Electrochemical device with multifunctional electrode separator assembly with internal reference electrode

Abstract

Electrochemical devices having in-stack reference electrodes, methods for making / using such devices, and battery cells having stacked electrodes separated by an electrode separator assembly having built-in reference electrodes are presented. An electrochemical device includes a protective housing containing an ion conducting electrolyte. The working electrode stack is encapsulated within the device housing in electrochemical contact with the electrolyte. At least one electrode separator assembly is located within the housing, interposed between adjacent pairs of the working electrodes. The electrode separator assembly includes an electrically insulating separator sheet having a reference electrode. A tab pocket protruding from one end of the separator sheet includes a tab chamber having a chamber opening. The electrode tab is formed of an electrically conductive material and is attached to the tab pocket. One end of the electrode tab is disposed within the tab chamber and the other end protrudes from the chamber opening.

Description

Technical Field

[0001] The present disclosure relates generally to electrochemical devices. More specifically, aspects of the present disclosure relate to stacked electrode assemblies with in-stack reference electrodes for lithium-based battery cells. Background Art

[0002] The present disclosure relates generally to electrochemical devices. More specifically, aspects of the present disclosure relate to stacked electrode assemblies with in-stack reference electrodes for lithium-based battery cells.

[0003] The motor vehicles currently produced, such as modern cars, are initially equipped with a powertrain that operates to propel the vehicle and provide power for the vehicle's onboard electronics. For example, in automotive applications, the vehicle powertrain is generally represented by a prime mover that transmits drive torque to the final drive system (e.g., differential, axle, corner module, wheel, etc.) of the vehicle through an automatic or manual shift transmission. Automobiles have historically been powered by reciprocating piston internal combustion engine (ICE) components because they are readily available and relatively inexpensive, lightweight, and overall efficient. As some non-limiting examples, such engines include compression ignition (CI) diesel engines, spark ignition (SI) gasoline engines, two-stroke, four-stroke, and six-stroke structures, and rotary engines. On the other hand, hybrid electric vehicles and all-electric vehicles (collectively referred to as "electrically driven vehicles") utilize alternative energy sources to propel the vehicle, and thereby minimize or eliminate dependence on fossil fuel-based engines for traction power.

[0004] A full electric vehicle (FEV) – colloquially known as an “electric vehicle” – is a class of electrically driven vehicle configurations that completely omits the internal combustion engine and accompanying peripheral components from the powertrain system, instead relying on a rechargeable energy storage system (RESS) and traction motors for vehicle propulsion. In a battery-based FEV, the engine components, fuel supply system, and exhaust system of an ICE-based vehicle are replaced by a single or multiple traction motors, a traction battery pack, and battery pack cooling and charging hardware. In contrast, a hybrid electric vehicle (HEV) powertrain employs a variety of types of traction power to propel the vehicle, most commonly combining an internal combustion engine component with a battery-powered or fuel cell-powered traction motor. Because a hybrid electric drive vehicle is able to derive its power from sources other than the engine, the HEV engine can be fully or partially shut down when the vehicle is propelled by the electric motor(s).

[0005] High voltage (HV) electrical systems control the transfer of power between traction motors and rechargeable battery packs to provide the power required for the operation of many hybrid electric and all-electric powertrains. To provide the power capacity and energy density required to propel the vehicle at the desired speed for the desired range, modern traction battery packs group multiple battery pack cells (e.g., 8-16+ cells / pack) into individual battery pack modules (e.g., 10-40+ modules / pack) that are electrically interconnected in series or parallel and mounted to the vehicle chassis via a battery pack housing or support tray. Located on the battery pack side of the HV power system is a front-end DC-DC power converter that is electrically connected to the traction battery pack(s) to increase the voltage supply to the main DC bus and DC-AC power inverter module (PIM). High frequency bulk capacitors can be arranged across the positive and negative rails of the main DC bus to provide electrical stability and store supplemental electrical energy. A dedicated Electronic Battery Control Module (EBCM) controls the operation of the battery pack(s) and traction motor(s) by operating in cooperation with the Powertrain Control Module (PCM) and the power electronics packages of each motor.

[0006] There are four main types of batteries used in electric vehicles: lithium batteries, nickel-metal hydride batteries, supercapacitor batteries, and lead-acid batteries. According to the lithium design, lithium metal and lithium ion (secondary) batteries constitute the majority of commercial lithium battery (LiB) configurations, with lithium ion (Li-ion) variants being used in automotive applications due to their enhanced stability, high energy density, and rapid recharge capabilities. Standard lithium-ion batteries are typically composed of at least two conductive electrodes, an electrolyte material, and a permeable separator, all of which are enclosed in an electrically insulating package. During battery discharge, one electrode acts as a positive ("cathode") electrode, and the other electrode acts as a negative ("anode") electrode. A separator (usually a microporous polymer membrane) is disposed between the two electrodes to prevent electrical short circuits while also allowing the transport of ionic charge carriers. The electrolyte is suitable for conducting lithium ions and can be in solid form (e.g., solid-state diffusion), liquid form (e.g., liquid phase diffusion), or quasi-solid form (e.g., a solid electrolyte entrained in a liquid carrier). Rechargeable lithium-ion batteries operate by reversibly transferring lithium ions back and forth between these working electrodes. Summary of the invention

[0007] Electrochemical devices with in-stack reference electrodes, methods for making and operating such devices, and lithium-based battery cells with stacked working electrodes separated by electrode separator assemblies with built-in reference electrodes are presented herein. For example, a pouch-type lithium-ion battery cell includes an electrode stack having a series of first (anode) working electrodes interlaced with the same number of second (cathode) working electrodes. An electrically insulating and ionically conductive separator is disposed between each pair of adjacent electrodes, and the separator may have the properties of a polymer separator sheet immersed in a liquid electrolyte or bonded to a solid electrolyte. The interlaced electrodes and separator sheets may be stacked and contained in a protective pouch, jelly-rolled and contained in a cylindrical can, or flat-rolled and contained in a prismatic container. The reference electrode may be baked into the separator sheet or otherwise formed integrally with the separator sheet.

[0008] One or more of these electrode separator sheets can be manufactured as a multifunctional separator assembly having a conductive reference electrode tab protruding from a tab pocket, the tab pocket protruding longitudinally from one end of the separator sheet. The tab pocket may include a tab panel of reduced width, the tab panel being coplanar and integrally formed with the body of the separator sheet. Laterally protruding from one side of the tab panel is an integral tab flap, which is folded against the tab panel to form a compartment in which the reference electrode tab is rigidly fixed. In order to operably attach the reference electrode tab to the separator sheet, a first (proximal) end of the tab may be cleaned and roughened; a conductive adhesive is applied to both sides of the proximal end of the tab. One side of the tab is aligned with the tab panel and pressed against the tab panel; then, the tab flap is folded against the opposite side of the tab and adhered to the opposite side of the tab. After attachment, at least about 50% of the tab protrudes from the tab pocket with its proximal end spaced apart from the longitudinal end of the separator sheet.

[0009] Ancillary benefits of at least some of the disclosed concepts include a functional separator assembly that enables in-stack measurement of electrode electrical properties while ensuring electrical and thermal separation of adjacent working electrodes. By measuring electrode electrical properties using an in-stack reference electrode, the disclosed concepts help detect potential battery pack failures and control battery pack operation in an optimized manner. The disclosed separator assembly features also help reduce packaging space requirements and reduce manufacturing complexity of the reference electrode and its conductive electrode lugs. In addition to improved battery cell monitoring and operation, the disclosed concepts can also help increase the driving range, fuel economy, and battery pack performance of electric drive vehicles.

[0010] Aspects of the present disclosure relate to electrochemical devices, such as cylindrical, pouch, and prismatic LiB batteries used in battery modules such as vehicle traction battery packs. In one example, the electrochemical device is constructed with an insulating and sealed housing for storing an electrolyte composition chemically configured to conduct ions therein. An electrode stack located in the device housing and in electrochemical contact with the electrolyte includes one or more first (e.g., anode) working electrodes interlaced with one or more second (e.g., cathode) working electrodes. At least one electrode separator assembly is located in the device housing, interposed between a pair of adjacent working electrodes and physically separating them. Each electrode separator assembly includes a separator sheet formed entirely or partially of an electrically insulating material. The separator sheet includes a reference electrode. A tab bag protruding from one end of the separator sheet includes a tab chamber having a chamber opening. A conductive reference electrode tab is attached to the tab bag and electrically connected to the reference electrode. One end of the reference electrode tab is disposed in the tab chamber, and the other end of the electrode tab protrudes from the chamber opening.

[0011] Additional aspects of the present disclosure relate to lithium battery cells with stacked electrode assemblies having in-stack sensing capabilities, rechargeable battery packs employing such lithium battery cells, and motor vehicles equipped with such battery packs. As used herein, the terms "vehicle" and "motor vehicle" may be used interchangeably and synonymously to include any relevant vehicle platform, such as passenger cars (ICE, HEV, FEV, fuel cell, fully and partially autonomous, etc.), commercial vehicles, industrial vehicles, tracked vehicles, off-road and all-terrain vehicles (ATVs), motorcycles, agricultural equipment, electric bicycles, electric scooters, boats, aircraft, etc. For non-automotive applications, the disclosed concepts may be implemented for any logically related purposes, including stand-alone power stations and portable power packs, photovoltaic systems, handheld electronic devices, pumping equipment, machine tools, appliances, etc. Although not limiting in themselves, the disclosed concepts may be particularly advantageously used for lithium metal (secondary) cylindrical, soft pack and prismatic can batteries.

[0012] In one example, a motor vehicle includes a body having a passenger compartment, a plurality of drive wheels rotatably mounted to the body (e.g., via corner modules coupled to a unibody or body-on-frame chassis), and other standard original equipment. For electric drive vehicle applications, one or more traction motors operate alone (e.g., for a FEV powertrain) or in conjunction with an internal combustion engine assembly (e.g., for a HEV powertrain) to selectively drive one or more roadwheels to propel the motor vehicle. A rechargeable traction battery pack is mounted to the body and is operable to power the traction motor(s).

[0013] Continuing the discussion of the previous example, the traction battery pack includes a plurality of lithium battery cells, for example, stacked in one or more battery modules and / or arranged in a battery pack housing. Each battery cell is manufactured with a protective battery housing in which a liquid, solid or quasi-solid electrolyte composition for conducting ions is stored. The electrode stack is located in the battery housing and is in electrochemical contact with the electrolyte. The electrode stack includes a series of first (anode) working electrodes, which are interlaced with a corresponding number of second (cathode) working electrodes. An electrode separator assembly is also located in the battery housing, and the electrode separator assembly is inserted between the corresponding pair of working electrodes. The electrode separator assembly includes a separator sheet formed entirely or partially of an electrically insulating material and a tab bag integrally formed with the separator sheet and protruding from the longitudinal end of the separator sheet. The reference electrode is carried by the separator sheet. The tab bag includes an internal tab chamber having a chamber opening at one end thereof. The reference electrode tab is rigidly attached to the tab bag, for example, via a conductive adhesive and is formed entirely or partially of a conductive material. The reference electrode tab has a first (proximal) end disposed within the tab chamber and a second (distal) end opposite the first end that protrudes from the chamber opening.

[0014] Aspects of the present disclosure also relate to manufacturing methods, control logic, and computer readable media (CRM) for making and / or using any disclosed electrochemical device, battery pack, and / or vehicle. In one example, a method for assembling an electrochemical device is proposed. The representative method includes, in any order and with any combination of any of the options and features disclosed above and below: receiving a device housing of an electrochemical device; placing an electrolyte in the device housing, the electrolyte being configured to conduct ions; placing an electrode stack in the device housing in electrochemical contact with the electrolyte, the electrode stack including a first working electrode and a second working electrode; and placing an electrode separator assembly between the first working electrode and the second working electrode, the electrode separator assembly including: a separator sheet formed of an electrically insulating material and including a reference electrode; a tab bag protruding from one end of the separator sheet and defining a tab chamber having a chamber opening; and an electrode tab, which is attached to the tab bag and formed of a conductive material, the electrode tab having a first end disposed in the tab chamber and a second end protruding from the chamber opening.

[0015] For any of the disclosed vehicles, methods, and devices, the tab bag may include a tab plate protruding from a separator sheet and coplanar with the separator sheet. In this case, the separator sheet may have a sheet (first) width and height, and the tab plate may have a plate (second) width and height that are respectively smaller than the width and height of the sheet. The tab bag may also include a tab fold protruding from one side of the tab plate; the tab fold may be pressed against and rigidly attached to the tab plate to jointly define a tab chamber therebetween. In this case, the tab fold may have a fold (third) height that is less than the height of the separator sheet and the height of the tab plate. In order to simplify design and manufacturing, it may be desirable that the separator sheet and the tab bag (including the tab fold and the tab plate) are integrally formed of an electrically insulating material into a single, single-piece structure. As another option, the separator sheet, the tab fold, and the tab plate may each have a different polyhedral shape (e.g., a square or rectangular polyhedron) with different sizes (e.g., total surface area).

[0016] For any of the disclosed vehicles, methods, and devices, the reference electrode electrode sheet can be rigidly attached to the tab bag via a conductive adhesive. As a further option, the reference electrode tab can have a substantially flat rectangular tab body, wherein one (first) side thereof has a (first) surface facing the plate member that is finished with a non-smooth surface texture. On the opposite side of the tab body is its other (second) side having a (second) surface facing the flap, which second surface can also be finished with a non-smooth surface texture. In this case, the conductive adhesive can be located on one or both of the tab body surfaces having a non-smooth surface texture. In this case, the non-smooth surface texture may include indentations, scribes, cross-hatched grooves, sinusoidal grooves, horizontal grooves, and / or angled grooves.

[0017] For any of the disclosed vehicles, methods, and apparatus, the reference electrode tab may be formed in whole or in part of gold, gold-plated plastic, aluminum, nickel, copper, copper-plated aluminum, stainless steel, and the like. Alternatively, the conductive adhesive may be an air-cured, heat-cured, and / or UV-cured adhesive, may include filler materials, conductive additive materials, and / or binder materials, and may have an epoxy base, an acrylate base, and / or a silicone base. Optionally, the reference electrode tab may include an elongated tab body, wherein at least 50% of the tab body protrudes from the chamber opening. It may be desirable that the proximal (first) end of the reference electrode tab disposed within the tab chamber is spaced apart from an end of the separator sheet from which the tab pocket protrudes.

[0018] The present invention discloses the following scheme:

[0019] Solution 1. An electrochemical device comprising:

[0020] Device housing;

[0021] an electrolyte disposed within the device housing and configured to conduct ions;

[0022] an electrode stack located within the device housing and comprising a first working electrode and a second working electrode in electrochemical contact with the electrolyte; and

[0023] an electrode separator assembly, which is interposed between the first working electrode and the second working electrode, the electrode separator assembly comprising:

[0024] a separator sheet formed of an electrically insulating material and including a reference electrode;

[0025] a tab bag protruding from one end of the separator sheet and defining a tab chamber having a chamber opening; and

[0026] An electrode tab is attached to the tab bag and is formed of a conductive material, the electrode tab having a first end disposed in the tab chamber and a second end protruding from an opening of the chamber.

[0027] Option 2. An electrochemical device according to Option 1, wherein the pole lug bag includes a pole lug plate protruding from the separator sheet and coplanar with the separator sheet, the separator sheet has a first width and a first height, and the pole lug plate has a second width and a second height that are respectively smaller than the first width and the first height.

[0028] Option 3. An electrochemical device according to Option 2, wherein the tab bag further comprises a tab fold protruding from one side of the tab plate, the tab fold being pressed against and rigidly attached to the tab plate to jointly define the tab chamber therebetween.

[0029] Option 4. The electrochemical device according to Option 3, wherein the tab flap has a third height that is smaller than the first height of the separator sheet and the second height of the tab plate.

[0030] Option 5. The electrochemical device according to Option 3, wherein the tab bag includes the tab fold and the tab plate, and the separator sheet and the tab bag are integrally formed into a single-piece structure using the electrical insulating material.

[0031] Embodiment 6. The electrochemical device according to Embodiment 3, wherein the separator sheet, the tab fold, and the tab plate each have a corresponding polyhedral shape with different sizes.

[0032] Embodiment 7. The electrochemical device according to Embodiment 1, wherein the electrode tab is rigidly attached to the tab bag via a conductive adhesive.

[0033] Option 8. An electrochemical device according to Option 7, wherein the electrode tab has a first side, the first side has a first surface including a non-smooth surface texture, and the conductive adhesive is located on the first surface having the non-smooth surface texture.

[0034] Option 9. An electrochemical device according to Option 8, wherein the electrode tab has a second side opposite to the first side, the second side having a second surface including the non-smooth surface texture, and wherein the conductive adhesive is also located on the second surface having the non-smooth surface texture.

[0035] Embodiment 10. An electrochemical device according to Embodiment 9, wherein the non-smooth surface texture comprises indentations, scribes, cross-hatched grooves, sinusoidal grooves, horizontal grooves and / or angled grooves.

[0036] Option 11. An electrochemical device according to Option 7, wherein the electrode tabs are formed of gold, gold-plated plastic, aluminum, nickel and / or stainless steel, and wherein the conductive adhesive is air-cured, heat-cured and / or UV-cured, comprises fillers, conductive additives and / or binder materials, and has an epoxy resin, acrylate and / or silicone base.

[0037] Embodiment 12. An electrochemical device according to Embodiment 1, wherein the electrode tab comprises an elongated tab body, wherein at least 50% of the elongated tab body protrudes from the chamber opening.

[0038] Aspect 13. The electrochemical device according to aspect 1, wherein a first end of the electrode tab disposed in the tab chamber is spaced apart from an end of the separator sheet from which the tab pocket protrudes.

[0039] Solution 14. A motor vehicle, comprising:

[0040] Car body;

[0041] a plurality of wheels attached to the vehicle body;

[0042] a traction motor attached to the body and operable to drive one or more of the wheels to propel the motor vehicle; and

[0043] a traction battery pack attached to the vehicle body and operable to power the traction motor, the traction battery pack comprising a plurality of lithium battery cells, each lithium battery cell comprising:

[0044] Battery pack housing;

[0045] an electrolyte enclosed within the battery housing and configured to conduct ions;

[0046] an electrode stack enclosed within the battery housing and in electrochemical contact with the electrolyte, the electrode stack comprising a first working electrode in spaced-apart facing relationship with a second working electrode; and

[0047] an electrode separator assembly interposed between the first working electrode and the second working electrode, the electrode separator assembly comprising:

[0048] a separator sheet formed of an electrically insulating material and including a reference electrode;

[0049] a tab bag formed integrally with the separator sheet and protruding from one end of the separator sheet, the tab bag defining a tab chamber having a chamber opening therein; and

[0050] An electrode tab is rigidly attached to the tab bag by a conductive adhesive and is formed of a conductive material, the electrode tab having a first end disposed in the tab chamber and a second end protruding from the chamber opening.

[0051] Embodiment 15. A method for assembling an electrochemical device, the method comprising:

[0052] a device housing for receiving an electrochemical device;

[0053] placing an electrolyte within the device housing, the electrolyte being configured to conduct ions;

[0054] placing an electrode stack within the device housing in electrochemical contact with the electrolyte, the electrode stack comprising a first working electrode and a second working electrode; and

[0055] An electrode separator assembly is placed between the first working electrode and the second working electrode, the electrode separator assembly comprising:

[0056] a separator sheet formed of an electrically insulating material and including a reference electrode;

[0057] a tab bag protruding from one end of the separator sheet and defining a tab chamber having a chamber opening; and

[0058] An electrode tab is attached to the tab bag and is formed of a conductive material, the electrode tab having a first end disposed in the tab chamber and a second end protruding from an opening of the chamber.

[0059] Option 16. A method according to Option 15, wherein the pole lug bag includes a pole lug plate protruding from the separator sheet and coplanar with the separator sheet, the separator sheet has a first width and a first height, and the pole lug plate has a second width and a second height that are respectively smaller than the first width and the first height.

[0060] Solution 17. The method according to Solution 16, wherein the tab bag further comprises a tab fold protruding laterally from one side of the tab plate, and the method further comprises:

[0061] folding the tab flaps to press against the tab plate; and

[0062] The tab flaps are rigidly attached to the tab plate to collectively define the tab chamber therebetween.

[0063] Option 18. The method according to Option 17 further includes integrally forming the separator sheet and the tab bag into a single-piece structure using the electrically insulating material.

[0064] Option 19. The method according to Option 15 further includes rigidly attaching the electrode tab to the tab bag via a conductive adhesive.

[0065] Embodiment 20. The method according to embodiment 19, further comprising:

[0066] applying a non-smooth surface texture to a surface of the electrode tab; and

[0067] The conductive adhesive is applied to the surface of the electrode tab so as to cover the non-smooth surface texture.

[0068] The above summary of the invention does not represent every embodiment or every aspect of the present disclosure. On the contrary, the above summary of the invention only provides a summary of some novel concepts and features set forth herein. When combined with the accompanying drawings and the appended claims, the above-mentioned features and advantages of the present disclosure and other features and accompanying advantages will be easily apparent from the following specific embodiments of the illustrated examples and representative modes for performing the present disclosure. In addition, the present disclosure explicitly includes any and all combinations and sub-combinations of the elements and features presented above and below. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 is a partially schematic side view of a representative motor vehicle propelled by an electrified powertrain having a motor generator unit powered by a traction battery pack including battery cells having an in-stack reference electrode in accordance with aspects of the present disclosure.

[0070] Figure 2 is a schematic diagram of a representative electrochemical device that can be used to practice aspects of the present disclosure.

[0071] Figure 3 is a plan view of a representative multifunctional electrode-separator assembly with a built-in reference electrode for an electrode stack of an electrochemical device according to aspects of the present disclosure.

[0072] Figure 4is a flow chart illustrating a representative method for making an electrode-separator assembly with a built-in reference electrode according to aspects of the present disclosure.

[0073] The present disclosure may be subjected to various modifications and alternative forms, and some representative embodiments of the present disclosure are shown in the accompanying drawings by way of example and will be described in detail herein. However, it should be understood that the novel aspects of the present disclosure are not limited to the specific forms shown in the accompanying drawings listed above. On the contrary, the present disclosure encompasses all modifications, equivalents, combinations, arrangements, groupings, and alternatives that fall within the scope of the present disclosure, such as those contained in the appended claims. DETAILED DESCRIPTION

[0074] The present disclosure allows for many different forms of embodiments. Representative embodiments of the present disclosure are shown in the drawings and will be described in detail herein, and it should be understood that these embodiments are provided as examples of the disclosed principles, rather than limitations on the broad aspects of the present disclosure. In this regard, elements and limitations that are described in the abstract, background technology, summary of the invention, illustrations, and specific implementation sections but not explicitly set forth in the claims should not be incorporated into the claims individually or by implication, inference, or otherwise. In addition, "first", "second", "third", etc. mentioned in the specification or claims are not used to establish order or numerical limitations; unless otherwise specifically stated, these names can be used to facilitate reference to similar features in the specification and drawings and to distinguish between similar elements in the claims.

[0075] For purposes of this Detailed Description, unless expressly stated otherwise: the singular includes the plural and vice versa; the words "and" and "or" shall be both conjunctions and disjunctions; the words "any" and "all" shall mean "any and all"; and the words "including," "containing," "comprising," "having," and the like shall mean "including but not limited to." In addition, approximate words such as "about," "almost," "substantially," "roughly," "approximately," and the like may each be used herein to mean, for example, "at, approximately, or nearly at," or "within 0-5%," or "within acceptable manufacturing tolerances," or any logical combination thereof. Finally, directional adjectives and adverbs, such as front, rear, inside, outside, right, left, vertical, horizontal, upward, downward, front, rear, left, right, and the like, may be relative to the motor vehicle, such as the forward direction of travel of the motor vehicle when the vehicle is operably oriented on a level running surface.

[0076] Referring now to the drawings, in which like reference numerals refer to like features throughout the several views, Figure 1A representative motor vehicle is shown, which is generally designated 10 and is depicted herein as a sedan-type electric drive vehicle for purposes of discussion. The illustrated vehicle 10 - also referred to herein as a "motor vehicle" or simply "vehicle" - is merely an exemplary application that can be used to practice the novel aspects of the present disclosure. By the same token, the incorporation of the present concept into the FEV powertrain should be understood as a non-limiting embodiment of the disclosed features. Therefore, it should be understood that the aspects and features of the present disclosure can be applied to other electrochemical device form factors, can be incorporated into any logically related type of motor vehicle, and can be used in automotive and non-automotive applications alike. In addition, only selected components of the motor vehicle and battery pack assembly are shown and described in additional detail herein. However, the vehicles and assemblies discussed below may include many additional and alternative features and other available peripheral components for performing the various methods and functions of the present disclosure.

[0077] Figure 1 The representative vehicle 10 is initially equipped with a central stack telecommunications and information ("telematics") unit 14 that communicates with a remotely located cloud computing host service 24 (e.g., ) for wireless communication. Figure 1 Other on-board hardware components 16 shown in the vehicle include, as non-limiting examples, an electronic video display device 18, a microphone 28, an audio speaker 30, and various user input controls 32 (e.g., buttons, knobs, switches, touch screens, etc.). These hardware components 16 act as a human / machine interface (HMI) that enables a user to communicate with the telematics unit 14 and other components resident on and away from the vehicle 10. For example, the microphone 28 provides a means for the occupant to input verbal commands. In contrast, the speaker 30 provides audio output to the vehicle occupants and can be a separate speaker dedicated to the telematics unit 14 or can be part of the audio system 22. The audio system 22 is operably connected to the network connection interface 34 and the audio bus 20 to receive analog information and present it as sound via one or more speaker assemblies.

[0078] The network connection interface 34 is communicatively coupled to the telematics unit 14, and suitable examples thereof include twisted pair / fiber optic Ethernet switches, parallel / serial communication buses, local area network (LAN) interfaces, controller area network (CAN) interfaces, etc. The network connection interface 34 enables the vehicle hardware 16 to send and receive signals to each other and to send and receive signals to and from systems and subsystems on and off the vehicle body 12. This allows the vehicle 10 to perform various vehicle functions, such as regulating powertrain output, activating the vehicle braking system, controlling vehicle steering, regulating the charging and discharging of the vehicle battery pack, and other automated functions. For example, the telematics unit 14 can receive and send signals from a powertrain control module (PCM) 52, an on-board charging module (OBCM) 54, an electronic battery control module (EBCM) 56, a steering control module (SCM) 58, a brake system control module (BSCM) 60, and various other vehicle ECUs.

[0079] Continue to refer Figure 1 , the telematics unit 14 is an onboard computing device that provides hybrid services both alone and through its communication with other networked devices. The telematics unit 14 is typically comprised of one or more processors 40, each of which may be embodied as a discrete microprocessor, an application specific integrated circuit (ASIC), or a dedicated control module. The vehicle 10 may provide centralized vehicle control via a central processing unit (CPU) 36, which may be operably coupled to an IC real time clock (RTC) 42 and one or more electronic memory devices 38, each of which may take the form of a CD-ROM, solid state drive (SSD) memory, hard disk drive (HDD) memory, semiconductor memory, or the like.

[0080] Long range communications (LRC) capabilities with off-board devices may be provided by a cellular communications component, a navigation and positioning component (e.g., a global positioning system (GPS) transceiver), or a wireless modem, all of which are collectively indicated at 44. Short range communications (SRC) may be provided via a short range wireless communications device 46 (e.g., Unit), dedicated short-range communication (DSRC) component 48 and / or dual antenna 50. It should be understood that the vehicle 10 can be implemented without one or more of the components listed above, or can optionally include additional components and functions required for a specific end use. The above communication devices can provide data exchange as part of periodic broadcasts in a vehicle-to-vehicle (V2V) communication system or a vehicle-to-everything (V2X) communication system.

[0081] The CPU 36 receives sensor data from one or more sensing devices that use, for example, light detection, radar, laser, ultrasonic, optical, infrared, or other suitable technologies, including short-range communication technologies (e.g., DSRC) or ultra-wideband (UWB) radio technologies, such as for performing automated vehicle operation or vehicle navigation services. According to the illustrated example, the automobile 10 may be equipped with one or more digital cameras 62, one or more range sensors 64, one or more vehicle speed sensors 66, one or more vehicle dynamic sensors 68, and any necessary filtering, classification, fusion, and analysis hardware and software for processing the raw sensor data. The type, placement, number, and interoperability of the distributed array of on-board sensors can be adapted individually or collectively to a given vehicle platform to achieve a desired level of autonomous vehicle operation.

[0082] To propel the motor vehicle 10 , the electrified powertrain is operable to generate tractive torque and transmit it to one or more of the vehicle's drive wheels 26 . Figure 1 , the powertrain is represented by an electric traction motor 78 connected to a rechargeable energy storage system (RESS), which may have the properties of a traction battery pack 70 mounted on the chassis. The battery pack 70 may include one or more battery modules 72, each of which houses a group of electrochemical battery cells 74, such as lithium-ion or lithium-polymer battery cells of the soft pack type, can type, or prismatic type. One or more motors, such as multi-phase permanent magnet motor / generator (M) units 78, draw power from the battery pack 70 and optionally deliver power to the battery pack 70. The HV electrical system with a power inverter module (PIM) 80 electrically connects the battery pack 70 to (one or more) motor / generator units 78 and modulates the current transfer therebetween. The battery pack 70 can be configured so that module management, battery sensing, and module-to-host communication functions are directly integrated into each module 72 and performed wirelessly via a wireless-enabled battery monitoring unit (CMU) 76.

[0083] Figure 2 Presented in FIG. 1 is an exemplary electrochemical device in the form of a rechargeable lithium-based battery 110 that is a desired electrical load (e.g., Figure 1The battery pack 110 includes a series of conductive electrodes, namely a first (negative or anode) working electrode 122 and a second (positive or cathode) working electrode 124 stacked and encapsulated within a protective housing 120. Referring to the working electrodes 122, 124 as "anode" or "cathode", or for that matter, as "positive" or "negative" does not limit the electrodes 122, 124 to a particular polarity, as the system polarity may change depending on whether the battery pack 110 is operating in a charging mode or a discharging mode. In at least some configurations, the battery housing 120 (or "battery case") may be in the form of a can-shaped cylindrical configuration, an envelope-shaped soft-pack configuration, or a box-shaped prismatic configuration formed of aluminum, nickel-plated steel, ABS, PVC, or other suitable materials or composite materials. The surface of the metal battery case may be coated with a polymer finish to insulate the metal from the internal battery elements and adjacent batteries. Although Figure 2 A single galvanic battery cell is shown enclosed within a battery housing 120, but it should be understood that the housing 120 may store a stack or roll of cells (eg, 5 to 500 cells or more).

[0084] The anode electrode 122 may be made of an active anode electrode material that is capable of binding lithium ions during a battery pack charging operation and releasing lithium ions during a battery pack discharging operation. For at least some designs, the anode electrode 122 is made entirely or partially of lithium metal, such as a lithium-aluminum (LiAl) alloy material having a Li / Al atomic ratio (as represented by the atomic percentage (at.%) of one type of atom relative to the total number of atoms) of 0 at.% ≤ Li / Al < 70 at.%, and / or an aluminum alloy (e.g., smelted lithium metal) having an Al atomic ratio > 50 at.%. Additional examples of suitable active anode electrode materials include carbonaceous materials (e.g., graphite, hard carbon, soft carbon, etc.), silicon, silicon-carbon blended materials (silicon-graphite composite materials), Li4Ti5O 12 , transition metals (alloy types, such as Sn), metal oxides / sulfides (such as SnO2, FeS, etc.), etc.

[0085] Continue to refer Figure 2, the cathode electrode 124 can be made of an active cathode electrode material that is capable of providing lithium ions during battery charging operations and binding lithium ions during battery discharging operations. The cathode 124 material may include, for example, lithium transition metal oxides, phosphates (including olivine), or silicates, such as LiMO2 (M=Co, Ni, Mn, or a combination thereof); LiM2O4 (M=Mn, Ti, or a combination thereof), LiMPO4 (M=Fe, Mn, Co, or a combination thereof), and LiMxM'2-xO4 (M, M'=Mn or Ni). Additional non-limiting examples of suitable active cathode electrode materials include lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese aluminum oxide (NCMA), and other lithium transition metal oxides.

[0086] The electrically isolating porous spacer 126 is disposed at Figure 2 The battery cell housing 120 is provided in a battery pack cell housing 120 and is sandwiched between each pair of paired working electrodes 122, 124. The porous separator 126 can have the properties of a non-conductive, ion-transmitting microporous or nanoporous polymer separator sheet. The separator 126 can be a sheet structure composed of a porous polyolefin membrane, for example, having a porosity of about 35% to about 65% and a thickness of about 10-30 microns. Non-conductive ceramic particles (e.g., silicon dioxide) can be coated on the porous membrane surface of the separator 126. The porous separator 126 can be incorporated into a non-aqueous fluid electrolyte composition, a solid electrolyte composition and / or a quasi-solid electrolyte composition (collectively labeled 130), which can also be present in the negative electrode 122 and the positive electrode 124.

[0087] The negative electrode current collector 132 of the electrochemical battery cell 110 may be positioned on or near the negative electrode 122, and the positive electrode current collector 134 may be positioned on or near the positive electrode 124. The negative electrode current collector 132 and the positive electrode current collector 134 collect and move free electrons to and from the external circuit 140, respectively. An interruptible external circuit 140 having a load 142 is connected to the negative electrode 122 through its respective current collector 132 and electrode tab 136, and to the positive electrode 124 through its respective current collector 134 and electrode tab 138.

[0088] The porous separator 126 can act as an electrical insulator and mechanical support structure by being sandwiched between the two electrodes 122, 124 to prevent the electrodes from physically contacting each other and thus preventing the occurrence of a short circuit. In addition to providing a physical barrier between the two electrodes 122, 124, the separator 26 can also provide a minimum resistance path for the internal passage of lithium ions (and related anions) during lithium ion cycling to facilitate the functioning of the battery pack 110. For some configurations, the porous separator 126 can be a microporous polymer separator including a polyolefin. The polyolefin can be a homopolymer derived from a single monomer component, or a heteropolymer derived from more than one monomer component, and can be linear or branched. In a solid-state battery pack, the role of the separator can be partially / wholly provided by a solid electrolyte layer.

[0089] As a rechargeable energy storage system, the battery pack 110 generates an electric current that is transmitted to one or more loads 142 operably connected to an external circuit 140. Although the load 142 can be any number of electrical devices, some non-limiting examples of power consumption and power generation devices include electric motors for hybrid electric and all-electric vehicles, photovoltaic cell arrays, independent power stations and portable power packs, server systems, wind turbine power plants, etc. The battery pack 110 may include various other components, although not depicted herein for simplicity and brevity, these components are readily available. For example, the battery pack 110 may include one or more gaskets, terminal covers, tabs, battery pack terminals, cooling hardware, charging hardware, and other commercially available components or materials that may be located on or in the battery pack 110. In addition, the size and shape of the battery pack 110 and the operating characteristics may vary depending on the specific application for which it is designed.

[0090] Proposed herein is a multifunctional electrode separator assembly with a robust and compatible reference electrode connection design that enables current to pass through the separator sheet to measure and control the working electrode potential. The separator assembly uses a folded "sandwich" tab bag with a conductive adhesive that is used to rigidly attach and operably connect the reference electrode tab to the separator sheet. This space-saving tab connection solution uses a flexible substrate tab bag with a plate that is integrally formed with the top of the separator sheet and protrudes longitudinally from the top of the separator sheet. The foldable tab fold structure protrudes laterally from the lateral side of the tab plate; the tab fold is folded across the tab plate and adhered to the tab plate to form a bag with a double-sided bonding area, which can significantly improve the peel fatigue strength and fracture strength. In addition to helping prevent peel failure, the tab bag design can also increase (e.g., double) the contact interface area between the reference electrode tab and the separator sheet to resist shear fracture.

[0091] This article also proposes a simplified and efficient manufacturing method for manufacturing a multifunctional separator assembly with a built-in reference electrode. In one example, the manufacturing method for assembling a multifunctional electrode separator can start with stamping, cutting or forming a conductive workpiece by a metal blank or sheet metal feed roller, and then performing a surface preparation procedure for roughening the bottom 40-65% of the front and back of the workpiece. After applying the above-mentioned surface texture, the workpiece can be cleaned and, if necessary, other pretreatment procedures can be performed. At this time, a conductive adhesive is applied to the textured portion of the front and back of the workpiece, which can be achieved by masking, scraper coating and / or air blowing. The textured and coated workpiece is then pressed against the plate or wing portion of the pole ear bag protruding from the separator sheet. The pole ear fold is folded onto the pole ear plate at the same time to rigidly mount the electrode pole ear to the separator sheet and form a pole ear bag that encapsulates at least the lower half of the electrode pole ear.

[0092] As described above, the separator sheet can be manufactured as an integral, one-piece microporous or nanoporous structure formed of a non-conductive ion transport material, such as a polyolefin (e.g., polyethylene (PE), polypropylene (PP), or a blend of PE and PP), or can be a multilayer structure, such as a laminated porous film of PE and / or PP. The tab material can include, but is certainly not limited to: gold (Au), gold-plated plastic, aluminum (Al), nickel (Ni), copper (Cu), copper-plated aluminum, stainless steel, etc. In contrast, the conductive adhesive material can include, but is certainly not limited to: air-cured conductive adhesives, heat-cured conductive adhesives, ultraviolet light-cured conductive adhesives, which can include electrode binder materials, conductive additives and / or conductive particles and epoxy resin blends, etc. The disclosed separator assembly design can help reduce the packaging space requirements of the electrode tab, which in turn reduces the overall size and weight of the electrochemical device. Other incidental advantages may include reducing the manufacturing complexity and processing time of manufacturing / using the multifunctional separator assembly.

[0093] Next turn Figure 3 , another non-limiting example of an electrochemical device is shown, which is depicted as a rechargeable battery pack assembly 210 for storing and supplying high voltage electrical energy for use, for example, in propelling an electric drive vehicle such as Figure 1 The battery pack assembly 210 may be part of a deep cycle, high ampere capacity vehicle battery pack system rated, for example, at about 350 to 1200 high voltage direct current (HVDC) or more, depending on the desired vehicle range, gross vehicle weight, and the power ratings of the various accessory loads drawing power from the RESS. Although different in appearance, it is contemplated that the above referenced Figure 1 Battery Pack 70 and Figure 2Any features and options described for the lithium battery cell 110 may be incorporated individually or in any combination into Figure 3 and Figure 4 of the battery pack assembly 210, and vice versa.

[0094] As Figure 1 Battery Pack 70 and Figure 2 Representative similarities of the battery pack 110 are as follows, Figure 3 The battery assembly 210 may include a liquid-tight, electrically insulating battery assembly housing 220 (also referred to as a "device housing") for storing therein an electrolyte 212 material that is chemically configured to conduct ions (e.g., lithium hexafluorophosphate (LiPF6) in an organic solution). An electrode stack 214 is also enclosed within the device housing 220 and is in electrochemical contact with the electrolyte 212, the electrode stack 214 consisting of one or more (first) working electrodes 222 interlaced and juxtaposed face-to-face with one or more (second) working electrodes 224. Although Figure 3 While a single pair of working electrodes is depicted in FIG, each electrochemical device may include multiple electrode pairs (eg, 10-20 or more) that are stacked and connected in parallel or series for storing and supplying electrical energy.

[0095] Interposed between two adjacent electrodes 222, 224 is an electrode separator assembly 250, which is also disposed within the device housing 220, in electrochemical contact with the electrolyte 212. For device configurations including multiple pairs of paired electrodes of opposite polarity, the corresponding electrode separator assembly 250 may be sandwiched between one, some, or all of the pairs. According to the illustrated example, the electrode separator assembly 250 may include a separator sheet 230, a tab bag 252 protruding from the top end of the separator sheet 230, and a reference electrode tab 254 (also referred to herein as an "electrode tab") rigidly attached to the tab bag 252, or if desired, may be substantially composed of a separator sheet 230, a tab bag 252 protruding from the top end of the separator sheet 230, and a reference electrode tab 254 (also referred to herein as an "electrode tab") rigidly attached to the tab bag 252. Figure 3 and Figure 4 The spacer sheet 230 can be structurally Figure 2 The porous separator 126 is similar or identical to, and thus may include any of the corresponding features and options thereof, including being formed entirely or partially from an electrically insulating but porous material.

[0096] As Figure 2 The dividing point of the isolating member 126, Figure 3 and Figure 4The separator sheet 230 may include a reference electrode. As shown, the reference electrode may be carried by the separator sheet 230 or otherwise formed integrally with the separator sheet 230 (and therefore not identified using a separate reference numeral). For example, a dry conductive electrode material may be pressed and then baked onto one surface of the sheet 230 to form the reference electrode. The reference electrode may be formed entirely or partially from a conductive material in a manner similar to Figure 2 However, the reference electrode tab 254 may be different from the working electrodes 122, 124 in shape, size, and function.

[0097] Continue to refer Figure 3 The representative electrochemical device of the present invention, the tab bag 252 can be manufactured in a pre-assembled "L-shaped" configuration, which typically has a tab plate 256 and a tab fold 258, the tab plate 256 protruding longitudinally from the separator sheet 230 and being coplanar with the separator sheet 230, and the tab fold 258 being coplanar with the tab plate 256 and protruding laterally from the lateral (right-hand) side of the tab plate 256. After assembly, the tab bag 252 can have an "I-shaped" configuration, wherein the tab fold 258 is folded across the tab plate 256, pressed against and rigidly attached to the tab plate 256 to jointly define the tab chamber 251 therebetween, as in Figure 3 . It may be desirable that both the top and bottom ends of the tab chamber 251 have corresponding chamber openings 253 and 255 (as shown); alternatively, only the top end of the chamber 251 may have a corresponding opening 253. For ease of manufacture and assembly, it may be desirable that the separator sheet 230 and the tab bag 252 (including both the tab plate 256 and the tab flap 258) are integrally formed of the same electrically insulating material into a single, one-piece structure.

[0098] According to the example shown, the separator sheet 230, the tab plate 256, and the tab flap 258 can each have a corresponding polyhedral shape with corresponding dimensions. As a non-limiting example, the sheet 230, the plate 256, and the flap 258 can each be a rectangular polyhedron (prism) having different aspect ratios and different total surface areas on its opposite major faces. As shown, the separator sheet 230 has a sheet (first) width W S1 and the sheet (first) height H S1 , and the tab plate 256 has a plate (second) width W P2 , which is smaller than the sheet width W S1 , and the plate (second) height H P2 , which is less than the sheet height H S1 In contrast, the tab flap has a flap (third) width W F3 and the folding wing (third) height H F3 ; Wing width WF3 Smaller than the sheet width W S1 , and can be approximately equal to or less than the plate width W P2 ; and the folding wing height H F3 Smaller than the sheet height H S1 and can be less than or approximately equal to the plate height H P2 It will be appreciated that the sheet 230, panel 256, and flap 258 may take on other regular and irregular shapes and, if desired, may take on other individual and relative dimensions than those shown in the drawings.

[0099] Figure 3 and Figure 4 The reference electrode tab 254 shown in FIG. 2 is mounted directly to the tab pocket 252 and indirectly to the separator sheet 230 via the tab pocket 252. The bottom (first) end portion of the reference electrode tab 254 can be rigidly fixed within the tab chamber 251, while the top (second) end portion of the reference electrode tab 254 can protrude through the opening 253 in the top end of the tab chamber 251. Optionally, the proximal tip at the bottom end of the reference electrode tab 254 can be exposed through the opening 255 in the bottom end of the tab chamber 251. According to the illustrated example, the reference electrode tab 254 includes an elongated rectangular tab body, at least 50% of which can protrude from the chamber opening 253. Alternatively, 55%-75% of the rectangular tab body can be disposed within the tab chamber 251 to help ensure a rigid attachment between the reference electrode tab 254 and the tab pocket 252. As another option, the bottom (first) end of the reference electrode tab 254 disposed in the tab chamber 251 may be spaced apart from the top end of the separator sheet 230 by a predetermined distance (e.g., a gap of about 2 mm-10 mm), for example, to ensure that the electrode tab 254 does not interfere with the ion flow through the sheet 230. In addition, the bottom end of the tab body may present other geometric shapes, such as an enlarged rectangle or circle, to increase the contact area between the electrode tab 254 and the bag 252.

[0100] To help ensure a rigid attachment between the electrode tab 254 and the bag 252, the reference electrode tab 254 can be rigidly attached to the tab bag 252 via a conductive adhesive 260. The conductive adhesive 260 layer can employ any of the options described herein, including air-cured, heat-cured, and UV-cured conductive adhesives, conductive additives containing electrode binder materials, conductive additives having a mixture of conductive particles entrained in epoxy resin. For example, Figure 3The illustration of FIG. 2 shows a reference electrode tab 254 having a pair of opposing (first / front and second / rear) sides; the front side has a lower (first / front) surface and the rear side has a lower (second / rear) surface, both of which are located within the tab pocket 252. One or both of these surfaces may be machined or formed to include a non-smooth surface texture 261. The conductive adhesive 260 may be applied to the reference electrode tab 254 so that it is located on and substantially covers the surface texture 261 on the front and / or rear surfaces. The surface texture 261 may take any suitable surface texturing treatment that will enhance adhesion to the conductive adhesive 260, such as indentations, scribes, cross-hatched grooves, sinusoidal grooves, horizontal grooves, and / or angled grooves. The surface texture may be imparted at two levels: a surface profile level and a roughness level. For the profile level, the texturing may be linear scribes, cross-hatching, indents, etc., of sub-millimeter size. With respect to roughness level, the texturing may have an average roughness (Ra) height of at least 0.5 micrometers (um) and a developed interface area ratio (Sdr) of at least 50%.

[0101] Once constructed, the electrode separator assembly 250 can be sandwiched between two working electrodes 222, 224; in doing so, the separator sheet 230 can physically separate the three electrodes 222, 224, 254 (anode, cathode and reference electrode). By mounting the reference electrode tab 254 to the tab bag 252 (a flexible surface extension of the non-conductive separator sheet 230), the separator sheet 230 substrate can also act as an electrical insulator for the reference electrode tab 254. The reference electrode tab 254 has a predefined "stable" potential and can therefore be paired with any of the working electrodes 222, 224 to measure the voltage across the paired electrodes (e.g., cathode / reference or anode / reference). In doing so, the battery pack system controller is able to measure the absolute potential of the paired electrodes based on the predefined potential of the reference electrode tab 254. It is foreseeable that the disclosed multifunctional separator design is not limited to the reference electrode and can also be applied to other electrodes.

[0102] Figure 4 A flow chart illustrating a representative method 300 for manufacturing an electrode-separator assembly with a built-in reference electrode is presented. Figure 4Some or all of the operations shown in and described in further detail below may represent algorithms corresponding to non-transitory processor-executable instructions that may be stored, for example, in a primary or secondary or remote memory and executed, for example, by an electronic controller, a processing unit, a dedicated control module, a logic circuit, or other module or device or a network of modules / devices to perform any or all of the functions described above and below associated with the disclosed concepts. It should be recognized that the order of execution of the illustrated operation blocks may be changed, additional operation blocks may be added, and some of the operations described herein may be modified, combined, or eliminated. Although various aspects of the present disclosure are discussed in the context of rectangular separator sheets and electrode tabs, those skilled in the art will appreciate that the present disclosure may be applicable to workpieces of approximately any size, shape, and cross-section.

[0103] Method 300 may begin with processor executable instructions executed by a programmable controller or control module or similar suitable processor to call an initialization routine for performing a closed-loop control sequence for performing the various illustrated operations. The initial stages of the manufacturing method may include supplying, acquiring, manufacturing and / or utilizing (collectively referred to as "providing") the various materials, tools and machines required to manufacture the electrode separator assembly. Additional control commands, tolerances and parameters may be entered at this time before commencing the desired assembly operations. After completing any necessary preparatory procedures, method 300 proceeds to a first method step (1) for stamping, cutting or otherwise manufacturing a conductive workpiece 254A from a metal blank, a sheet metal feed roll or a metal-coated plastic substrate.

[0104] Thereafter, the method 300 proceeds to a second method step (2) for applying a non-smooth surface texture to one or more selected portions of one or more major surfaces of the workpiece 254A to generate a textured workpiece 254B. As described above, the bottom portion (e.g., about 40-65%) of the front and / or rear surfaces of the workpiece 254A may be roughened with scribe lines, channels, grooves, etc. At this point, the textured workpiece 254B may be cleaned and may undergo other metal pretreatment procedures (e.g., flood rinse-free, polishing, air drying, etc.). Proceeding to a third method step (3), the method 300 applies an adhesive to the selected portions of the textured and cleaned workpiece 254B to define a coated workpiece 254C. After masking the non-roughened surface(s) of the textured workpiece 254B, for example, with a low tac (viscous), pressure sensitive adhesive (PSA) tape, a conductive adhesive may be applied to the roughened surface(s) of the textured workpiece 254B, for example, by squeegee coating or air blowing.

[0105] Continue to refer Figure 4, method 300 continues to a fourth method step (4) for attaching the adhesive-coated workpiece 254C to an electrically insulating, ionically conductive separator sheet. As shown, the textured and coated workpiece 254C is pressed against a tab plate 256 portion (or tab fold 258 portion) of a tab pocket 252 extending coplanarly from one end of the separator sheet 230. The workpiece 254C is placed so that it is electrically connected to a reference electrode carried by the separator sheet 230, for example, via a conductive adhesive. The method 300 then performs a fifth method step (5) to form a tab pocket around the workpiece 254C and thereby operably secure the workpiece 254C to the separator. For example, Figure 4 A tab flap 258 is depicted folded onto and pressed against the tab plate 256 ; in doing so, the conductive adhesive 260 rigidly attaches the electrode tab 254 to both the plate 256 and the flap 258 , and simultaneously forms a tab pocket 252 encapsulating at least the lower half of the electrode tab 254 .

[0106] Various aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; however, those skilled in the art will recognize that many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise configurations and compositions disclosed herein; any and all modifications, changes and variations apparent from the foregoing description are within the scope of the present disclosure as defined by the appended claims. Furthermore, the present concept expressly includes any and all combinations and sub-combinations of the foregoing elements and features.

Claims

1. An electrochemical device comprising: Device housing; an electrolyte disposed within the device housing and configured to conduct ions; an electrode stack located within the device housing and comprising a first working electrode and a second working electrode in electrochemical contact with the electrolyte; and an electrode separator assembly, which is interposed between the first working electrode and the second working electrode, the electrode separator assembly comprising: a separator sheet formed of an electrically insulating material and including a reference electrode; a tab bag protruding from one end of the separator sheet and defining a tab chamber having a chamber opening; and An electrode tab is attached to the tab bag and is formed of a conductive material, the electrode tab having a first end disposed in the tab chamber and a second end protruding from an opening of the chamber.

2. The electrochemical device according to claim 1, wherein the tab bag includes a tab plate protruding from the separator sheet and coplanar with the separator sheet, the separator sheet having a first width and a first height, and the tab plate having a second width and a second height respectively smaller than the first width and the first height. 3 . The electrochemical device according to claim 2 , wherein the tab bag further comprises a tab flap protruding from one side of the tab plate, the tab flap being pressed against and rigidly attached to the tab plate to jointly define the tab chamber therebetween. 4 . The electrochemical device according to claim 3 , wherein the tab flap has a third height that is smaller than the first height of the separator sheet and the second height of the tab plate. 5 . The electrochemical device according to claim 3 , wherein the tab bag comprises the tab flap and the tab plate, and the separator sheet and the tab bag are integrally formed into a single-piece structure using the electrical insulating material.

6. The electrochemical device according to claim 3, wherein the separator sheet, the tab flaps, and the tab plate each have a corresponding polyhedral shape having different sizes.

7. The electrochemical device of claim 1, wherein the electrode tab is rigidly attached to the tab pocket via a conductive adhesive.

8. The electrochemical device of claim 7, wherein the electrode tab has a first side having a first surface having a non-smooth surface texture, wherein the conductive adhesive is located on the first surface having the non-smooth surface texture.

9. The electrochemical device of claim 8, wherein the electrode tab has a second side opposite the first side, the second side having a second surface including the non-smooth surface texture, wherein the conductive adhesive is also located on the second surface having the non-smooth surface texture.

10. The electrochemical device of claim 9, wherein the non-smooth surface texture comprises dimples, score lines, cross-hatched grooves, sinusoidal grooves, horizontal grooves, and / or angled grooves.

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