DIELECTRIC CERAMIC COMPOSITE COATING

Abstract

A battery with a positive electrode assembly includes a metal foil current collector, a portion of which is coated with a positive active material. Adjacent to the positive active material-coated portion, the metal foil current collector is coated with a dielectric ceramic composite material from the positive active material-coated portion to an uncoated portion. The dielectric ceramic composite material includes a polyimide binder and a ceramic filler. This coating extends from the positive active material region toward the uncoated end of the metal foil current collector.

Description

FIELD OF TECHNOLOGY

[0001] This disclosure relates to electrode coatings used in batteries. GENERAL STATE OF THE ART

[0002] A variety of materials can be used in the manufacture of battery electrodes. Some materials are used as substrates. Other materials are used as coatings. SUMMARY

[0003] A battery is provided having a negative electrode assembly and a positive electrode assembly. The positive electrode assembly includes a metal foil current collector, a portion of which is coated with a positive active material. Additionally, another portion of the metal foil current collector is coated with a dielectric ceramic composite material made of a polyimide binder and a ceramic filler. This coating extends adjacent to and away from the positive active material toward an uncoated end of the metal foil current collector. A separator is disposed between the negative electrode assemblies and the positive electrode assemblies such that the dielectric ceramic composite material extends at least to the end of the separator.The movement of the uncoated end towards the separator results in contact between the dielectric ceramic composite material and the end of the separator.

[0004] The ceramic filler in the battery can be a carbon oxide, such as Al2O3 (aluminum oxide), ZrO2 (zirconium dioxide), as well as other materials such as Al2O3 (aluminum oxide), ZrO2 (zirconium dioxide), AlOOH (aluminum oxide hydroxide), Al(OH)3 (aluminum hydroxide), Pb(Zr,Ti)O3 (lead zirconate titanate, PZT), TiO2 (titanium dioxide), Y2O3 (yttrium oxide), YSZ (yttria-stabilized zirconia), Dy2O3 (dysprosium oxide), Gd2O3 (gadolinium oxide), CeO2 (cerium oxide), GDC (gadolinium-doped cerium oxide), MgO (magnesium oxide), BaTiO3 (barium titanate), NiMn2O4 (nickel manganese oxide), KNaNbO3 (potassium sodium niobate), BiKTiO3 (bismuth potassium titanate), BiFeO3 (bismuth ferrite), Bi 1,5 ZnNb 1,5O7 (bismuth zinc niobate), WO (tungsten oxide, typically WO3 or WO2), SnO2 (tin oxide), LSMO (lanthanum strontium manganese oxide), LSFC (lanthanum strontium ferrite cobaltite), AlN (aluminum nitride), SiN (silicon nitride, typically Si3N4), SiO2 (silicon dioxide), ZnO (zinc oxide), HfO2 (hafnium oxide), TiN (titanium nitride), SiC (silicon carbide), TiC (titanium carbide), WC (tungsten carbide), MgB (magnesium boride, typically MgB2), TiB (titanium boride), CaO (calcium oxide), CoFe2O4 (cobalt ferrite), NiFe2O4 (nickel ferrite), BaFe2O4 (barium ferrite), NiZnFe2O4 (Nickel-Zinc-Ferrite), ZnFe2O4 (Zinc Ferrite) or MnxCo 3-x O4 (manganese cobalt oxide). Alternatively, the ceramic filler may be a nitride, such as aluminum nitride (AlN), silicon nitride (Si3N4), or titanium nitride (TiN). In other configurations, the ceramic filler 28 may be a carbide, such as silicon carbide (SiC), titanium carbide (TiC), or tungsten carbide (WC).

[0005] The ratio of polyimide binder to ceramic filler can be between 10:90 and 30:70. The polymeric binder can be PI, PAI, PVDF, PU, ​​and others. The particle size of the ceramic can be less than 10 micrometers, preferably between 0.1 and 2.0 micrometers. The thickness of the dielectric ceramic composite can be between 1 and 100 micrometers and should most preferably be between 1 and 50 micrometers, measured from the face of the metal foil current collector to the face of the dielectric ceramic composite. In some configurations, the dielectric ceramic composite extends beyond the end of the separator.

[0006] A manufacturing method for battery positive electrode assemblies is described. Each assembly includes a metal foil current collector, a positive active material on a portion of the current collector, and a dielectric ceramic composite material. This material comprises a polyimide binder and a ceramic filler, with another portion of the metal foil extending from the positive active material to an uncoated end being coated therewith. During manufacturing, automated chromatic analysis is used to inspect the dielectric ceramic composite material. If this analysis reveals an absence of yellow or brown color in any region of the material, the affected electrode assembly is separated from the batch. The ceramic filler in the dielectric material may be selected from a group including oxides, nitrides, carbides, or borides.An optional additional step of the process includes assembling the positive electrode assemblies with separators and negative electrodes to form complete battery cells.

[0007] Another method for fabricating a positive electrode assembly for a battery involves applying a slurry of a dielectric ceramic composite containing polyamide acid and a ceramic filler to a metal foil serving as a current collector. This slurry is applied from a portion of the metal foil already coated with an active material and extends to an uncoated end of the foil. After application, the slurry is cured into a dielectric ceramic composite material. This material comprises a polyimide binder and the ceramic filler. This forms a positive electrode assembly incorporating the ceramic composite dielectric with the metal foil current collector.

[0008] A battery is provided having a negative electrode assembly and a positive electrode assembly. The positive electrode assembly includes a metal foil current collector, a portion of which is coated with a positive active material. Additionally, another portion of the metal foil current collector is coated with a dielectric ceramic composite material made of a polyimide binder and a ceramic filler. This coating extends adjacent to and away from the positive active material toward an uncoated end of the metal foil current collector. A separator is placed between the negative and positive electrode assemblies such that the dielectric ceramic composite material extends beyond the end of the separator.The movement of the uncoated end towards the separator results in contact between the dielectric ceramic composite material and the end of the separator. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic illustration of a battery according to an embodiment; Fig. 1' is a schematic illustration of a battery according to an embodiment; Fig. 2 is a schematic illustration of a dielectric ceramic composite material according to an embodiment; Fig. 3 is a schematic representation of a polyamide acid undergoing a curing process to form polyimides according to one embodiment; and Fig. 4 is a flowchart of a method according to an embodiment. DETAILED DESCRIPTION

[0009] Embodiments are described herein. It should be understood, however, that the disclosed embodiments are merely examples, and other embodiments may take various and alternative forms. The figures are not necessarily to scale. Some features may be exaggerated or reduced to show details of specific components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art.

[0010] Various features illustrated and described with respect to any of the figures may be combined with features illustrated in one or more other figures to produce embodiments not explicitly illustrated or described. The illustrated combinations of features provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of this disclosure may be desired for particular applications or implementations.

[0011] In some batteries, electrical contact may occur between the cathode tab and the anode layer. In some designs, the cathode tab, which connects the cathode to the external circuitry, may be positioned close to the anode layer. This proximity increases the likelihood of electrical contact. This can occur in various types of batteries, including cylindrical, prismatic, and pouch cells. Each type has different structural aspects that can contribute to the contact potential. For example, in cylindrical cells, the winding process can cause the cathode tab to shift or deform, increasing the likelihood of contact with the anode. Similarly, in prismatic and pouch cells, the method of stacking the layers and the pressure applied to maintain cell integrity can create conditions that favor contact.

[0012] One aspect of this disclosure includes the application of dielectric coatings to prevent the aforementioned contact. In this context, polyamic acid is used as a binder and precursor to polyimide in the coating slurry. This substance converts to polyimide when subjected to thermal curing, thereby forming a stable dielectric coating layer. This process helps create a barrier to electrical contact between the cathode tab and the anode layer. Polyamic acids used in this process can take various forms, including carboxylic acids, neutralized carboxylates, or a mixture thereof. The presence of neutralized carboxylates containing cations such as Li + , N / a + , K + , NH4 + , Cs +etc., affects the curing process. The cations in neutralized carboxylates can act as catalysts. The cations facilitate the rearrangement and polymerization reactions that convert polyamide acids into polyimides. By lowering the activation energy required for the curing reaction, these cations also reduce the need for high temperatures in the manufacturing process. Polyimides exhibit an intrinsic yellow to brownish color. This property is advantageous in the context of manufacturing because it allows for easier detection of coating defects by conventional vision systems. The polyimide used can be an unsubstituted polyimide, a bisphenyl-substituted polyimide, a polyimide with an ethylenic compound, a trifluoromethyl-substituted polyimide, a keto-substituted polyimide, or other suitable polyimides.Specific examples of polyimides can be PI (polyimide), PAI (polyamideimide), PVDF (polyvinylidene fluoride), PU (polyurethane), polyurea, PC (polycarbonate), PET (polyethylene terephthalate), PMMA (polymethyl methacrylate), PBT (polybutylene terephthalate), PVA (polyvinyl alcohol) or PVB (polyvinyl butyral).

[0013] The composition of the dielectric coating mentioned can be formulated such that the ratio of polyimide binder to ceramic filler can be adjusted within a range of 1:99 to 99:1. A preferred ratio can be between 10:90 and 30:70. The ceramic filler can be Al2O3 (aluminum oxide), ZrO2 (zirconium dioxide), as well as other materials such as Al2O3 (aluminum oxide), ZrO2 (zirconium dioxide), AlOOH (aluminum oxide hydroxide), Al(OH)3 (aluminum hydroxide), Pb(Zr,Ti)O3 (lead zirconate titanate, PZT), TiO2 (titanium dioxide), Y2O3 (yttrium oxide), YSZ (yttria-stabilized zirconia), Dy2O3 (dysprosium oxide), Gd2O3 (gadolinium oxide), CeO2 (cerium oxide), GDC (gadolinium-doped cerium oxide), MgO (magnesium oxide), BaTiO3 (barium titanate), NiMn2O4 (nickel manganese oxide), KNaNbO3 (potassium sodium niobate), BiKTiO3 (bismuth potassium titanate), BiFeO3 (bismuth ferrite), Bi 1,5 ZnNb 1,5O7 (bismuth zinc niobate), WO (tungsten oxide, typically WO3 or WO2), SnO2 (tin oxide), LSMO (lanthanum strontium manganese oxide), LSFC (lanthanum strontium ferrite cobaltite), AlN (aluminum nitride), SiN (silicon nitride, typically Si3N4), SiO2 (silicon dioxide), ZnO (zinc oxide), HfO2 (hafnium oxide), TiN (titanium nitride), SiC (silicon carbide), TiC (titanium carbide), WC (tungsten carbide), MgB (magnesium boride, typically MgB2), TiB (titanium boride), CaO (calcium oxide), CoFe2O4 (cobalt ferrite), NiFe2O4 (nickel ferrite), BaFe2O4 (barium ferrite), NiZnFe2O4 (Nickel-Zinc-Ferrite), ZnFe2O4 (Zinc Ferrite) or MnxCo 3-x O4 (manganese cobalt oxide) or other suitable oxides, nitrides, or carbides. The particle size of the ceramic filler material can be up to 10 micrometers, but preferably less than 2 micrometers.

[0014] The thickness of the coating layer can range from 1 to 100 micrometers on each side, but is preferably between 1 and 50 micrometers. This coating is applied to the cathode current collector, such as an aluminum foil, and extends slightly beyond the edge of the cathode coatings. This configuration can reduce deformation of the current collector foil and maintain an equal thickness of the top and bottom dielectric coatings.

[0015] With reference to the drawings Fig. 1 is a schematic view of a battery 10 according to one aspect of the disclosure. The battery 10 may be any lithium-ion battery, such as a prismatic, pouch, or cylindrical cell battery. The battery 10 has a positive electrode 12, a negative electrode 14, and a separator 16. The positive electrode 12 includes a current collector 18, which may be any suitable metal foil current collector, such as aluminum metal foil. A portion of the current collector 18 is coated with positive active material 20. A portion of the current collector 18 is coated with a dielectric ceramic composite material 22 adjacent to the positive active material 20 and extending away from it toward an uncoated end 24 of the current collector 18. The dielectric ceramic composite material 22 extends at least as far as the separator 16, as shown by line 1-1.However, in some configurations, the dielectric ceramic composite material 22' extends, as shown in . Fig. 1', beyond the separator 16', as shown by the line 1'-1'.

[0016] A thickness of the dielectric ceramic composite material 22 is between 1 and 100 micrometers, preferably between 1 and 50 micrometers, measured from the surface of the current collector 16 to the surface of the dielectric ceramic composite material 22. The arrangement of the separator 16 between the negative electrode assembly 14 and the positive electrode assembly 12, together with the dielectric ceramic composite material 22, is intended to reduce contact modes that may occur, such as separator edge folding or undulation. If there is movement of the uncoated portion 24 of the positive electrode 12 toward the separator 16, this results in contact between the dielectric ceramic composite material 22 and the separator 16 or the negative electrode 14, rather than direct contact with the uncoated end 24.

[0017] Fig. Figure 2 illustrates a schematic view of the dielectric ceramic composite material 22 according to one aspect of the disclosure. The dielectric ceramic composite material 22 includes a polyimide binder 26 and a ceramic filler 28. The diameter of a particle of the ceramic filler 28 may be less than 10 micrometers, and preferably between 0.1 and 2.0 micrometers.The ceramic filler 28 may be a carbon oxide selected from a group consisting of aluminum oxide (Al2O3), aluminum oxyhydroxide (AlOOH), aluminum hydroxide (Al(OH)3), lead zirconate titanate (Pb(Zr,Ti)O3), titanium dioxide (TiO2), zirconium dioxide (ZrO2), yttrium oxide (Y2O3), yttrium oxide-stabilized zirconia (YSZ), dysprosium oxide (Dy2O3), gadolinium oxide (Gd2O3), cerium dioxide (CeO2), gadolinium-doped ceria (GDC), magnesium oxide (MgO), barium titanate (BaTiO3), nickel manganese oxide (NiMn2O4), potassium sodium niobate (KNaNbO3), bismuth potassium titanate (BiKTiO3), bismuth ferrite (BiFeO3), bismuth zinc niobate (Bi. 1,5 Zn1Nb 1,5O7), tungsten oxide (WO), tin dioxide (SnO2), lanthanum strontium manganese oxide (LSMO), lanthanum strontium ferrite cobaltite (LSFC) silicon dioxide (SiO2), zinc oxide (ZnO), hafnium dioxide (HfO2), calcium oxide (CaO), cobalt ferrite (CoFe2O4), nickel ferrite (NiFe2O4), Barium ferrite (BaFe2O4), nickel-zinc ferrite (NiZnFe2O4), zinc ferrite (ZnFe2O4) or manganese-cobalt oxide (Mn x Co 3-x O4).

[0018] In some configurations, the ceramic filler 28 may be a nitride, such as aluminum nitride (AlN), silicon nitride (Si3N4), or titanium nitride (TiN). In other configurations, the ceramic filler 28 may be a carbide, such as silicon carbide (SiC), titanium carbide (TiC), or tungsten carbide (WC). In other configurations, the ceramic filler 28 may be a boride, such as magnesium boride (MgB2) or titanium boride (TiB2). The ratio of polyimide binder 26 to ceramic filler 28 is at least 1:99. However, the ratio of polyimide binder 26 to ceramic filler 28 is preferably between 10:90 and 30:70. The polyimide binder 26 may be selected from a group consisting of polyimide (PI), polyamideimide (PAI), polyvinylidene fluoride (PVDF), polyurethane (PU), polyurea, polycarbonate (PC), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polyvinyl alcohol (PVA), or polyvinyl butyral (PVB).

[0019] Fig. Figure 3 illustrates a polyamic acid 30 undergoing a process 32 to form potential polyimides 34 according to one aspect of the disclosure. The polyamic acid 30 may contain various cationic substitutions at position X, including, but not limited to, hydrogen (H), lithium (Li), sodium (Na), potassium (K), ammonium (NH4), and cesium (Cs). The presence of cations and carboxylate forms may affect the curing rate and temperature of the resulting polyimide 34. Additionally, the molecular structure of the polyamic acid 30 includes variable groups at positions R1 and R2, which may consist of substituted aromatic compounds, alkyl groups, and other possible substituents.In process 32, the polyamide acid 30 is mixed with a ceramic filler in a slurry and then thermally cured to form polyimides 34. This can be done in the manufacture of a dielectric ceramic composite material 22, as shown in FIG. Fig. 1 and Fig. 2 described.

[0020] The yellow to brownish color of the polyimide 34 facilitates easier defect detection in the vision system.

[0021] Fig.4 illustrates a flow diagram of a method according to one aspect of the disclosure. In block one 36, during the fabrication of a plurality of positive electrode assemblies, each assembly includes a metal foil current collector, wherein a portion of the metal foil current collector is coated with a positive active material. Adjacent to the active material and extending away from it toward the uncoated end of the metal foil current collector, a dielectric ceramic composite material is coated. The dielectric composite material comprises a polyimide binder and a ceramic filler. As part of the quality control process, chromatic analysis is performed on these positive electrode assemblies.If the analysis indicates that a region of the dielectric ceramic composite material in any of the assemblies lacks the expected yellow or brown color, that particular assembly is identified and separated from the rest. In some configurations, the method may include an optional further step in block two 38, further comprising sending the plurality of positive electrode assemblies exhibiting the expected yellow or brown color for packaging with a plurality of separators and negative electrodes to form complete cells of a battery.

[0022] The algorithms, methods, or processes disclosed or suggested herein may be implementable by or adapted for use by a computer, controller, or processing device, which may include any dedicated electronic control unit or programmable electronic control unit. Furthermore, the algorithms, methods, or processes may be stored in many forms as computer- or controller-executable data and instructions, including, but not limited to, information permanently stored on non-writable storage media, such as read-only memory devices, and information modifiably stored on writable storage media, such as compact discs, random access memory devices, or other magnetic and optical media. The algorithms, methods, or processes may also be implemented in software-executable objects.Alternatively, the algorithms, methods, or processes may be implemented in whole or in part using suitable hardware components, such as application-specific integrated circuits, field-programmable gate arrays, state machines, or other hardware components or devices, or a combination of firmware, hardware, and software components.

[0023] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms covered by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosed subject matter.

[0024] As previously described, the features of various embodiments may be combined to form further embodiments of the disclosure that may not be explicitly described or illustrated. While various embodiments may have been described as providing advantages or being preferred over other prior art embodiments or implementations with respect to one or more desired characteristics, one of ordinary skill in the art will understand that one or more features or characteristics may be compromised to achieve desired overall system attributes depending on the specific application and implementation. These attributes may include, but are not limited to, strength, durability, market capacity, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc.Thus, embodiments that are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for certain applications.

[0025] According to the present invention, there is provided a battery comprising: a negative electrode assembly; a positive electrode assembly including a metal foil current collector, a positive active material coated on a portion of the metal foil current collector, and a dielectric ceramic composite material of polyimide binder and ceramic filler coated on another portion of the metal foil current collector adjacent to the positive active material and extending away therefrom toward an uncoated end of the metal foil current collector;and a separator disposed between the negative electrode assembly and the positive electrode assembly such that the dielectric ceramic composite material extends at least to one end of the separator and movement of the uncoated end toward the separator results in contact between the dielectric ceramic composite material and the end.;

[0026] According to one embodiment, the ceramic filler is a carbon oxide.

[0027] According to one embodiment, the carbon oxide is selected from a group comprising Al2O3, AlOOH, Al(OH)3, Pb(Zr,Ti)O3, TiO2, ZrO2, Y2O3, YSZ, Dy2O3, Gd2O3, CeO2, GDC, MgO, BaTiO3, NiMn2O4, KNaNbO3, BiKTiO3, BiFeO3, Bi 1.5 Zn1Nb 1.5 O7, WO, SnO2, LSMO, LSFC, SiO2, ZnO, HfO2, CaO, CoFe2O4, NiFe2O4, BaFe2O4, NiZnFe2O4, ZnFe2O4 or MnxCo 3-x O4.

[0028] According to one embodiment, the ceramic filler is a nitride.

[0029] According to one embodiment, the nitride is selected from a group comprising aluminum nitride, silicon nitride or titanium nitride.

[0030] According to one embodiment, the ceramic filler is a carbide.

[0031] According to one embodiment, the carbide is selected from a group comprising silicon carbide, titanium carbide or tungsten carbide.

[0032] According to one embodiment, the ceramic filler is a boride.

[0033] According to one embodiment, the boride is selected from a group comprising magnesium boride or titanium boride.

[0034] According to one embodiment, a ratio of polyimide binder to ceramic filler is between 10:90 and 30:70.

[0035] According to one embodiment, the polyimide binder is selected from a group comprising PI, PAI, PVDF, PU, ​​polyurea, PC, PET, PMMA, PBT, PVA, or PVB. According to one embodiment, a particle diameter of the ceramic filler is less than 10 micrometers.

[0036] According to one embodiment, a diameter of a particle of the ceramic filler is between 0.1 and 2.0 micrometers.

[0037] According to one embodiment, the thickness of the dielectric ceramic composite material is between 1 and 100 micrometers from a surface of the metal foil current collector to a surface of the dielectric ceramic composite material. According to one embodiment, the thickness of the dielectric ceramic composite material is between 1 and 50 micrometers from a surface of the current collector to a surface of the dielectric ceramic composite material.

[0038] According to one embodiment, the dielectric ceramic composite material extends beyond one end of the separator.

[0039] According to the present invention, a method includes: during manufacture of a plurality of positive electrode assemblies, each including a metal foil current collector, a positive active material coated on a portion of the metal foil current collector, and a polyimide binder-ceramic filler dielectric ceramic composite coated on another portion of the metal foil current collector adjacent to the positive active material and extending away from it toward an uncoated end of the metal foil current collector, and in response to automatic chromatic analysis of one of the positive electrode assemblies indicating that a yellow or brown color is absent in a region of the corresponding dielectric ceramic composite, separating it from the plurality.

[0040] In one aspect of the invention, the ceramic filler is selected from a group comprising oxides, nitrides, carbides or borides.

[0041] In one aspect of the invention, the method includes packaging the plurality of positive electrode assemblies with a plurality of separators and negative electrodes to form complete cells of a battery.

[0042] According to the present invention, a method includes: applying a slurry of dielectric ceramic composite comprising polyamide acid and ceramic filler to a metal foil current collector from a portion of the metal foil current collector coated with active material to an uncoated end of the metal foil current collector; and curing to form a positive electrode assembly including a dielectric ceramic composite of polyimide binder and ceramic filler.

Claims

[1] Battery comprising: a negative electrode assembly; a positive electrode assembly including a metal foil current collector, a positive active material coated on a portion of the metal foil current collector, and a dielectric ceramic composite of polyimide binder and ceramic filler coated on another portion of the metal foil current collector adjacent to and extending away from the positive active material toward an uncoated end of the metal foil current collector; and a separator disposed between the negative electrode assembly and the positive electrode assembly such that the dielectric ceramic composite material extends at least to one end of the separator and movement of the uncoated end toward the separator results in contact between the dielectric ceramic composite material and the end. [2] The battery of claim 1, wherein the ceramic filler is a carbon oxide. [3] The battery of claim 1, wherein the ceramic filler is a nitride. [4] The battery of claim 1, wherein the ceramic filler is a carbide. [5] The battery of claim 1, wherein the ceramic filler is a boride. [6] The battery of claim 1, wherein a ratio of polyimide binder to ceramic filler is between 10:90 and 30:

70. [7] The battery of claim 1, wherein the polyimide binder is selected from a group comprising PI, PAI, PVDF, PU, ​​polyurea, PC, PET, PMMA, PBT, PVA or PVB. [8] The battery according to claim 1, wherein a diameter of a particle of the ceramic filler is between 0.1 and 2.0 micrometers. [9] The battery of claim 1, wherein a thickness of the dielectric ceramic composite material is between 1 and 100 micrometers from a surface of the metal foil current collector to a surface of the dielectric ceramic composite material. [10] The battery of claim 9, wherein a thickness of the dielectric ceramic composite material is between 1 and 50 micrometers from a surface of the current collector to a surface of the dielectric ceramic composite material. [11] The battery of claim 1, wherein the dielectric ceramic composite material extends beyond one end of the separator. [12] Method comprising: during the manufacture of a plurality of positive electrode assemblies, each including a metal foil current collector, a positive active material coated on a portion of the metal foil current collector, and a polyimide binder-ceramic filler dielectric ceramic composite coated on another portion of the metal foil current collector adjacent to the positive active material and extending away from it toward an uncoated end of the metal foil current collector, and in response to automatic chromatic analysis of one of the positive electrode assemblies indicating that a yellow or brown color is absent in a region of the corresponding dielectric ceramic composite, separating it from the plurality. [13] The method of claim 12, wherein the ceramic filler is selected from a group comprising oxides, nitrides, carbides or borides. [14] The method of claim 12, further comprising packaging the plurality of positive electrode assemblies with a plurality of separators and negative electrodes to form complete cells of a battery. [15] Method comprising: Applying a slurry of dielectric ceramic composite with polyamide acid and ceramic filler to a metal foil current collector from a portion of the metal foil current collector coated with active material to an uncoated end of the metal foil current collector; and Curing to form a positive electrode assembly including a dielectric ceramic composite material of polyimide binder and ceramic filler.

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