry of the negative electrode were simultaneously coated on the negative electrode tab, and the positions of the first heat dissipation material layer slurry of the negative electrode and the second heat dissipation layer slurry of the negative electrode corresponded to the coating areas of the first conductive material layer slurry of the negative electrode and the second conductive layer slurry of the negative electrode, respectively. After oven baking and roll cutting processing, the required negative electrode tab was obtained. The width of the first conductive material layer of the negative electrode formed was 5 mm, and the thickness was 25 μm. The width of the first heat dissipation material layer of the negative electrode was 5 mm, and the thickness was 75 μm. The width of the second conductive material layer of the negative electrode formed was 5 mm, and the thickness was 25 μm. The width of the second heat dissipation material layer of the negative electrode was 5 mm, and the thickness was 75 μm.

[0151] Comparative Example 1

[0152] The preparation method of Comparative Example 1 was basically the same as that of Example 3, and the only difference was that:

[0153] In the preparation process of the first heat dissipation layer of the positive electrode tab, only the first heat dissipation material and the first binder were included, and the first conductive material was not included. In the preparation process of the second heat dissipation layer of the positive electrode tab, only the second heat dissipation material and the second binder were included, and the second conductive material was not included. As shown in Table 1.

[0154] The first heat dissipation layer of the negative electrode does not contain a first conductive material, but only a first heat dissipation material and a first binder. The second heat dissipation layer of the negative electrode does not contain a second conductive material, but only a second heat dissipation material and a second binder. See Table 2.

[0155] Comparative Example 2

[0156] The preparation methods of Comparative Example 2 and Example 3 are basically the same, with the only difference being:

[0157] The first heat dissipation layer of the positive electrode does not contain a first heat dissipation material, but only a first conductive material and a first binder. The second heat dissipation layer of the positive electrode does not contain a second heat dissipation material, but only a second conductive material and a second binder. See Table 1.

[0158] The first heat dissipation layer of the negative electrode does not contain a first heat dissipation material, but only a first conductive material and a first binder. The second heat dissipation layer of the negative electrode does not contain a second heat dissipation material, but only a second conductive material and a second binder. See Table 2.

[0159] Table 1

[0160]

[0161] Table 2

[0162]

[0163] Test example:

[0164] Ear temperature rise test:

[0165] Drill a hole with a diameter of <5mm on the outside of the battery casing, introduce the thermocouple temperature sensing wire from the outside of the hole to the tab, and seal the hole with sealant. Connect this temperature sensing wire to a data acquisition instrument to test the tab temperature rise of the batteries in the above embodiment and comparative example under high-rate charging conditions.

[0166] First, the batteries after production were subjected to a capacity test. The charge / discharge rate was 0.33C, the cutoff current rate was 0.05C, the charging cutoff voltage was 3.8V, the discharging cutoff voltage was 2V, and the charge / discharge cycle was 3 cycles. The discharge capacity of the third cycle was taken as the actual capacity. The batteries were then placed in an ambient temperature of 25℃ and a 4C high-rate charging test was conducted. Temperature data at the tabs was collected using a data acquisition instrument. The results are shown in Table 3.

[0167] Table 3

[0168]

[0169] As can be seen from Table 3, compared with Comparative Example 1-2, the temperature rise of the positive electrode tab and the temperature rise of the negative electrode tab of Example 1-21 are effectively reduced, and it can be seen that by introducing the heat dissipation layer containing the heat dissipation material and the conductive material at the tab, the temperature rise at the tab can be effectively reduced, thereby facilitating the improvement of the tab overcurrent capacity.

[0170] As can be seen from Table 3, compared with Examples 1 and 5, the temperature rise of the positive electrode tab and the temperature rise of the negative electrode tab of Examples 2-4 are further reduced, and it can be seen that by limiting the mass ratio of the conductive material in the total mass of the heat dissipation material and the conductive material to be within the range of 5% to 50%, the temperature rise at the tab can be further effectively reduced, thereby facilitating the improvement of the tab overcurrent capacity.

[0171] As can be seen from Table 3, compared with Examples 10 and 13, the temperature rise of the positive electrode tab and the temperature rise of the negative electrode tab of Examples 3 and 11-12 are further reduced, and it can be seen that by limiting the width of the heat dissipation layer to be within the range of 2mm to 8mm, the temperature rise at the tab can be further effectively reduced, thereby facilitating the improvement of the tab overcurrent capacity.

[0172] As can be seen from Table 3, compared with Examples 14 and 17, the temperature rise of the positive electrode tab and the temperature rise of the negative electrode tab of Examples 3 and 15-16 are further reduced, and it can be seen that by limiting the thickness of the heat dissipation layer to be within the range of 50μm to 160μm, the temperature rise at the tab can be further effectively reduced, thereby facilitating the improvement of the tab overcurrent capacity.

[0173] As can be seen from Table 3, compared with Examples 18-20, the temperature rise of the positive electrode tab and the temperature rise of the negative electrode tab of Example 3 are further reduced, and it can be seen that by simultaneously arranging the heat dissipation layer at the tab and the slitting side of the positive electrode tab and simultaneously arranging the heat dissipation layer at the tab and the slitting side of the negative electrode tab, the temperature rise at the tab can be further effectively reduced, thereby facilitating the improvement of the tab overcurrent capacity.

[0174] As can be seen from Table 3, compared with Example 21, the temperature rise of the positive electrode tab and the temperature rise of the negative electrode tab of Example 3 are further reduced, and it can be seen that by mixing and doping the heat dissipation material and the conductive material in the heat dissipation layer, the temperature rise at the tab can be further effectively reduced, thereby facilitating the improvement of the tab overcurrent capacity.

[0175] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0176] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. An electrode sheet, characterized in that, include: current collector; A tab is disposed at one end of the current collector; A first heat dissipation layer is disposed on the current collector in the portion near the electrode tab; An active material layer is disposed on a portion of the current collector and, along a first direction, is located on the side of the first heat dissipation layer away from the tab. The first heat dissipation layer includes a first heat dissipation material layer and a first conductive material layer. The first conductive material layer is directly disposed on the current collector, and the first heat dissipation material layer is disposed on the surface of the first conductive material layer away from the current collector. The first heat dissipation material layer includes a first heat dissipation material, and the first conductive material layer includes a first conductive material. The first heat dissipation material includes at least one of hexagonal boron nitride, aluminum nitride, alumina, mica sheets, ultra-high molecular weight polyethylene fiber / epoxy resin composite material, and polyimide-filled boron nitride composite material; the first conductive material includes at least one of MXene material, carbon black, carbon nanotubes, graphene, metal oxides, and conductive polymers. The width d1 of the first heat dissipation layer is 2mm~8mm; the thickness of the first heat dissipation layer is 50μm~160μm. The thickness ratio of the first conductive material layer to the first heat dissipation material layer is (10~40):(60~90); the sum of the thicknesses of the first conductive material layer and the first heat dissipation material layer is 50μm~160μm.

2. The electrode sheet according to claim 1, characterized in that, The MXene material includes materials with the general formula M n+1 X n T x At least one of a one-dimensional transition metal carbide, nitride, and carbonitride; Wherein, M is selected from at least one of Ti, V, Nb, Mo, Ta, Cr, Hf, Zr, and Mn, and n is 1, 2, or 3; X is at least one of C and N; T x The surface terminal group includes at least one of -O, -OH, -F, and -Cl, and x is a positive real number in the range of 1 to 3 that satisfies the stoichiometric ratio.

3. The electrode sheet according to any one of claims 1 to 2, characterized in that, Also includes: A second heat dissipation layer is disposed on the current collector and along the first direction, the second heat dissipation layer is located on the side of the active material layer away from the first heat dissipation layer; The second heat dissipation layer includes a second heat dissipation material layer and a second conductive material layer. The second conductive material layer is directly disposed on the current collector, and the second heat dissipation material layer is disposed on the surface of the second conductive material layer away from the current collector. The second heat dissipation material layer includes a second heat dissipation material, and the second conductive material layer includes a second conductive material.

4. The electrode sheet according to claim 3, characterized in that, The width d2 of the second heat dissipation layer is 2mm~8mm; And / or, the thickness of the second heat dissipation layer is 50μm~160μm.

5. The electrode sheet according to claim 3, characterized in that, The thickness ratio of the second conductive material layer to the second heat dissipation material layer is (10~40):(60~90); And / or, the sum of the thicknesses of the second conductive material layer and the second heat dissipation material layer is 50 μm to 160 μm.

6. The electrode sheet according to claim 3, characterized in that, The second heat dissipation material includes at least one of hexagonal boron nitride, aluminum nitride, alumina, mica sheets, ultra-high molecular weight polyethylene fiber / epoxy resin composite material, and polyimide-filled boron nitride composite material; And / or, the second conductive material includes at least one of MXene material, carbon black, carbon nanotubes, graphene, metal oxides and conductive polymers.

7. The electrode sheet according to claim 6, characterized in that, The MXene material includes materials with the general formula M n+1 X n T x At least one of a one-dimensional transition metal carbide, nitride, and carbonitride; Wherein, M is selected from at least one of Ti, V, Nb, Mo, Ta, Cr, Hf, Zr, and Mn, and n is 1, 2, or 3; X is at least one of C and N; T x The surface terminal group includes at least one of -O, -OH, -F, and -Cl, and x is a positive real number in the range of 1 to 3 that satisfies the stoichiometric ratio.

8. A battery, characterized in that, It includes a positive electrode sheet, wherein the positive electrode sheet is the electrode sheet according to any one of claims 1 to 7; and / or, it includes a negative electrode sheet, wherein the negative electrode sheet is the electrode sheet according to any one of claims 1 to 7.

9. The battery according to claim 8, characterized in that, The width of the first heat dissipation layer of the positive electrode is greater than the width of the first heat dissipation layer of the negative electrode; and / or, both the positive electrode and the negative electrode include a second heat dissipation layer, the second heat dissipation layer is disposed on the current collector and along the first direction, the second heat dissipation layer is located on the side of the active material layer away from the first heat dissipation layer, the second heat dissipation layer includes a second heat dissipation material layer and a second conductive material layer, the second conductive material layer is directly disposed on the current collector, the second heat dissipation material layer is disposed on the surface of the second conductive material layer away from the current collector, the second heat dissipation material layer includes a second heat dissipation material, the second conductive material layer includes a second conductive material, and the width of the second heat dissipation layer of the positive electrode is greater than the width of the second heat dissipation layer of the negative electrode.

10. A battery device, characterized in that, It includes a housing and the battery as described in claim 8 or 9, wherein the battery is disposed within the housing.

11. An electrical appliance, characterized in that, Includes the battery as described in claim 8 or 9, or the battery device as described in claim 10.

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