WO2023087301A1 - 电化学装置和包含该电化学装置的电子装置 - Google Patents

电化学装置和包含该电化学装置的电子装置 Download PDF

Info

Publication number
WO2023087301A1
WO2023087301A1 PCT/CN2021/132074 CN2021132074W WO2023087301A1 WO 2023087301 A1 WO2023087301 A1 WO 2023087301A1 CN 2021132074 W CN2021132074 W CN 2021132074W WO 2023087301 A1 WO2023087301 A1 WO 2023087301A1
Authority
WO
WIPO (PCT)
Prior art keywords
functional layer
lithium
electrochemical device
current collector
adhesive
Prior art date
Application number
PCT/CN2021/132074
Other languages
English (en)
French (fr)
Inventor
李志愿
李娅洁
Original Assignee
东莞新能源科技有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 东莞新能源科技有限公司 filed Critical 东莞新能源科技有限公司
Priority to PCT/CN2021/132074 priority Critical patent/WO2023087301A1/zh
Publication of WO2023087301A1 publication Critical patent/WO2023087301A1/zh

Links

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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof

Definitions

  • the present application relates to the technical field of energy storage, and in particular to an electrochemical device and an electronic device including the electrochemical device.
  • Lithium-ion batteries have the advantages of high energy density, high power, and long cycle life, and are widely used in electric vehicles and consumer electronics. However, during the use of lithium-ion batteries, they may be subject to mechanical abuse such as extrusion, impact, and acupuncture, resulting in short-circuiting of the battery, which poses a great risk of safety performance. Therefore, the safety issues of lithium-ion batteries limit the application scenarios of lithium-ion batteries to a certain extent.
  • the present application provides an electrochemical device, which includes a double-layer coating between the current collector of the positive electrode and the active material layer, and uses a combination of a strong bonding interface and a weak bonding interface, so that the The protection of the current collector is increased during mechanical abuse, which significantly improves the mechanical safety performance of the electrochemical device.
  • the present application also relates to electronic devices comprising such electrochemical devices.
  • the application provides an electrochemical device, which includes a positive electrode, and the positive electrode includes a current collector, an active material layer, a first functional layer between the current collector and the active material layer, and a first functional layer between the first functional layer and the active material layer.
  • the second functional layer between the material layers, wherein the adhesive force between the current collector and the first functional layer is F1, the adhesive force between the first functional layer and the second functional layer is F2, and the second functional layer
  • the adhesive force with the active material layer is F3, satisfying: F1>F2, F3>F2.
  • the first functional layer and the second functional layer are sequentially arranged between the positive electrode current collector and the active material layer, thereby producing three kinds of bonding interfaces of strong and weak bonds in the positive electrode, wherein the current collector and the first functional layer There is a strong adhesive interface between them, and a weak adhesive interface between the first functional layer and the second functional layer.
  • the interface is easy to peel off from the weak bonding interface between the second functional layer and the first functional layer, ensuring the integrity of the first functional layer on the surface of the positive electrode current collector, thus avoiding the negative electrode active material layer between the positive electrode current collector and the negative electrode active material layer. Or direct contact with the negative electrode collector, reducing the risk of short circuit.
  • the arrangement of the first functional layer and the second functional layer can better protect the current collector, which can prevent the positive electrode current collector from directly contacting the negative electrode or the negative electrode current collector (such as copper foil), reduce short-circuit heat release, and further improve the electrochemical performance. device safety features.
  • the adhesive force between the second functional layer and the active material layer is higher than the adhesive force between the first functional layer and the second functional layer, which can reduce the risk of defilming when the electrochemical device is used for a long time.
  • F1/F2 25 ⁇ F1/F2 ⁇ 100.
  • F1/F2 the value of F1/F2 is within this range, a strong bonding interface between the positive current collector and the first functional layer and a weak bonding interface between the first functional layer and the second functional layer can be realized, which is conducive to strengthening the first functional layer.
  • the protection of the positive current collector by the first functional layer makes the interface easy to peel off from the weakly bonded interface during mechanical abuse, thereby reducing damage to the first functional layer and improving the safety performance of the electrochemical device.
  • F1/F2 the protection of the first functional layer to the positive electrode current collector is limited, and if F1/F2>100, then F2 is too small, which is not conducive to maintaining the stability of the electrode structure of the electrochemical device during the long cycle process.
  • the value of F1/F2 can be 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 and their any value in between.
  • F3/F2 ⁇ 1.5 The value of F3/F2 is within this range, which can ensure excellent cycle performance of the electrochemical device while achieving excellent mechanical safety performance of the electrochemical device. If F3/F2 ⁇ 1.5, there are two weakly bonded interfaces in the positive electrode, namely the weakly bonded interface between the first functional layer and the second functional layer and the weakly bonded interface between the second functional layer and the active material layer. During the long cycle of electrochemical devices, the more weak bonding interfaces there are, the higher the risk of defilming will be, which will deteriorate the cycle performance. In some embodiments of the present application, the value of F3/F2 may be 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, 10 and any value therebetween.
  • F1 200N/m ⁇ F1 ⁇ 400N/m.
  • the value range of F1 is within this range, which can realize a strong bonding interface between the positive electrode current collector and the first functional layer, so as to reduce the risk of damage to the first functional layer, thereby strengthening the protection of the positive electrode current collector and reducing the
  • the probability of direct contact between the positive electrode collector and the negative electrode sheet or negative electrode collector (such as copper foil) improves the mechanical safety performance of the electrochemical device. If F1 ⁇ 200N/m, the protection ability of the first functional layer to the electrochemical device is limited, and if F1>400N/m, then the first functional layer has little influence on the safety performance of the electrochemical device.
  • the value of F1 can be 200N/m, 220N/m, 240N/m, 260N/m, 280N/m, 300N/m, 320N/m, 340N/m, 360N/m , 380N/m, 400N/m and any value between them.
  • F2 the value of F2 is within this range, a weak bonding interface between the first functional layer and the second functional layer can be realized, which is beneficial to improving the mechanical safety performance of the electrochemical device and ensuring its cycle performance. If F2>8N/m, the bonding effect between the second functional layer and the first functional layer is too strong, and the peeling of the second functional layer will destroy the integrity of the first functional layer during mechanical abuse, thereby affecting the electrical properties. Mechanical safety performance of chemical installations. If F2 ⁇ 4N/m, the adhesion between the first functional layer and the second functional layer in the positive electrode is too low.
  • the value of F2 can be 4N/m, 4.5N/m, 5N/m, 5.5N/m, 6N/m, 6.5N/m, 7N/m, 7.5N/m , 8N/m and any value between them.
  • the thickness of the first functional layer is 2 ⁇ m to 8 ⁇ m. If the thickness of the first functional layer is less than 2 ⁇ m, the protective effect of the first functional layer on the positive current collector is weak, which is not conducive to the improvement of the mechanical safety performance of the electrochemical device. As the thickness of the first functional layer increases, its degree of protection to the positive electrode current collector also increases; however, excessive thickness will lose energy density, so controlling the thickness of the first functional layer within the above range is beneficial to improve the electrochemical device. mechanical safety performance.
  • the thickness of the first functional layer is 2 ⁇ m, 2.5 ⁇ m, 3 ⁇ m, 3.5 ⁇ m, 4 ⁇ m, 4.5 ⁇ m, 5 ⁇ m, 5.5 ⁇ m, 6 ⁇ m, 6.5 ⁇ m, 7 ⁇ m, 7.5 ⁇ m, 8 ⁇ m, or any of them any value in between.
  • the thickness of the second functional layer is 0.1 ⁇ m to 0.3 ⁇ m.
  • the thickness of the second functional layer within this range can enable the electrochemical device to achieve good mechanical safety performance.
  • the adhesive force between it and the first functional layer is too large, which is not conducive to the formation of a weak bonding interface between the first functional layer and the second functional layer;
  • the increase in the thickness of the second functional layer prolongs the electronic path of electrons in the positive electrode from the active material layer to the positive electrode current collector, which is not conducive to the rate performance of the electrochemical device; in addition, the thickness of the second functional layer is too large, which is also not conducive to the electrochemical device.
  • the thickness of the first functional layer is 0.1 ⁇ m, 0.12 ⁇ m, 0.14 ⁇ m, 0.16 ⁇ m, 0.18 ⁇ m, 0.2 ⁇ m, 0.22 ⁇ m, 0.24 ⁇ m, 0.26 ⁇ m, 0.28 ⁇ m, 0.3 ⁇ m and their any value in between.
  • the first functional layer includes a first adhesive, a first conductive agent and a first filler.
  • the first adhesive includes at least one of polyacrylic acid, polyvinyl alcohol, polyacrylonitrile, polyacrylamide, carboxymethyl cellulose, polyimide, styrene-butadiene rubber or polyurethane .
  • the first adhesive contains a large number of polar groups such as carboxyl, cyano or amine groups. When the polar groups are in contact with the current collector, the current collector is easy to lose electrons, and the polar groups are easy to gain electrons, and the electrons are easy to flow from the collector.
  • the fluid transfers to the polar groups in the adhesive, which generates contact potential on both sides of the interface, and forms an electric double layer to generate electrostatic attraction, which plays a role in bonding, so that there is a strong bond between the first functional layer and the current collector effect, thereby achieving a strong bonding interface.
  • the weight percentage of the first adhesive is 5% to 40%, and the weight percentage of the first conductive agent is 3% to 10%.
  • the weight percentage of the first filler is 50% to 92%.
  • the weight percentage of the first adhesive is 5% to 40%, such as 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or any value in between.
  • the content of the first binder is increased, and the adhesive force F1 between the first functional layer and the positive electrode current collector is increased, which is conducive to improving the mechanical safety performance of the electrochemical device; but the weight percentage of the first binder should not be high. In this case, it is difficult to ensure the coverage of the filler on the positive electrode collector, and there is a risk of missing coating, which weakens the protection of the first functional layer on the positive electrode collector and deteriorates the mechanical safety performance. risks of.
  • the weight percentage of the first conductive agent is 3% to 10%, for example, it can be 3%, 4%, 5%, 6%, 7%. %, 8%, 9%, 10%, or any value in between.
  • the weight percentage of the first conductive agent is within this range, the rate performance of the electrochemical device is not affected and excellent mechanical safety performance is ensured. If the weight percentage of the first conductive agent is less than 3%, the content of the conductive agent in the first functional layer is too small, the electronic resistance increases, and the electronic path in the positive electrode is greatly affected, which is not conducive to the improvement of the rate performance of the electrochemical device.
  • the weight percentage of the first conductive agent is greater than 10%, the electronic conductivity of the first functional layer is too strong, and the resistance of the first functional layer is too small, so even if the positive electrode current collector can be protected, it will avoid contact with the negative electrode sheet or The negative current collector is in direct contact, but the low resistance of the first functional layer itself is not conducive to the improvement of the safety performance of the electrochemical device.
  • the weight percentage of the first filler is 50% to 92%, such as 50%, 55%, 60%, 65%, 70%. , 75%, 80%, 85%, 90%, 92%, or any value in between. If the weight percentage of the first filler is less than 50%, the low filler content in the first functional layer is difficult to ensure the high coverage of the first functional layer to the positive electrode current collector, and there is a risk of missing coating, so that the first functional layer has a high degree of coverage on the positive electrode collector. The protection of the positive current collector is weakened, and there is a risk of deteriorating mechanical properties.
  • the weight percentage of the first filler is greater than 92%, then too little binder content in the first functional layer is difficult to ensure strong bonding between the positive electrode current collector and the first functional layer; the reduction of the conductive agent content makes The resistance of the first functional layer increases, which is not conducive to the rate performance of the electrochemical device.
  • the second functional layer includes a second adhesive, a second conductive agent and a second filler.
  • the second adhesive includes at least one of polyvinylidene fluoride or polytetrafluoroethylene.
  • the second adhesive contains less polar groups, so that the adhesive force between the first functional layer and the second functional layer is very low, thereby realizing a weak adhesive interface.
  • the weight percentage of the second adhesive is 5% to 40%, and the weight percentage of the second conductive agent is 3% to 10%.
  • the weight percentage of the second filler is 50% to 92%.
  • the weight percentage of the second adhesive is 5% to 40%, such as 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or any value in between. Controlling the content of the second binder within the above range is beneficial to increase the safety performance of the electrochemical device.
  • the adhesive force between the first functional layer and the second functional layer is too large, and it is difficult to realize a weak bonding interface, which is not conducive to the mechanical safety performance of the electrochemical device; if the second If the content of the second binder is less than 5%, the adhesive force between the first functional layer and the second functional layer is too small, and there is a risk of defilming of the positive electrode during circulation and cold pressing.
  • the weight percentage of the second conductive agent is 3% to 10%, such as 3%, 4%, 5%, 6%, 7% %, 8%, 9%, 10%, or any value in between. If the weight percentage of the second conductive agent is less than 3%, the content of the second conductive agent is too small, and the electronic resistance increases, which has a great impact on the electronic path in the positive electrode sheet, which is not conducive to the improvement of the rate performance of the cell. If the weight percentage of the second conductive agent is greater than 10%, the filler content in the second functional layer is too small, which may affect the coverage of the first functional layer by the second functional layer.
  • the weight percentage of the second filler is 50% to 92%, such as 50%, 55%, 60%, 65%, 70%. , 75%, 80%, 85%, 90%, 92%, or any value in between. If the weight percentage of the second filler is less than 50%, the low filler content in the second functional layer is difficult to ensure high coverage of the first functional layer, and there is a risk of missing coating, which is not conducive to the relationship between the first functional layer and the second functional layer. Weakly bonded interfaces between the layers are formed, with the risk of deteriorating mechanical properties.
  • the binder content in the second functional layer is too small, it is difficult to ensure proper bonding between the second functional layer and the active material layer, and there is a risk of stripping the pole piece. It affects the cycle performance of the electrochemical device; the reduction of the content of the conductive agent increases the resistance of the second functional layer, which is not conducive to the rate performance of the electrochemical device.
  • the first filler and the second filler each independently include lithium iron phosphate, lithium iron phosphate, silica, titania, alumina, boehmite, magnesia, zirconia, titania , silicon carbide, boron carbide, barium carbonate, potassium titanate, barium sulfate, vanadium trioxide, polyetheretherketone powder, polyamide powder or cellulose powder.
  • the first conductive agent and the second conductive agent each independently include at least one of conductive carbon black, acetylene black, graphite, graphene, carbon nanotubes, carbon fibers, aluminum powder, nickel powder or gold powder. kind.
  • the active material layer includes lithium cobaltate, lithium nickel manganese cobaltate, lithium nickel manganese aluminate, lithium iron phosphate, lithium vanadium phosphate, lithium cobalt phosphate, lithium manganese phosphate, lithium manganese iron phosphate, silicon At least one of lithium iron oxide, lithium vanadium silicate, lithium cobalt silicate, lithium manganese silicate, spinel lithium manganese oxide, spinel lithium nickel manganese oxide or lithium titanate.
  • the current collector in the positive electrode is aluminum foil.
  • the preparation method of the positive electrode includes the following steps:
  • the present application provides an electronic device comprising the electrochemical device of the first aspect of the present application.
  • the electrochemical device of the present application can better protect the positive electrode collector, thereby avoiding direct contact between the positive electrode collector and the negative electrode or the negative electrode collector, and reducing short-circuit heat release.
  • the electrochemical device of the present application has higher mechanical safety performance.
  • Fig. 1 shows a schematic structural diagram of a positive electrode of an electrochemical device according to an embodiment of the present application, wherein 1 is a current collector, 2 is a first functional layer, 3 is a second functional layer, and 4 is an active material layer.
  • FIG. 2 shows a schematic diagram of the mechanism of interface peeling of the positive electrode in the mechanical abuse process in the prior art, where 5 is a current collector, 6 is a conventional coating, and 7 is an active material layer.
  • Figure 3 shows a schematic diagram of the mechanism of interface peeling of the positive electrode during mechanical abuse in an electrochemical device according to an embodiment of the present application, wherein 1 is a current collector, 2 is a first functional layer, and 3 is a second functional layer, 4 is an active material layer, the interface between 1 and 2 is a strong bonding interface, and the interface between 2 and 3 is a weak bonding interface.
  • any lower limit can be combined with any upper limit to form an unexpressed range; and any lower limit can be combined with any other lower limit to form an unexpressed range, just as any upper limit can be combined with any other upper limit to form an unexpressed range.
  • each individually disclosed point or individual value may serve as a lower or upper limit by itself in combination with any other point or individual value or with other lower or upper limits to form an unexpressly recited range.
  • a list of items to which the terms "at least one of”, “at least one of”, “at least one of” or other similar terms are concatenated can mean any combination of the listed items. For example, if the items A and B are listed, the phrase “at least one of A and B" means only A; only B; or A and B. In another example, if the items A, B, and C are listed, the phrase “at least one of A, B, and C” means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C.
  • Item A may comprise a single component or multiple components.
  • Item B may comprise a single component or multiple components.
  • Item C may comprise a single component or multiple components.
  • the application provides an electrochemical device, which includes a positive electrode, and the positive electrode includes a current collector, an active material layer, a first functional layer between the current collector and the active material layer, and a first functional layer between the first functional layer and the active material layer.
  • the second functional layer between the material layers, wherein the adhesive force between the current collector and the first functional layer is F1, the adhesive force between the first functional layer and the second functional layer is F2, and the second functional layer
  • the adhesive force with the active material layer is F3, satisfying: F1>F2, F3>F2.
  • the first functional layer and the second functional layer are sequentially arranged between the positive electrode current collector and the active material layer, thereby producing three kinds of bonding interfaces of strong and weak bonds in the positive electrode, wherein the current collector and the first functional layer There is a strong adhesive interface between them, and a weak adhesive interface between the first functional layer and the second functional layer.
  • the interface is easy to peel off from the weak bonding interface between the second functional layer and the first functional layer, ensuring the integrity of the first functional layer on the surface of the positive electrode current collector, thus avoiding the negative electrode active material layer between the positive electrode current collector and the negative electrode active material layer. Or direct contact with the negative electrode collector, reducing the risk of short circuit.
  • the arrangement of the first functional layer and the second functional layer can better protect the current collector, which can prevent the positive electrode current collector from directly contacting the negative electrode or the negative electrode current collector (such as copper foil), reduce short-circuit heat release, and further improve the electrochemical performance. device safety features.
  • the adhesive force between the second functional layer and the active material layer is higher than the adhesive force between the first functional layer and the second functional layer, which can reduce the risk of defilming when the electrochemical device is used for a long time.
  • F1/F2 25 ⁇ F1/F2 ⁇ 100.
  • F1/F2 the value of F1/F2 is within this range, a strong bonding interface between the positive current collector and the first functional layer and a weak bonding interface between the first functional layer and the second functional layer can be realized, which is conducive to strengthening the first functional layer.
  • the protection of the positive current collector by a functional layer makes the interface easy to peel off from the weak bonding interface during mechanical abuse, thereby reducing damage to the first functional layer and improving the safety performance of the electrochemical device.
  • F1/F2 the protection of the first functional layer to the positive electrode current collector is limited, and if F1/F2>100, then F2 is too small, which is not conducive to maintaining the stability of the electrode structure of the electrochemical device during the long cycle process.
  • the value of F1/F2 can be 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 and their any value in between.
  • F3/F2 ⁇ 1.5 When the value of F3/F2 is within this range, excellent mechanical safety performance of the electrochemical device can be achieved while ensuring excellent cycle performance of the electrochemical device. If F3/F2 ⁇ 1.5, there are two weakly bonded interfaces in the positive electrode, namely the weakly bonded interface between the first functional layer and the second functional layer and the weakly bonded interface between the second functional layer and the active material layer. During the long cycle of electrochemical devices, the more weak bonding interfaces there are, the higher the risk of defilming will be, which will deteriorate the cycle performance. In some embodiments of the present application, the value of F3/F2 can be 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, 10 and any value between them.
  • F1 200N/m ⁇ F1 ⁇ 400N/m.
  • the value range of F1 is within this range, which can realize a strong bonding interface between the positive electrode current collector and the first functional layer, so as to reduce the risk of damage to the first functional layer, thereby strengthening the protection of the positive electrode current collector and reducing the
  • the probability of direct contact between the positive electrode collector and the negative electrode sheet or negative electrode collector (such as copper foil) improves the mechanical safety performance of the electrochemical device. If F1 ⁇ 200N/m, the protection ability of the first functional layer to the electrochemical device is limited, and if F1>400N/m, then the first functional layer has little influence on the safety performance of the electrochemical device.
  • the value of F1 can be 200N/m, 220N/m, 240N/m, 260N/m, 280N/m, 300N/m, 320N/m, 340N/m, 360N/m , 380N/m, 400N/m and any value between them.
  • F2 the value of F2 is within this range, a weak bonding interface between the first functional layer and the second functional layer can be realized, which is beneficial to improving the mechanical safety performance of the electrochemical device and ensuring its cycle performance. If F2>8N/m, the bonding effect between the second functional layer and the first functional layer is too strong, and the peeling of the second functional layer will destroy the integrity of the first functional layer during mechanical abuse, thereby affecting the electrical properties. Mechanical safety performance of chemical installations. If F2 ⁇ 4N/m, the adhesion between the first functional layer and the second functional layer in the positive electrode is too low.
  • the value of F2 can be 4N/m, 4.5N/m, 5N/m, 5.5N/m, 6N/m, 6.5N/m, 7N/m, 7.5N/m , 8N/m and any value between them.
  • the thickness of the first functional layer is 2 ⁇ m to 8 ⁇ m. If the thickness of the first functional layer is less than 2 ⁇ m, the protective effect of the first functional layer on the positive current collector is weak, which is not conducive to the improvement of the mechanical safety performance of the electrochemical device. As the thickness of the first functional layer increases, its degree of protection to the positive electrode current collector also increases; however, excessive thickness will lose energy density, so controlling the thickness of the first functional layer within the above range is beneficial to improve the electrochemical device. mechanical safety performance.
  • the thickness of the first functional layer is 2 ⁇ m, 2.5 ⁇ m, 3 ⁇ m, 3.5 ⁇ m, 4 ⁇ m, 4.5 ⁇ m, 5 ⁇ m, 5.5 ⁇ m, 6 ⁇ m, 6.5 ⁇ m, 7 ⁇ m, 7.5 ⁇ m, 8 ⁇ m, or any of them any value in between.
  • the thickness of the second functional layer is 0.1 ⁇ m to 0.3 ⁇ m.
  • the thickness of the second functional layer within this range can enable the electrochemical device to achieve good mechanical safety performance.
  • the adhesive force between it and the first functional layer is too large, which is not conducive to the formation of a weak bonding interface between the first functional layer and the second functional layer;
  • the increase in the thickness of the second functional layer prolongs the electronic path of electrons in the positive electrode from the active material layer to the positive electrode current collector, which is not conducive to the rate performance of the electrochemical device; in addition, the thickness of the second functional layer is too large, which is also not conducive to the electrochemical device.
  • the thickness of the first functional layer is 0.1 ⁇ m, 0.12 ⁇ m, 0.14 ⁇ m, 0.16 ⁇ m, 0.18 ⁇ m, 0.2 ⁇ m, 0.22 ⁇ m, 0.24 ⁇ m, 0.26 ⁇ m, 0.28 ⁇ m, 0.3 ⁇ m and their any value in between.
  • the first functional layer includes a first adhesive, a first conductive agent and a first filler.
  • the first adhesive includes at least one of polyacrylic acid, polyvinyl alcohol, polyacrylonitrile, polyacrylamide, carboxymethyl cellulose, polyimide, styrene-butadiene rubber or polyurethane .
  • the first adhesive contains a large number of polar groups such as carboxyl, cyano or amine groups. When the polar groups are in contact with the current collector, the current collector is easy to lose electrons, and the polar groups are easy to gain electrons, and the electrons are easy to flow from the collector.
  • the fluid transfers to the polar groups in the adhesive, which generates contact potential on both sides of the interface, and forms an electric double layer to generate electrostatic attraction, which plays a role in bonding, so that there is a strong bond between the first functional layer and the current collector effect, thereby achieving a strong bonding interface.
  • the weight percentage of the first adhesive is 5% to 40%, and the weight percentage of the first conductive agent is 3% to 10%.
  • the weight percentage of the first filler is 50% to 92%.
  • the weight percentage of the first adhesive is 5% to 40%, such as 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or any value in between.
  • the content of the first binder is increased, and the adhesive force F1 between the first functional layer and the positive electrode current collector is increased, which is conducive to improving the mechanical safety performance of the electrochemical device; but the weight percentage of the first binder should not be high. In this case, it is difficult to ensure the coverage of the filler on the positive electrode collector, and there is a risk of missing coating, which weakens the protection of the first functional layer on the positive electrode collector and deteriorates the mechanical safety performance. risks of.
  • the weight percentage of the first conductive agent is 3% to 10%, for example, it can be 3%, 4%, 5%, 6%, 7%. %, 8%, 9%, 10%, or any value in between.
  • the weight percentage of the first conductive agent is within this range, the rate performance of the electrochemical device is not affected and excellent mechanical safety performance is ensured. If the weight percentage of the first conductive agent is less than 3%, the content of the conductive agent in the first functional layer is too small, the electronic resistance increases, and the electronic path in the positive electrode is greatly affected, which is not conducive to the improvement of the rate performance of the electrochemical device.
  • the weight percentage of the first conductive agent is greater than 10%, the electronic conductivity of the first functional layer is too strong, and the resistance of the first functional layer is too small, so even if the positive electrode current collector can be protected, it will avoid contact with the negative electrode sheet or The negative current collector is in direct contact, but the low resistance of the first functional layer itself is not conducive to the improvement of the safety performance of the electrochemical device.
  • the weight percentage of the first filler is 50% to 92%, such as 50%, 55%, 60%, 65%, 70%. , 75%, 80%, 85%, 90%, 92%, or any value in between. If the weight percentage of the first filler is less than 50%, the low filler content in the first functional layer is difficult to ensure the high coverage of the first functional layer to the positive electrode current collector, and there is a risk of missing coating, so that the first functional layer has a high degree of coverage on the positive electrode collector. The protection of the positive current collector is weakened, and there is a risk of deteriorating mechanical properties.
  • the weight percentage of the first filler is greater than 92%, then too little binder content in the first functional layer is difficult to ensure strong bonding between the positive electrode current collector and the first functional layer; the reduction of the conductive agent content makes The resistance of the first functional layer increases, which is not conducive to the rate performance of the electrochemical device.
  • the second functional layer includes a second adhesive, a second conductive agent and a second filler.
  • the second adhesive includes at least one of polyvinylidene fluoride or polytetrafluoroethylene.
  • the second adhesive contains less polar groups, so that the adhesive force between the first functional layer and the second functional layer is very low, thereby realizing a weak adhesive interface.
  • the weight percentage of the second adhesive is 5% to 40%, and the weight percentage of the second conductive agent is 3% to 10%.
  • the weight percentage of the second filler is 50% to 92%.
  • the weight percentage of the second adhesive is 5% to 40%, such as 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or any value in between. Controlling the content of the second binder within the above range is beneficial to increase the safety performance of the electrochemical device.
  • the adhesive force between the first functional layer and the second functional layer is too large, and it is difficult to realize a weak bonding interface, which is not conducive to the mechanical safety performance of the electrochemical device; if the second If the content of the second binder is less than 5%, the adhesive force between the first functional layer and the second functional layer is too small, and there is a risk of defilming of the positive electrode during circulation and cold pressing.
  • the weight percentage of the second conductive agent is 3% to 10%, such as 3%, 4%, 5%, 6%, 7% %, 8%, 9%, 10%, or any value in between. If the weight percentage of the second conductive agent is less than 3%, the content of the second conductive agent is too small, and the electronic resistance increases, which has a great impact on the electronic path in the positive electrode sheet, which is not conducive to the improvement of the rate performance of the cell. If the weight percentage of the second conductive agent is greater than 10%, the filler content in the second functional layer is too small, which may affect the coverage of the first functional layer by the second functional layer.
  • the weight percentage of the second filler is 50% to 92%, such as 50%, 55%, 60%, 65%, 70%. , 75%, 80%, 85%, 90%, 92%, or any value in between. If the weight percentage of the second filler is less than 50%, the low filler content in the second functional layer is difficult to ensure high coverage of the first functional layer, and there is a risk of missing coating, which is not conducive to the relationship between the first functional layer and the second functional layer. Weakly bonded interfaces between the layers are formed, with the risk of deteriorating mechanical properties.
  • the binder content in the second functional layer is too small, it is difficult to ensure proper bonding between the second functional layer and the active material layer, and there is a risk of stripping the pole piece. It affects the cycle performance of the electrochemical device; the reduction of the content of the conductive agent increases the resistance of the second functional layer, which is not conducive to the rate performance of the electrochemical device.
  • the first filler and the second filler each independently include lithium iron phosphate, lithium iron phosphate, silica, titania, alumina, boehmite, magnesia, zirconia, titania , silicon carbide, boron carbide, barium carbonate, potassium titanate, barium sulfate, vanadium trioxide, polyetheretherketone powder, polyamide powder or cellulose powder.
  • the first conductive agent and the second conductive agent each independently include at least one of conductive carbon black, acetylene black, graphite, graphene, carbon nanotubes, carbon fibers, aluminum powder, nickel powder or gold powder. kind.
  • the active material layer includes lithium cobaltate, lithium nickel manganese cobaltate, lithium nickel manganese aluminate, lithium iron phosphate, lithium vanadium phosphate, lithium cobalt phosphate, lithium manganese phosphate, lithium manganese iron phosphate, silicon At least one of lithium iron oxide, lithium vanadium silicate, lithium cobalt silicate, lithium manganese silicate, spinel lithium manganese oxide, spinel lithium nickel manganese oxide or lithium titanate.
  • the current collector in the positive electrode is aluminum foil.
  • the preparation method of the positive electrode includes the following steps:
  • the electrochemical device of the present application includes any device that undergoes an electrochemical reaction, and specific examples thereof include primary batteries or secondary batteries.
  • the electrochemical device is a lithium secondary battery, including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery or a lithium ion polymer secondary battery.
  • the positive electrode in the present application can be used in electrochemical devices of different structures such as wound lithium ion batteries, specifically, for example, in lithium ion structures such as laminated structures and multi-tab structures.
  • the positive electrode in the present application can also be used in different types of lithium-ion batteries such as soft-pack lithium-ion batteries, specifically, for example, in lithium-ion batteries such as square aluminum shell batteries and cylindrical aluminum shell batteries.
  • the electrochemical device of the present application further includes a negative electrode, a separator, and an electrolyte.
  • the material, composition, and manufacturing method of the negative electrode used in the electrochemical device of the present application may include any technology disclosed in the prior art.
  • the negative electrode includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.
  • the negative electrode active material layer includes a negative electrode active material
  • the negative electrode active material may include materials that reversibly intercalate/deintercalate lithium ions, lithium metal, lithium metal alloys, materials capable of doping/dedoping lithium Or transition metal oxides, such as Si, SiO x (0 ⁇ x ⁇ 2) and other materials.
  • the material that reversibly intercalates/deintercalates lithium ions may be a carbon material.
  • the carbon material can be any carbon-based negative active material commonly used in lithium-ion rechargeable electrochemical devices. Examples of carbon materials include crystalline carbon, amorphous carbon, and combinations thereof.
  • the crystalline carbon may be amorphous, plate-like, platelet-like, spherical or fibrous natural or artificial graphite.
  • the amorphous carbon may be soft carbon, hard carbon, mesophase pitch carbonization product, fired coke, or the like. Both low-crystalline carbon and high-crystalline carbon can be used as the carbon material.
  • soft carbon and hard carbon may be generally included.
  • highly crystalline carbon materials natural graphite, crystalline graphite, pyrolytic carbon, mesophase pitch-based carbon fibers, mesocarbon microbeads, mesophase pitch, and high-temperature calcined carbons (such as petroleum or coke derived from coal tar pitch) may generally be included. ).
  • the negative electrode active material layer contains a binder
  • the binder may include various binder polymers, such as vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP) , polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, containing Polymers of ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyethylene, polypropylene, styrene-butadiene rubber, acrylic (ester)ized styrene-butadiene rubber, epoxy resin, nylon, etc., but not limited thereto wait.
  • PVDF-co-HFP vinylidene fluoride-hexafluoropropylene copolymer
  • the negative electrode active material layer further includes a conductive material to improve electrode conductivity.
  • a conductive material can be used as the conductive material as long as it does not cause a chemical change.
  • conductive materials include: carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fibers, etc.; metal-based materials such as metal powder or metal fibers including copper, nickel, aluminum, silver, etc. ; Conductive polymers, such as polyphenylene derivatives, etc.; or their mixtures.
  • the negative electrode current collector can be copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, or a combination thereof.
  • the material and shape of the separator used in the electrochemical device of the present application are not particularly limited, and it can be any technology disclosed in the prior art.
  • the separator includes a polymer or an inorganic substance formed of a material stable to the electrolyte of the present application.
  • a release film may include a substrate layer and a surface treatment layer.
  • the substrate layer is non-woven fabric, film or composite film with a porous structure, and the material of the substrate layer is at least one selected from polyethylene, polypropylene, polyethylene terephthalate and polyimide.
  • polypropylene porous film, polyethylene porous film, polypropylene non-woven fabric, polyethylene non-woven fabric or polypropylene-polyethylene-polypropylene porous composite film can be selected.
  • At least one surface of the substrate layer is provided with a surface treatment layer, and the surface treatment layer may be a polymer layer or an inorganic layer, or a layer formed by mixing polymers and inorganic materials.
  • the inorganic layer includes inorganic particles and a binder, and the inorganic particles are selected from aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium oxide, tin oxide, cerium oxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, At least one of yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide and barium sulfate.
  • the adhesive is selected from polyvinylidene fluoride, copolymer of vinylidene fluoride-hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinyl pyrrolidone, polyvinyl alkoxy , polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene at least one.
  • Polymer is contained in the polymer layer, and the material of polymer is selected from polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinyl pyrrolidone, polyvinyl alkoxide, polyvinylidene fluoride, At least one of poly(vinylidene fluoride-hexafluoropropylene).
  • composition of the electrolytic solution used in the electrochemical device of the present application and its manufacturing method may include any techniques disclosed in the prior art.
  • the electrolyte in the electrochemical device of the present application includes a lithium salt and a non-aqueous solvent.
  • the lithium salt is selected from LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiB(C 6 H 5 ) 4 , LiCH 3 SO 3 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2.
  • LiPF 6 may be selected as a lithium salt because it can give high ion conductivity and improve cycle characteristics.
  • the non-aqueous solvent can be carbonate compound, carboxylate compound, ether compound, other organic solvent or their combination.
  • the above-mentioned carbonate compound can be a chain carbonate compound, a cyclic carbonate compound, a fluorocarbonate compound or a combination thereof.
  • Examples of the aforementioned chain carbonate compounds are dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), carbonic acid Methyl ethyl ester (MEC) and combinations thereof.
  • Examples of cyclic carbonate compounds are ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylethylene carbonate (VEC), and combinations thereof.
  • fluorocarbonate compounds are fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate Ethyl carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-dicarbonate Fluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate, and combinations thereof.
  • FEC fluoroethylene carbonate
  • 1,2-difluoroethylene carbonate 1,1-difluoroethylene carbonate
  • 1,1,2-trifluoroethylene carbonate Ethyl carbonate 1,1,2,2-tetrafluoroethylene carbonate
  • 1-fluoro-2-methylethylene carbonate 1-fluoro-1-methylethylene carbonate
  • 1,2-dicarbonate Fluoro-1-methylethylene carbonate
  • Examples of the above carboxylate compounds are methyl formate, methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, ⁇ -butyrolactone , decanolactone, valerolactone, mevalonolactone, caprolactone, and combinations thereof.
  • ether compounds examples include dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethyl Oxyethane, 2-methyltetrahydrofuran, tetrahydrofuran, and combinations thereof.
  • Examples of the aforementioned other organic solvents are dimethylsulfoxide, 1,2-dioxolane, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, Formamide, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate, trioctyl phosphate, and phosphate esters, and combinations thereof.
  • the present application further provides an electronic device comprising the electrochemical device of the present application.
  • electronic devices of the present application include, but are not limited to, notebook computers, pen-input computers, mobile computers, e-book players, cellular phones, portable fax machines, portable copiers, portable printers, headsets , VCR, LCD TV, Portable Cleaner, Portable CD Player, Mini Disc, Transceiver, Electronic Notepad, Calculator, Memory Card, Portable Recorder, Radio, Backup Power, Motor, Automobile, Motorcycle, Assisted Bicycle, Bicycle , Lighting appliances, toys, game consoles, clocks, electric tools, flashlights, cameras or large batteries for household use, etc.
  • the SOC is 0% of the cell at 1.5C CC to 100% SOC, CV to 0.05C.
  • the positive electrode sheet includes a current collector 1, a first functional layer 2, a second functional layer 3 and an active material layer 4, and the preparation method is as follows:
  • the current collector 1 is aluminum foil, and the active material layer is lithium cobaltate; the specific first binder, first conductive agent, first filler, second binder, and second conductive agent in each embodiment and comparative example and the composition of the second filler are detailed in Table 1 below.
  • the positive electrode active material lithium cobaltate, acetylene black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 94:3:3, and then N-methylpyrrolidone (NMP) was added as a solvent to prepare a solid content of 75%. paste, and stir well.
  • NMP N-methylpyrrolidone
  • the slurry was uniformly coated on both sides of the aluminum foil, dried at 110° C., and cold-pressed to obtain a double-sided electrode sheet with a positive electrode active material layer thickness of 130 ⁇ m. Cut the positive pole piece into a size of 74mm ⁇ 867mm and weld the tabs for use.
  • lithium-ion battery Stack the positive electrode, separator, and negative electrode in order, so that the separator is between the positive electrode and the negative electrode to play the role of isolation. Winding to get bare cells. Put the bare cell in the outer package, after vacuum drying, inject electrolyte, and package. Lithium-ion batteries are obtained through processes such as formation, degassing, and trimming.
  • Examples 1 to 9 show the influence of the type and content of the first binder in the first functional layer on the performance of the prepared lithium-ion battery. According to Examples 1 to 5, it can be seen that the first adhesive has more polar groups, so that a strong bonding interface is formed between the first functional layer and the aluminum foil, and the second adhesive PVDF has no polarity.
  • the integrity of the first functional layer on the surface of the fluid avoids the direct contact between the positive electrode current collector and the negative electrode active material layer or the negative electrode current collector, reduces the risk of short circuit, reduces short circuit heat release, and makes the battery have a high impact test passing rate and nail penetration
  • the test pass rate improves the safety performance of the battery.
  • Example 1 and Example 6 to Example 9 it can be seen that as the content of the first adhesive increases, the adhesive force F1 between the first functional layer and the aluminum foil increases, which is conducive to improving the safety performance of the battery; but the second 1.
  • the content of the adhesive should not be higher than 40%, otherwise the filler content will decrease, it will be difficult to ensure the coverage of the filler on the aluminum foil, and there will be a risk of missing coating, which will weaken the protection of the first functional layer on the aluminum foil and cause the risk of deterioration of the mechanical safety performance.
  • Example 1 and Example 10 to Example 15 show the influence of the type of the first conductive agent and the type of the first filler in the first functional layer on the performance of the prepared lithium-ion battery. According to Example 1 and Example 10 to Example 15, it can be seen that the type of the first conductive agent has a slight influence on the adhesive force F1 between the first functional layer and the aluminum foil, and the type of the first filler has a great influence on the first functional layer. The adhesion force F1 between the aluminum foil and the aluminum foil has no significant effect, but they are all high, and the safety performance of the battery is also good.
  • Example 1 and Example 16 to Example 19 show the influence of the thickness of the first functional layer on the performance of the prepared lithium ion battery. According to Example 1 and Example 16 to Example 19, it can be seen that the thickness of the first functional layer increases, and the degree of protection of the aluminum foil increases; but too high a thickness will lose energy density, so the thickness of the first functional layer needs to be increased within a reasonable range of control.
  • Example 1 and Example 20 to Example 25 show the influence of the type and content of the second binder in the second functional layer on the performance of the prepared lithium-ion battery.
  • the second adhesive has no polar groups, so that a weak bonding interface is formed between the first functional layer and the second functional layer
  • the first adhesive Polyacrylic acid has more polar groups, so that a strong bonding interface is formed between the first functional layer and the aluminum foil, so that the interface is easy to change from the weak bonding interface between the second functional layer and the first functional layer during mechanical abuse.
  • Example 1 and Example 22 to Example 25 it can be seen that as the content of the second adhesive increases, the adhesive force F2 between the first functional layer and the second functional layer increases, and it is difficult to achieve a weak bonding interface. , which is not conducive to the mechanical safety performance of the battery; but the second adhesive should not be too low, otherwise the adhesive force F2 between the first functional layer and the second functional layer is too small, and there is a risk of film removal during processing and use.
  • Example 1 and Example 26 to Example 28 show the influence of the second filler in the second functional layer on the performance of the prepared lithium-ion battery. According to Example 1 and Example 26 to Example 28, it can be seen that the type of the second filler has no significant influence on the adhesive force F2 between the first functional layer and the second functional layer, and the safety performance of the battery is also good. .
  • Example 1 and Example 29 to Example 30 show the influence of the thickness of the second functional layer on the performance of the prepared lithium-ion battery. According to Example 1 and Example 29 to Example 30, it can be seen that the thickness of the second functional layer increases, and its adhesive force with the first functional layer is too large, which is not conducive to the bonding between the first functional layer and the second functional layer. However, if the thickness of the second functional layer is too small, the bonding force F2 between the first functional layer and the second functional layer is too low, and the process of battery preparation and use There is a risk of stripping, so the thickness of the second functional layer needs to be controlled within a reasonable range.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Secondary Cells (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本申请涉及电化学装置和包含该电化学装置的电子装置。本申请提供的电化学装置包括正极，所述正极包括集流体、活性物质层、位于所述集流体和所述活性物质层之间的第一功能层和位于所述第一功能层和所述活性物质层之间的第二功能层，其中，所述集流体与所述第一功能层之间的粘接力为F1，所述第一功能层与所述第二功能层之间的粘接力为F2，所述第二功能层与所述活性物质层之间的粘接力为F3，满足：F1＞F2，F3＞F2。本申请的电化学装置能够提升机械滥用时的安全性能。

Description

电化学装置和包含该电化学装置的电子装置 技术领域
本申请涉及储能技术领域，尤其涉及一种电化学装置和包含该电化学装置的电子装置。
背景技术
锂离子电池具有能量密度大、功率高、循环寿命长等优点，在电动汽车以及消费类电子产品中有广泛应用。但锂离子电池在使用过程中，可能会受到挤压、冲击、针刺等机械滥用，导致电池短路，有极大的安全性能风险。因此，锂离子电池的安全问题一定程度上限制了锂离子电池的应用场景。
在现有技术中，通过在正极集流体表面涂一层涂层，从而增加正极集流体与负极、正极集流体与负极集流体的接触电阻，减少短路放热，但现有涂层与正极活性物质层之间粘接力强(如图2所示)，使其对正极集流体保护有限，导致在电池的冲击、穿钉测试中，正极活性物质层剥离时带动该涂层剥离，使正极集流体实际处于暴露状态，负极活性物质层或负极集流体极易与正极集流体直接接触导致短路，大量放热。
发明内容
鉴于现有技术中存在的不足，本申请提供一种电化学装置，其正极的集流体和活性物质层之间包括双层涂层，采用强粘接界面与弱粘接界面相结合，从而在机械滥用时增加对集流体的保护，使电化学装置的机械安全性能显著提升。本申请还涉及包括这种电化学装置的电子装置。
在第一方面，本申请提供了一种电化学装置，其包括正极，正极包括集 流体、活性物质层、位于集流体和活性物质层之间的第一功能层和位于第一功能层和活性物质层之间的第二功能层，其中，集流体与第一功能层之间的粘接力为F1，第一功能层与第二功能层之间的粘接力为F2，第二功能层与活性物质层之间的粘接力为F3，满足：F1＞F2，F3＞F2。
本申请中，在正极集流体和活性物质层之间依次设置第一功能层和第二功能层，从而在正极中产生强弱结合的三种粘接界面，其中，集流体与第一功能层之间为强粘接界面，第一功能层与第二功能层之间为弱粘接界面。在机械滥用过程中，界面容易从第二功能层与第一功能层的弱粘接界面处剥离，确保正极集流体表面第一功能层的完整性，从而避免了正极集流体与负极活性物质层或负极集流体直接接触，降低了短路风险。该第一功能层和第二功能层的设置对集流体产生较好的保护，可避免正极集流体直接与负极或负极集流体(例如铜箔)接触，减少短路放热，从而进一步提升电化学装置的安全性能。此外，第二功能层与活性物质层之间的粘接力高于第一功能层与第二功能层之间的粘接力，可以降低电化学装置长时间使用时出现脱膜的风险。
根据本申请的一些实施方式，25≤F1/F2≤100。F1/F2的取值在此范围内，可实现正极集流体与第一功能层之间的强粘接界面以及第一功能层与第二功能层之间的弱粘接界面，有利于加强第一功能层对正极集流体的保护，使得在机械滥用过程中，界面易从弱粘结界面处剥离，从而降低对第一功能层的破坏，进而提升电化学装置的安全性能。若F1/F2<25，则第一功能层对正极集流体的保护有限，若F1/F2>100，则F2太小，不利于电化学装置在长循环过程中保持极片结构稳定。在本申请的一些实施方式中，F1/F2的取值可以是25、30、35、40、45、50、55、60、65、70、75、80、85、90、95、100以及它们之间的任意值。
根据本申请的一些实施方式，F3/F2≥1.5。F3/F2的取值在此范围内，可在实现电化学装置的机械安全性能优异的同时，保证电化学装置的循环性能 也较优异。若F3/F2<1.5，则在正极中存在两个弱粘接界面，即第一功能层与第二功能层之间的弱粘接界面以及第二功能层与活性物质层之间的弱粘接界面，而电化学装置在长循环过程中，弱粘接界面越多，出现脱膜的风险就越高，进而使循环性能变差。在本申请的一些实施方式中，F3/F2的取值可以是1.5、2、2.5、3、4、5、6、7、8、9、10以及它们之间的任意值。
根据本申请的一些实施方式，200N/m≤F1≤400N/m。F1的取值范围在此范围内，可实现正极集流体与第一功能层之间的强粘接界面，以减小第一功能层被破坏的风险，进而加强对正极集流体的保护，减少正极集流体与负极极片或负极集流体(例如铜箔)直接接触的概率，提升电化学装置的机械安全性能。若F1<200N/m，则第一功能层对电化学装置的保护能力有限，若F1>400N/m，则第一功能层对电化学装置的安全性能影响较小。在本申请的一些实施方式中，F1的取值可以是200N/m、220N/m、240N/m、260N/m、280N/m、300N/m、320N/m、340N/m、360N/m、380N/m、400N/m以及它们之间的任意值。
根据本申请的一些实施方式，4N/m≤F2≤8N/m。F2的取值在此范围内，可实现第一功能层与第二功能层之间的弱粘接界面，有利于提升电化学装置的机械安全性能并保证其循环性能。若F2>8N/m，则第二功能层与第一功能层之间的粘接作用过强，机械滥用过程中，第二功能层的剥离会破坏第一功能层的完整性，从而影响电化学装置的机械安全性能。若F2<4N/m，则在正极中第一功能层与第二功能层之间粘接力过低，在这种情况下，电化学装置在循环过程中难以维持极片多层结构的紧密结合，出现循环脱膜的概率高，因此影响电化学装置的循环性能。在本申请的一些实施方式中，F2的取值可以是4N/m、4.5N/m、5N/m、5.5N/m、6N/m、6.5N/m、7N/m、7.5N/m、8N/m以及它们之间的任意值。
根据本申请的一些实施方式，第一功能层的厚度为2μm至8μm。若第一 功能层厚度小于2μm，则第一功能层对正极集流体的保护作用较弱，不利于电化学装置的机械安全性能的提升。随着第一功能层的厚度增加，其对正极集流体的保护程度也增加；但是，过高的厚度会损失能量密度，因此第一功能层的厚度控制在上述范围内有利于提高电化学装置的机械安全性能。在本申请的一些实施方式中，第一功能层的厚度为2μm、2.5μm、3μm、3.5μm、4μm、4.5μm、5μm、5.5μm、6μm、6.5μm、7μm、7.5μm、8μm以及它们之间的任意值。
根据本申请的一些实施方式，第二功能层的厚度为0.1μm至0.3μm。第二功能层的厚度在此范围内能够使电化学装置实现良好的机械安全性能。一方面，若第二功能层厚度太大，则其与第一功能层的粘接力过大，不利于第一功能层与第二功能层之间的弱粘接界面形成；另一方面，第二功能层厚度增加使正极中电子从活性物质层到正极集流体的电子通路延长，不利于电化学装置的倍率性能；此外，第二功能层的厚度过大，也不利于电化学装置的能量密度提升。若第二功能层的厚度太小，则第一功能层和第二功能层之间的粘接力太低，在电化学装置的制备与使用过程中存在脱膜风险。在本申请的一些实施方式中，第一功能层的厚度为0.1μm、0.12μm、0.14μm、0.16μm、0.18μm、0.2μm、0.22μm、0.24μm、0.26μm、0.28μm、0.3μm以及它们之间的任意值。
根据本申请的一些实施方式，第一功能层包括第一粘接剂、第一导电剂和第一填料。
根据本申请的一些实施方式，第一粘接剂包括聚丙烯酸、聚乙烯醇、聚丙烯腈、聚丙烯酰胺、羧甲基纤维素、聚酰亚胺、丁苯橡胶或聚氨酯中的至少一种。第一粘接剂含有大量的羧基、氰基或胺基等极性基团，极性基团与集流体接触时，集流体容易失去电子，而极性基团容易得到电子，电子易从集流体向粘接剂中的极性基团转移，使界面两侧产生接触电势，并形成双电 层产生静电引力，起到了粘接作用，使第一功能层与集流体之间有强粘接作用，从而实现强粘接界面。
根据本申请的一些实施方式，以第一功能层的总重量计，第一粘接剂的重量百分含量为5％至40％，第一导电剂的重量百分含量为3％至10％，第一填料的重量百分含量为50％至92％。
根据本申请的一些实施方式，以第一功能层的总重量计，第一粘接剂的重量百分含量为5％至40％，例如可以是5％、10％、15％、20％、25％、30％、35％、40％或它们之间的任意值。第一粘接剂的含量增加，第一功能层与正极集流体之间的粘接力F1增加，有利于提升电化学装置的机械安全性能；但是第一粘接剂的重量百分含量不宜高于40％，因为会导致填料含量过少，这种情况下难以保证填料对正极集流体的覆盖度，存在漏涂风险，使得第一功能层对正极集流体的保护减弱，存在恶化机械安全性能的风险。
根据本申请的一些实施方式，以第一功能层的总重量计，第一导电剂的重量百分含量为3％至10％，例如可以是3％、4％、5％、6％、7％、8％、9％、10％或它们之间的任意值。第一导电剂的重量百分含量在此范围内，可实现电化学装置的倍率性能不受影响并保证优异的机械安全性能。若第一导电剂的重量百分含量小于3％，则第一功能层中导电剂含量过少，电子电阻增加，对正极中电子通路影响较大，不利于电化学装置的倍率性能提升。若第一导电剂的重量百分含量大于10％，则第一功能层的电子电导能力过强，第一功能层的电阻过小，这样即使能够保护正极集流体，避免其与负极极片或负极集流体直接接触，但第一功能层本身的低电阻仍不利于电化学装置安全性能的提升。
根据本申请的一些实施方式，以第一功能层的总重量计，第一填料的重量百分含量为50％至92％，例如可以是50％、55％、60％、65％、70％、75％、80％、85％、90％、92％或它们之间的任意值。若第一填料的重量百分含量小 于50％，则第一功能层中的低填料含量难以保证第一功能层对正极集流体的高的覆盖度，存在漏涂风险，使得第一功能层对正极集流体的保护减弱，存在恶化机械性能的风险。若第一填料的重量百分含量大于92％，则第一功能层中粘接剂含量的太少难以保证正极集流体与第一功能层之间的强粘接作用；导电剂含量的减少使第一功能层的电阻增加，不利于电化学装置的倍率性能。
根据本申请的一些实施方式，第二功能层包括第二粘接剂、第二导电剂和第二填料。
根据本申请的一些实施方式，第二粘接剂包括聚偏氟乙烯或聚四氟乙烯中的至少一种。第二粘接剂中含有较少的极性基团，使得第一功能层与第二功能层之间的粘接力很低，从而实现弱粘接界面。
根据本申请的一些实施方式，以第二功能层的总重量计，第二粘接剂的重量百分含量为5％至40％，第二导电剂的重量百分含量为3％至10％，第二填料的重量百分含量为50％至92％。
根据本申请的一些实施方式，以第二功能层的总重量计，第二粘接剂的重量百分含量为5％至40％，例如可以是5％、10％、15％、20％、25％、30％、35％、40％或它们之间的任意值。第二粘接剂的含量控制在上述范围内有利于增加电化学装置的安全性能。若第二粘接剂的含量大于40％，则第一功能层与第二功能层之间的粘接力过大，难以实现弱粘接界面，不利于电化学装置的机械安全性能；若第二粘接剂的含量小于5％，则第一功能层与第二功能层之间的粘接力太小，正极在循环与冷压过程中存在脱膜风险。
根据本申请的一些实施方式，以第二功能层的总重量计，第二导电剂的重量百分含量为3％至10％，例如可以是3％、4％、5％、6％、7％、8％、9％、10％或它们之间的任意值。若第二导电剂的重量百分含量小于3％，则第二导电剂含量过少，电子电阻增加，对正极极片中电子通路影响较大，不利于电芯倍率性能提升。若第二导电剂的重量百分含量大于10％，则第二功能层中 的填料含量过少，可能影响第二功能层对第一功能层的覆盖度。
根据本申请的一些实施方式，以第二功能层的总重量计，第二填料的重量百分含量为50％至92％，例如可以是50％、55％、60％、65％、70％、75％、80％、85％、90％、92％或它们之间的任意值。若第二填料的重量百分含量小于50％，则第二功能层中的低填料含量难以保证对第一功能层的高覆盖度，存在漏涂风险，不利于第一功能层与第二功能层之间的弱粘接界面形成，存在恶化机械性能的风险。若第二填料的重量百分含量大于92％，则第二功能层中粘接剂含量过小，难以保证第二功能层与活性物质层之间的适当粘接，存在极片脱膜风险，影响电化学装置的循环性能；导电剂含量的减少使第二功能层电阻增加，不利于电化学装置的倍率性能。
根据本申请的一些实施方式，第一填料和第二填料各自独立地包括磷酸铁锂、磷酸亚铁锂、二氧化硅、二氧化钛、三氧化二铝、勃姆石、氧化镁、氧化锆、二氧化钛、碳化硅、碳化硼、碳酸钡、钛酸钾、硫酸钡、三氧化二钒、聚醚醚酮粉、聚酰胺粉或纤维素粉中的至少一种。
根据本申请的一些实施方式，第一导电剂和第二导电剂各自独立地包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管、碳纤维、铝粉、镍粉或金粉中的至少一种。
根据本申请的一些实施方式，活性物质层包括钴酸锂、镍锰钴酸锂、镍锰铝酸锂、磷酸铁锂、磷酸钒锂、磷酸钴锂、磷酸锰锂、磷酸锰铁锂、硅酸铁锂、硅酸钒锂、硅酸钴锂、硅酸锰锂、尖晶石型锰酸锂、尖晶石型镍锰酸锂或钛酸锂中的至少一种。
根据本申请的一些实施方式，正极中的集流体为铝箔。
根据本申请的一些实施方式，正极的制备方法包括以下步骤：
S1：在集流体表面涂覆包括第一粘接剂、第一导电剂和第一填料的浆料，干燥后得到涂覆第一功能层的集流体；
S2：在第一功能层上涂覆包括第二粘接剂、第二导电剂和第二填料的浆料，干燥后得到涂覆有第一功能层和第二功能层的集流体；
S3：在第二功能层上涂覆活性物质层，干燥并冷压得到正极。
在第二方面，本申请提供了一种电子装置，其包括本申请第一方面的电化学装置。
本申请的电化学装置能够较好地保护正极集流体，从而避免正极集流体直接与负极或负极集流体接触，减少短路放热。本申请的电化学装置具有更高的机械安全性能。
附图说明
图1显示了根据本申请的一个实施方式的电化学装置的正极的结构示意图，其中，1为集流体，2为第一功能层，3为第二功能层，4为活性物质层。
图2显示了现有技术中电化学装置中正极在机械滥用过程中界面剥离的作用机理示意图，其中，5为集流体，6为常规涂层，7为活性物质层。
图3显示了根据本申请的一个实施方式的电化学装置中正极在机械滥用过程中界面剥离的作用机理示意图，其中，1为集流体，2为第一功能层，3为第二功能层，4为活性物质层，1和2之间的界面为强粘接界面，2和3之间的界面为弱粘接界面。
具体实施方式
为使本申请的目的、技术方案和优点更加清楚，下面将结合实施例对本申请的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。在此所描述的有关实施例为说明性质的且用于提供对本申请的基本理解。本申请的实施例不应该被解释为对本申请 的限制。
为了简明，本文仅具体地公开了一些数值范围。然而，任意下限可以与任何上限组合形成未明确记载的范围；以及任意下限可以与其它下限组合形成未明确记载的范围，同样任意上限可以与任意其它上限组合形成未明确记载的范围。此外，每个单独公开的点或单个数值自身可以作为下限或上限与任意其它点或单个数值组合或与其它下限或上限组合形成未明确记载的范围。
在本文的描述中，除非另有说明，“以上”、“以下”包含本数。
除非另有说明，本申请中使用的术语具有本领域技术人员通常所理解的公知含义。除非另有说明，本申请中提到的各参数的数值可以用本领域常用的各种测量方法进行测量(例如，可以按照在本申请的实施例中给出的方法进行测试)。
术语“中的至少一者”、“中的至少一个”、“中的至少一种”或其他相似术语所连接的项目的列表可意味着所列项目的任何组合。例如，如果列出项目A及B，那么短语“A及B中的至少一者”意味着仅A；仅B；或A及B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的至少一者”意味着仅A；或仅B；仅C；A及B(排除C)；A及C(排除B)；B及C(排除A)；或A、B及C的全部。项目A可包含单个组分或多个组分。项目B可包含单个组分或多个组分。项目C可包含单个组分或多个组分。
一、电化学装置
在第一方面，本申请提供了一种电化学装置，其包括正极，正极包括集流体、活性物质层、位于集流体和活性物质层之间的第一功能层和位于第一功能层和活性物质层之间的第二功能层，其中，集流体与第一功能层之间的粘接力为F1，第一功能层与第二功能层之间的粘接力为F2，第二功能层与活性物质层之间的粘接力为F3，满足：F1＞F2，F3＞F2。
本申请中，在正极集流体和活性物质层之间依次设置第一功能层和第二功能层，从而在正极中产生强弱结合的三种粘接界面，其中，集流体与第一功能层之间为强粘接界面，第一功能层与第二功能层之间为弱粘接界面。在机械滥用过程中，界面容易从第二功能层与第一功能层的弱粘接界面处剥离，确保正极集流体表面第一功能层的完整性，从而避免了正极集流体与负极活性物质层或负极集流体直接接触，降低了短路风险。该第一功能层和第二功能层的设置对集流体产生较好的保护，可避免正极集流体直接与负极或负极集流体(例如铜箔)接触，减少短路放热，从而进一步提升电化学装置的安全性能。此外，第二功能层与活性物质层之间的粘接力高于第一功能层与第二功能层之间的粘接力，可以降低电化学装置长时间使用时出现脱膜的风险。
根据本申请的一些实施方式，25≤F1/F2≤100。F1/F2的取值在此范围内，可实现正极集流体与第一功能层之间的强粘接界面以及第一功能层与第二功能层之间的弱粘接界面，有利于加强第一功能层对正极集流体的保护，使得在机械滥用过程中界面易从弱粘结界面处剥离，从而降低对第一功能层的破坏，进而提升电化学装置的安全性能。若F1/F2<25，则第一功能层对正极集流体的保护有限，若F1/F2>100，则F2太小，不利于电化学装置在长循环过程中保持极片结构稳定。在本申请的一些实施方式中，F1/F2的取值可以是25、30、35、40、45、50、55、60、65、70、75、80、85、90、95、100以及它们之间的任意值。
根据本申请的一些实施方式，F3/F2≥1.5。F3/F2的取值在此范围内，可在实现电化学装置的机械安全性能优异的同时，保证电化学装置的循环性能也较优异。若F3/F2<1.5，则在正极中存在两个弱粘接界面，即第一功能层与第二功能层之间的弱粘接界面以及第二功能层与活性物质层之间的弱粘接界面，而电化学装置在长循环过程中，弱粘接界面越多，出现脱膜的风险就越高，进而使循环性能变差。在本申请的一些实施方式中，F3/F2的取值可以是 1.5、2、2.5、3、4、5、6、7、8、9、10以及它们之间的任意值。
根据本申请的一些实施方式，200N/m≤F1≤400N/m。F1的取值范围在此范围内，可实现正极集流体与第一功能层之间的强粘接界面，以减小第一功能层被破坏的风险，进而加强对正极集流体的保护，减少正极集流体与负极极片或负极集流体(例如铜箔)直接接触的概率，提升电化学装置的机械安全性能。若F1<200N/m，则第一功能层对电化学装置的保护能力有限，若F1>400N/m，则第一功能层对电化学装置的安全性能影响较小。在本申请的一些实施方式中，F1的取值可以是200N/m、220N/m、240N/m、260N/m、280N/m、300N/m、320N/m、340N/m、360N/m、380N/m、400N/m以及它们之间的任意值。
根据本申请的一些实施方式，4N/m≤F2≤8N/m。F2的取值在此范围内，可实现第一功能层与第二功能层之间的弱粘接界面，有利于提升电化学装置的机械安全性能并保证其循环性能。若F2>8N/m，则第二功能层与第一功能层之间的粘接作用过强，机械滥用过程中，第二功能层的剥离会破坏第一功能层的完整性，从而影响电化学装置的机械安全性能。若F2<4N/m，则在正极中第一功能层与第二功能层之间粘接力过低，在这种情况下，电化学装置在循环过程中难以维持极片多层结构的紧密结合，出现循环脱膜的概率高，因此影响电化学装置的循环性能。在本申请的一些实施方式中，F2的取值可以是4N/m、4.5N/m、5N/m、5.5N/m、6N/m、6.5N/m、7N/m、7.5N/m、8N/m以及它们之间的任意值。
根据本申请的一些实施方式，第一功能层的厚度为2μm至8μm。若第一功能层厚度小于2μm，则第一功能层对正极集流体的保护作用较弱，不利于电化学装置的机械安全性能的提升。随着第一功能层的厚度增加，其对正极集流体的保护程度也增加；但是，过高的厚度会损失能量密度，因此第一功能层的厚度控制在上述范围内有利于提高电化学装置的机械安全性能。在本 申请的一些实施方式中，第一功能层的厚度为2μm、2.5μm、3μm、3.5μm、4μm、4.5μm、5μm、5.5μm、6μm、6.5μm、7μm、7.5μm、8μm以及它们之间的任意值。
根据本申请的一些实施方式，第二功能层的厚度为0.1μm至0.3μm。第二功能层的厚度在此范围内能够使电化学装置实现良好的机械安全性能。一方面，若第二功能层厚度太大，则其与第一功能层的粘接力过大，不利于第一功能层与第二功能层之间的弱粘接界面形成；另一方面，第二功能层厚度增加使正极中电子从活性物质层到正极集流体的电子通路延长，不利于电化学装置的倍率性能；此外，第二功能层的厚度过大，也不利于电化学装置的能量密度提升。若第二功能层的厚度太小，则第一功能层和第二功能层之间的粘接力太低，在电化学装置的制备与使用过程中存在脱膜风险。在本申请的一些实施方式中，第一功能层的厚度为0.1μm、0.12μm、0.14μm、0.16μm、0.18μm、0.2μm、0.22μm、0.24μm、0.26μm、0.28μm、0.3μm以及它们之间的任意值。
根据本申请的一些实施方式，第一功能层包括第一粘接剂、第一导电剂和第一填料。
根据本申请的一些实施方式，第一粘接剂包括聚丙烯酸、聚乙烯醇、聚丙烯腈、聚丙烯酰胺、羧甲基纤维素、聚酰亚胺、丁苯橡胶或聚氨酯中的至少一种。第一粘接剂含有大量的羧基、氰基或胺基等极性基团，极性基团与集流体接触时，集流体容易失去电子，而极性基团容易得到电子，电子易从集流体向粘接剂中的极性基团转移，使界面两侧产生接触电势，并形成双电层产生静电引力，起到了粘接作用，使第一功能层与集流体之间有强粘接作用，从而实现强粘接界面。
根据本申请的一些实施方式，以第一功能层的总重量计，第一粘接剂的重量百分含量为5％至40％，第一导电剂的重量百分含量为3％至10％，第一 填料的重量百分含量为50％至92％。
根据本申请的一些实施方式，以第一功能层的总重量计，第一粘接剂的重量百分含量为5％至40％，例如可以是5％、10％、15％、20％、25％、30％、35％、40％或它们之间的任意值。第一粘接剂的含量增加，第一功能层与正极集流体之间的粘接力F1增加，有利于提升电化学装置的机械安全性能；但是第一粘接剂的重量百分含量不宜高于40％，因为会导致填料含量过少，这种情况下难以保证填料对正极集流体的覆盖度，存在漏涂风险，使得第一功能层对正极集流体的保护减弱，存在恶化机械安全性能的风险。
根据本申请的一些实施方式，以第一功能层的总重量计，第一导电剂的重量百分含量为3％至10％，例如可以是3％、4％、5％、6％、7％、8％、9％、10％或它们之间的任意值。第一导电剂的重量百分含量在此范围内，可实现电化学装置的倍率性能不受影响并保证优异的机械安全性能。若第一导电剂的重量百分含量小于3％，则第一功能层中导电剂含量过少，电子电阻增加，对正极中电子通路影响较大，不利于电化学装置的倍率性能提升。若第一导电剂的重量百分含量大于10％，则第一功能层的电子电导能力过强，第一功能层的电阻过小，这样即使能够保护正极集流体，避免其与负极极片或负极集流体直接接触，但第一功能层本身的低电阻仍不利于电化学装置安全性能的提升。
根据本申请的一些实施方式，以第一功能层的总重量计，第一填料的重量百分含量为50％至92％，例如可以是50％、55％、60％、65％、70％、75％、80％、85％、90％、92％或它们之间的任意值。若第一填料的重量百分含量小于50％，则第一功能层中的低填料含量难以保证第一功能层对正极集流体的高的覆盖度，存在漏涂风险，使得第一功能层对正极集流体的保护减弱，存在恶化机械性能的风险。若第一填料的重量百分含量大于92％，则第一功能层中粘接剂含量的太少难以保证正极集流体与第一功能层之间的强粘接作用； 导电剂含量的减少使第一功能层的电阻增加，不利于电化学装置的倍率性能。
根据本申请的一些实施方式，第二功能层包括第二粘接剂、第二导电剂和第二填料。
根据本申请的一些实施方式，第二粘接剂包括聚偏氟乙烯或聚四氟乙烯中的至少一种。第二粘接剂中含有较少的极性基团，使得第一功能层与第二功能层之间的粘接力很低，从而实现弱粘接界面。
根据本申请的一些实施方式，以第二功能层的总重量计，第二粘接剂的重量百分含量为5％至40％，第二导电剂的重量百分含量为3％至10％，第二填料的重量百分含量为50％至92％。
根据本申请的一些实施方式，以第二功能层的总重量计，第二粘接剂的重量百分含量为5％至40％，例如可以是5％、10％、15％、20％、25％、30％、35％、40％或它们之间的任意值。第二粘接剂的含量控制在上述范围内有利于增加电化学装置的安全性能。若第二粘接剂的含量大于40％，则第一功能层与第二功能层之间的粘接力过大，难以实现弱粘接界面，不利于电化学装置的机械安全性能；若第二粘接剂的含量小于5％，则第一功能层与第二功能层之间的粘接力太小，正极在循环与冷压过程中存在脱膜风险。
根据本申请的一些实施方式，以第二功能层的总重量计，第二导电剂的重量百分含量为3％至10％，例如可以是3％、4％、5％、6％、7％、8％、9％、10％或它们之间的任意值。若第二导电剂的重量百分含量小于3％，则第二导电剂含量过少，电子电阻增加，对正极极片中电子通路影响较大，不利于电芯倍率性能提升。若第二导电剂的重量百分含量大于10％，则第二功能层中的填料含量过少，可能影响第二功能层对第一功能层的覆盖度。
根据本申请的一些实施方式，以第二功能层的总重量计，第二填料的重量百分含量为50％至92％，例如可以是50％、55％、60％、65％、70％、75％、80％、85％、90％、92％或它们之间的任意值。若第二填料的重量百分含量小 于50％，则第二功能层中的低填料含量难以保证对第一功能层的高覆盖度，存在漏涂风险，不利于第一功能层与第二功能层之间的弱粘接界面形成，存在恶化机械性能的风险。若第二填料的重量百分含量大于92％，则第二功能层中粘接剂含量过小，难以保证第二功能层与活性物质层之间的适当粘接，存在极片脱膜风险，影响电化学装置的循环性能；导电剂含量的减少使第二功能层电阻增加，不利于电化学装置的倍率性能。
根据本申请的一些实施方式，第一填料和第二填料各自独立地包括磷酸铁锂、磷酸亚铁锂、二氧化硅、二氧化钛、三氧化二铝、勃姆石、氧化镁、氧化锆、二氧化钛、碳化硅、碳化硼、碳酸钡、钛酸钾、硫酸钡、三氧化二钒、聚醚醚酮粉、聚酰胺粉或纤维素粉中的至少一种。
根据本申请的一些实施方式，第一导电剂和第二导电剂各自独立地包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管、碳纤维、铝粉、镍粉或金粉中的至少一种。
根据本申请的一些实施方式，活性物质层包括钴酸锂、镍锰钴酸锂、镍锰铝酸锂、磷酸铁锂、磷酸钒锂、磷酸钴锂、磷酸锰锂、磷酸锰铁锂、硅酸铁锂、硅酸钒锂、硅酸钴锂、硅酸锰锂、尖晶石型锰酸锂、尖晶石型镍锰酸锂或钛酸锂中的至少一种。
根据本申请的一些实施方式，正极中的集流体为铝箔。
根据本申请的一些实施方式，正极的制备方法包括以下步骤：
S1：在集流体表面涂覆包括第一粘接剂、第一导电剂和第一填料的浆料，干燥后得到涂覆第一功能层的集流体；
S2：在第一功能层上涂覆包括第二粘接剂、第二导电剂和第二填料的浆料，干燥后得到涂覆有第一功能层和第二功能层的集流体；
S3：在第二功能层上涂覆活性物质层，干燥并冷压得到正极。
在一些实施方式中，本申请的电化学装置包括发生电化学反应的任何装 置，它的具体实例包括一次电池或二次电池。特别地，该电化学装置是锂二次电池，包括锂金属二次电池、锂离子二次电池、锂聚合物二次电池或锂离子聚合物二次电池。
本申请中的正极可用于不同结构的电化学装置例如卷绕型锂离子电池，具体例如应用于叠片结构、多极耳结构等锂离子结构中。本申请中的正极也可用于不同类型的锂离子电池中例如软包型锂离子电池中，具体例如应用于方形铝壳电池、圆柱形铝壳电池等锂离子电池中。
根据本申请的一些实施方式，本申请的电化学装置还包括负极、隔离膜和电解液。
1、负极
本申请的电化学装置中使用的负极的材料、构成和其制造方法可包括任何现有技术中公开的技术。
根据本申请的一些实施方式，负极包括负极集流体和设置于负极集流体至少一个表面上的负极活性物质层。
根据本申请的一些实施方式，负极活性物质层包括负极活性材料，负极活性材料可以包括可逆地嵌入/脱嵌锂离子的材料、锂金属、锂金属合金、能够掺杂/脱掺杂锂的材料或过渡金属氧化物，例如Si、SiO x(0<x<2)等材料。可逆地嵌入/脱嵌锂离子的材料可以是碳材料。碳材料可以是在锂离子可再充电电化学装置中通常使用的任何碳基负极活性物质。碳材料的示例包括结晶碳、非晶碳和它们的组合。结晶碳可以是无定形的、板形的、小片形的、球形的或纤维形的天然石墨或人造石墨。非晶碳可以是软碳、硬碳、中间相沥青碳化产物、烧制焦炭等。低结晶碳和高结晶碳均可以用作碳材料。作为低结晶碳材料，可通常包括软碳和硬碳。作为高结晶碳材料，可通常包括天然石墨、结晶石墨、热解碳、中间相沥青基碳纤维、中间相碳微珠、中间相沥青和高温锻烧炭(如石油或衍生自煤焦油沥青的焦炭)。
根据本申请的一些实施方式，负极活性物质层包含有粘合剂，且该粘合剂可以包括各种粘合剂聚合物，如二氟乙烯一六氟丙烯共聚物(PVDF-co-HFP)、聚偏二氟乙烯、聚丙烯腈、聚甲基丙烯酸甲醋、聚乙烯醇、羧甲基纤维素、羟丙基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂、尼龙等，但不限于此等。
根据本申请的一些实施方式，负极活性物质层还包括导电材料来改善电极导电率。可以使用任何导电的材料作为该导电材料，只要它不引起化学变化即可。导电材料的示例包括：碳基材料，例如天然石墨、人造石墨、炭黑、乙炔黑、科琴黑、碳纤维等；金属基材料，例如包括铜、镍、铝、银等的金属粉或金属纤维；导电聚合物，例如聚亚苯基衍生物等；或它们的混合物。负极集流体可以为铜箔、镍箔、不锈钢箔、钛箔、泡沫镍、泡沫铜、包覆有导电金属的聚合物基板或它们的组合。
2、隔离膜
本申请的电化学装置中使用的隔离膜的材料和形状没有特别限制，其可为任何现有技术中公开的技术。在一些实施例中，隔离膜包括由对本申请的电解液稳定的材料形成的聚合物或无机物等。
例如隔离膜可包括基材层和表面处理层。基材层为具有多孔结构的无纺布、膜或复合膜，基材层的材料选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯和聚酰亚胺中的至少一种。具体的，可选用聚丙烯多孔膜、聚乙烯多孔膜、聚丙烯无纺布、聚乙烯无纺布或聚丙烯-聚乙烯-聚丙烯多孔复合膜。
基材层的至少一个表面上设置有表面处理层，表面处理层可以是聚合物层或无机物层，也可以是混合聚合物与无机物所形成的层。
无机物层包括无机颗粒和粘接剂，无机颗粒选自氧化铝、氧化硅、氧化 镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙和硫酸钡中的至少一种。粘接剂选自聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯烷氧、聚甲基丙烯酸甲酯、聚四氟乙烯和聚六氟丙烯中的至少一种。
聚合物层中包含聚合物，聚合物的材料选自聚酰胺、聚丙烯腈、丙烯酸酯聚合物、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯烷氧、聚偏氟乙烯、聚(偏氟乙烯-六氟丙烯)中的至少一种。
3、电解液
本申请的电化学装置中使用的电解液的构成和其制造方法可包括任何现有技术中公开的技术。
在一些实施方式中，本申请的电化学装置中电解液包括锂盐和非水溶剂。
在本申请一些实施方案中，锂盐选自LiPF 6、LiBF 4、LiAsF 6、LiClO 4、LiB(C 6H 5) 4、LiCH 3SO 3、LiCF 3SO 3、LiN(SO 2CF 3) 2、LiC(SO 2CF 3) 3、LiSiF 6、LiBOB和二氟硼酸锂中的一种或多种。举例来说，锂盐可以选用LiPF 6，因为它可以给出高的离子导电率并改善循环特性。
非水溶剂可为碳酸酯化合物、羧酸酯化合物、醚化合物、其它有机溶剂或它们的组合。
上述碳酸酯化合物可为链状碳酸酯化合物、环状碳酸酯化合物、氟代碳酸酯化合物或其组合。
上述链状碳酸酯化合物的实例为碳酸二甲酯(DMC)、碳酸二乙酯(DEC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸甲乙酯(MEC)及其组合。环状碳酸酯化合物的实例为碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)、碳酸乙烯基亚乙酯(VEC)及其组合。氟代碳酸酯化合物的实例为碳酸氟代亚乙酯(FEC)、碳酸1,2-二氟亚乙酯、 碳酸1,1-二氟亚乙酯、碳酸1,1,2-三氟亚乙酯、碳酸1,1,2,2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1,2-二氟-1-甲基亚乙酯、碳酸1,1,2-三氟-2-甲基亚乙酯、碳酸三氟甲基亚乙酯及其组合。
上述羧酸酯化合物的实例为甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸叔丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、γ-丁内酯、癸内酯、戊内酯、甲瓦龙酸内酯、己内酯及其组合。
上述醚化合物的实例为二丁醚、四甘醇二甲醚、二甘醇二甲醚、1,2-二甲氧基乙烷、1,2-二乙氧基乙烷、乙氧基甲氧基乙烷、2-甲基四氢呋喃、四氢呋喃及其组合。
上述其它有机溶剂的实例为二甲亚砜、1,2-二氧戊环、环丁砜、甲基环丁砜、1,3-二甲基-2-咪唑烷酮、N-甲基-2-吡咯烷酮、甲酰胺、二甲基甲酰胺、乙腈、磷酸三甲酯、磷酸三乙酯、磷酸三辛酯、和磷酸酯及其组合。
二、电子装置
本申请进一步提供了一种电子装置，其包括本申请的电化学装置。
本申请的电子设备或装置没有特别限定。在一些实施例中，本申请的电子设备包括但不限于，笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机或家庭用大型蓄电池等。
下面结合实施例，进一步阐述本申请。应理解，这些实施例仅用于说明本申请而不用于限制本申请的范围。
测试方法
1、厚度测试
取40cm长、20cm宽的样品(集流体(铝箔)+第一功能层+第二功能层)，保证平整无打皱，使用Mitutoyo万分尺测试此尺寸范围内的12个不同位置厚度，取平均值D2。将第二功能层剥离，同种方法测试12点的平均厚度D1。继续将第一功能层剥离，同种方法测试12点的平均厚度D0。则第一功能层的厚度为：D1-D0，第二功能层的厚度为：D2-D1。
2、粘接力测试
取宽5cm、长15cm钢板，沿长度方向贴上5cm长、2cm宽的双面胶。将样品(集流体(铝箔)+第一功能层+第二功能层+活性物质层)裁为2cm宽、15cm长的样条，沿长度方向贴在双面胶上，保证将双面胶完全覆盖，使用3kg的压力辊压15s。使用Instron3365万能试验机，选择拉伸夹具进行180°剥离测试，下夹具固定钢板，上夹具固定样品，拉伸速率10mm/min，剥离长度为50mm，取10mm至50mm的力计算平均值为剥离力，测试12根样条取剥离力平均值为F2’。则第二功能层与活性物质层之间的粘接力F2＝50×F2’。同样的方法对集流体(铝箔)+第一功能层+第二功能层进行测试，得到剥离力F1’，则第一功能层与第二功能层之间的粘接力F1＝50×F1’。同样的方法对集流体(铝箔)+第一功能层进行测试，得到剥离力F0’，则集流体与第一功能层之间的粘接力F0＝50×F0’。
3、冲击测试
25℃下将SOC为0％的电芯以1.5C CC至100％SOC、CV至0.05C。在电芯表面画对角线，交点为几何中心。将直径为φ15.8±0.1mm，长度至少6cm圆棒置于几何中心，并垂直于集流体。使用9.1±0.1Kg的重锤，距离圆棒与试样交叉处61±2.5cm，垂直自由状态落下。电芯不起火、不***为通过测试。
4、穿钉测试
25℃下将SOC为0％的电池以1.5C CC至100％SOC、CV至0.05C。在电池表面画对角线，交点为几何中心。使用直径4mm钢钉，穿刺速度30mm/s，穿钉位置在电池几何中心，测试进行3min，电池不起火、不***为通过测试。
实施例及对比例
1、正极极片的制备
参见图1，正极极片包括集流体1、第一功能层2、第二功能层3和活性物质层4，制备方法如下：
S1：在集流体1表面分别涂覆包括表1所示的第一粘接剂、第一导电剂和第一填料的浆料，干燥后在集流体1表面得到第一功能层2；
S2：在第一功能层2表面涂覆包括表1所示的第二粘接剂、第二导电剂和第二填料的浆料，干燥后在第一功能层1表面得到第二功能层3；
S3：在第二功能层3表面涂覆正极活性物质层4，干燥并冷压得到正极极片；
其中，集流体1为铝箔，活性物质层为钴酸锂；各实施例与对比例中具体的第一粘接剂、第一导电剂、第一填料、第二粘接剂、第二导电剂和第二填料的组成详见下表1。
将正极活性材料钴酸锂、乙炔黑、聚偏二氟乙烯(PVDF)按质量比94：3：3混合，然后加入N-甲基吡咯烷酮(NMP)作为溶剂，调配成固含量为75％的浆料，并搅拌均匀。将浆料均匀涂覆在上述铝箔两面上，110℃条件下烘干，冷压后得到正极活性物质层厚度为130μm的双面极片。将正极极片裁切成74mm×867mm的规格并焊接极耳后待用。
2、负极极片的制备
将负极活性材料人造石墨、乙炔黑、丁苯橡胶及羧甲基纤维素钠按质量 比96：1：1.5：1.5混合，然后加入去离子水作为溶剂，调配成固含量为70％的浆料，并搅拌均匀。将浆料均匀涂覆在上述铜箔两面上，110℃条件下烘干，冷压后得到负极活性物质层厚度为150μm双面极片。将负极极片裁切成74mm×867mm的规格并焊接极耳后待用。
3、隔离膜的制备：PE隔离膜
4、电解液的制备
电解液的有机溶剂为碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸二乙酯(DEC)、丙酸乙酯环氧树脂(EP)，且质量比EC∶PC∶DEC∶EP＝3∶1∶3∶3，溶质为六氟磷酸锂(LiPF 6)，LiPF 6的浓度为1mol/L。
5、锂离子电池的制备：将正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正极和负极中间以起到隔离的作用。卷绕得到裸电芯。将裸电芯置于外包装中，经真空干燥后，注入电解液，封装。经过化成、脱气、切边等工艺流程得到锂离子电池。
表1中，实施例1至实施例9示出了第一功能层中第一粘接剂的种类和含量对所制备得到的锂离子电池的性能影响。根据实施例1至实施例5可以看出，第一粘接剂均有较多的极性基团，使得第一功能层与铝箔之间形成强粘接界面，第二粘接剂PVDF无极性基团，使得第一功能层与第二功能层之间形成弱粘接界面，从而在机械滥用时，界面容易从第二功能层与第一功能层的弱粘结界面处剥离，确保正极集流体表面第一功能层的完整性，从而避免了正极集流体与负极活性物质层或负极集流体直接接触，降低了短路风险，减少短路放热，使得电池具有高的冲击测试通过率和穿钉测试通过率，提升了电池的安全性能。根据实施例1与实施例6至实施例9可以看出，第一粘接剂的含量增加，第一功能层与铝箔之间的粘接力F1增加，有利于提升电池的安全性能；但是第一粘接剂的含量不宜高于40％，否则填料含量下降，难 以保证填料对铝箔的覆盖度，存在漏涂风险，使得第一功能层对铝箔的保护减弱，存在恶化机械安全性能的风险。
表1中，实施例1与实施例10至实施例15示出了第一功能层中第一导电剂的种类和第一填料的种类对所制备得到的锂离子电池的性能影响。根据实施例1与实施例10至实施例15可以看出，第一导电剂的种类对第一功能层与铝箔之间的粘接力F1略有影响，第一填料的种类对第一功能层与铝箔之间的粘接力F1无显著影响，但均很高，电池的安全性能也均较好。
表1中，实施例1与实施例16至实施例19示出了第一功能层的厚度对所制备得到的锂离子电池的性能影响。根据实施例1与实施例16至实施例19可以看出，第一功能层的厚度增加，对铝箔的保护程度增加；但过高的厚度会损失能量密度，因此需要将第一功能层的厚度控制的合理范围内。
表1中，实施例1与实施例20至实施例25示出了第二功能层中第二粘接剂的种类和含量对所制备得到的锂离子电池的性能影响。根据实施例1与实施例20至实施例21可以看出，第二粘接剂均无极性基团，使得第一功能层与第二功能层之间形成弱粘接界面，第一粘接剂聚丙烯酸有较多的极性基团，使得第一功能层与铝箔之间形成强粘接界面，从而在机械滥用时，界面容易从第二功能层与第一功能层的弱粘结界面处剥离，确保正极集流体表面第一功能层的完整性，从而避免了正极集流体与负极活性物质层或负极集流体直接接触，降低了短路风险，减少短路放热，使得电池具有高的冲击测试通过率和穿钉测试通过率，提升了电池的安全性能。根据实施例1与实施例22至实施例25可以看出，第二粘接剂的含量增加，则第一功能层与第二功能层之间的粘接力F2增加，难以实现弱粘接界面，不利于电池的机械安全性能；但是第二粘接剂不宜太低，否则第一功能层与第二功能层之间的粘接力F2太小，加工与使用过程存在脱膜风险。
表1中，实施例1与实施例26至实施例28示出了第二功能层中第二填 料对所制备得到的锂离子电池的性能影响。根据实施例1与实施例26至实施例28可以看出，第二填料的种类对第一功能层和第二功能层之间的粘接力F2无显著影响，电池的安全性能也均较好。
表1中，实施例1与实施例29至实施例30示出了第二功能层的厚度对所制备得到的锂离子电池的性能影响。根据实施例1与实施例29至实施例30可以看出，第二功能层的厚度增加，其与第一功能层的粘接力过大，不利于第一功能层与第二功能层之间的弱粘接界面形成，不利于电池的安全性能；但若第二功能层的厚度太小，则第一功能层和第二功能层之间的粘接力F2太低，电池制备与使用过程存在脱膜风险，因此需要将第二功能层的厚度控制的合理范围内。
表1中，对比例1采用的正极极片中，铝箔和活性物质层之间不进行任何涂层，结果显示其无法通过冲击测试和穿钉测试；对比例2采用的正极极片中，铝箔和活性物质层之间仅涂覆第一功能层，结果显示其冲击测试通过率和穿钉测试通过率均很低，安全性能差。对比例3采用的正极极片中，第一功能层和第二功能层的粘接剂中均有较多的极性基团，使得第一功能层与铝箔之间、第一功能层与第二功能层之间以及第二功能层与活性物质层之间均形成强粘接界面，从而在机械滥用时，结果显示其冲击测试通过率和穿钉测试通过率均很低，安全性能差。对比例4采用的正极极片中，第一功能层和第二功能层的粘接剂中均无极性基团，使得第一功能层与铝箔之间、第一功能层与第二功能层之间以及第二功能层与活性物质层之间均形成弱粘接界面，结果显示其无法通过冲击测试和穿钉测试。对比例5采用的正极极片中，第一功能层的粘接剂中无极性基团，使得第一功能层与铝箔之间形成弱粘接界面，第二功能层的粘接剂中有较多的极性基团，使得第一功能层与第二功能层之间形成强粘接界面，结果显示其无法通过冲击测试和穿钉测试。
Figure PCTCN2021132074-appb-000001
Figure PCTCN2021132074-appb-000002
Figure PCTCN2021132074-appb-000003
尽管已经演示和描述了说明性实施例，本领域技术人员应该理解上述实施例不能被解释为对本申请的限制，并且可以在不脱离本申请的精神、原理及范围的情况下对实施例进行改变，替代和修改。

Claims (11)

  1. 一种电化学装置，包括正极，所述正极包括集流体、活性物质层、位于所述集流体和所述活性物质层之间的第一功能层和位于所述第一功能层和所述活性物质层之间的第二功能层，其中，所述集流体与所述第一功能层之间的粘接力为F1，所述第一功能层与所述第二功能层之间的粘接力为F2，所述第二功能层与所述活性物质层之间的粘接力为F3，满足：F1＞F2，F3＞F2。
  2. 根据权利要求1所述的电化学装置，其中，25≤F1/F2≤100。
  3. 根据权利要求1所述的电化学装置，其中，F3/F2≥1.5。
  4. 根据权利要求1所述的电化学装置，其中，200N/m≤F1≤400N/m，4N/m≤F2≤8N/m。
  5. 根据权利要求1所述的电化学装置，其中，所述第一功能层的厚度为2μm至8μm，所述第二功能层的厚度为0.1μm至0.3μm。
  6. 根据权利要求1所述的电化学装置，其中，所述第一功能层包括第一粘接剂、第一导电剂和第一填料，和/或所述第二功能层包括第二粘接剂、第二导电剂和第二填料。
  7. 根据权利要求6所述的电化学装置，其中，所述第一粘接剂包括聚丙烯酸、聚乙烯醇、聚丙烯腈、聚丙烯酰胺、羧甲基纤维素、聚酰亚胺、丁苯橡胶或聚氨酯中的至少一种；和/或所述第二粘接剂包括聚偏氟乙烯或聚四氟乙烯中的至少一种。
  8. 根据权利要求6所述的电化学装置，其中，满足条件(a)至(d)中的至少一者：
    (a)以所述第一功能层的总重量计，所述第一粘接剂的重量百分含量为5％至40％，所述第一导电剂的重量百分含量为3％至10％，所述第一填料的重量百分含量为50％至92％；
    (b)以所述第二功能层的总重量计，所述第二粘接剂的重量百分含量为 5％至40％，所述第二导电剂的重量百分含量为3％至10％，所述第二填料的重量百分含量为50％至92％；
    (c)所述第一填料和第二填料各自独立地包括磷酸铁锂、磷酸亚铁锂、二氧化硅、二氧化钛、三氧化二铝、勃姆石、氧化镁、氧化锆、二氧化钛、碳化硅、碳化硼、碳酸钡、钛酸钾、硫酸钡、三氧化二钒、聚醚醚酮粉、聚酰胺粉或纤维素粉中的至少一种；
    (d)所述第一导电剂和第二导电剂各自独立地包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管、碳纤维、铝粉、镍粉或金粉中的至少一种。
  9. 根据权利要求1所述的电化学装置，其中，所述活性物质层包括钴酸锂、镍锰钴酸锂、镍锰铝酸锂、磷酸铁锂、磷酸钒锂、磷酸钴锂、磷酸锰锂、磷酸锰铁锂、硅酸铁锂、硅酸钒锂、硅酸钴锂、硅酸锰锂、尖晶石型锰酸锂、尖晶石型镍锰酸锂或钛酸锂中的至少一种。
  10. 根据权利要求1所述的电化学装置，其中，所述集流体为铝箔。
  11. 一种电子装置，包括权利要求1-10中任一项所述的电化学装置。
PCT/CN2021/132074 2021-11-22 2021-11-22 电化学装置和包含该电化学装置的电子装置 WO2023087301A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2021/132074 WO2023087301A1 (zh) 2021-11-22 2021-11-22 电化学装置和包含该电化学装置的电子装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2021/132074 WO2023087301A1 (zh) 2021-11-22 2021-11-22 电化学装置和包含该电化学装置的电子装置

Publications (1)

Publication Number Publication Date
WO2023087301A1 true WO2023087301A1 (zh) 2023-05-25

Family

ID=86396100

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/132074 WO2023087301A1 (zh) 2021-11-22 2021-11-22 电化学装置和包含该电化学装置的电子装置

Country Status (1)

Country Link
WO (1) WO2023087301A1 (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117117205A (zh) * 2023-10-25 2023-11-24 宁德时代新能源科技股份有限公司 复合负极集流体、负极极片、卷绕结构电芯及二次电池
CN117133927A (zh) * 2023-10-25 2023-11-28 宁德时代新能源科技股份有限公司 复合正极集流体、正极极片、卷绕结构电芯及用电装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101884125A (zh) * 2007-10-26 2010-11-10 赛昂能源有限公司 用于电池电极的底涂料
CN105703010A (zh) * 2014-11-28 2016-06-22 宁德时代新能源科技股份有限公司 电极片及电化学储能装置
CN106816575A (zh) * 2015-11-30 2017-06-09 宁德新能源科技有限公司 正极片及锂离子电池
JP2018174064A (ja) * 2017-03-31 2018-11-08 トヨタ自動車株式会社 非水電解質二次電池
CN112582580A (zh) * 2020-12-14 2021-03-30 珠海冠宇电池股份有限公司 一种正极片及包括该正极片的锂离子电池
CN112599722A (zh) * 2020-12-14 2021-04-02 珠海冠宇电池股份有限公司 一种正极片及包括该正极片的锂离子电池

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101884125A (zh) * 2007-10-26 2010-11-10 赛昂能源有限公司 用于电池电极的底涂料
CN105703010A (zh) * 2014-11-28 2016-06-22 宁德时代新能源科技股份有限公司 电极片及电化学储能装置
CN106816575A (zh) * 2015-11-30 2017-06-09 宁德新能源科技有限公司 正极片及锂离子电池
JP2018174064A (ja) * 2017-03-31 2018-11-08 トヨタ自動車株式会社 非水電解質二次電池
CN112582580A (zh) * 2020-12-14 2021-03-30 珠海冠宇电池股份有限公司 一种正极片及包括该正极片的锂离子电池
CN112599722A (zh) * 2020-12-14 2021-04-02 珠海冠宇电池股份有限公司 一种正极片及包括该正极片的锂离子电池

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117117205A (zh) * 2023-10-25 2023-11-24 宁德时代新能源科技股份有限公司 复合负极集流体、负极极片、卷绕结构电芯及二次电池
CN117133927A (zh) * 2023-10-25 2023-11-28 宁德时代新能源科技股份有限公司 复合正极集流体、正极极片、卷绕结构电芯及用电装置
CN117133927B (zh) * 2023-10-25 2024-04-02 宁德时代新能源科技股份有限公司 复合正极集流体、正极极片、卷绕结构电芯及用电装置
CN117117205B (zh) * 2023-10-25 2024-04-02 宁德时代新能源科技股份有限公司 复合负极集流体、负极极片、卷绕结构电芯及二次电池

Similar Documents

Publication Publication Date Title
WO2022204967A1 (zh) 电化学装置和电子装置
WO2021185014A1 (zh) 负极活性材料及使用其的电化学装置和电子装置
WO2021184531A1 (zh) 电化学装置和电子装置
CN113366673B (zh) 电化学装置和电子装置
CN113066961B (zh) 负极极片、电化学装置和电子装置
CN211879509U (zh) 电极极片、电化学装置及包含其的电子装置
KR20230093520A (ko) 전기화학 장치, 전자 장치 및 전기화학 장치의 제조방법
WO2023087301A1 (zh) 电化学装置和包含该电化学装置的电子装置
CN113422063B (zh) 电化学装置和电子装置
WO2021189255A1 (zh) 一种电解液及电化学装置
CN113078288B (zh) 电化学装置和电子装置
WO2021120434A1 (zh) 一种电解液及电化学装置
CN113097432B (zh) 电化学装置和电子装置
KR20190069073A (ko) 리튬 이차전지용 양극 활물질, 이의 제조방법, 이를 포함하는 리튬 이차전지용 양극 및 리튬 이차전지
WO2022061562A1 (zh) 电化学装置和电子装置
WO2022041194A1 (zh) 极片、电化学装置和电子装置
JP2024501526A (ja) 負極片、電気化学装置及び電子装置
WO2023082247A1 (zh) 电极及其制备方法、电化学装置和电子装置
CN113421999A (zh) 电化学装置和电子装置
CN114144919A (zh) 一种正极极片、包含该正极极片的电化学装置和电子装置
CN114497498B (zh) 电化学装置和电子装置
WO2023078059A1 (zh) 电解液以及使用其的电化学装置和电子装置
CN113097474B (zh) 电化学装置和电子装置
CN112802990B (zh) 极片、电化学装置和电子装置
CN116111037B (zh) 电化学装置和电子装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21964453

Country of ref document: EP

Kind code of ref document: A1