Capacitor-supported current collector

Abstract

A battery for a vehicle battery pack, a capacitor-supported current collector, and a method are provided. The vehicle battery pack comprises a battery pack housing and at least one vehicle battery cell supported by the battery pack housing. The at least one vehicle battery cell comprises a cathode, an anode, a separator, and an electrolyte. The at least one vehicle battery cell further comprises a current collector and a multifunctional coating layer arranged and adhered to at least one side of the current collector. The multifunctional coating layer is configured to provide fast-charging capability for the vehicle battery pack.The multifunctional coating layer comprises a capacitor material designed to enhance pulsed and continuous charging rate capability, a conductive filler designed to provide electrical conductivity, and a binder designed to provide adhesion between the multifunctional coating layer and the current collector.

Description

INTRODUCTION

[0001] The present disclosure relates to vehicles and in particular to a pantograph in a vehicle battery system.

[0002] Electrically powered vehicles use multi-cell batteries to provide electrical energy, to supply power to propel the vehicle, and to power many of the vehicle's devices. Batteries comprising many electrochemical lithium-ion cells are examples of such electrical power sources.

[0003] In some applications, it can be beneficial to combine a lithium-ion battery with a capacitor. Such capacitors can be charged during vehicle braking. The resulting stored electrical charge can then be used to recharge the lithium-ion battery cells. Capacitors can provide a fast-charging capability for the lithium-ion battery cells.

[0004] While state-of-the-art methods and systems attempt to charge lithium-ion battery cells with capacitors and can achieve their specific purpose, there is still a need for new and improved battery charging. DESCRIPTION

[0005] According to several aspects of the present disclosure, a vehicle battery pack with a capacitor-supported current collector is provided. The vehicle battery pack comprises a battery pack housing and at least one vehicle battery cell supported by the battery pack housing. The at least one vehicle battery cell comprises a cathode, an anode, a separator, and an electrolyte. The at least one vehicle battery cell further comprises a current collector and a multifunctional coating layer arranged and adhered to at least one side of the current collector. The multifunctional coating layer is configured to provide fast-charging capability for the vehicle battery pack.The multifunctional coating layer comprises a capacitor material designed to enhance pulsed and continuous charging rate capability, a conductive filler designed to provide electrical conductivity, and a binder designed to provide adhesion between the multifunctional coating layer and the current collector.

[0006] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector includes a current collector with an aluminum foil approximately 10 micrometers thick.

[0007] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported pantograph comprises a capacitor material that is arranged and adhered to the pantograph in a shaft configuration and a rivet interface that provides an adhesive force.

[0008] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported pantograph includes a capacitor material in a deep-printed configuration on the pantograph.

[0009] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector includes a multifunctional coating layer with a thickness between approximately 4 and approximately 30 micrometers.

[0010] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector includes a capacitor material that is spherical with a diameter of about one micrometer.

[0011] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector comprises a multifunctional coating layer with a flat surface and a thickness between approximately 0.5 micrometers and 20 micrometers.

[0012] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported pantograph comprises a multifunctional coating layer with a carbon layer arranged on the pantograph and a capacitor layer arranged on the carbon layer.

[0013] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector comprises a multifunctional coating layer consisting of approximately 40-80 wt.% active carbon, approximately 18-40 wt.% conductive carbon, and approximately 2-20 wt.% binder.

[0014] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector comprises a multifunctional coating layer with a dispersion agent comprising at least one of polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP), wherein the dispersion agent constitutes between about 0.1-5 wt.% of the multifunctional coating layer.

[0015] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector comprises a multifunctional coating layer with a mass loading of approximately 0.01-1 milligrams per square centimeter.

[0016] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector includes a capacitor material comprising at least one of carbon, metal oxide or a polymer.

[0017] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector comprises a conductive filler comprising at least one of carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, Ketjen black, single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs) or oxides, wherein the oxides comprise at least one of a simple oxide, a superconducting oxide, a carbide or a silicide.

[0018] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector includes a binder comprising at least one of polyacrylic acid (PAA), carboxymethylcellulose (CMC) / styrene-butadiene rubber (SBR), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF) or N-methyl-2-pyrrolidone (NMP).

[0019] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector comprises a current collector formed from at least one of a closed metal foil, a mesh foil or a three-dimensional foam composite.

[0020] According to another aspect of the disclosure, the vehicle battery pack with a capacitor-supported current collector includes a current collector formed from at least one of aluminum or copper.

[0021] According to several aspects of the present disclosure, a capacitor-supported current collector is provided. The capacitor-supported current collector comprises a current collector and a multifunctional coating layer applied to at least one side of the current collector. The multifunctional coating layer is configured to provide fast-charging capability for a vehicle battery pack. The multifunctional coating layer comprises a capacitor material configured to enhance pulsed and continuous charging rate capability, a conductive filler configured to provide electrical conductivity, and a binder configured to provide adhesion between the multifunctional coating layer and the current collector.

[0022] According to several aspects of the present disclosure, a method for forming a capacitor-supported current collector is provided. The method comprises mixing a first slurry using a solvent and intaglio printing the first slurry onto an aluminum current collector. The first slurry comprises a conductive carbon. The method also includes drying the first slurry using a heating device to form a dried first slurry layer and a multifunctional coating layer. The solids content of the multifunctional coating layer is about 20 wt%, and the multifunctional coating layer is designed to provide fast-charging capability for a vehicle battery pack.

[0023] According to another aspect of the disclosure, the process includes an initial slurry comprising the conductive carbon, a conductive filler, and a binder.

[0024] According to another aspect of the disclosure, the process further comprises mixing a second slurry comprising an active carbon, coating the dried first slurry layer with the second slurry, and drying the second slurry to form a condenser layer.

[0025] Further applications of the present disclosure will become apparent from the detailed description provided below. It is understood that the detailed description and specific examples serve only for illustrative purposes and are not intended to limit the scope of the disclosure.

[0026] The foregoing features and advantages, as well as other features and advantages of the system and method disclosed herein, are readily apparent from the detailed description, including the claims and examples, in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present disclosure will be better understood from the detailed description and the accompanying drawings, whereby: Fig. 1 is a perspective view illustrating an example of a vehicle with a battery pack comprising battery cells with a capacitor-supported current collector according to the present disclosure. Fig. 2 is a cross-sectional view showing a capacitor-supported current collector in the Fig. Figure 1 illustrates the vehicle battery pack shown, wherein the capacitor-supported current collector has a deep-printed multifunctional coating layer according to the present disclosure. Fig. Figure 3 shows a cross-sectional view showing a capacitor-supported current collector in the Fig. Figure 1 illustrates the vehicle battery pack shown, wherein the capacitor-supported current collector has spherical capacitor material embedded in the multifunctional coating layer, according to the present disclosure. Fig. 4 is a cross-sectional view showing a capacitor-supported current collector in the Fig. Figure 1 illustrates the vehicle battery pack shown, wherein the capacitor-supported current collector has a multifunctional coating layer comprising a carbon layer and a capacitor layer arranged on the carbon layer, according to the present disclosure. Fig. 5 is a flowchart that shows a procedure for forming the capacitor-supported current collector, as in Fig. 2 to Fig. 4 shown, illustrated according to the present revelation. DETAILED DESCRIPTION

[0028] Now, several examples of the disclosure, illustrated in the accompanying drawings, will be discussed in detail. Wherever possible, the same or similar reference symbols will be used in the drawings and the description to refer to the same or similar parts or steps. The following description is merely exemplary and is not intended to limit the present disclosure, application, or uses.

[0029] This document discloses a vehicle battery pack that includes a capacitor-based current collector. The capacitor-based current collector features a multifunctional coating layer with specific designs for ultra-fast charging capability and suitability for use in high-performance cells.

[0030] With reference to Fig. Figure 1 illustrates a perspective view of a vehicle 10 with a battery pack 12 as described in the present disclosure. The battery pack 12 is illustrated with an exemplary vehicle 10. The vehicle 10 is an electric or hybrid vehicle with wheels 14, which are driven by at least one electric motor / inverter 16. The electric motors / inverters 16 receive power from the battery pack 12. Although the vehicle 10 is illustrated as a passenger car, it is understood that the battery pack 12 can be used with various other types of vehicles. For example, the battery pack 12 can be used in watercraft, such as boats, or aircraft, such as drones or passenger airplanes. Furthermore, the battery pack 12 can be used as a stationary power source that is separate and independent from a vehicle.The battery pack 12 includes a housing 18 for carrying and supporting a plurality of battery cells 20. In one example, the battery pack 12 can have fifty or more battery cells 20. Each battery cell 20 includes a cathode electrode (not shown), an anode electrode (not shown), a separator (not shown), and an electrolyte (not shown).

[0031] Fig. Figure 2 illustrates a capacitor-supported current collector 22 with a multifunctional coating layer 24, wherein the current collector 22 is incorporated as part of the cathode electrode and / or the anode electrode in each battery cell 20. The current collector 22 serves as a bridge for supporting active material, for example, active cathode and anode materials, binders, and conductive additives, and for electrochemically connecting the overall cathode and anode structure to an external circuit. The current collector 22 can be made of aluminum, stainless steel, copper, a three-dimensional (3D) foam composite, a composite material, or other suitable conductive materials. Furthermore, the current collector 22 can be in the form of a closed metal foil, a mesh foil, and / or a three-dimensional (3D) composite or composite-type current collector.Some examples of a 3D composite or composite-type current collector 22 may include carbon fiber and carbon nanotubes (CNTs), a polymer-carbon composite, conductive resins, carbon-coated aluminum foil, and the like. One example of a composite-type current collector 22 comprises a battery collector material having a three-layer structure made of metal, polymer, and metal (e.g., aluminum, polyethylene terephthalate (PET), aluminum). The layers may be formed by metallizing or magnetron sputtering a biaxially oriented film substrate, for example, polyethylene terephthalate (PET) or polypropylene (PP), with thin-film metal. The middle layer may also be made of polyimide (PI) or another suitable polymer or non-metallic material. Additionally, the current collector 22 may have a variety of thicknesses depending on its application (e.g.,4-30 micrometers (µm)). For example, a copper current collector 22, used for an anode, can have a thickness h. CC between approximately 4-12 µm. In another example, an aluminum current collector 22, used for a cathode, can have a thickness h CC between approximately 10-20 µm. In the specific example, which is in Fig. As illustrated in Figure 2, the current collector 22 is a closed metal foil made of aluminum and has a thickness h. CC of approximately 10 µm. In this context, a specialist would understand the meaning of the term "approximately". Alternatively, the term "about" means plus or minus 0.5 µm.

[0032] The multifunctional coating layer 24 is arranged and applied to at least one side of the pantograph 22. Fig. Figure 2 shows the multifunctional coating layer 24 on two sides of the pantograph 22, although in some cases the multifunctional coating layer 24 may only be arranged on one side of the pantograph 22. The multifunctional coating layer 24 is configured to provide fast-charging capability for the vehicle battery pack 12. The multifunctional coating layer 24 may include a dispersant, for example, polyvinyl alcohol (PVA) and / or polyvinylpyrrolidone (PVP). If included, the dispersant may constitute between approximately 0.1 and 5 wt% of the total multifunctional coating layer 24.

[0033] The multifunctional coating layer 24 has a mass loading of approximately 0.01-1 milligrams per square centimeter (mg / cm²). 2 ). Preferably, the multifunctional coating layer 24 has a mass loading of between approximately 0.03 and 0.2 mg / cm². 2In this context, a specialist would understand the meaning of the term "approximately". Alternatively, the term "about" means plus or minus 0.01 mg / cm². 2 Furthermore, the multifunctional coating layer 24 has a thickness h depending on the application. CL between approximately 0.1 and 30 µm. Preferably, the multifunctional coating layer 24 has a thickness h CL between approximately 1-10 µm.

[0034] The multifunctional coating layer 24 comprises a capacitor layer 26, a conductive filler 28, and a binder 30. In an example, the multifunctional coating layer 24 consists of approximately 40–80 wt.% capacitor layer 26, approximately 18–40 wt.% conductive carbon, and approximately 2–20 wt.% binder. In this context, a person skilled in the art would understand the meaning of the term "approximately". Alternatively, the term "about" means plus or minus 1 wt.%.

[0035] The capacitor layer 26 is designed to enhance the pulsed and continuous charging capability of each battery cell 20 and the entire vehicle battery pack 12. The capacitor layer 26 can comprise a carbon-based material, for example, activated carbon, graphene, carbon nanotubes, and the like. Preferably, the capacitor layer 26 comprises activated carbon with a particle size distribution D50 between 0.5 and 20 µm. The term D50 refers to the mean particle size in a distribution, meaning that 50% of the particles are smaller than this size and 50% are larger. Even more preferably, the capacitor layer 26 comprises activated carbon with a particle size distribution D50 between 1 and 8 µm. The capacitor layer 26 can also comprise metal oxides, for example, MO. x, where M can be cobalt (Co), ruthenium (Ru) and / or niobium (Nb) and the like. The capacitor layer 26 can also comprise a polymer, for example polyaniline, polyacetylene and the like, or a combination of the above.

[0036] The conductive filler 28 is designed to provide electrical conductivity for the capacitor-supported current collector 22 and the vehicle battery pack 12. The conductive filler 28 can comprise a carbon-based material, for example, carbon black, graphite, graphene, graphene oxide, Super P, acetylene carbon black, Ketjen carbon black, single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), other electronically conductive additives, or a combination thereof. The conductive filler 28 can also include oxides, for example simple oxides (e.g., ruthenium(IV) oxide (RuO2), tin(IV) oxide (SnO2), zinc oxide (ZnO), germanium(III) oxide (Ge2O3), and the like), a superconducting oxide (e.g., yttrium barium copper oxide (YBa2Cu3O7), lanthanum calcium manganite (La 0,75 Approx 0,25 MnO3)), a carbide (e.g. silicon dicarbide (SiC2)), a silicide (e.g. molybdenum disilicide (MoSi2)) or a combination thereof.

[0037] The binder 30 is designed to provide adhesion between the multifunctional coating layer 24 and the current collector 22. The binder 30 can comprise an aqueous binder, for example, polyacrylic acid (PAA), carboxymethylcellulose (CMC) / styrene-butadiene rubber (SBR), polyacrylonitrile (PAN), combinations thereof, and the like. The binder 30 can also comprise a non-aqueous binder, for example, polyvinylidene fluoride (PVDF), N-methyl-2-pyrrolidone (NMP), combinations thereof, and the like.

[0038] With further reference to Fig. Figure 2 shows that the multifunctional coating layer 24 has a wave configuration and a rivet interface. In this configuration, the capacitor layer 26 can be intaglio printed onto the current collector 22. Intaglio printing involves using a process in which an image or pattern is cut, engraved, and / or etched into a surface. For example, the capacitor layer 26 can be formed by depositing a layer of active carbon onto the current collector 22 and then intaglio printing, including engraving or etching a surface of the active carbon layer to form a series of protrusions 32 and depressions 34 in the capacitor layer 26. The resulting shape gives the capacitor layer 26 an intaglio configuration and a rivet interface, which improves the bond strength between the multifunctional coating layer 24 (e.g., the “active layer”) and the current collector 22.It is understood that, while the sinks 34 and protrusions 32 are shown in a cross-sectional view, they can be arranged in an ordered manner (e.g., in rows) or randomly within the capacitor layer 26. The multifunctional coating layer 24 also includes the conductive filler 28 and the binder 30, which are arranged in the sinks 34 of the capacitor layer 26. Due to the height of the protrusions 32, the multifunctional coating layer 24 can have a thickness between about 4 and 30 µm, with a preferred thickness between about 5 and 10 µm. In this context, the term "about" is understood by those skilled in the art. Alternatively, the term "about" means plus or minus 0.1 µm. Fig. 3 illustrated configuration is used, and in a specific example, the capacitor-supported pantograph 22 has a loading of 0.069 milligrams per square centimeter (mg / cm2) and a resistance of 0.37 ohm·cm, whereas a conventional carbon-coated aluminum pantograph has a resistance of 3.654 ohm·cm, which is almost 10 times greater.

[0039] Fig. Figure 3 illustrates another example of the multifunctional coating layer 24, where the capacitor layer 26 comprises spherical capacitor particles 36. In this example, the spherical capacitor particles 36 are embedded in the conductive filler 28 and the binder 30. The conductive filler 28 and the binder 30 fill in around the spherical capacitor layer 26 and the spherical capacitor particles 36. For this reason, the multifunctional coating layer 24 generally has a smooth and flat surface 38. The spherical capacitor particles 36 can have a variety of sizes (e.g., 0.75–3 µm). In one example, the spherical capacitor particles 36 have a mean particle size distribution D50 with a diameter of about one micrometer (µm). In this context, the term "about" is familiar to those skilled in the art. Alternatively, the term "about" means plus or minus 0.05 µm.The multifunctional coating layer 24 can have a variety of thicknesses h. P (e.g., 1-3 µm). In one example, a thickness h is P The multifunctional coating layer 24 is approximately 1.25 µm thick. In this context, the term "approximately" is familiar to experts. Alternatively, "approximately" means plus or minus 0.05 µm.

[0040] Fig. Figure 4 illustrates the multifunctional coating layer 24, which has several material layers arranged on the current collector 22. The several material layers include a carbon layer 40 (e.g., carbon black) arranged directly on the current collector 22 (e.g., aluminum foil) and a capacitor layer 26 (e.g., activated carbon) arranged on top of the carbon layer 40. This example of the multifunctional coating layer 24 is formed in a two-stage process using intaglio printing, as described below.

[0041] With reference to Fig. Section 5 presents a process 100 for forming a capacitor-supported current collector according to the present disclosure. The process begins at block 102. Block 102 describes the mixing of a first slurry using a solvent. The first slurry comprises at least one conductive carbon. In a specific example, the first slurry comprises the conductive carbon, the conductive filler, and the binder. In this specific example, the slurry may comprise carbon black, a binder comprising polyacrylic acid (PAA), styrene-butadiene rubber (SBR), and carboxymethylcellulose (CMC), and active carbon in a mass ratio of 30 / 20 / 50. The slurry may have a solids content of about 20%, although the slurry may also have other solids content percentages (e.g., 15%, 18%, 22%, 25%, and so on). In this context, the term "approximately" is familiar to experts.Alternatively, the term "approximately" means plus or minus 1%. An example of a suitable solvent is an N-methyl-2-pyrrolidone (NMP) solvent. Procedure 100 then proceeds to Block 104.

[0042] Block 104 depicts the intaglio printing of the first slurry onto the pantograph 22. The pantograph 22 can be made of copper and / or aluminum. The pantograph 22 can be manufactured using process steps such as alkaline etching or the application of a carbon coating. Using the intaglio printing process, the first slurry is printed and / or a pattern is incised, engraved, and / or etched onto the first slurry. For example, the first slurry is printed onto the pantograph 22 in a specific pattern using an intaglio printer, or printed and then etched to create a plurality of protrusions 32 and depressions 34. The use of intaglio printing allows for precise control over the thickness and pattern of the first slurry.

[0043] Block 106 describes drying the first slurry. Drying the first slurry may involve the use of a heating device. Using a heating device may involve heating the first slurry to a specific temperature to evaporate solvents and solidify the carbon slurry. Drying the first slurry may be performed, for example, in an oven or using a heat press. In some cases, drying the first slurry may involve the use of a solvent recovery system (e.g., an N-methyl-2-pyrrolidone (NMP) solvent recovery system). Additionally, other examples of drying the first slurry may include the use of a UV curing process and / or a pressure curing process.The drying of the first slurry results in the multifunctional coating layer 24, which is arranged and adhered to the pantograph 22.

[0044] Process 100 may further comprise blocks 108, 110, and 112. Block 108 represents the mixing of a second slurry comprising an active carbon. In this case, the first slurry comprises a carbon, for example, Ketjen carbon black, which, upon drying, forms a carbon layer 40, as in the [reference to be added]. Fig. The example shown in Figure 4 illustrates this. The second slurry, for example, includes activated carbon, which forms the condenser layer 26 during drying, as shown in Figure 4. Fig. 4 shown. Mixing the second slurry may involve the use of a solvent, for example N-methyl-2-pyrrolidone (NMP), to form the second slurry.

[0045] Block 110 represents the coating of the dried first slurry layer or the carbon layer 40 with the second slurry. The coating of the dried first slurry layer with the second slurry may involve the use of processes such as a spray coating process, a dipping process, a slot nozzle process, or other suitable processes.

[0046] Block 112 describes the drying of the second slurry to form the condenser layer 26. Drying the second slurry may involve the use of a heating device. The use of a heating device may involve heating the second slurry to a specific temperature to evaporate solvents and solidify the second slurry. Drying the second slurry may be performed, for example, in an oven or using a heat press. In some cases, drying the second slurry may involve the use of a solvent recovery system (e.g., an N-methyl-2-pyrrolidone (NMP) solvent recovery system). Additionally, other examples of drying the second slurry may include the use of a UV curing process and / or a pressure curing process.The drying of the second slurry leads to the capacitor layer 26, which is deposited on the carbon layer 40, which in turn forms the multifunctional coating layer 24, which is arranged and adhered to the current collector 22.

[0047] The capacitor-based current collector 22 of the present disclosure is advantageous and useful compared to prior art solutions. The capacitor-based current collector 22 provides ultra-fast charging capability in a battery, for example an electric vehicle battery, and is suitable for use in high-performance cells.

[0048] This description is merely illustrative and is in no way intended to limit the revelation, its application, or uses. The broad teachings of revelation can be implemented in a variety of forms. Although this revelation includes certain examples, the true scope of revelation should therefore not be so limited, since other modifications will become apparent upon studying the drawings, the description, and the claims that follow.

Claims

[1] Vehicle battery pack with a capacitor-supported current collector, comprising: a battery pack housing; and at least one vehicle battery cell supported by the battery pack housing, wherein the at least one vehicle battery cell comprises a cathode, an anode, a separator and an electrolyte, and wherein the at least one vehicle battery cell further comprises: a current collector; and a multifunctional coating layer arranged and adhered to at least one side of the pantograph, wherein the multifunctional coating layer is configured to provide fast charging capability for the vehicle battery pack, and wherein the multifunctional coating layer comprises: a capacitor material designed to increase pulsed and continuous charging rate capability; a conductive filler designed to provide electrical conductivity; and a binder designed to provide adhesion between the multifunctional coating layer and the current collector. [2] Vehicle battery pack according to claim 1, wherein the current collector comprises an aluminum foil with a thickness of about 10 micrometers. [3] Vehicle battery pack according to claim 1, wherein the capacitor material is arranged and adhered to the current collector in a shaft configuration and a rivet interface, wherein the rivet interface provides an adhesive force. [4] Vehicle battery pack according to claim 3, wherein the capacitor material is in a deep-printed configuration on the current collector. [5] Vehicle battery pack according to claim 3, wherein the multifunctional coating layer has a thickness between about 4 and about 30 micrometers. [6] Vehicle battery pack according to claim 1, wherein the capacitor material is spherical with a diameter of about one micrometer. [7] Vehicle battery pack according to claim 6, wherein the multifunctional coating layer has a flat surface with a thickness between about 0.5 micrometers and 20 micrometers. [8] Vehicle battery pack according to claim 1, wherein the multifunctional coating layer comprises a carbon layer arranged on the current collector and a capacitor layer arranged on the carbon layer. [9] Vehicle battery pack according to claim 1, wherein the multifunctional coating layer is between about 40-80 wt.% active carbon, between about 18-40 wt.% conductive carbon and between about 2-20 wt.% binder. [10] Vehicle battery pack according to claim 1, wherein the multifunctional coating layer comprises a dispersion agent comprising at least one of polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP), and wherein the dispersion agent constitutes between about 0.1-5 wt.% of the multifunctional coating layer.

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