Electrochemical cell and ventilation assembly

Abstract

An electrochemical cell is described comprising an electrode layer having an electrode layer thickness wherein the electrode layer comprises an electrode material and an electrolyte material; and a ventilation assembly comprising a breathable material. The vent assembly is disposed adjacent to the electrode layer thickness such that, in use, the vent assembly retains electrolyte within the electrode layer and allows gases formed within the electrode layer to exit from the electrode layer.

Description

Technical Field

[0001] This disclosure relates to an electrochemical cell including a ventilation component, specifically a ventilation component for allowing gas to permeate from the electrode layer within the electrochemical cell. Background Technology

[0002] The performance and safety of lithium-ion batteries depend to a large extent on the electrolyte, which acts as the medium for ion transport between the positive and negative electrodes.

[0003] The performance of an electrolyte is influenced by several key properties, including its ionic conductivity, viscosity, electrochemical stability, and compatibility with electrode materials. High ionic conductivity is crucial for efficient ion transport, which improves battery performance. Viscosity affects flowability and the ease of electrode / electrolyte penetration, thus impacting battery power and energy density. Electrochemical stability ensures the electrolyte remains stable during charging and discharging, preventing side reactions and degradation. Compatibility with electrode materials is also critical, avoiding unwanted chemical reactions and extending battery life.

[0004] Recent advances in electrolyte research aim to address the limitations of high-performance batteries, such as lithium-ion batteries, and improve their overall performance. For example, novel electrolyte additives are being explored, including lithium salts with improved stability and new solvents with enhanced safety properties. Solid-state electrolytes have also gained attention, with the potential to achieve higher energy densities (e.g., by providing lithium metal anodes) and improved safety. Furthermore, efforts are underway to develop electrolytes capable of operating at high voltages, thereby increasing energy storage capacity.

[0005] Electrolyte solvent decomposition and solid-state electrolyte interface (SEI) instability can lead to gas generation. The generated gases typically include carbon monoxide, carbon dioxide, and ethylene. Gas generation is evident during the battery formation process in manufacturing, but can also occur throughout the battery's lifespan. This can cause safety and cell performance issues, including electrode degradation, reduced storage life, decreased cycle life, electrolyte displacement, and increased cell impedance.

[0006] For example, in solid-state lithium-ion batteries, gas generation during the fabrication process is often a result of initial battery activation and conditioning. The fabrication process typically includes initial charge and discharge cycles to bring the solid-state battery to its optimal performance. During this process, gas generation can be caused by a variety of factors, including: incomplete or imperfect electrode-electrolyte interfaces leading to localized reactions at these interfaces; impurities and defects in the electrolyte and electrode materials causing localized reactions; and electrolyte decomposition. Factors such as high temperature, overvoltage, or inappropriate solid electrolyte composition can all lead to electrolyte decomposition and gas formation. Gas generation during the fabrication process is highly detrimental as it can lead to gas pocket formation, delamination of the solid-state battery structure, or degradation. Therefore, efforts are made to optimize the fabrication process to minimize gas generation and ensure the long-term stability and performance of solid-state batteries.

[0007] During use, gas generation typically occurs due to various factors, such as overcharging, over-discharging, or internal malfunctions. During overcharging, excess lithium ions can cause electrolyte decomposition, resulting in gas production. For example, overcharging often leads to the release of oxygen from the positive electrode, which then reacts with the electrolyte to produce carbon dioxide and carbon monoxide. Similarly, over-discharging can cause lithium ions to be driven into the negative electrode, leading to electrolyte decomposition and gas generation. These factors can also increase the battery's internal impedance.

[0008] Increased impedance can be caused by a variety of factors, including the formation of a solid electrolyte interphase (SEI) layer on the electrodes, electrode degradation, or dendrite growth. Gas generation can also increase impedance by affecting the integrity of battery components. The generated bubbles can impede the movement of ions and electrons, thereby reducing battery performance and increasing its internal resistance.

[0009] The formation and accumulation of gases can affect battery performance and lifespan. The formation of bubbles creates internal pressure gradients and hinders the movement of ions within the battery, thus reducing its efficiency and capacity. Furthermore, gas evolution can lead to the loss of active electrode materials, resulting in a decline in overall battery performance over time. The accumulation of gases inside the battery can cause several problems. First, it increases internal pressure, which in extreme cases can cause the battery to swell or even rupture. This poses a safety hazard, as it can lead to the release of hazardous substances or cause a fire or explosion.

[0010] Sealing batteries to protect them from external gases and moisture can also lead to the accumulation of internal gases.

[0011] Electrolyte migration is a concern in battery cells that require isolated electrolytes (specifically, the positive and / or negative electrolytes). For example, dual-electrolyte batteries contain two distinct electrolytes, each optimized for the application at the negative and positive electrode interfaces. To prevent cross-contamination between the two electrolytes and ensure efficient battery operation, solid-state or semi-solid-state batteries may contain only the positive electrolyte. These positive electrolytes can be solid or gel-based, or contain a small amount of liquid to improve performance. Isolating this positive electrolyte is crucial to prevent it from reacting with the lithium metal negative electrode.

[0012] Therefore, new solutions are still needed to address the problem of preventing gas accumulation within electrochemical cell cells while simultaneously preventing electrolyte migration within the cells. Summary of the Invention

[0013] According to a first aspect, an electrochemical battery cell is provided, comprising: an electrode layer having an electrode layer thickness, wherein the electrode layer includes an electrode material and an electrolyte material; and a ventilation assembly including a permeable material, wherein the ventilation assembly is arranged adjacent to the electrode layer thickness such that, in use, the ventilation assembly retains the electrolyte material within the electrode layer and allows gas formed within the electrode layer to be discharged from the electrode layer.

[0014] This invention provides an electrochemical cell with a ventilation component that, during use, both retains the electrolyte within the electrode layer and allows gas to escape from the electrode layer. Therefore, the arrangement of the ventilation component prevents electrolyte migration from the electrode layer, avoids cross-contamination with other electrochemical cell components, and also reduces the possibility of gas accumulation within the electrode layer. Consequently, compared to existing electrochemical cell arrangements, the electrochemical cell of this disclosure can have a longer lifespan and better performance. The use of the electrochemical cell can include the formation of the electrochemical cell, such as its activation and regulation.

[0015] The use of an electrochemical cell may also encompass the use of a cell in its usual sense, including but not limited to using the electrochemical cell for its intended purpose, such as providing electricity and any associated charging or discharging of the cell. An electrode layer may include two electrode surfaces extending in the xy plane and an electrode perimeter surface extending between the electrode surfaces in the z direction. The electrode perimeter surface may define the electrode layer thickness. Electrode materials and electrolyte materials may together form the electrode layer surface and electrode layer thickness. The electrode layer surface may include a theoretical surface, which can be used herein to describe the arrangement of the electrode layer including electrolyte materials and electrode materials.

[0016] For example, the electrode layer may include an electrode material mixed with an electrolyte material. The electrode material may include at least one of the following: discrete electrode material particles, a network of electrode material particles, or a film or layer of solid electrolyte material. The electrolyte may include a liquid electrolyte, a solid electrolyte, or a gel-based electrolyte.

[0017] For example, the electrode layer may include electrode material particles suspended in a liquid electrolyte. The electrode layer may include a three-dimensional network of electrode particles and electrolyte particles, wherein the electrolyte may be a liquid, gel, or solid material. The electrode particles and electrolyte particles may be dispersed throughout the electrode layer, wherein the electrolyte may be a liquid, gel, or solid material.

[0018] The electrode material can be a positive electrode material. The electrode material can be selected from at least one of the following: lithium nickel manganese cobalt oxide (“NMC”), lithium nickel cobalt aluminum oxide (“NCA”), lithium manganese oxide (“LMO”), lithium iron phosphate (“LFP”), lithium cobalt oxide (“LCO”), lithium vanadium oxide, or any combination thereof.

[0019] The electrode material can be a negative electrode material. The electrode material can be selected from at least one of the following: silicon, graphite, silicon-graphite composite material, lithium, lithium alloy (including lithium-silicon or lithium-tin), lithium titanate (“LTO”), tin-cobalt alloy or any combination thereof.

[0020] Electrolyte materials may include polymers, ceramics, glass, or any combination thereof, and may be in at least one of the following forms: liquid, gel, or solid. Electrolyte materials may include organic liquid, solid, or gel electrolyte materials.

[0021] Electrolyte materials may include an electrolyte solution comprising at least one solvent and at least one electrolytic salt. The solvent may be selected from at least one of the following: ethylene carbonate (EC), dimethyl carbonate (DMC), and diethyl carbonate (DEC), or combinations thereof. The electrolytic salt may be a lithium salt, selected from at least one of the following: lithium hexafluorophosphate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), or combinations thereof. Electrolyte materials may include ionic liquid electrolytes. Ionic liquid electrolytes are low-melting-point salts, such as below 100°C, and they typically possess unique properties such as high thermal stability, low volatility, and good ionic conductivity.

[0022] Electrolyte materials can include polymeric electrolyte materials. Polymeric electrolyte materials can include solid or gel-like materials comprising a polymer matrix. The polymer matrix can include, for example, at least one of the following: polyethylene oxide, or polyacrylonitrile gel, poly(vinylidene fluoride-co-hexafluoropropylene), or any combination thereof. The polymer matrix can include an electrolytic salt, such as a lithium salt. The lithium salt can be selected from at least one of the following: lithium hexafluorophosphate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), or combinations thereof. In some examples, the polymer matrix may also include a plasticizer. Using polymeric electrolytes offers advantages including improved safety, enhanced stability, and the potential for flexible battery designs. Polymer electrolytes can include polymeric ionic liquid-based gel electrolytes. Using polymeric electrolytes comprising polymeric ionic liquid-based gel electrolytes combines the advantages of polymeric electrolytes and ionic liquid electrolytes, providing improved conductivity and thermal stability.

[0023] Electrolyte materials can include solid-state electrolyte materials. Solid-state electrolyte materials include solid materials that conduct lithium ions. Solid-state electrolyte materials can improve safety and hold promise for enabling high-energy-density batteries. Solid-state electrolyte materials can include at least one of the following: lithium ceramics, such as lithium oxynitride (LiPON), lithium garnet (e.g., Li7La3Zr2O12 or LLZO), or sulfides (e.g., Li10GeP2S12 or LGPS); and solid polymer electrolytes comprising a polymer matrix with added lithium salts.

[0024] A ventilation assembly may include an electrode contact surface. The electrode contact surface may also be referred to as an electrolyte contact surface. The electrode contact surface may be part of an adjacent electrode layer in the ventilation assembly. As used herein, adjacent may include a situation where the electrode contact surface is adjacent to and in direct physical contact with the electrode layer. The term adjacent may also include a situation where the electrode contact surface is adjacent to but not in direct physical contact with the electrode assembly. The ventilation assembly may be arranged in the xy plane relative to the electrode layer such that the electrode contact surface is adjacent to at least a portion of the electrode layer. For example, the ventilation assembly may include an electrode contact surface configured to be positioned adjacent to at least a portion of one side of the electrode layer. The ventilation assembly may be arranged in the xy plane relative to the electrode layer such that the electrode contact surface surrounds at least a portion of the electrode perimeter surface. The ventilation assembly may be arranged in the xy plane relative to the electrode layer such that the electrode contact surface surrounds the electrode perimeter surface. Arranging the ventilation assembly around the electrode perimeter surface allows the ventilation assembly to retain the electrolyte within the electrode layer, for example, in the xy plane. This arrangement may also allow any gas formed within the electrode layer to be exhausted through the ventilation assembly via the electrode perimeter surface. The electrode contact surface may include a height in the z-direction corresponding to the electrode layer thickness.

[0025] The ventilation assembly can be configured to adapt to changes in electrode layer thickness. For example, the ventilation assembly can be configured to adapt to compression and / or expansion of the electrode layer thickness during the manufacture of the electrochemical cell. Additionally or alternatively, the ventilation assembly can be configured to adapt to compression and / or expansion of the electrode layer thickness during use of the electrochemical cell. The permeable material can be elastic, allowing the ventilation assembly including the permeable material to expand and contract to adapt to changes in electrode layer thickness.

[0026] Ventilation components may include air-permeable but liquid-impermeable materials. Ventilation components may include at least a portion of air-permeable but liquid-impermeable materials. The air-permeability and liquid-impermeability requirements of ventilation components may depend on the electrode and electrolyte materials.

[0027] Liquid impermeability requirements may depend on the state of the electrolyte, such as whether the electrolyte material is solid, gel, or liquid. Liquid impermeability requirements may also depend on the viscosity of the electrolyte material, such as when the electrolyte material is liquid or gel-based. Ventilation component materials can have sufficient liquid impermeability to retain the electrolyte within the electrode layer.

[0028] The permeability requirements for ventilation component materials may depend on the electrode and electrolyte materials. Permeability requirements may also depend on the gas generation conditions of the electrochemical cell. For example, ventilation component materials should have sufficient permeability to allow the venting of gases generated during the activation and conditioning processes of the electrochemical cell. The term permeable material is intended to cover materials that allow gases to flow through them via permeation (e.g., according to Darcy's law) and / or diffusion (e.g., according to Fick's law).

[0029] Ventilation components may include at least one of porous fabrics, porous strips, fabrics, or foams. Ventilation components may include polymeric materials. Ventilation components may include inflatable materials. Ventilation components may include inflatable polymeric materials. Ventilation components may include densified materials. Ventilation components may include densified polymeric materials. The breathable material may be a porous material. As used herein, the term "porous" is intended to refer to a structure comprising a plurality of pores (i.e., voids) within a solid matrix. These pores define the total pore volume of the porous material. At least some of the pores may be interconnected and form channels through the material. The solid matrix refers to the solid portion of the porous material other than its pore volume. The porous material may be a microporous material. As used herein, the term "micropore" refers to a material comprising pores not visible to the naked eye. The breathable material may include at least one of porous fabrics, porous strips, or porous foams. The breathable material may include polymeric materials. The breathable material may include inflatable materials. The breathable material may include inflatable polymeric materials. The breathable material may include densified materials. The breathable material may include densified polymeric materials.

[0030] Ventilation components may include breathable materials selected from the group consisting of: polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), polyvinylidene fluoride (PVDF), polyethylene (PE), polyether ketone ketone (PEKK), polyether ether ketone (PEEK), poly(tetramethyl-p-silylphenylsiloxane) (PTMPS), polydimethylsiloxane (PDMS), poly(p-xylene) (PPX), polyamide 6, polyurethane, thermoplastic polyurethane, polypropylene, polyimide or polyacrylonitrile (PAN), or combinations thereof.

[0031] If the ventilation assembly includes a breathable material comprising an expandable material, the expandable material may be selected from the group consisting of: expanded PTFE (ePTFE), expanded FEP (eFEP), expanded PVDF (ePVDF), expanded polyethylene (ePE), expanded PEKK (ePEKK), expanded PEEK (ePEEK), expanded PTMPS (ePTMPS), expanded polydimethylsiloxane (ePDMS), expanded PPX (ePPX), expanded polyamide 6, expanded polyurethane, expanded thermoplastic polyurethane, expanded polypropylene, expanded polyimide or expanded polyacrylonitrile (PAN) or combinations thereof.

[0032] Ventilation components may include a deformation-resistant, breathable material, meaning the deformation resistance is along the thickness direction of the ventilation component. The thickness of the ventilation component can be measured in the z-direction corresponding to the electrode layer thickness. For example, the breathable material may be crush-resistant. For instance, the breathable material may include high-strength ePTFE according to U.S. Patent No. 4,598,011, the contents of which are incorporated herein by reference. Ventilation components including a breathable material resistant to deformation along its thickness direction can ensure breathability during the manufacture, formation, and other uses of electrochemical cell cells.

[0033] The ventilation assembly may include an airflow direction that defines the direction of gas travel through the ventilation assembly. The ventilation assembly may be arranged such that the airflow direction is orthogonal to the electrode layer thickness. This arrangement allows gas to flow through the ventilation assembly in the desired direction to ensure adequate venting from the electrode material. In some examples, the airflow through the ventilation assembly may be coplanar with the electrode layer in the xy plane. In some examples, the airflow through the ventilation assembly may be orthogonal to the electrode layer in the xy plane. The ventilation assembly is air-permeable and liquid-impermeable at least at the electrode contact surface and extends across the width of the ventilation assembly along the xy plane at the electrode contact surface. The ventilation assembly may be air-permeable and liquid-impermeable across its entire width in the xy plane.

[0034] The ventilation assembly can be formed of a breathable material. Therefore, the ventilation assembly can be breathable substantially across the entire electrode contact surface and in corresponding portions of the ventilation assembly. The ventilation assembly can include a frame. The ventilation assembly can be formed from component portions that are joined together in use to constitute the ventilation assembly frame. The component portions can include the same or different materials. The frame can include a monolithic structure. The frame can include frame components having a first configuration and a second configuration, wherein in the second configuration, the frame components can be arranged adjacent to the electrode layer thickness. The frame components can include at least one cutout or notch, wherein the at least one cutout or notch can facilitate reconfiguration of the frame components from the first configuration to the second configuration. The first configuration can be a substantially linear arrangement. The ventilation assembly can include a layer of breathable material that is wrapped around or positioned near the peripheral surface of the electrode layer in use. The ventilation assembly can include an orifice having a volume, wherein the volume is configured to hold a portion of the electrode layer. The electrode contact surface of the ventilation assembly can define the perimeter of the volume.

[0035] An electrochemical cell may also include a current collector. The current collector can be configured to collect charge from the electrode layer. The current collector can be a positive electrode current collector. The current collector can be a negative electrode current collector. The current collector can be arranged in a parallel layer adjacent to the electrode layer. The current collector can be in physical contact with the electrode layer. An electrochemical cell may include both a positive electrode current collector and a negative electrode current collector.

[0036] When the current collector is a positive current collector, the current collector may include at least one of the following materials: copper, aluminum, nickel, titanium, stainless steel, graphite, other carbon-based materials such as carbon nanotubes, or any combination thereof.

[0037] When the current collector is a negative current collector, the current collector may include at least one of the following materials: copper, aluminum, platinum, lithium, graphite, other carbon-based materials such as carbon nanotubes, or any combination thereof.

[0038] An electrochemical cell may also include an electrochemical separator. The electrochemical separator may comprise any material suitable for allowing selective ion transport through it. The electrochemical separator may be positioned adjacent to the electrode layer. The electrochemical separator may be arranged as a parallel layer adjacent to the electrode layer. The electrochemical separator may be in physical contact with the electrode layer.

[0039] The electrochemical isolator may also include an electrolyte material. This electrolyte material may be the same as or different from the electrolyte material in the electrode layer.

[0040] Electrochemical separators may include materials selected from at least one of the following: polyolefins, such as polypropylene and / or polyethylene; polyethylene oxide; at least one of tetrafluoroethylene (TFE) polymers or copolymers; at least one homopolymer of vinylidene fluoride; at least one hexafluoropropylene (HFP)-vinylidene fluoride copolymer; or any combination thereof. Electrochemical separators may include polymeric and / or ceramic materials. Ceramic materials may include, for example, alumina (AL2O3), lithium aluminum titanium phosphate (LATP), or lithium lanthanum zirconate (LLZO). Electrochemical separators may include ceramic-coated separators. For example, a separator comprising a ceramic coating on the surface of a polyolefin-based separator. The ceramic coating helps improve the thermal stability and safety of the battery. The ceramic material used for the coating may include, for example, alumina (Al2O3) using polyvinylidene fluoride (PVDF) as a binder. Electrochemical separators may include composite electrochemical separators, such as composite mixtures of polymeric materials and ceramic particles or fibers. Electrochemical separators may include nonwoven electrochemical separators. Nonwoven electrochemical separators may include, for example, porous materials, such as polyester or cellulose fibers.

[0041] The ventilation assembly can be sealed relative to at least one of the current collector or the electrochemical separator. Sealing the ventilation assembly relative to at least one other component of the electrochemical cell can further facilitate the retention of the electrolyte within the electrode layer and the channeling of gas in the airflow direction for discharge through the ventilation assembly. Sealing the ventilation assembly relative to at least one of the current collector or the electrochemical separator can include using pressure, bonding, welding, adhesives, or any other suitable method or apparatus to provide a seal between the ventilation assembly and at least one of the current collector or the electrochemical separator. The ventilation assembly can be sealed relative to at least one of the current collector or the electrochemical separator such that the ventilation assembly can be configured to adapt to variations in the electrode layer thickness. For example, when an adhesive is used to achieve the seal, the adhesive can have elastic properties, allowing the ventilation assembly to move relative to the electrode layer.

[0042] Ventilation components may include at least one treated surface configured to promote adhesion between an adhesive and a breathable material of the ventilation component. Examples of surface treatments include, but are not limited to, corona or plasma surface treatments or similar treatments configured to alter surface properties of the material, such as surface energy, thereby improving adhesion, for example, of the adhesive. Another example of a surface treatment may be irradiation-induced surface grafting, in which the surface energy of the ventilation component is altered by chemically bonding other polymeric materials to the surface.

[0043] An electrochemical cell may be configured to retain gases formed within an electrode layer. A ventilation assembly may be configured to act as a reservoir for gases expelled from the electrode layer. The ventilation assembly may include a porous, breathable material, and may be configured such that a portion or all of the total pore volume of the breathable material may be void space. As used herein, void space is intended to encompass a situation where at least a portion or substantially all of the total pore volume of the breathable material is free of gas or liquid. Typically, prior to use, the total pore volume of the breathable material may be occupied, for example, by air. The electrochemical cell may include an outer layer, such as a shell, bag, or coating, which may be arranged to allow gases expelled from the electrode layer to be retained within the ventilation assembly. For example, the outer layer may include an impermeable material. The outer layer may include a vacuum bag, and the electrochemical cell may be placed under a vacuum. For example, the electrochemical cell may be placed under a vacuum so that most or all of the air or residual gas present during the formation of the cell can be removed from the pore volume of the breathable material. During use of the electrochemical cell, gases generated in the electrode layer may enter and reside in the void space of the breathable material. An electrochemical cell may include an adsorbent, which is provided to absorb gases expelled from the electrode layer. A ventilation assembly may include this adsorbent. The chemical composition of the adsorbent will depend on the gases expelled from the electrode layer. For example, a suitable adsorbent for absorbing CO2 may be polyethyleneimine-functionalized silica. The adsorbent serves to prevent expansion of the ventilation assembly, for example, due to gas accumulation in the electrode layer during the use and / or manufacture of the electrochemical device. A permeable material may include the adsorbent. For example, the permeable material may be a porous strip or film that may include the adsorbent.

[0044] An electrochemical cell may also include a negative electrode. In some examples, the negative electrode may be formed during the use of the electrochemical cell, such as in solid-state or semi-solid-state lithium batteries. The negative electrode may include a lithium negative electrode. The negative electrode may include at least one of the following: silicon, graphite, silicon-graphite composite material, lithium, lithium alloy (including lithium-silicon or lithium-tin), lithium titanate (“LTO”), lithium iron phosphate, tin-cobalt alloy, or any combination thereof.

[0045] The peripheral surface of the electrode layer may define the outer perimeter of the electrode layer in the xy plane. The electrochemical isolator may include a surface having an outer perimeter in the xy plane, corresponding to the outer perimeter of the electrode layer. The current collector may include a surface having an outer perimeter in the xy plane, corresponding to the outer perimeter of the electrode layer. The ventilation assembly may include a thickness corresponding to the thickness of the electrode layer. The ventilation assembly may be sealed at the adjacent edge between the ventilation assembly and at least one of the electrochemical isolator or the current collector.

[0046] The electrochemical isolator may include a peripheral surface extending in the z-direction relative to the surface of the electrochemical isolator in the xy-plane. The current collector may include a peripheral surface extending in the z-direction relative to the surface of the current collector in the xy-plane. The ventilation assembly may include a thickness greater than the electrode layer thickness. When the thickness of the ventilation assembly is greater than the electrode layer thickness, the electrode contact surface of the ventilation assembly may extend to the peripheral surface of an adjacent current collector or the peripheral surface of the electrochemical isolator. The ventilation assembly may seal between the electrode contact surface and an adjacent peripheral surface of at least one of the electrochemical isolator or the current collector. This arrangement can facilitate the manufacture of the electrochemical cell. For example, by providing a surface on the exterior of the electrochemical cell component, the boundary of the electrochemical cell can be defined, keeping the component within the boundary.

[0047] An electrochemical separator may include a surface in the xy-plane having a portion extending beyond the outer perimeter of the electrode layer. A current collector may include a surface in the xy-plane having a portion extending beyond the outer perimeter of the electrode layer. An electrochemical cell may include an electrochemical separator and a current collector, and an electrode layer may be located between them. A ventilation assembly may be sandwiched between those portions of the electrochemical separator and the current collector extending beyond the outer perimeter of the electrode layer in the xy-plane. The ventilation assembly may be in physical contact with at least one of the portions of the electrochemical separator and the current collector extending beyond the outer perimeter of the electrode layer in the xy-plane. This arrangement facilitates the manufacture of the electrochemical cell while allowing the electrolyte to be retained within the electrode layer during use of the cell.

[0048] A ventilation assembly can be configured to surround the surface of the current collector in the xy-plane. For example, the ventilation assembly may also include a surface extending in the xy-plane, which can be arranged adjacent to the outer surface of the current collector in the xy-plane. Therefore, the ventilation assembly in this arrangement can serve as a barrier between adjacent cell sections (when multiple electrochemical cells are present), or it can serve as a barrier between adjacent current collector portions (e.g., if the electrochemical cell includes a wound configuration). The ventilation assembly's configuration around the surface of the current collector in the xy-plane can also facilitate cell fabrication during the formation of the electrochemical cell by holding the electrode layer in place relative to the current collector.

[0049] An electrochemical cell may include multiple electrochemical cell components, including a positive current collector, an electrode layer (wherein the electrode materials include a positive electrode material and an electrolyte material), an electrochemical separator, a negative electrode, and a negative current collector, wherein each of these electrochemical cell components is arranged in a stacked configuration. A ventilation assembly is arranged at least adjacent to the thickness of the electrode layer.

[0050] An electrochemical cell can be a battery. An electrochemical cell can be a rechargeable battery. An electrochemical cell can be a solid-state or semi-solid-state battery.

[0051] An electrochemical cell may include multiple electrochemical cell units. Each of the multiple electrochemical cell units may include an electrode layer having an electrode material and an electrolyte material. Therefore, an electrochemical cell unit may include multiple electrode layers. The electrochemical cell unit may include multiple ventilation components, and each of the multiple ventilation components may be arranged adjacent to an electrode layer. The multiple electrode layers may have a total electrode layer thickness. The ventilation components may be arranged adjacent to the total electrode layer thickness. The contact surface of the ventilation component may include a height in the z-direction, which is at least equal to the total electrode layer thickness. The ventilation components may be arranged adjacent to the total electrode layer thickness such that the ventilation components retain the electrolyte material within each of the multiple electrode layers and allow gases formed within each electrode layer to escape from that electrode layer.

[0052] The electrochemical cell may also include a housing arranged to house an electrode layer and a ventilation assembly, as well as (multiple) current collectors and electrochemical separators (if present). The housing may include a housing volume within which the electrode layer and ventilation assembly are housed. The housing may be arranged to retain the ventilation assembly such that gases generated in the electrode layer are exhausted through the ventilation assembly into the housing volume. The electrochemical cell may be arranged such that the ventilation assembly forms part of the housing. In this arrangement, gases generated in the electrode layer can be exhausted through the ventilation assembly to the environment outside the housing volume.

[0053] According to a second aspect, a ventilation assembly for an electrochemical cell is provided, the electrochemical cell including an electrode layer having an electrode layer thickness, wherein the electrode layer includes an electrode material and an electrolyte material; wherein the ventilation assembly includes a breathable ventilation material arranged in use to retain the electrolyte within the electrode layer and allow gas formed within the electrode layer to escape from the electrode layer.

[0054] The ventilation assembly may include the ventilation assembly described in the first aspect.

[0055] According to a third aspect, a positive electrode assembly for a solid-state or semi-solid-state battery is provided, wherein the positive electrode assembly includes a positive electrode layer having a positive electrode material and a positive electrode electrolyte, and a ventilation assembly arranged to surround at least a portion of the positive electrode layer, and the ventilation assembly is configured in use to retain the positive electrode electrolyte within the portion of the positive electrode layer and to allow gas formed within the positive electrode layer to be discharged from the positive electrode layer.

[0056] The ventilation assembly may include the ventilation assembly described in the first aspect. The positive electrode layer may include the features of the electrode layer described in the first aspect. The positive electrode material may include the features of the electrode material described in the first aspect. The positive electrode electrolyte may include the features of the electrolyte material described in the first aspect.

[0057] According to a fourth aspect, a method for manufacturing an electrochemical cell according to the first aspect is provided. The method may include providing an electrode layer comprising an electrode material and an electrolyte material, providing a ventilation assembly comprising a permeable material, and arranging the ventilation assembly adjacent to the thickness of the electrode layer such that the ventilation assembly can retain the electrolyte material within the electrode layer and allow gases formed within the electrode layer to escape from the electrode layer. Attached Figure Description

[0058] Embodiments of the invention will now be described by way of non-limiting example with reference to the accompanying drawings.

[0059] Figure 1 : An exploded view of an illustrative electrochemical cell including an exemplary ventilation assembly according to this disclosure; Figure 2 : Figure 1 A schematic three-dimensional view of a single electrochemical cell is shown. Figure 3 : Figure 1 A schematic cross-sectional view of a single electrochemical cell; Figure 4 : Figure 1 A schematic end view of a single electrochemical cell; Figure 5A : An exploded view of an exemplary ventilation assembly prior to construction, based on this disclosure; Figure 5B : Figure 5A A three-dimensional view of the ventilation components after construction; Figure 5C : An exploded view of an exemplary ventilation assembly before construction; Figure 5D : Figure 5C A three-dimensional view of the ventilation components after construction; Figure 6 : An exploded view of an illustrative electrochemical cell including an exemplary ventilation assembly according to this disclosure; Figure 7 : Figure 6 A schematic three-dimensional view of a single electrochemical cell is shown. Figure 8 : Figure 6 A schematic cross-sectional view of a single electrochemical cell; Figure 9 : Figure 6 A schematic end view of a single electrochemical cell; Figure 10 : An exploded view of an illustrative electrochemical cell including an exemplary ventilation assembly according to this disclosure; Figure 11 : Figure 10 A schematic three-dimensional view of a single electrochemical cell is shown. Figure 12 : Figure 10 A schematic cross-sectional view of a single electrochemical cell; Figure 13a : A perspective view of an exemplary ventilation assembly according to this disclosure before it is placed in an electrochemical cell; Figure 13b : Figure 13a A three-dimensional view of the ventilation components configured to be placed within an electrochemical cell. Figure 13c According to this disclosure, including Figure 13a and 13b A schematic exploded view of an electrochemical cell for a ventilation assembly; Figure 13d : Figure 13c A schematic three-dimensional diagram of a single electrochemical cell; Figure 14 : A schematic perspective view of an electrochemical cell having a wound configuration and including an exemplary ventilation assembly according to the present disclosure; Figure 15 : Figure 14 The image shows a cross-sectional view of a single electrochemical cell in its unfolded configuration. Figure 16 : A schematic perspective view of an electrochemical cell having a wound configuration and including another exemplary ventilation assembly according to the present disclosure; Figure 17 : Figure 16 The image shows a cross-sectional view of a single electrochemical cell in its unfolded configuration. Figure 18 : A schematic cross-sectional view of an electrochemical cell having a ventilation assembly according to the present disclosure, the cell also including an outer casing; Figure 19 : A schematic cross-sectional view of an electrochemical cell having a ventilation assembly according to the present disclosure, wherein the ventilation assembly forms part of the outer casing of the cell. Figure 20 : A schematic diagram of a battery comprising multiple electrochemical cell units arranged in a stacked configuration and multiple ventilation assemblies according to the present disclosure; and Figure 21 : A schematic diagram of a battery comprising multiple electrochemical cell units arranged in a stacked configuration and a ventilation assembly according to the present disclosure.

[0060] Figure 22: A cross-sectional view of an illustrative electrochemical cell according to this disclosure.

[0061] Figure 23 : A schematic diagram of an electrochemical cell with a vacuum bag according to the present disclosure.

[0062] Figure 24 After applying a vacuum Figure 23 A schematic diagram of the arrangement shown. Detailed Implementation

[0063] Although the manufacture and use of various embodiments of the invention are discussed in detail below, it should be understood that the invention provides many applicable inventive concepts that can be embodied in various specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways of manufacturing and using the invention and do not limit the scope of the invention.

[0064] To facilitate understanding of this invention, several terms are defined below. The terms defined herein have meanings commonly understood by one of ordinary skill in the art related to this invention. Terms such as “a,” “an,” and “the” are not intended to refer to a single entity only, but rather to encompass general categories that can be illustrated by specific examples. The terms used herein are used to describe specific embodiments of the invention, but their use does not limit the invention unless set forth in the claims.

[0065] Figures 1 to 4 A schematic electrochemical cell 10 according to this disclosure, including a ventilation assembly 20, is shown. The electrochemical cell 10 includes a positive current collector 12, a negative current collector 14, and a positive electrode layer 18 disposed therebetween. An electrochemical separator 16 is also disposed adjacent to the positive electrode layer 18 and the negative current collector 14. The electrochemical cell 10 is a solid-state or semi-solid-state battery, wherein the positive electrode layer 18 includes a positive electrode material and an electrolyte (or positive electrode electrolyte) material. The positive electrode material and the electrolyte material are dispersed, and the electrolyte material may primarily be in gel or solid form. In use, ion transport generated within the positive electrode layer 18 passes through the electrochemical separator 16, forming a negative electrode near the electrochemical separator 16 and the negative current collector 14. It should be understood that in some examples, the positive electrode layer 18 may also include a liquid-based electrolyte material. It should also be understood that in some examples, the electrochemical cell may include a permanent negative electrode, i.e., a negative electrode that is always present within the cell.

[0066] The ventilation assembly 20 includes a housing in the form of a frame 22 made of a breathable, liquid-impermeable material. The frame 22 is a monolithic structure formed from a single piece of breathable, liquid-impermeable material and includes an opening 23 defining a volume 24 that is configured to retain part of the positive electrode layer 18 during use.

[0067] like Figure 1 As shown, the positive electrode layer 18 is sandwiched between the positive electrode current collector 12 and the electrochemical separator 16, and there is an exposed peripheral surface 19 between them, which extends around the perimeter of the positive electrode layer 18 and defines the thickness (or height) 18a of the positive electrode layer 18 (see Figure 19). Figure 3 ).

[0068] The completed electrochemical cell 10 Figure 2 As shown, Figure 3 A cross-sectional view taken along line A-A' is shown. The ventilation assembly 20, together with the positive current collector 12 and the electrochemical separator 16, forms a closed volume encapsulating the positive electrode layer 18 therein. The ventilation assembly 20 works in conjunction with at least one other component of the electrochemical cell 10 (in this example, the positive current collector 12 and the electrochemical separator 16) to support and retain the electrolyte material within the positive electrode layer 18, while allowing gas to permeate from the electrolyte 18 via the ventilation assembly 20.

[0069] In this example, the ventilation assembly frame 22 includes two main surfaces 22a and 22b located in the xy plane, and a peripheral surface 22c between them, which defines the thickness (or height) 22d of the frame 22 (in the z-direction). An aperture 23 extends through the thickness 22d of the frame 22, defining an internal electrolyte contact surface 26, sized to correspond to the size of the exposed peripheral surface 19 of the positive electrode layer 18. The electrolyte contact surface 26 can also be referred to as the electrode contact surface. That is, the size (i.e., surface area) of the electrolyte contact surface 26 corresponds to the size (i.e., surface area) of the exposed surface 19 of the positive electrode layer 18. Figure 3 As shown, the thickness 22d of the frame 22 corresponds to the height of the electrolyte contact surface 26 and also to the thickness 18a of the positive electrode layer 18. Therefore, the ventilation assembly 20 is configured such that the volume 24 of the orifice 23 allows the ventilation assembly 20 to surround the peripheral surface 19 of the positive electrode layer 18.

[0070] It should be understood that, in some embodiments, the thickness 18a of the positive electrode layer 18 may be defined by the spacing between the positive electrode current collector 12 and the electrochemical separator 16.

[0071] The ventilation component frame 22 can be formed of any suitable air-permeable and liquid-impermeable material. Such materials typically have an airflow direction that defines the direction in which gas flows through the material. In this example, frame 22 is formed of an expanded polymer material with a porous structure through which gas can permeate. The expanded polymer material is porous, with at least some pores interconnected, serving as channels for gas to pass through the material. The permeation direction of gas through frame 22 is as follows: Figure 3As indicated by arrow 28. Therefore, the frame 22 is arranged around the positive electrode layer 18 such that the gas permeation direction 28 through the ventilation assembly 20 is orthogonal to the thickness 18a of the positive electrode layer 18. Thus, the permeable direction 28 is also orthogonal to the height of the electrolyte contact surface 26. The permeable direction 28 of the ventilation assembly 20 is also considered to be coplanar with the positive electrode assembly 18 (in the xy plane). The frame 22 can be constructed, for example, by die-cutting a permeable material of the desired thickness to form pores 23 within that material. Although an expanded polymer has been described, it should be understood that any suitable permeable material can be used depending on the permeability requirements of the electrochemical cell.

[0072] In some applications, breathable materials can adapt to variations in electrode layer thickness. For example, the electrode layer may expand or contract during the manufacturing or use of the electrochemical cell. The breathable material can be elastic, allowing the ventilation assembly, which includes the breathable material, to expand and contract to accommodate changes in electrode layer thickness. It is also desirable for the breathable material to resist deformation along the thickness direction of the ventilation assembly to ensure that breathability is maintained during the manufacturing and use of the electrochemical cell.

[0073] Ventilation assembly 20 is positioned adjacent to the outer periphery of positive current collector 12 and the outer periphery of electrochemical separator 16. Ventilation assembly 20 can be sealed to positive current collector 12 and electrochemical separator 16 at their respective connecting edges 30. Therefore, positive electrode layer 18 is sealed between ventilation assembly 20, positive current collector 12, and electrochemical separator 16, such that the electrolyte in positive electrode layer 18 is retained within positive electrode layer 18, and gas formed in positive electrode layer 18 can permeate through ventilation assembly in the airflow direction 28. Ventilation assembly 20 can be sealed to positive current collector 12 and electrochemical separator 16 at their connecting edges using any suitable method or device, including but not limited to pressure, adhesives, welding, such as ultrasonic welding. When adhesives are used for sealing, the adhesives can have elastic properties, allowing ventilation assembly to move relative to the electrode layer, thereby adapting to changes in electrode layer thickness.

[0074] In some applications, a surface treatment can be provided for the ventilation assembly 20, configured to promote adhesion between the adhesive and the breathable material of the ventilation assembly 20. For example, the ventilation assembly 20 may include at least one treated surface configured to promote adhesion between the adhesive and the breathable material of the ventilation assembly 20. Examples of surface treatments include, but are not limited to, corona or plasma surface treatments, or irradiation-induced surface grafting, or similar treatments configured to alter the surface properties of the material, such as surface energy, thereby improving, for example, the adhesion of the adhesive. Another example of a surface treatment could be irradiation-induced surface grafting, in which the surface energy of the ventilation assembly is altered by chemically bonding other polymeric materials to the surface.

[0075] Figure 4 An end view of the completed electrochemical cell 10 is shown. In this example, the ventilation assembly frame 22 is dimensioned such that the positive electrode layer 18 is nested within the volume 24 of the orifice 23. The main surfaces 22a, 22b of the frame 22 are considered to lie in the xy plane and include a length 21. The positive electrode layer 18 also includes two main surfaces in the same xy plane and includes a length 13. The length 21 of the main surfaces 22a, 22b of the frame 22 is greater than the length 13 of the positive electrode layer 18. The same applies to the width of the frame 22 and the width of the positive electrode layer 18. Therefore, the ventilation assembly 20 extends beyond the outer perimeter of the positive electrode layer 18 in the xy plane.

[0076] Figure 5A and Figure 5B An alternative ventilation assembly 40 is shown, comprising a frame 42 composed of a plurality of frame members 42a-42d. Each frame member 42a-42d comprises a breathable but liquid-impermeable material and has a beveled edge 45. Members 42a-42d may be joined 30 at the beveled edges 45 to form a frame 42 having an orifice 43 and an electrolyte contact surface 46, defining a volume that retains a portion of the positive electrode layer, as described above. Figures 1 to 4 The miter edge 45 can be joined by any suitable means, such as using adhesive, welding, or overlapping edges and joining them by pressure and welding or using adhesive.

[0077] Figure 5C and Figure 5D An alternative ventilation assembly 50 is shown, comprising a frame 52 composed of multiple frame components 52a-52d. Each frame component 52a-52d comprises a breathable but liquid-impermeable material and has a straight edge 55. Components 52a-52d may be joined 30 at the straight edges 55 to form a frame 52 having orifices 53 and an electrolyte contact surface 56, defining a volume that retains a portion of the positive electrode layer, as described above. Figures 1 to 4The straight edges 55 can be joined by any suitable means, such as using adhesives, welding, or overlapping edges and joining them by pressure and welding or using adhesives.

[0078] In some examples, frame components 42a-42d, 52a-52d may be made of different materials. For example, a frame component may be made of a breathable but liquid-impermeable material, or at least a portion of a frame component may be made of a breathable but liquid-impermeable material to provide gas venting from the electrode layer through the xy plane at the location of that frame component. Other frame components may be made of, for example, liquid-impermeable materials.

[0079] Figures 6 to 9 A schematic electrochemical cell 100 according to this disclosure includes another exemplary ventilation assembly 120. The ventilation assembly 120 may be the same as the ventilation assemblies 20, 40, or 50 described above. The completed electrochemical cell 100 is as follows: Figures 7 to 9 As shown, Figure 8 It shows its along Figure 7 A cross-sectional view taken along line B-B'. The electrochemical cell 100 includes a positive current collector 112, a negative current collector 114, and a positive electrode layer 118 disposed between them. An electrochemical separator 116 is also disposed adjacent to the positive electrode layer 118 and the negative current collector 114.

[0080] In this example, the ventilation assembly 120 is sized such that it includes an orifice 123 having a volume 124 that allows the ventilation assembly 120 to surround the positive electrode layer 118 at the exposed surface 119 of the positive electrode layer 118. The orifice 123 extends through the thickness 122d of the ventilation assembly, defining an internal electrolyte contact surface 126, which is sized to correspond to the dimensions of the exposed periphery surface 119 of the positive electrode layer 118.

[0081] The positive current collector 112 and the electrochemical separator 116 extend in the xy plane beyond the outer perimeter of the positive electrode layer 118 in the xy plane. A ventilation assembly 120 is configured to be sandwiched between the extension 112a of the positive current collector 112 and the extension 116a of the electrochemical separator 116, respectively. In some examples, the ventilation assembly 120 may be configured to correspond to the external dimensions of the positive electrode and / or the separator and / or the current collector. A ventilation assembly 130 is sealed to the positive current collector 112 and the electrochemical separator 116, for example, by forming a sealed volume between adjacent surfaces at the extensions 112a, 116a, encapsulating the positive electrode layer 118 within it. Therefore, the electrolyte within the positive electrode layer 118 is retained within the positive electrode layer 118, and gases generated within the positive electrode layer 118 can be exhausted through the ventilation assembly 120. In this example, the ventilation assembly 120 extends beyond the outer perimeter boundaries of the positive current collector 112 and the electrochemical separator 116. However, it should be understood that the dimensions of the ventilation assembly 120 may also be set within or to match the outer perimeter boundaries of the positive current collector 112 and the electrochemical separator 116. This arrangement facilitates manufacturing because the ventilation assembly can retain the positive electrode layer relative to the positive current collector 112 during the construction of the electrochemical cell 100.

[0082] The ventilation assembly 120 can be sealed to the positive current collector 112 and the electrochemical separator 116 between adjacent surfaces at the extensions 112a, 116a using any suitable means or means, including but not limited to using pressure, using adhesives or bonding agents, using welding, such as ultrasonic welding.

[0083] Similar to the previous example, the ventilation assembly 120 is arranged such that the airflow permeation direction 128 through the ventilation assembly 120 is orthogonal to the thickness (or height) 118a of the positive electrode layer 118 and the height 122d of the ventilation assembly 120, as shown below. Figure 8 As shown.

[0084] Figures 10 to 12 An illustrative electrochemical cell 200 including another exemplary ventilation component 220 is shown according to this disclosure. Figure 11 The completed electrochemical cell 200 is shown. Figure 12 Provided its along Figure 11 A cross-sectional view taken along line C-C'. The electrochemical cell 200 includes a positive current collector 212, a negative current collector 214, and a positive electrode layer 218 disposed between them. An electrochemical separator 216 is also disposed adjacent to the positive electrode layer 218 and the negative current collector 214.

[0085] In this example, the ventilation assembly 220 includes a breathable, liquid-impermeable material layer 222 configured to be positioned around the outer periphery of the positive electrode layer 218 and connected at an adjacent edge 223 of the layer 222. The layer 222 includes an electrolyte contact surface 226 extending around its inner periphery and defines a volume 224 for encapsulating a portion of the positive electrode layer 218 around the exposed surface 219 of the positive electrode layer 218.

[0086] In addition, such as Figure 12 As shown, the ventilation assembly 220 includes a height 222d, which is greater than the thickness (or height) 218a of the electrolyte 218. Therefore, layer 222 also surrounds at least a portion of the outer surfaces of the positive current collector 212 and the electrochemical separator 216. The ventilation assembly 230 is sealed to the adjacent outer surfaces of the positive current collector 212 and the electrochemical separator 216, respectively. The ventilation assembly 220 can be sealed to the positive current collector 212 and the electrochemical separator 216 using any suitable method or device, including but not limited to pressure, bonding or adhesive, welding, such as ultrasonic welding.

[0087] In some examples, the ventilation assembly 220 may include a height in the z-direction corresponding to the total height of the positive current collector, the positive electrode layer, the electrochemical separator, and the negative current collector.

[0088] The ventilation assembly 220 is arranged such that the airflow permeation direction 228 through the ventilation assembly 220 is orthogonal to the thickness (or height) 218a of the electrolyte 218 and the height 222d of the ventilation assembly 220, as shown below. Figure 12 As shown.

[0089] Figures 13a to 13d An illustrative electrochemical cell 250 including another exemplary ventilation component 270 is shown according to this disclosure.

[0090] In this example, the ventilation assembly 270 includes a frame member 272 made of a breathable, liquid-impermeable material and configured to be positioned around the outer periphery of the positive electrode layer 268, and connected at the adjacent edge 273 of the frame member 272. The frame member 272 includes... Figure 13a The first configuration shown can be substantially linear. The adjacent edges 273 can be joined using any suitable method, such as by adhesive, welding, or overlapping edges and joining by pressure and welding or by adhesive. The adjacent edges 273 can be joined before being positioned in the electrochemical cell (e.g., as shown in...). Figure 13b (as shown), or it can be connected in situ (e.g., by orienting the frame component 272 around a portion of the positive electrode layer 268 and then connecting the adjacent edge 273).

[0091] The frame member 272 includes an electrolyte contact surface 276, which, in a second configuration, can extend around the inner periphery of the frame member 272 and define a volume 274 for encapsulating a portion of the positive electrode layer 268 around the exposed surface 269 of the positive electrode layer 268. To facilitate positioning of the frame member 272, cutouts 275 are provided on the frame member 272, allowing the frame member 272 to be oriented (e.g., bent) into the second configuration, thereby enabling the ventilation assembly 270 to be placed around a portion of the positive electrode layer 268. In this example, three cutouts 275 are provided, and the frame member 272 is bent into a generally cuboid shape, such as... Figure 13b As shown. It should be understood that any number of cuts 275 can be provided to allow the frame component 272 to be oriented (e.g., bent) into a desired shape. This arrangement allows for increased flexibility in the ventilation assembly 270, making it suitable for electrochemical cell cells of various shapes and sizes. Furthermore, the method of forming the ventilation assembly 270 from the frame component 272 with cuts 275 can improve manufacturing efficiency, for example, by increasing material utilization compared to die-cutting the desired shape from a single piece of material.

[0092] Figure 13c An exploded view of the electrochemical cell 250 and the ventilation assembly 270 is shown. Figure 13d An assembled electrochemical cell 250 is shown. Similar to electrochemical cell 100, electrochemical cell 250 includes a positive current collector 262 and an electrochemical separator 266, which extend in the xy plane beyond the outer periphery of the positive electrode layer 268 in the xy plane. A ventilation assembly 270 is configured to be sandwiched between the extension 262a of the positive current collector 262 and the extension 266a of the electrochemical separator 266, respectively. A negative current collector 264 is positioned adjacent to the electrochemical separator 266. In some examples, the ventilation assembly 270 may be configured to correspond to the external dimensions of the positive electrode and / or the separator and / or the current collector (e.g., similar to...). Figures 10 to 12 The arrangement shown, or configured to be positioned near the outer perimeter edge of the positive current collector and the outer perimeter edge of the electrochemical separator (e.g., similar to...). Figures 1 to 4 (The arrangement shown).

[0093] Ventilation assembly 270 is sealed to the positive current collector 262 and the electrochemical separator 266, for example, by forming a sealed volume between adjacent surfaces at extensions 262a and 266a, encapsulating the positive electrode layer 268 within it. Therefore, the electrolyte within the positive electrode layer 268 is retained within the positive electrode layer 268, and gases generated within the positive electrode layer 268 can be exhausted through ventilation assembly 270. Ventilation assembly 270 is sealed to the positive current collector 262 and the electrochemical separator 266 using any suitable means or means, including but not limited to pressure, bonding or adhesive, welding, such as ultrasonic welding.

[0094] Figure 14 and Figure 15 A schematic electrochemical cell 300 according to this disclosure includes another exemplary ventilation assembly 320. The electrochemical cell 300 is configured to have a wound configuration 340. Therefore, Figure 14 A schematic diagram of the battery cell 300 in a partially wound configuration is shown. Figure 15 The end view of this device in its expanded configuration is shown.

[0095] Ventilation assembly 320 is a gas-permeable, liquid-impermeable material arranged to encapsulate the positive electrode layer 318 and the positive current collector 312, and is sealed 330 to an electrochemical separator 316 adjacent to the positive electrode layer 318. The electrochemical separator 316 extends beyond the outer periphery of the positive electrode layer 318, providing an extended surface 316a to which the ventilation assembly 320 can be sealed. The ventilation assembly 320 can be sealed to the electrochemical separator 316 using any suitable method or device, including but not limited to pressure, bonding or adhesive, welding, such as ultrasonic welding. Therefore, the ventilation assembly 320, in conjunction with the electrochemical separator 316, forms a closed volume surrounding the positive electrode layer 318 and the positive current collector 312, retaining the electrolyte material within the positive electrode layer 318 while allowing gases formed in the positive electrode layer 318 to be released from the positive electrode layer 318 via the ventilation assembly 320. The ventilation component 320 is arranged such that the permeable direction 328 is orthogonal to the thickness 318a of the positive electrode layer 318.

[0096] In a wound configuration, the ventilation assembly 320 can also act as a barrier between the positive current collector 312 and the negative current collector 314. The ventilation assembly 320 is configured to surround the outer surface of the positive current collector 312, which also has the advantage of simplifying the manufacturing process of the electrochemical cell 300.

[0097] Figure 16 and Figure 17 A schematic electrochemical cell 400 is shown, including another exemplary ventilation assembly 420. The electrochemical cell 400 is configured to have a wound configuration 440. Therefore, Figure 16 A schematic diagram of the battery cell 400 in a partially wound configuration is shown. Figure 17 The end view of this device in its expanded configuration is shown.

[0098] Ventilation assembly 420 includes two air-permeable, liquid-impermeable strips of material arranged near the positive electrode layer 418, such that ventilation assembly 420 extends along two sides 419a, 419b of the peripheral surface 419 of the positive electrode layer 418. In some examples, only one strip of ventilation assembly 420 is air-permeable. In a wound configuration, the third and fourth sides of the peripheral surface 419 of the positive electrode layer 418 (one side 419c is...) Figure 17 (As shown in the figure) is encapsulated by a second electrochemical isolator 417 (or an insulating material layer).

[0099] In this example, the positive current collector 412 and the electrochemical isolator 416 extend beyond the outer perimeter of the positive electrode layer 418. The negative current collector 414 is arranged adjacent to the electrochemical isolator 416. A venting assembly 420 may be clamped and sealed 430 between the adjacent surfaces of the venting assembly 420 and the portions of the positive current collector 412 and the electrochemical isolator 416 extending beyond the outer perimeter of the positive electrode layer 418. The venting assembly 420 may be sealed to the electrochemical isolator 416 and the positive current collector 412 using any suitable means or means, including but not limited to using pressure, using adhesives or bonding agents, using welding, such as ultrasonic welding. The venting assembly 420 is arranged such that the permeable direction 428 is orthogonal to the thickness 418a of the positive electrode layer 418.

[0100] Each of the electrochemical cell units 10, 100, 200, 250, 300, and 400 as described above can be further provided with an outer casing, such as... Figure 18 and Figure 19 As shown in the figures. Electrochemical cell 10 is shown in these figures; however, it should be understood that these concepts also apply to electrochemical cell 100, 200, 250, 300 and 400.

[0101] Figure 18 An electrochemical cell 500 is shown, comprising an electrochemical cell 10 and an outer casing 560 housing all components of the electrochemical cell 10. Therefore, gas formed within the positive electrode layer 18 of the electrochemical cell 10 can be exhausted into the casing 560 via a ventilation assembly 20. If necessary, the casing 560 may be provided with another ventilation assembly to allow gas to be exhausted into the environment outside the cell 500.

[0102] Figure 19An alternative electrochemical cell 600 with an outer casing 660 is shown. The outer peripheral surface 22e of the ventilation assembly 20 forms part of the outer casing 660 that houses the electrochemical cell 10 therein. Therefore, gas formed within the positive electrode layer 18 of the electrochemical cell 10 is discharged to the environment outside the casing 660 through the ventilation assembly 20.

[0103] Electrochemical cell units of 10, 100, 200 and 250 can be stacked to form a battery comprising multiple electrochemical cell units. Figure 20 A schematic diagram of a battery 700 comprising multiple electrochemical cell units is shown. For simplicity, only the positive electrode layer 718 of each cell is shown; however, it should be understood that other cell components outlined above with respect to electrochemical cell units 10, 100, and 200 will also be present. In this example, the positive electrode layers 718 are stacked, and multiple ventilation assemblies 720 are provided. Each ventilation assembly 720 is arranged adjacent to the positive electrode layer 718 and sealed to at least one other cell component (e.g., the positive current collector and electrochemical separator as described for electrochemical cell unit 10) to retain electrolyte material within the positive electrode layer 718 and allow gas to flow from the positive electrode layer 718 into the interior of the battery housing 760. The battery 700 may include an vent 762 within the battery housing 760 to allow gas to escape from the battery housing 760. The ventilation assembly 720 may alternatively or additionally form part of the battery housing 760 to allow direct venting to the external environment.

[0104] Figure 21 An alternative battery 800 comprising multiple electrochemical cell units is shown. For simplicity, only the positive electrode layer 818 of each cell is shown; however, it should be understood that other cell components outlined above with respect to electrochemical cell units 10, 100, 200, and 250 will also be present. In this example, a venting assembly 820 is provided, comprising a thickness 822d that corresponds at least to the total thickness 818a of the positive electrode layers 818 in the stacked arrangement. The total thickness 818a of the positive electrode layers 818 in the stacked configuration will also include the thickness of any intermediate electrochemical cell components between the positive electrode layers 818. The venting assembly 820 is arranged adjacent to the positive electrode layers 818 and sealed to at least one other cell component (e.g., the positive current collector and electrochemical separator as described for electrochemical cell unit 10) to retain electrolyte material within each positive electrode layer 818 and allow gas to flow from each positive electrode layer 818 into the interior of the battery housing 860. The battery 800 may include an exhaust port 862 within the battery housing 860 to allow gas to escape from the battery housing 860. A ventilation assembly 820 may alternatively or additionally form part of the battery housing 860 to allow direct exhaust to the external environment.

[0105] Figure 22 A cross-sectional view of an electrochemical cell 900 is depicted, the cell including a positive current collector 912, a negative current collector 914, and a positive electrode layer 918 disposed between them. An electrochemical separator 916 is also disposed adjacent to the positive electrode layer 918 and the negative current collector 914. A ventilation assembly 920 is dimensioned such that it includes an orifice with a volume that allows the ventilation assembly 920 to surround the positive electrode layer 918 at the exposed surface 919 of the positive electrode layer 918. The orifice extends through the thickness of the ventilation assembly 920, defining an internal electrode contact surface 926, which is dimensioned corresponding to the dimensions of the exposed peripheral surface 919 of the positive electrode layer 918. Figure 22 As shown, a gap 925 exists between the exposed perimeter surface 919 and the electrode contact surface 926. Providing the gap 925 between the positive electrode layer 918 and the ventilation assembly 920 allows space for the positive electrode layer 918 to expand and contract during the manufacture and use of the electrochemical cell 900. The gap 925 between the positive electrode layer 918 and the ventilation assembly also provides space for the lateral expansion of the ventilation assembly, for example, if external pressure is applied to it during operation or assembly of the electrochemical cell 900.

[0106] In another example of this disclosure, the ventilation assembly described herein can be placed under a vacuum to form a porous, air-permeable material with a total pore volume equal to the void space. Therefore, the ventilation assembly can be used as a reservoir for gases formed and discharged from the electrode layer. The ventilation assembly of this disclosure includes a porous, air-permeable material having a plurality of interconnected pores that allow gas to flow through the air-permeable material and define the total pore volume of the air-permeable material. Prior to the use of electrochemical cell cells, the total pore volume of the air-permeable material is typically filled with air. Figures 23 to 24 As shown, the electrochemical cell 100 can be placed inside a vacuum bag 950. During use of the electrochemical cell 100, a vacuum is applied to the vacuum bag 950 holding the electrochemical cell 100, and substantially all air that might reside within the total pore volume of the permeable material of the ventilation assembly 120 is removed. Figure 24Therefore, any gas generated within the positive electrode layer of the electrochemical cell 100 is exhausted into the permeable material of the ventilation assembly 120, and the gas resides within the pore volume of the permeable material. A vacuum bag 950 will be relatively tightly wrapped around the electrochemical cell 100. Thus, the ventilation assembly 120 acts as a reservoir for gas generated in the positive electrode layer. The use of the electrochemical cell 100 is also intended to include the formation of the electrochemical cell 100, such as the activation and regulation of the electrochemical cell 100. The use of the electrochemical cell 100 is also intended to cover the use of the cell in its usual sense, such as, but not limited to, using the electrochemical cell 100 for its intended purpose, to provide electricity and any associated charging or discharging of the cell. Although the electrochemical cell 100 is shown in this example, it should be understood that this concept applies to all electrochemical cells of this disclosure.

[0107] Although approved embodiments of the invention have been described above, it will be readily understood that many and various changes and modifications in form, design, structure, and arrangement of components can be made for other embodiments without departing from the invention, and it should be understood that all such changes and modifications are considered to be embodiments that are part of the invention as defined in the appended claims.

Claims

1. An electrochemical battery cell, comprising: An electrode layer having an electrode layer thickness, wherein the electrode layer comprises an electrode material and an electrolyte material; as well as A ventilation assembly comprising a breathable material is provided, wherein the ventilation assembly is arranged adjacent to the thickness of the electrode layer such that, in use, the ventilation assembly retains the electrolyte material within the electrode layer and allows gas formed within the electrode layer to escape from the electrode layer.

2. The electrochemical battery cell according to claim 1, characterized in that: The electrode layer includes two electrode surfaces extending in the xy plane and an electrode perimeter surface extending between the electrode surfaces in the z direction, wherein the electrode perimeter surface defines the thickness of the electrode layer; and The ventilation assembly includes an electrode contact surface; wherein the ventilation assembly is arranged in an xy plane relative to the electrode layer such that the electrode contact surface surrounds at least a portion of the electrode perimeter surface.

3. The electrochemical battery cell according to claim 1 or 2, characterized in that, The ventilation components comprise a material that is breathable but impermeable to liquid.

4. The electrochemical battery cell according to any one of claims 1 to 3, characterized in that, The ventilation assembly includes at least one of a porous membrane, a porous strip, a fabric, or a foam material.

5. The electrochemical battery cell according to any one of claims 1 to 4, characterized in that, The breathable material includes materials selected from the group consisting of: polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), polyvinylidene fluoride (PVDF), polyethylene (PE), polyether ketone ketone (PEKK), polyether ether ketone (PEEK), poly(tetramethyl-p-silylphenylsiloxane) (PTMPS), polydimethylsiloxane (PDMS), poly(p-xylene) (PPX), polyamide 6, polyurethane, thermoplastic polyurethane, polypropylene, polyimide or polyacrylonitrile (PAN), or combinations thereof.

6. The electrochemical battery cell according to any one of claims 1 to 4, characterized in that, The breathable material includes materials selected from the group consisting of: expanded PTFE (ePTFE), expanded FEP (eFEP), expanded PVDF (ePVDF), expanded polyethylene (ePE), expanded PEKK (ePEKK), expanded PEEK (ePEEK), expanded PTMPS (ePTMPS), expanded polydimethylsiloxane (ePDMS), expanded PPX (ePPX), expanded polyamide 6, expanded polyurethane, expanded thermoplastic polyurethane, expanded polypropylene, expanded polyimide or expanded polyacrylonitrile (PAN) or combinations thereof.

7. The electrochemical battery cell according to any one of the preceding claims, characterized in that, The breathable material is elastic, allowing the ventilation assembly, which includes the breathable material, to expand and contract to accommodate changes in the electrode layer thickness.

8. The electrochemical battery cell according to any one of claims 1 to 7, characterized in that, The ventilation assembly includes an airflow direction that defines the direction of gas travel through the ventilation assembly, and wherein the ventilation assembly is arranged such that the airflow direction is orthogonal to the electrode layer thickness.

9. The electrochemical battery cell according to any one of the preceding claims, characterized in that, The electrode material includes a positive electrode material.

10. The electrochemical battery cell according to any one of the preceding claims, characterized in that, The electrolyte material includes at least one of solid electrolyte material, gel-based electrolyte material, or liquid electrolyte material.

11. The electrochemical battery cell according to any one of the preceding claims, characterized in that, It also includes a current collector and an electrochemical isolator, wherein the ventilation assembly is sealed relative to at least one of the current collector or the electrochemical isolator.

12. The electrochemical battery cell according to claim 11, characterized in that, The current collector and the electrochemical isolator include surfaces having portions in the xy plane that extend beyond the outer perimeter of the electrode layer, and wherein the ventilation assembly is sandwiched between the portions extending beyond the outer perimeter of the electrode layer.

13. The electrochemical battery cell according to any one of the preceding claims, characterized in that, The ventilation assembly includes a thickness corresponding to the thickness of the electrode layer.

14. The electrochemical battery cell according to claim 11, characterized in that, The ventilation assembly includes a thickness greater than the electrode thickness, such that the electrode contact surface of the ventilation assembly is adjacent to at least one of the peripheral surface of the current collector or the peripheral surface of the electrochemical isolator.

15. The electrochemical cell according to claim 13 or 14, characterized in that, The breathable material is resistant to deformation along the thickness direction of the ventilation component.

16. The electrochemical battery cell according to any one of the preceding claims, characterized in that, The ventilation assembly may include at least one treated surface configured to promote adhesion between an adhesive and a breathable material of the ventilation assembly.

17. The electrochemical battery cell according to any one of the preceding claims, characterized in that, The breathable material is a porous breathable material having multiple pores that define a total pore volume, and the ventilation assembly is configured such that part or all of the total pore volume is void space; and wherein the ventilation assembly acts as a reservoir for gas formed from the electrode layer.

18. The electrochemical battery cell according to any one of the preceding claims, characterized in that, The breathable material also includes an adsorbent.

19. The electrochemical battery cell according to any one of the preceding claims, characterized in that, The electrochemical cell is a solid-state battery or a semi-solid-state battery.

20. The electrochemical cell according to any one of the preceding claims, characterized in that, The electrochemical cell includes multiple electrode layers, each of which includes an electrode material and an electrolyte material; and multiple ventilation components, each of which is arranged adjacent to one of the multiple electrode layers.

21. The electrochemical cell according to any one of claims 1 to 19, characterized in that, The electrochemical cell includes multiple electrode layers, each of which includes an electrode material and an electrolyte material; and the multiple electrode layers include a total electrode layer thickness; and the ventilation assembly is arranged adjacent to the total electrode layer thickness such that the ventilation assembly contains the electrolyte material within each of the multiple electrode layers and allows gas formed within each of the electrode layers to be discharged from the electrode layer.

22. A ventilation assembly for an electrochemical cell, characterized in that, The electrochemical cell includes an electrode layer of thickness, wherein the electrode layer includes an electrode material and an electrolyte material; wherein the ventilation assembly includes a breathable ventilation material, which, in use, is arranged to contain the electrolyte within the electrode layer and allow gas formed within the electrode layer to escape from the electrode layer.

23. A positive electrode assembly for a solid-state or semi-solid-state battery, characterized in that, The positive electrode assembly includes a positive electrode layer having a positive electrode material and a positive electrode electrolyte, and a ventilation assembly arranged to encapsulate at least a portion of the positive electrode layer, the ventilation assembly being configured to contain the positive electrode electrolyte within the positive electrode layer and to allow gas formed within the positive electrode layer to escape from the positive electrode layer.

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