LITHIUM ION CONDUCTIVE DIELECTRIC 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 portion coated with the positive active material, the metal foil current collector is coated with a lithium ion-conducting dielectric composite material from the portion coated with the positive active material to an uncoated portion. The lithium ion-conducting dielectric composite material includes a polyimide binder and a ferroelectric filler. This coating extends from the region of the positive active material 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 with 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 lithium ion-conducting dielectric composite material made of a polyimide binder and a ferroelectric filler. The ferroelectric filler may include materials such as BaTiO3 (barium titanate), KNbO3 (potassium niobate), CdNb2O6 (cadmium niobate), PbNb2O6 (lead niobate), PbTa2O6 (lead antalate), PbBi2Nb2O9 (lead bismuth niobate), PbTiO3 (lead titanium), PZT (lead zirconate titanate), PLZT (lead lanthanum zirconate titanate), or PMN (lead magnesium niobate).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 positioned between the negative and positive electrode assemblies so that the lithium-ion conductive dielectric composite material extends at least to the end of the separator. Movement of the uncoated end toward the separator results in contact between the lithium-ion conductive dielectric composite material and the end of the separator. In some configurations, the dielectric material filler can be either ferroelectric, ceramic, or a combination of both.

[0004] The ceramic fillers in the battery may include, without limitation, Al2O3 (aluminum oxide), AlOOH (aluminum oxide hydroxide), Al(OH)3 (aluminum hydroxide), TiO2 (titanium dioxide), ZrO2 (zirconium 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), NiMn2O4 (nickel manganese oxide), KNaNbO3 (potassium sodium niobate), BiKTiO3 (bismuth potassium titanate), BiFeO3 (bismuth ferrite), Bi 1.5 Zn1Nb 1.5<h2 style=";text-align:left;direction:ltr">O7 (Bismuth-Zinc-Niobat), WO (Wolframoxide), SnO2 (Zinnoxide), LSMO (Lanthan-Strontium-Mangan-Oxide), LSFC (Lanthan-Strontium-Ferrit-Kobaltit), AlN (Aluminiumnitrides), SiN (Siliziumnitrides), SiO2 (Siliziumdioxides), ZnO (Zinkoxides), HfO2 (Hafniumoxides), TiN (Titannitride), SiC (Siliziumcarbide), TiC (Titancarbide), WC (Wolframcarbide), MgB (Magnesiumboride), TiB (Titanborides), CaO (Calciumoxide), CoFe2O4 (Kobaltferrit), NiFe2O4 (Nickelferrit), BaFe2O4 (Bariumferrit), NiZnFe2O4 (Nickel-Zink-Ferrit), ZnFe2O4 (Zink-Ferrit) oder Mn<h2 style=";text-align:left;direction:ltr"> x <h2 style=";text-align:left;direction:ltr"> Co<h2 style=";text-align:left;direction:ltr"> 3-x <h2 style=";text-align:left;direction:ltr"> O4 (Manganese-Kobalt-Oxide).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0005] The ratio of polyimide binder to fillers, either ferroelectric, ceramic, or both, can be between 10:90 and 30:70. Can be PI (polyimide), PAI (polyamideimide), PVDF (polyvinylidene fluoride), PU (polyurethane), or others. The particle size of the filler can be less than 10 micrometers, preferably between 0.1 and 2.0 micrometers. The thickness of the lithium ion conductive dielectric composite material can be between 1 and 100 micrometers, and more preferably should be between 1 and 50 micrometers, measured from the face of the metal foil current collector to the face of the lithium ion conductive dielectric composite material. In some configurations, the lithium ion conductive dielectric composite material 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 lithium-ion conductive dielectric composite material. This material comprises a polyimide binder and a ferroelectric 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 lithium-ion conductive dielectric composite material. If this analysis reveals a lack of yellow or brown color in any region of the material, the affected electrode assembly is separated from the batch.An optional additional step of the process includes assembling the positive electrode assemblies with separators and negative electrodes to form complete battery cells.

[0007] The battery further includes a configuration wherein the positive electrode assembly comprises a metal foil current collector, a portion of which is coated with a positive active material. Adjacent thereto and extending toward an uncoated end of the metal foil is coated a lithium ion conductive material made of a polyimide binder and a ferroelectric filler. A separator is disposed between the negative and positive electrode assemblies such that the lithium ion conductive dielectric composite material extends at least to the end of the separator. Movement of the uncoated end toward the separator results in contact between the lithium ion conductive dielectric composite material and the end of the separator.

[0008] In this arrangement, the ferroelectric filler can be selected from a group including BaTiO3 (barium titanate), KNbO3 (potassium niobate), CdNb2O6 (cadmium niobate), PbNb2O6 (lead niobate), PbTa2O6 (lead antalate), PbBi2Nb2O9 (lead bismuth niobate), PbTiO3 (lead titanium), PZT (lead zirconate titanate), PLZT (lead lanthanum zirconate titanate), or PMN (lead magnesium niobate). The ferroelectric filler can also be mixed with ceramic fillers. The ceramic fillers can be Al2O3 (aluminum oxide), AlOOH (aluminum oxide hydroxide), Al(OH)3 (aluminum hydroxide), TiO2 (titanium dioxide), ZrO2 (zirconium 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), NiMn2O4 (nickel manganese oxide), KNaNbO3 (potassium sodium niobate), BiKTiO3 (bismuth potassium titanate), BiFeO3 (bismuth ferrite), Bi 1.5 Zn1Nb 1.5O7 (bismuth zinc niobate), WO (tungsten oxide), SnO2 (tin oxide), LSMO (lanthanum strontium manganese oxide), LSFC (lanthanum strontium ferrite cobaltite), AlN (aluminum nitride), SiN (silicon nitride), SiO2 (silicon dioxide), ZnO (zinc oxide), HfO2 (hafnium oxide), TiN (titanium nitride), SiC (silicon carbide), TiC (titanium carbide), WC (tungsten carbide), MgB (magnesium boride), TiB (titanium boride), CaO (calcium oxide), CoFe2O4 (cobalt ferrite), NiFe2O4 (nickel ferrite), BaFe2O4 (barium ferrite), NiZnFe2O4 (Nickel-Zinc-Ferrite), ZnFe2O4 (Zinc Ferrite) or Mn x Co 3-x O4 (manganese cobalt oxide). 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 lithium ion conductive dielectric composite material according to one 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 can occur between the cathode tab and the anode layer. In some configurations, the cathode tab, which connects the cathode to the external circuitry, can 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 favorable for contact.

[0012] One aspect of this disclosure includes the application of dielectric coatings to prevent the aforementioned contact. In this context, polyamide acid is used as a binder and precursor to polyimide in the coating slurry. This substance converts to polyimide when subjected to thermal curing, forming a stable dielectric coating layer. This process helps create a barrier to electrical contact between the cathode tab and the anode layer.

[0013] Polyamide acids used in this process can take various forms, including carboxylic acids, neutralized carboxylates, or a mixture of both. 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, as 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).

[0014] The ferroelectric filler in the dielectric can be used either as a sole component or in combination with ceramic fillers. The composition of the coating is adjustable, with a ratio of polyimide binder to ferroelectric filler, ceramic filler, or a mixture of both within a range of 1:99 to 99:1. A preferred ratio is typically between 10:90 and 30:70. The ferroelectric fillers can be BaTiO3 (barium titanate), KNbO3 (potassium niobate), CdNb2O6 (cadmium niobate), PbNb2O6 (lead niobate), PbTa2O6 (lead antalate), PbBi2Nb2O9 (lead bismuth niobate), PbTiO3 (lead titanium), PZT (lead zirconate titanate), PLZT (lead lanthanum zirconate titanate) and PMN (lead magnesium niobate).The ceramic fillers can be Al2O3 (aluminum oxide), AlOOH (aluminum oxide hydroxide), Al(OH)3 (aluminum hydroxide), TiO2 (titanium dioxide), ZrO2 (zirconium 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), NiMn2O4 (nickel manganese oxide), KNaNbO3 (potassium sodium niobate), BiKTiO3 (bismuth potassium titanate), BiFeO3 (bismuth ferrite), Bi. 1.5 Zn1Nb 1.5O7 (bismuth zinc niobate), WO (tungsten oxide), SnO2 (tin oxide), LSMO (lanthanum strontium manganese oxide), LSFC (lanthanum strontium ferrite cobaltite), AlN (aluminum nitride), SiN (silicon nitride), SiO2 (silicon dioxide), ZnO (zinc oxide), HfO2 (hafnium oxide), TiN (titanium nitride), SiC (silicon carbide), TiC (titanium carbide), WC (tungsten carbide), MgB (magnesium boride), TiB (titanium boride), CaO (calcium oxide), CoFe2O4 (cobalt ferrite), NiFe2O4 (nickel ferrite), BaFe2O4 (barium ferrite), NiZnFe2O4 (nickel-zinc ferrite), ZnFe2O4 (zinc ferrite) and Mn x Co 3-x O4 (manganese cobalt oxide). The particle size of the ferroelectric or ceramic filler material can be up to 10 micrometers, but preferably less than 2 micrometers.

[0015] 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.

[0016] 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 lithium ion conductive dielectric 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 lithium ion conductive dielectric composite material 22 extends at least as far as the separator 16, as shown by line 1-1.However, in some configurations, the lithium ion conductive dielectric composite material 22' extends, as shown in . Fig. 1', beyond the separator 16', as shown by the line 1'-1'.

[0017] The thickness of the lithium-ion conductive dielectric 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 lithium-ion conductive dielectric composite material 22. The arrangement of the separator 16 between the negative electrode assembly 14 and the positive electrode assembly 12, together with the lithium-ion conductive dielectric composite material 22, is intended to reduce contact modes that may occur, such as separator edge folding or undulation. Movement of the uncoated portion 24 of the positive electrode 12 toward the separator 16 results in contact between the lithium-ion conductive dielectric composite material 22 and the separator 16 or the negative electrode 14, rather than direct contact with the uncoated end 24.

[0018] Fig. 2 illustrates a schematic view of the lithium ion conductive dielectric composite material 22 according to one aspect of the disclosure. The ferroelectric dielectric composite material 22 comprises a polyimide binder 26 and a ferroelectric filler 28. In the embodiment shown, the lithium ion conductive dielectric composite material 22 comprises a polyimide binder 26 and a combination of a ferroelectric filler 28 and a ceramic filler 30. The ferroelectric particles used include, without limitation: BaTiO3 (barium titanate), KNbO3 (potassium niobate), CdNb2O6 (cadmium niobate), PbNb2O6 (lead niobate), PbTa2O6 (lead antalate), PbBi2Nb2O9 (lead bismuth niobate), PbTiO3 (lead titanium), PZT (lead zirconate titanate), PLZT (lead lanthanum zirconate titanate), and PMN (lead magnesium niobate).These ferroelectric fillers 28, when used alone or in conjunction with ceramic fillers 30, can reduce the interfacial resistance between the dielectric layer 22 and the cathode layer 12, thereby influencing lithium-ion conductivity. The diameter of a particle of both the ceramic fillers 30 and the ferroelectric particles 28 can be less than 10 micrometers and preferably between 0.1 and 2.0 micrometers. The ceramic filler 30 may be Al2O3 (aluminum oxide), AlOOH (aluminum oxide hydroxide), Al(OH)3 (aluminum hydroxide), TiO2 (titanium dioxide), ZrO2 (zirconium 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), NiMn2O4 (nickel manganese oxide), KNaNbO3 (potassium sodium niobate), BiKTiO3 (bismuth potassium titanate), BiFeO3 (bismuth ferrite), Bi. 1.5 Zn1Nb 1.5O7 (bismuth zinc niobate), WO (tungsten oxide), SnO2 (tin oxide), LSMO (lanthanum strontium manganese oxide), LSFC (lanthanum strontium ferrite cobaltite), AlN (aluminum nitride), SiN (silicon nitride), SiO2 (silicon dioxide), ZnO (zinc oxide), HfO2 (hafnium oxide), TiN (titanium nitride), SiC (silicon carbide), TiC (titanium carbide), WC (tungsten carbide), MgB (magnesium boride), TiB (titanium boride), CaO (calcium oxide), CoFe2O4 (cobalt ferrite), NiFe2O4 (nickel ferrite), BaFe2O4 (barium ferrite), NiZnFe2O4 (nickel-zinc ferrite), ZnFe2O4 (zinc ferrite) and MnxCo3-xO4 (manganese cobalt oxide).

[0019] The ratio of the polyimide binder 26 to the ferroelectric filler 28, the ceramic filler 30, or a mixture of both can be adjusted from 1:99 to 99:1, with a preferred range of 10:90 to 30:70. The particle sizes for both the ferroelectric 28 and the ceramic fillers 30 are up to 10 micrometers, ideally less than 2 micrometers.

[0020] Fig. Figure 3 illustrates a polyamic acid 32 undergoing a process 34 to form potential polyimides 36 according to one aspect of the disclosure. The polyamic acid 32 may contain various cationic substitutions at position X, including, but not limited to, H (hydrogen), Li (lithium), Na (sodium), K (potassium), NH4 (ammonium), Cs (cesium). The presence of cations and carboxylate forms may affect the curing rate and temperature of the resulting polyimide 36. Additionally, the molecular structure of the polyamic acid 32 includes variable groups at positions R1 and R2, which may consist of substituted aromatic compounds, aliphatic cyclic groups, alkyl groups, and other possible substituents.In process 34, the polyamide acid 32 is mixed with a ferroelectric filler in a slurry and then thermally cured to form polyimides 36. This can be done in the manufacture of a lithium ion conductive dielectric composite material 22, as shown in FIG. Fig. 1 and Fig. 2. The yellow to brownish color of Polyimide 36 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 38, 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 coating of a lithium ion conductive dielectric composite material is applied. The lithium ion conductive dielectric composite material includes a polyimide binder and a ferroelectric 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 lithium-ion conductive dielectric composite material lacks the expected yellow or brown color in any of the assemblies, that particular assembly is identified and separated from the rest. In some configurations, the method may include an optional further step in block two 40, 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. Similarly, 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, these embodiments are not intended to 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, a battery is provided 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 lithium ion conductive dielectric composite material of polyimide binder and ferroelectric 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 lithium ion conductive dielectric composite material extends to at least one end of the separator and movement of the uncoated end toward the separator results in contact between the lithium ion conductive dielectric composite material and the end.;

[0026] According to one embodiment, the ferroelectric filler is selected from a group comprising BaTiO3, KNbO3, C d Nb2O6, PbNb2O6, PbTa2O6, PbBi2Nb2O9, PbTiO3, PZT, PLZT or PMN.

[0027] According to one embodiment, the ferroelectric filler is BaTiO3.

[0028] According to one embodiment, the invention is further characterized by a ceramic filler mixed with the ferroelectric filler.

[0029] According to one embodiment, the ceramic filler is selected from a group comprising Al2O3, AlOOH, Al(OH)3, 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 Mn x Co 3-x O4.

[0030] According to one embodiment, a diameter of a particle of the ferroelectric filler is less than 10 micrometers.

[0031] According to one embodiment, a diameter of a particle of the ferroelectric filler is between 0.1 and 2.0 micrometers.

[0032] According to one embodiment, a thickness of the lithium ion conductive dielectric composite material is between 1 and 100 micrometers from a surface of the metal foil current collector to a surface of the lithium ion conductive dielectric composite material.

[0033] According to one embodiment, a thickness of the lithium ion conductive dielectric composite material is between 1 and 50 micrometers from a surface of the current collector to a surface of the lithium ion conductive dielectric composite material.

[0034] According to one embodiment, the lithium ion conductive dielectric composite material extends beyond one end of the separator.

[0035] According to one embodiment, a ratio of polyimide binder to ferroelectric filler is between 10:90 and 30:70.

[0036] 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.

[0037] According to one embodiment, a diameter of a particle of the ceramic filler is less than 10 micrometers.

[0038] According to one embodiment, a diameter of a particle of the ceramic filler is between 0.1 and 2.0 micrometers.

[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 lithium ion conductive dielectric composite material of polyimide binder and ferroelectric filler 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 region of the corresponding lithium ion conductive dielectric composite material lacks a yellow or brown color, separating it from the plurality.

[0040] 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.

[0041] According to the present invention, a battery is provided 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 lithium ion conductive dielectric composite material of polyimide binder and ferroelectric 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 lithium ion conductive dielectric composite material extends past one end of the separator and movement of the uncoated end toward the separator results in contact between the lithium ion conductive dielectric composite material and the end.;

[0042] According to one embodiment, the ferroelectric filler is selected from a group comprising BaTiO3, KNbO3, C d Nb2O6, PbNb2O6, PbTa2O6, PbBi2Nb2O9, PbTiO3, PZT, PLZT or PMN.

[0043] According to one embodiment, the invention is further characterized by a ceramic filler mixed with the ferroelectric filler.

[0044] According to one embodiment, the ceramic filler is selected from a group comprising Al2O3, AlOOH, Al(OH)3, 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 Mn x Co 3-x O4.

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 lithium ion conductive dielectric composite material of polyimide binder and ferroelectric 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 lithium ion conductive dielectric composite material extends to at least one end of the separator and movement of the uncoated end toward the separator results in contact between the lithium ion conductive dielectric composite material and the end. [2] The battery according to claim 1, wherein the ferroelectric filler is selected from a group comprising BaTiO3, KNbO3, C d Nb2O6, PbNb2O6, PbTa2O6, PbBi2Nb2O9, PbTiO3, PZT, PLZT or PMN. [3] The battery of claim 2, wherein the ferroelectric filler is BaTiO3. [4] The battery of claim 1, further comprising a ceramic filler mixed with the ferroelectric filler. [5] The battery according to claim 4, wherein the ceramic filler is selected from a group comprising Al2O3, AlOOH, Al(OH)3, 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 Mn x Co 3-x O4. [6] The battery according to claim 1, wherein a diameter of a particle of the ferroelectric filler is less than 10 micrometers. [7] The battery according to claim 6, wherein a diameter of a particle of the ferroelectric filler is between 0.1 and 2.0 micrometers. [8] The battery of claim 1, wherein a thickness of the lithium ion conductive dielectric composite material is between 1 and 100 micrometers from a surface of the metal foil current collector to a surface of the lithium ion conductive dielectric composite material. [9] The battery of claim 8, wherein a thickness of the lithium ion conductive dielectric composite material is between 1 and 50 micrometers from a surface of the current collector to a surface of the lithium ion conductive dielectric composite material. [10] The battery of claim 1, wherein the lithium ion conductive dielectric composite material extends beyond one end of the separator. [11] The battery of claim 4, wherein a ratio of polyimide binder to ferroelectric filler is between 10:90 and 30:

70. [12] 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. [13] The battery of claim 4, wherein a diameter of a particle of the ceramic filler is less than 10 micrometers. [14] The battery of claim 12, wherein a diameter of a particle of the ceramic filler is between 0.1 and 2.0 micrometers. [15] 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 lithium ion conductive dielectric composite material of polyimide binder and ferroelectric 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 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 lithium ion conductive dielectric composite material, separating it from the plurality.

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