阅读说明：本技术 用于医疗装置的电池组合件 (Battery assembly for medical device ) 是由 J·卢瓦齐 P·B·阿莫特 V·布拉玛 N·H·芬斯托姆 M·B·辛茲 V·A·雅科夫列夫 于 2020-04-10 设计创作，主要内容包括：公开了一种用于可植入医疗装置的电池组合件。所述电池组合件包含：电极堆叠,其包括多个电极板,其中所述多个电极板包括第一电极板和第二电极板,所述第一电极板包含从所述第一电极板延伸的第一接线片；所述第二电极板包含从所述第二电极板延伸的第二接线片；间隔件,其在所述第一接线片与所述第二接线片之间；以及铆钉,其延伸穿过所述第一接线片、所述第二接线片和所述间隔件,其中所述铆钉被配置成将所述第一接线片、所述第二接线片和所述间隔件机械地附接到彼此。(A battery assembly for an implantable medical device is disclosed. The battery assembly includes: an electrode stack comprising a plurality of electrode plates, wherein the plurality of electrode plates comprises a first electrode plate and a second electrode plate, the first electrode plate comprising a first tab extending from the first electrode plate; the second electrode plate includes a second tab extending from the second electrode plate; a spacer between the first and second tabs; and a rivet extending through the first tab, the second tab, and the spacer, wherein the rivet is configured to mechanically attach the first tab, the second tab, and the spacer to one another.)

1. A battery assembly for an implantable medical device, the assembly comprising:

an electrode stack comprising a plurality of electrode plates, wherein the plurality of electrode plates comprises a first electrode plate and a second electrode plate, the first electrode plate comprising a first tab extending from the first electrode plate; the second electrode plate includes a second tab extending from the second electrode plate;

a spacer between the first and second tabs; and

a rivet extending through the first tab, the second tab, and the spacer, wherein the rivet is configured to mechanically attach the first tab, the second tab, and the spacer to one another.

2. The assembly of claim 1, wherein the rivet includes a flared head, a deformed tail, and a rivet body extending between the flared head and the deformed tail, and wherein the flared head is on a first side of the electrode stack and the deformed tail is on a second side of the electrode stack.

3. The combination of claim 1 or 2, wherein the spacer comprises a first spacer, wherein the plurality of electrode plates includes a third electrode plate including a third tab extending from the third electrode plate, wherein the second tab is between the first tab and the third tab, the combination further comprising a second spacer between the third tab and the second tab, wherein the rivet extends through the third tab and the second spacer.

4. The assembly of claim 3, wherein the first spacer has a first thickness different from a second thickness of the second spacer.

5. The assembly of claim 1 or 2, wherein the spacer comprises a first spacer, the assembly further comprising a second spacer between the first tab and a second tab adjacent to the first spacer.

6. The assembly of any of the above claims, further comprising a weld on the electrode stack extending from the first tab across the spacer to the second tab.

7. The assembly of claim 1 or 2, wherein the first electrode plate is a top plate of the plurality of electrode plates of the electrode stack, the assembly further comprising:

a battery case surrounding the electrode stack; and

a gasket located on top of the first tab between the first tab and an inner surface of the battery case.

8. The assembly of claim 7, wherein the first electrode plate comprises a first anode plate and the second electrode plate comprises a second anode plate, wherein the plurality of electrode plates further comprises a first cathode plate and a second cathode plate, the first cathode plate including a third tab extending from the first cathode plate, the second cathode plate including a fourth tab extending from the second cathode plate, wherein the third tab and the second tab are stacked adjacent to the first tab and the second tab, and wherein a top spacer spans a gap between the first tab and the third tab.

9. The assembly of claim 7 or 8, wherein the top spacer is formed of an electrically insulating material to electrically isolate the first tab from the battery case.

Technical Field

The present disclosure relates to batteries, and more particularly, to batteries for medical devices.

Background

Medical devices, such as Implantable Medical Devices (IMDs), include a variety of devices that deliver therapy (e.g., electrical stimulation or drugs) to a patient, monitor physiological parameters of the patient, or both. IMDs typically include a number of functional components enclosed in a housing. The housing is implanted in the patient. For example, the shell may be implanted in a recess formed in the torso of a patient. The housing may contain various internal components such as batteries and capacitors to deliver energy for therapy delivered to the patient and/or to provide energy to power circuitry for monitoring physiological parameters of the patient and controlling functionality of the medical device.

Disclosure of Invention

In some aspects, the present disclosure relates to battery assemblies, such as used in medical devices, and techniques for manufacturing battery assemblies.

In one example, the present disclosure is directed to a battery assembly for an implantable medical device. The assembly may comprise: an electrode stack comprising a plurality of electrode plates, wherein the plurality of electrode plates comprises a first electrode plate and a second electrode plate, the first electrode plate comprising a first tab extending from the first electrode plate; the second electrode plate includes a second tab extending from the second electrode plate; a spacer between the first and second tabs; and a rivet extending through the first tab, the second tab, and the spacer, wherein the rivet is configured to mechanically attach the first tab, the second tab, and the spacer to one another. In another example, the present disclosure relates to an implantable medical device that includes such a battery assembly within an outer housing of the implantable medical device, and processing circuitry, wherein the processing circuitry is configured to control delivery of electrical therapy from the implantable medical device to a patient using power supplied by the battery assembly.

In another example, the present disclosure is directed to a battery assembly for an implantable medical device. The assembly may comprise: a battery case; an electrode stack comprising a plurality of electrode plates, wherein the plurality of electrode plates includes a first tab stack of anode tabs extending from anode plates of the electrode stack and a second tab stack of cathode tabs extending from cathode plates of the electrode stack, wherein the first tab stack is adjacent to the second tab stack and a gap separates the first tab stack from the second tab stack; and a gasket located on the top tab of at least one of the first or second tab stacks, wherein the gasket is located between the battery case and at least one of the first tabs of the first or second tab stacks. In another example, the present disclosure relates to an implantable medical device that includes such a battery assembly within an outer housing of the implantable medical device, and processing circuitry, wherein the processing circuitry is configured to control delivery of electrical therapy from the implantable medical device to a patient using power supplied by the battery assembly.

The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.

Drawings

Fig. 1 is a conceptual diagram illustrating an example medical device system that may be used to deliver therapy to a patient.

Fig. 2 is a conceptual diagram illustrating a partially exploded view of the IMD of fig. 1.

Fig. 3 and 4 are conceptual diagrams illustrating portions of example battery assemblies according to examples of the present disclosure.

Fig. 5 is a conceptual diagram of a portion of an example battery assembly illustrating a stack of tabs and spacers including electrodes.

Fig. 6 is a conceptual diagram illustrating a cross-sectional view of the stack of lugs and spacers of fig. 5.

Fig. 7 is a conceptual diagram illustrating an example rivet that may be included in a battery assembly.

FIG. 8 is a conceptual diagram illustrating an example assembly for forming a battery assembly including a rivet.

Fig. 9 is a flow diagram illustrating an example technique according to an example of the present disclosure.

Fig. 10 is a conceptual diagram illustrating portions of an example battery assembly, according to an example of the present disclosure.

FIG. 11 is a conceptual diagram illustrating the example shim shown in FIG. 10.

Fig. 12 is a conceptual diagram illustrating an example battery including an example gasket.

Detailed Description

Various medical devices may utilize one or more batteries as a power source to provide operating power. For example, an Implantable Medical Device (IMD) that provides cardiac rhythm management therapy to a patient may include a battery to power generation of electrical therapy or other functions of the IMD. For ease of illustration, examples of the present disclosure will be described primarily with respect to a battery employed in an IMD that provides cardiac rhythm management therapy. However, as will be apparent from the description herein, examples of the present disclosure are not limited to IMDs that provide such therapy. For example, in some cases, one or more of the example batteries described herein may be used by a medical device configured to deliver electrical stimulation to a patient in the form of neurostimulation therapy (e.g., spinal cord stimulation therapy, deep brain stimulation therapy, peripheral nerve stimulation therapy, pelvic floor stimulation therapy, etc.). In some examples, example batteries of the present disclosure may be used in medical devices configured to monitor one or more patient physiological parameters (e.g., by monitoring electrical signals of a patient, either alone or in conjunction with delivery of therapy to the patient).

In some examples, a battery of an IMD may include a plurality of electrode plates (e.g., including both anode and cathode plates) stacked on one another, with each of the plates including a tab extending therefrom. The tabs of the anode plates may be aligned with each other in the stack and electrically connected to each other to form the anode of the cell. In this sense, the tab stack may serve as an electrical interconnect between the plates of the anode. Similarly, the tabs of the cathode plates may be aligned with each other in the stack and electrically connected to each other to form the cathode of the cell. In some examples, such batteries may be referred to as flat cells.

In some examples, in each stack of anode and cathode tabs, a spacer may be located between adjacent individual tabs in the stack of tabs, e.g., such that each individual tab is separated from an adjacent tab by a spacer. The spacers may be electrically conductive to electrically couple respective tabs in the stack to one another and to at least partially define an electrical interconnect between respective plates of the electrode. For each electrode, the tabs in the stack of tabs and spacers may be attached to each other by one or more side laser welds that span the height of the stack of tabs.

In some examples, the tabs of the electrode stack may flex or bend due to the nature of the spacer and tab interconnect design. This can result in material stress that can lead to side weld failure and/or insulation failure.

In some examples, stacked plate-like battery interconnect spacer stacks may be subject to "fan out" (e.g., open like pages of a bound book) due to mechanical forces applied by expansion of the electrode stack (e.g., during discharge of the battery). The applied force may displace the spacer stack, causing an electrical short to the surrounding cell casing, and/or causing a laser weld on the interconnect spacer stack to fail.

In some examples, the laser welds on the sides of the stack of interconnected spacers are subjected to mechanical loads, for example, as the electrode stack expands during the life of the cell. Electrode stack expansion may be due to plate warpage or cathode expansion during cell discharge. As described above, mechanical loads on the stack of interconnected spacers may cause the stack of interconnected spacers to "fan out," opening much like a book and many of its pages are open.

In accordance with at least some examples of the present disclosure, a battery assembly including a stack of electrode tabs may include spacers of different thicknesses and/or may include multiple spacers between individual tabs. The spacer and lug stack sequence can be adapted to provide a desired deflection/bend that reduces material stress in the interconnect and nearby electrode materials. In some examples, a predictive model may be used to predict a desired stacking sequence, e.g., using spacers of a desired thickness. In some examples, the model may take into account the source of variation in the components used to generate the battery assembly. For example, modeling can be used to evaluate thickness variations of the spacer and associated lug. The model may be used to strategically place spacers based on inferred or measured changes in each component of the stacked assembly.

Additionally or alternatively, a battery assembly according to some examples of the present disclosure may include a rivet passing through an aperture in the tab/spacer stack (e.g., through a hole in or near the center of the stack of tabs). The rivet prevents mechanical "fan out" of the spacer. The rivet may be a length of wire that is mechanically fastened and/or laser welded to the outermost plate tabs of the stack assembly (e.g., the top and bottom tabs of a tab stack). The rivet may be configured to counteract a force applied by expansion of the electrode stack.

Additionally or alternatively, battery assemblies according to some examples of the present disclosure may include one or more spacers (also referred to as gaskets) between the stack of interconnected spacer tabs and the surrounding battery housing (e.g., between the top of the stack of spacer tabs and the surrounding battery housing). In some examples, the spacers may be formed of a polymer material that acts as an electrical insulator to prevent electrical shorting. The shims occupy space between the stack of interconnected spacers and the housing wall, thus limiting "fan out" that imparts stress to the laser welds. The gasket can transfer the forces of electrode expansion away from the interconnecting laser weld joints and impart those forces to the more robust cell housing walls.

In some examples, the shim may be a relatively simple molded polymer component that is added during assembly, or it may be designed as an integral feature of another insulator (e.g., a headspace insulator, a stack insulator, and/or a feedthrough insulator). In some examples, a "gasket" may be attached as a foldable feature that allows ease of assembly, while also preventing inadvertent un-installation of the gasket during battery assembly.

Fig. 1 is a conceptual diagram illustrating an example medical device system 10 that may be used to provide electrical therapy to a patient 12. Patient 12 is typically, but not necessarily, a human. System 10 may include IMD 16 and external device 24. In the example illustrated in fig. 1, IMD 16 has battery 26 positioned within an outer housing 40 of IMD 16. The battery 26 may be a primary battery or a secondary battery.

Although examples in the present disclosure are described primarily with respect to battery 26 positioned within housing 40 of IMD 16 for delivering electrical therapy to the heart of patient 12, in other examples, battery 26 may be utilized with other implantable medical devices. For example, the battery 26 may be utilized with an implantable drug delivery device, an implantable monitoring device that monitors one or more physiological parameters of the patient 12, an implantable neurostimulator (e.g., spinal cord stimulator, deep brain stimulator, pelvic floor stimulator, peripheral neurostimulator, etc.), and the like. Furthermore, although examples of the present disclosure are described primarily with respect to implantable medical devices, examples are not so limited. In particular, some examples of batteries described herein may be employed in any medical device including non-implantable medical devices. For example, an example battery may be used to power a medical device configured to deliver therapy to a patient externally or via a percutaneously implanted lead or drug delivery catheter.

In the example depicted in fig. 1, IMD 16 is connected (or "coupled") to leads 18, 20, and 22. IMD 16 may be, for example, a device that provides cardiac rhythm management therapy to heart 14, and may include, for example, an implantable pacemaker, cardioverter, and/or defibrillator that provides therapy to heart 14 of patient 12 via electrodes coupled to one or more of leads 18, 20, and 22. In some examples, IMD 16 may deliver a pacing pulse but not a cardioversion or defibrillation shock, while in other examples, IMD 16 may deliver a cardioversion or defibrillation shock but not a pacing pulse. Additionally, in other examples, IMD 16 may deliver pacing pulses, cardioversion shocks, and defibrillation shocks.

IMD 16 may include electronics and other internal components necessary or desired for performing functions associated with the device. In one example, IMD 16 includes one or more of the following: processing circuitry, memory, signal generation circuitry, sensing circuitry, telemetry circuitry and a power supply. In general, the memory of IMD 16 may include computer readable instructions that, when executed by the processor of the IMD, cause the processor to perform various functions attributed to the devices herein. For example, processing circuitry of IMD 16 may control signal generator and sensing circuitry according to instructions and/or data stored on memory to deliver therapy to patient 12 and perform other functions related to treating a condition of the patient with IMD 16.

IMD 16 may include or may be one or more processors or processing circuits, such as one or more Digital Signal Processors (DSPs), general purpose microprocessors, Application Specific Integrated Circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the terms "processor" and "processing circuitry" as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein.

The memory may include any volatile or non-volatile media, such as Random Access Memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), Electrically Erasable Programmable ROM (EEPROM), flash memory, and so forth. The memory may be a storage device or other non-transitory medium.

As an example, signal generation circuitry of IMD 16 may generate electrical therapy signals for delivery to patient 12 via electrodes on one or more of leads 18, 20, and 22 in order to provide pacing signals or cardioversion/defibrillation shocks. Sensing circuitry of IMD 16 may monitor electrical signals from electrodes on leads 18, 20, and 22 of IMD 16 in order to monitor electrical activity of heart 14. In one example, the sensing circuitry may include switching circuitry to select which of the available electrodes on leads 18, 20, and 22 of IMD 16 are used to sense cardiac activity. Additionally, the sensing circuitry of IMD 16 may include a plurality of detection channels, each of which includes an amplifier and an analog-to-digital converter for digitizing signals received from the sensing channels (e.g., electrogram signal processing by the processing circuitry of the IMD).

The telemetry circuitry of IMD 16 may be used to communicate with another device (e.g., external device 24). Under control of the processing circuitry of IMD 16, the telemetry circuitry may receive downlink telemetry from external device 24 and transmit uplink telemetry to the external device by way of an antenna, which may be internal and/or external.

Various components of IMD 16 may be coupled to a power source, such as a battery 26. The battery 26 may be a lithium primary battery or a lithium secondary (rechargeable) battery, although other types of battery chemistries are contemplated. The battery 26 may be capable of holding a charge for several years. In general, battery 26 may supply power to one or more electrical components of IMD 16, e.g., signal generation circuitry, to allow IMD 16 to deliver therapy to patient 12, e.g., in the form of monitoring one or more patient parameters, delivery of electrical stimulation, or delivery of therapeutic drug fluid. The battery 26 may include a lithium-containing anode and cathode that include active materials that electrochemically react with lithium within the electrolyte to generate electricity. A wide variety of battery types and

leads 18, 20, 22 coupled to IMD 16 may extend into heart 14 of patient 12 to sense electrical activity of heart 14 and/or deliver electrical therapy to heart 14. In the example shown in fig. 1, Right Ventricular (RV) lead 18 extends through one or more veins (not shown), the superior vena cava (not shown), and right atrium 30, and into right ventricle 32. Left Ventricular (LV) coronary sinus lead 20 extends through one or more veins, the vena cava, the right atrium 30, and into the coronary sinus 34 to a region adjacent to the free wall of the left ventricle 36 of heart 14. Right Atrial (RA) lead 22 extends through one or more veins and the vena cava, and into right atrium 30 of heart 14. In other examples, IMD 16 may deliver therapy from an extravascular tissue site to heart 14 in addition to or in lieu of delivering therapy via electrodes of intravascular leads 18, 20, 22. In the illustrated example, there are no electrodes in the left atrium 36. However, other examples may include electrodes in the left atrium 36.

IMD 16 may sense electrical signals (e.g., cardiac signals) attendant to the depolarization and repolarization of heart 14 via electrodes (not shown in fig. 1) coupled to at least one of leads 18, 20, 22. In some examples, IMD 16 provides pacing pulses to heart 14 based on cardiac signals sensed within heart 14. The configuration of electrodes used by IMD 16 for sensing and pacing may be unipolar or bipolar. IMD 16 may also deliver defibrillation therapy and/or cardioversion therapy via electrodes located on at least one of leads 18, 20, 22. IMD 16 may detect arrhythmias of heart 14, such as fibrillation of ventricles 32 and 36, and deliver defibrillation therapy to heart 14 in the form of electrical shocks. In some examples, IMD 16 may be programmed to deliver a progression of therapy (e.g., a shock with an increased energy level) until fibrillation of heart 14 ceases. IMD 16 may detect fibrillation by employing one or more fibrillation detection techniques known in the art. For example, IMD 16 may identify a cardiac parameter of the cardiac signal (e.g., R-wave, and detect fibrillation based on the identified cardiac parameter).

In some examples, external device 24 may be a handheld computing device or a computer workstation. The external device 24 may include a user interface that receives input from a user. The user interface may include, for example, a keypad and a display, which may be, for example, a Cathode Ray Tube (CRT) display, a Liquid Crystal Display (LCD), or a Light Emitting Diode (LED) display. The keypad may take the form of an alphanumeric keypad or a reduced set of keys associated with a particular function. The exterior 24 may additionally or alternatively include a peripheral pointing device, such as a mouse, through which a user may interact with the user interface. In some embodiments, the display of exterior 24 may include a touch screen display, and a user may interact with programmer 24 via the display.

A user, such as a physician, technician, other clinician or caregiver, or a patient, may interact with external device 24 to communicate with IMD 16. For example, a user may interact with external device 24 to retrieve physiological or diagnostic information from IMD 16. The user may also interact with external device 24 to program IMD 16 (e.g., select values for operating parameters of IMD 16).

External device 24 may communicate with IMD 16 via wireless communication using any technique known in the art. Examples of communication techniques may include, for example, low frequency or Radio Frequency (RF) telemetry, although other techniques are also contemplated. In some examples, external device 24 may include a communication head that may be placed proximate to the body of the patient near the site of IMD 16 implantation in order to improve the quality or safety of communication between IMD 16 and external device 24.

In the example depicted in fig. 1, IMD 16 is connected (or "coupled") to leads 18, 20, and 22. In an example, leads 18, 20, and 22 are connected to IMD 16 using connector block 42. For example, leads 18, 20, and 22 are connected to IMD 16 using lead connector ports in connector block 42. Once connected, leads 18, 20, and 22 make electrical contact with the internal circuitry of IMD 16. Battery 26 may be positioned within a housing 40 of IMD 16. The housing 40 may be hermetically sealed and biologically inert. In some examples, the housing 40 may be formed of an electrically conductive material. For example, the housing 40 may be formed from materials including, but not limited to, titanium, stainless steel, and the like.

Fig. 2 is a conceptual diagram of IMD 16 of fig. 1 with portions of connector block 42 and housing 40 not shown removed to illustrate some of the internal components within housing 40. IMD 10 includes a housing 40, control circuitry 44 (which may include processing circuitry), a battery 26 (e.g., an organic electrolyte battery), and a capacitor 46. Control circuitry 44 may be configured to control one or more sensing and/or therapy delivery processes from IMD 16 via leads 18, 20, and 22 (not shown in fig. 2). The battery 26 includes a battery assembly housing 50 and an insulator 48 (or liner) disposed therearound. The battery 26 charges a capacitor 46 and powers the control circuit 44.

Fig. 3 and 4 are conceptual diagrams illustrating aspects of an example battery 26. The cell 26 includes an assembly housing 50 having a bottom housing portion 50A and a top housing portion 50B (shown in fig. 2), feedthrough terminals 56, and an electrode assembly 58. The electrolyte may be filled into the housing 50 through a fill port (not shown). The housing 50 fills the electrolyte into the electrode assembly 58. The top portion 50B and the bottom portion 50A of the housing may be welded or otherwise attached to seal the package components of the battery 26 within the housing 50. The feedthrough assembly 56 formed by the pin 62 and the insulator member/ferrule 64 is electrically connected to the jumper pin 60B. The connection between the pins 62 and the jumper pins 60B allows positive charge to be delivered from the electrode assembly 58 to electronic components outside of the battery 26.

As mentioned above, a fill port (not shown) allows for the introduction of liquid electrolyte to the electrode assembly 58. The electrolyte creates an ionic path between the anode and cathode of the electrode assembly 58. During the electrochemical reaction with these electrodes, the electrolyte acts as a medium for the migration of ions between the anode and cathode.

The electrode assembly 58 is depicted as a stacked assembly. The anode includes a collection of electrode plates 72 (including individual anode electrode plates 76A) having a collection of tabs 76 (including individual tabs 76A) extending therefrom that are conductively coupled via a conductive coupler 80 (also referred to as an anode current collector). Although not labeled, one or more spacers (e.g., conductive spacers) may be located between respective lugs in the lug set 76. The conductive couplers 80 may be pins that extend vertically through the lug set 76 and spacers located between respective lugs. Additionally or alternatively, one or more welds 90 may also conductively couple the tab set 76 and the spacer. In accordance with at least some examples of the present disclosure, as described below, the conductive coupler 80 may be a rivet that extends vertically through the set of lugs 76 and the spacer, which also mechanically attaches the individual lugs 76 and the spacer to one another.

Each anode electrode plate 72A includes a current collector or grid 82, a tab 76A extending therefrom, and an electrode material. The electrode material (or anode material) may include an element from group IA, group IIA, or group IIIB of the periodic table of elements (e.g., lithium, sodium, potassium, etc.), alloys thereof, intermetallics (e.g., Li-Si, Li-B, Li-Si-B, etc.), or alkali metals in metallic form (e.g., lithium, etc.).

The cathode tab 68 may be constructed in a similar manner as the anode tab 66. The cathode includes a collection of electrode plates 74 (including individual cathode electrode plates 74A) having a collection of tabs 78 (including individual tabs 78A) extending therefrom. As labeled in fig. 5, for example, one or more spacers (e.g., conductive spacers 86A-86C) may be located between respective lugs in the lug set 78. A conductive coupler 84 connects the lug set 78 and the spacer 86. A conductive coupler 84 or other cathode current collector may be connected to the conductive member 60A. The conductive member 60A shaped as a spacer plate may comprise titanium, aluminum/titanium clad metal, or other suitable material. The conductive member 60A allows the cathode tab 68 to be electrically coupled to an electronic component external to the cell 26. Each of the lugs in the lug set 78, including for example individual lugs 78A, may additionally or alternatively be attached to one another via laser welds 92.

In accordance with at least some examples of the present disclosure, as described below, the conductive coupler 84 may be a rivet that extends vertically through the lug set 78 and the spacer 86, which also mechanically attaches the individual lugs 76 and the spacer 86 to each other.

Each cathode electrode plate 74A includes a current collector (not shown) or grid, electrode material, and a tab 78A extending therefrom. The tab 78A includes a conductive material (e.g., aluminum, etc.). The tab 78A includes a conductive material (e.g., copper, titanium, aluminum, etc.). The electrode material (or cathode material) can comprise a metal oxide (e.g., vanadium oxide, Silver Vanadium Oxide (SVO), manganese dioxide, and the like), a mixture of carbon monofluoride and the manganese dioxide (e.g., CFx + MnO)₂) Combined Silver Vanadium Oxide (CSVO), lithium ions, other rechargeable chemicals, or other suitable compounds.

Fig. 5 is a conceptual diagram illustrating an enlarged view of a portion of the cathode tab 68 of the cell 26. Fig. 6 is a cross-sectional view of the stack of cathode tabs 78 shown in fig. 5. As shown, electrode plate 74 of cathode 66 includes cathode electrode plates 74A, 74B, 74C (etc.) in a stacked configuration. Cathode tabs 78A, 78B, 78C extend from cathode electrode plates 74A, 74B, 74C, respectively, and assume the same stacked configuration as electrode plates 74. At least one spacer is positioned between each respective lug. For example, spacer 86A is located between lug 78A and lug 78B, and two spacers 86B and 86C are located between lug 78B and lug 78C.

For ease of description and illustration, not all tabs and spacers of cathode stack 68 are labeled in fig. 5 and 6. However, it should be understood that the description of the lugs 78A-78C and the spacers 86A-86C may also apply to any of the lugs and spacers shown in fig. 5 and 6. Additionally, while fig. 5 is described with respect to a cathode stack 68, it is contemplated that the same configuration may be applied to the anode stack 66 of the cell 26 shown in fig. 3.

In some examples, the spacers 86A ensure that the tabs 78A and 78B extend substantially straight from the plates 74A and 74B, respectively, and do not bend during the sub-assembly process to connect the tab sets 78 (including, for example, individual tabs 78A) for the cathode stack 68. Although a single spacer 86A is depicted as being placed between two lugs, more than one spacer may be placed between two lugs, such as spacers 86B and 86C between lugs 78B and 78C.

The spacers 86A-86C may comprise a conductive material, for example, to electrically interconnect each of the lugs. For the electrode plates associated with the anode stack 66, titanium and its alloys or other suitable materials are used. For the electrode plates associated with the cathode stack 68, titanium, nickel, aluminum, alloys thereof, or other suitable materials are used.

The spacers 86A-86C may comprise a variety of shapes. Exemplary spacers include substantially H-shaped spacers, substantially rectangular, circular, or include at least one triangular shape (e.g., a single triangle, hexagon, etc.). The spacers 86A-86C may have different or substantially the same individual thicknesses in the z-direction labeled in fig. 5, for example, to achieve different design criteria. For example, thicker electrode plates may require thicker spacers. In the example of fig. 5, the spacer 86A may have a thickness that is substantially the same as the thickness of the spacer 86B, but the spacer 86C may be thinner than the spacers 86A and 86B. In some examples, the thickness of the spacer can be in the range of about.005 inches to about.030 inches, although other values are contemplated. Examples of spacers 86A-86C may include one or more of the example spacers described in U.S. published patent application 2009/0197180.

In some examples, the number of spacers between the tabs of the cathode and anode stacks 68, 66 and the thickness of the individual spacers may be selected such that tab bending is minimized but still fits in the cell housing 50.

As shown in fig. 5 and 6, cathode stack 68 may include rivets 84 extending through apertures 94 (shown in fig. 4) running in the z-direction through cathode tab set 78 (including, for example, individual tabs 78A), spacers 86, and conductive plate 60A. Rivet 84 includes a body 96, a head 100, and a deformed tail 98. The body 96 may be a solid body (e.g., as shown in fig. 6) or a body including an internal cavity (e.g., as shown in fig. 8). The head portion 100 has a flange portion located below the conductive plate 60A. Similarly, deformed tail 98 has a flange portion that is positioned above tab 78A, which is the "top" tab of the stack. In the example of fig. 5 and 6, spacer 86D is between tail 98 and lug 78A. In such examples, spacer 86D may be thicker and structurally more rigid than lug 78A, e.g., to prevent head 98 of rivet 84 from "pulling through" lug 78A in the absence of spacer 86D. In other examples, tail 98 may be directly adjacent to tab 78A.

The flanged shape of the head portion 100 and the deformed tail portion 98 allows the rivet 84 to fasten or otherwise mechanically attach the cathode tab 78, the spacer 86, and the conductive plate 60A to one another and prevent the stack from becoming separated from one another. As will be described in further detail below, prior to deformation, the tail 98 may be inserted into the aperture 94 such that it extends away from the top of the stack of lugs 78, spacers 86, and conductive plates 60A. The tail 98 is then deformed to form a flange and attach the stack of lugs 78, spacers 86 and conductive plates 60A together.

The rivet 84 may fix and define the thickness of the stack of the lug 78, the spacer 86, and the conductive plate 60A shown in the z-direction to correspond to the thickness of the body 96 in the z-direction. In some examples, the rivet 84 may apply a compressive force between the head 100 and the tail 98, e.g., to counteract a force in the other direction that would otherwise cause the lug 78 and the spacer 86 to separate. In this manner, during the operational life of the battery 26, the stack of tabs 78 is prevented from "fanning out," e.g., fanning out in the z-direction, and the tabs 78 are prevented from losing electrical interconnection with one another.

In some examples, the rivets 84 are configured to hold the stack of lugs 78 together so that the welds 92 do not accept a "book open" mechanical load. The welds 92 may be present in an assembly of rivets 84 included in a stack of tabs 78 to provide, for example, a secure electrical connection between the respective tabs. In the long term, corrosion and surface oxidation may degrade the quality of the interfacial contact, thus requiring the weld to be applied.

In some examples, the height (in the Z direction) of the rivets 84 is selected based on the stack modeling described above. The modeling work may suggest that only one rivet be used for all production variation options, or if the variation is too large, individual lug/spacer stacks may be actively measured during manufacturing and then any of several pre-rivet heights selected for a particular stack.

The rivet 84 may be formed of any suitable material, such as stainless steel (e.g., 300 series stainless steel), monel, or other nickel-copper alloy and/or nickel. In some examples, the rivet 84 may be a conductive material such that the rivet 84 is used to electrically couple the individual tabs 78, spacers 86, and conductive plate 60A together, e.g., alone or in combination with other features such as welds 92 and/or conductive spacers 86. In other examples, the rivet 84 may be formed of an electrically insulating material.

Fig. 7 is a photograph illustrating an example rivet 84 that may be employed in examples of the present disclosure. Rivet 84 includes a head 100, a tail 98, and a body 96 extending between head 100 and tail 98. For example, the rivet 84 is shown in a state prior to deformation of the tail 98 as shown in fig. 6. The body 96 of the rivet 84 has an outer diameter D that is less than the size of the aperture 94 extending through the stack of lugs 78, spacers 86, and conductive plates 60A shown in fig. 5 and 6. In some examples, the body 96 of the rivet 85 may have an outer diameter of about 28 mils or less, such as a head 100 and deformed tail 98 having a diameter of about 40 mils or more. In examples where the body 96 includes an internal cavity rather than being solid, the thickness of the body wall may be about 5 mils. In some examples, the overall length of the rivet 84 from the head portion 100 to the tail portion 98 may be about 272 mils or less. In some examples, the combined total height (in the Z direction) of the lug 78 and the spacer 86 can be about 0.230 inches (e.g., +/-0.03 inches). Other values are contemplated.

Fig. 8 is a schematic illustrating an example apparatus 106 for deforming the tail 98 when arranged with the cathode tab 78 and the spacer 86 to form a stacked assembly in which the tab 78 and the spacer 86 are attached to each other via the rivet 84. Fig. 9 is a flow diagram illustrating an example technique for attaching lugs 78 and spacers 86 to one another via rivets 84. For ease of description, the example technique of fig. 9 will be described with respect to the apparatus 106 shown in fig. 8.

As shown in fig. 9, the lugs 78 and spacers 86 may be stacked on the body 96 of the rivet 84 (102). For example, the apertures 94 and individual spacers 86 of individual ones of the lugs 78 may be placed sequentially over the tail 98 onto the body 96 in a desired order and arrangement, such as in the arrangement shown in fig. 8. In other examples, the lugs 78 and spacers 86 may be initially arranged in a stack with the apertures aligned (e.g., using fixed pins) and then placed as a single stack onto the body 96 over the tail 98. Stacking may be accomplished manually or by a robotic assembly device (e.g., a pick-and-place robotic device).

Once the lugs 78 and spacers 86 are assembled over the rivets 84, the tail portions 98 may be deformed to attach the lugs 78 and spacers 86 in a stacked arrangement (104). For example, collapsible support 110 may be used to press die forging 108 into tail 98, such as via a compressive force, against retaining pin 112 to deform the edge of tail 98 outward and form a flange end as shown in fig. 8. In some examples, the welds 92 may then be formed in the tabs 78 and the spacers 86 after the rivets 84 have been installed, such as via laser welding or other suitable processes. Alternatively, the weld 92 may be formed prior to installation of the rivet 84.

The example of fig. 9 illustrates just one example technique for deforming the tail 98 of the rivet 84 within the aperture 94 in the stack of the lug 78 and the spacer 86 to attach the lug 78 and the spacer 86 to each other. Other example suitable techniques may be employed, as well as other types of rivets, such as rivets having a solid body.

As mentioned above, some example battery assemblies of the present disclosure may additionally or alternatively include a gasket on the "top" of the stack of tabs 78 and spacers 86, e.g., to prevent "fan out" of tabs 78 as described herein. Fig. 10 is a schematic diagram illustrating an example of a cell 26 including a gasket 114. As shown in fig. 10, a spacer 114 is located on the stack of tabs 78 and spacers 86 of the cathode stack 68. In the example of fig. 10, the spacer 114 is not directly on top of the lug 78A, but is separated from the lug 78A by a spacer 86D. In other examples, the spacer 114 may be located directly on the tab 78A. Although not shown in fig. 10, in some examples, depending on the material used to form the shim 114, the weldment 92 may extend along the sides of the stacked assembly to include the shim 114.

In addition, a spacer 114 is positioned on the stack of tabs 76 of the anode stack 66 in a similar manner. The spacer 114 is a single component that spans the gap 116 between the stack of tabs 78 of the cathode stack 68 and the stack of tabs 76 of the anode stack 66, which also includes spacers (not labeled) between the individual tabs in the stack. Although the gasket 114 is a single component in the example of fig. 10, in other examples, the cell 26 may include one gasket on the stack of tabs and spacers for the cathode stack 68 and another gasket on the stack of tabs and spacers for the anode stack 66.

In some examples, the spacer 114 may be included as an integral feature of another component (e.g., of an insulating component), rather than as a separate component. For example, in some examples, the gasket 114 may be part of another typical insulator used to isolate electrical polarity within the cell 26, such as a headspace insulator, a stack insulator, and/or a feed-through insulator. In some examples, the gasket 114 may attach or otherwise incorporate a foldable feature as a component to facilitate assembly of the battery 26 while also preventing inadvertent un-installation from occurring during assembly of the battery 26.

Although not shown in fig. 10, when the battery case 50 is assembled with the top portion 50B (shown in fig. 2) and the bottom portion 50A sealed or otherwise attached to each other to form the case 50, the thickness (in the z-direction) of the gasket 114 can be selected such that the top surface of the gasket 114 is in contact with the inner surface of the top portion 50B of the battery case 50. In some examples, contact between the top surface of the gasket 114 and the inner surface of the top portion 50B of the housing 50 may apply a compressive force (represented by arrows 120 in fig. 10) or otherwise prevent the cathode stack 68 and the anode stack 66 from fanning out. For example, when the top portion 50B is attached to the bottom portion 50A of the housing 50, such as via a weld around the perimeter of the housing 50 at the interface between the top portion 50B and the bottom portion 50B, the compressive force 120 may be applied by the gasket 114 to the stack of tabs 78 of the cathode 68 and the stack of tabs 76 of the anode 66 between the top portion 50B and the bottom portion 50A. In this manner, the compressive force 120 may prevent the stack of tabs 78 of the cathode 68 and the stack of tabs 76 of the anode 66 from "fanning out," for example, during the operational life of the cell 26.

The gasket 114 may be formed of any suitable material. In some examples, the gasket 114 may be formed of an electrically insulating material, for example, to prevent electrical coupling of the cathode stack 68 and the anode stack 66 through the gasket 114 and/or electrical coupling of the cathode stack 68 and/or the anode stack 66 to the housing 50. Example insulating materials may include polypropylene, polyethylene, and the like. In other examples, the gasket 114 may be formed of a conductive material such as titanium, stainless steel, or the like. In some examples, the spacers 86D between the top tabs 78A of the cathode 68 and the spacers 114 between the top tabs 76A of the anode 66 and the spacer 114 may be electrically insulated to prevent electrical coupling between the respective electrode tabs and the spacer 114. In other examples, the gasket 114 may be configured such that the compressive force is applied once the cathode stack 68 and/or the anode stack 66 begin to fan out, such as at some point during the operational life of the cell 26.

Fig. 11 is a schematic diagram illustrating an example of the gasket 114. As shown, the shim 114 does not have a constant thickness, but rather exhibits a thickness T1 on one side of the shim 114 and a thickness T2 on the other side of the shim 114. This difference in this case may account for the difference in the distance between the tab/spacer stack of the cathode stack 68 and the inner surface of the top portion 50B of the casing 50 as compared to the distance between the tab/spacer stack of the anode stack 66 and the inner surface of the top portion 50B of the casing 50 when the casing 50 is assembled around the internal components of the cell 26.

As shown, in some examples, the gasket 114 may include posts 122A and 122B. The post 122A may be configured to fit within a portion of the aperture 94 of the stack of tabs 78 and spacers 86 of the cathode stack 68. Similarly, the post 122B may be configured to fit within a portion of a similar aperture in the tab/spacer stack of the anode stack 66. This feature may facilitate registration or alignment of the gasket 114 relative to the anode stack 66 and the cathode stack 68, and maintain the gasket 114 in position, e.g., before, during, and/or after assembly of the top portion 50B and the bottom portion 50A of the housing 50. Such a design may be useful in cases where rivets (e.g., rivet 84) do not extend through the stack of tabs and spacers of the anode and cathode stacks. For examples including rivets in one or both of the anode and cathode stacks, the spacer 114 may include another type of registration feature (e.g., a groove into the spacer 114 instead of a protrusion such as the posts 122A and 122B) than that shown in fig. 11, e.g., so that both the rivets and the spacer may prevent fan out of the stack of tabs during the operational life of the cell.

Fig. 12 is a conceptual diagram illustrating another example battery 126. The battery 126 may be similar to other battery assemblies described herein and similar features are similarly numbered. Fig. 12 illustrates an example in which a gasket 114 is employed between the inner surface of the top portion 50B of the housing 50 and the cathode and anode stacks 68, 66. As described above, contact between the top surface of the gasket 114 and the inner surface of the top portion 50B of the housing 50 may apply a compressive force (represented by the two arrows in fig. 12) or otherwise prevent the cathode stack 68 and the anode stack 66 from fanning out. For example, when the top portion 50B is attached to the bottom portion 50A of the housing 50, such as via a weld around the perimeter of the housing 50 at the interface between the top portion 50B and the bottom portion 50B, a compressive force may be applied by the gasket 114 to the stack of tabs 78 of the cathode 68 and the stack of tabs 76 of the anode 66 between the top portion 50B and the bottom portion 50A. In this manner, the compressive force may prevent the stack of tabs 78 of the cathode 68 and the stack of tabs 76 of the anode 66 from "fanning out," for example, during the operational life of the cell 126. In some examples, the gasket 114 may be configured such that the compressive force is applied once the cathode stack 68 and/or the anode stack 66 begin to fan out, such as at some point during the operational life of the cell 126.

Various examples have been described in this disclosure. These and other examples are within the scope of the following claims and appended claims.

A battery assembly for an implantable medical device, the assembly comprising: an electrode stack comprising a plurality of electrode plates, wherein the plurality of electrode plates comprises a first electrode plate comprising a first tab extending from the first electrode plate and a second electrode plate comprising a second tab extending from the second electrode plate; a spacer between the first and second tabs; and

a rivet extending through the first tab, the second tab, and the spacer, wherein the rivet is configured to mechanically attach the first tab, the second tab, and the spacer to one another.

The assembly of clause 2. the assembly of clause 1, wherein the rivet includes a flared head, a deformed tail, and a rivet body extending between the flared head and the deformed tail, and wherein the flared head is on a first side of the electrode stack and the deformed tail is on a second side of the electrode stack.

Item 3. the assembly of item 1, wherein the spacer comprises a first spacer, wherein the plurality of electrode plates comprises a third electrode plate comprising a third tab extending from the third electrode plate, wherein the second tab is between the first tab and the third tab, the assembly further comprising a second spacer between the third tab and the second tab, wherein the rivet extends through the third tab and the second spacer.

Clause 4. the assembly of clause 3, wherein the first spacer has a first thickness that is different than a second thickness of the second spacer.

The assembly of clause 5, the assembly of clause 1, wherein the spacer comprises a first spacer, the assembly further comprising a second spacer between the first tab and a second tab adjacent the first spacer.

The assembly of clause 6. the assembly of clause 1, further comprising a weld on the electrode stack extending from the first tab across the spacer to the second tab.

The assembly of clause 7, the assembly of clause 1, wherein the first electrode plate is a top plate of the plurality of electrode plates of the electrode stack, the assembly further comprising: a battery case surrounding the electrode stack; and a gasket located on top of the first tab between the first tab and an inner surface of the battery case.

Clause 8. the assembly of clause 7, wherein the first electrode plate comprises a first anode plate and the second electrode plate comprises a second anode plate, wherein the plurality of electrode plates further comprises a first cathode plate and a second cathode plate, the first cathode plate comprising a third tab extending from the first cathode plate, the second cathode plate comprising a fourth tab extending from the second cathode plate, wherein the third tab and the second tab are stacked adjacent to the first tab and the second tab, and wherein a top spacer spans a gap between the first tab and the third tab.

Clause 9. the combination of clause 7, wherein the top spacer is formed of an electrically insulating material to electrically isolate the first tab from the battery housing.

The article 10. a battery assembly for an implantable medical device, the assembly comprising: a battery case; an electrode stack comprising a plurality of electrode plates, wherein the plurality of electrode plates includes a first tab stack of anode tabs extending from anode plates of the electrode stack and a second tab stack of cathode tabs extending from cathode plates of the electrode stack, wherein the first tab stack is adjacent to the second tab stack and a gap separates the first tab stack from the second tab stack; and a spacer on a top tab of at least one of the first or second stack of tabs, wherein the spacer is between the battery case and at least one of the first tabs of the first or second stack of tabs.

Clause 11 the battery assembly of clause 10, wherein the spacer spans the gap between the first and second stacks of tabs.

Item 12 the assembly of item 10, wherein the gasket is formed of an electrically insulating material to electrically isolate the first and second stacks of tabs from the battery case.

Bar 13 the assembly of bar 10, wherein the battery housing is configured to apply a compressive force to the first stack of tabs and the second stack of tabs via the gasket.

Item 14. the assembly of item 10, wherein the second stack of tabs comprises a first cathode tab and a second cathode tab, the assembly further comprising a first spacer located between the first cathode tab and the second cathode tab.

Item 15 the assembly of item 14, further comprising a second spacer between the first cathode tab and the second cathode tab, and wherein the first spacer has a thickness that is less than a thickness of the second spacer.

Item 16 the assembly of item 14, wherein the second stack of tabs comprises a third cathode tab, the assembly further comprising a second spacer between the second cathode tab and the third cathode tab.

The assembly of clause 17, the assembly of clause 16, wherein the first spacer has a thickness that is less than a thickness of the second spacer.

Item 18. the assembly of item 10, further comprising a rivet extending through the second stack of tabs to mechanically attach the individual tabs of the second stack of tabs to each other.

Item 19. the combination of item 18, wherein the rivet comprises a flared head, a deformed tail, and a rivet body extending between the flared head and the deformed tail, and wherein the flared head is on a first side of the second stack of lugs and the deformed tail is on a second side of the second stack of lugs.

Item 20. the assembly of item 10, further comprising a weldment on the second stack of lugs extending from a top lug of the second stack of lugs to a bottom lug of the second stack of lugs.

Bar 21. the assembly of bar 10, wherein the weldment extends to the shim.

Item 22. the assembly of item 10, wherein the shim comprises a first protrusion configured to mate with an aperture in the first stack of wafers and a second protrusion configured to mate with an aperture in the second stack of wafers.

The assembly of clause 10, wherein the gasket is configured to transmit a compressive force from the battery housing to the at least one of the first stack of tabs or the second stack of tabs.

An implantable medical device, comprising: an outer housing;

a processing circuit; and the battery assembly of clause 1, within the outer housing, wherein the processing circuitry is configured to control delivery of electrical therapy from the implantable medical device to a patient using power supplied by the battery assembly.

An implantable medical device, comprising: an outer housing;

a processing circuit; and the battery assembly of clause 10, within the outer housing, wherein the processing circuitry is configured to control delivery of electrical therapy from the implantable medical device to a patient using power supplied by the battery assembly.

A method comprising any one of clauses 1-25.