Battery module with a hybrid monitoring circuit structure

Abstract

A battery module having a plurality of battery cells. A battery interconnect system connects the terminals of the battery cells to form a circuit arrangement. A hybrid monitoring circuit structure is connected to the battery interconnect system and one or more sensors are configured to collect and transmit operating data for monitoring operation of the battery module. The hybrid monitoring circuit structure includes a main circuit structure secured to a terminal connector and one or more branch circuit structures. The main circuit structure includes a conductive main circuit disposed on a main insulating layer, and each branch circuit structure includes a conductive branch circuit disposed on a branch insulating layer. The main circuit and the branch circuit(s) are connected together by one or more conductive joints. Each branch circuit is printed with a conductive ink that is inkjet printed on the branch insulating layer.

Description

BATTERY MODULE WITH A HYBRID MONITORING CIRCUIT STRUCTURECROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No.: 63 / 675,026 filed on 24 July 2024, and U.S.Provisional Patent Application No.: 63 / 712,859 filed on 28 October 2024, which are both herein incorporated by reference.BACKGROUND

[0002] A battery module typically includes a plurality of battery cells mounted in a housing and connected together so as to have a predetermined capacity and voltage output. Such a battery module is widely used as a power source for vehicles and various types of other devices and equipment. A plurality of the battery modules is often connected together to form a battery system, also having a predetermined capacity and voltage output. In a particular battery module, the battery cells may be connected together in parallel and / or in series to provide a desired capacity and voltage output. Often, the battery cells are arranged closely together and are individually fused to help avoid damage or excessive heating of adjacent battery cells and / or other components. In addition, the battery cells may be monitored to quickly detect problems, such as short circuits. Parameters that may be monitored include voltage, current and temperature.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:

[0004] Fig. 1 shows a schematic view of a battery module, in accordance with some embodiments;

[0005] Fig. 2 shows a housing of the battery module, in accordance with some embodiments;

[0006] Fig. 3 shows a plan view of the housing of Fig. 2 in which a lid of the housing and other components of the battery module have been removed to show a batteryinterconnect system, in accordance with some embodiments;

[0007] Fig. 4 shows a schematic view of a battery module having a battery interconnect system and a hybrid monitoring circuit structure, in accordance with some embodiments;

[0008] Fig. 5 shows a perspective view of a cylindrical battery cell, in accordance with some embodiments;

[0009] Fig. 6 shows a schematic view of a hybrid monitoring circuit structure, in accordance with some embodiments;

[0010] Fig. 7 shows sectional views of portions of a main circuit structure and a branch circuit structure of a monitoring circuit, in accordance with some embodiments;

[0011] Fig. 8 shows a sectional view of a portion of the main circuit structure connected to a portion of the branch circuit structure by a first joint comprising a ramp, in accordance with some embodiments;

[0012] Fig. 9 shows a sectional view of a portion of the main circuit structure connected to a portion of the branch circuit structure by a second joint, in accordance with some embodiments; and

[0013] Fig. 10 shows a schematic view of end portions of conductive lines configured to form an interconnected joint;

[0014] Fig. 11 shows a plan view of a hybrid monitoring circuit structure, in accordance with some embodiments, wherein insulating layers are transparent other than their outlines;

[0015] Fig. 12 shows a top, right end perspective view of conductive circuits of a portion of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0016] Fig. 13 shows a close-up perspective view of a portion of the conductive circuits of Fig. 12, wherein the insulating layers are removed;

[0017] Fig. 14 shows a sectional view of the right end of a portion of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layer are shown in solid form;

[0018] Fig. 15 shows a top perspective view of conductive joints of the hybridmonitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0019] Fig. 16 shows a perspective view of a ramp of the conductive joints of Fig. 15;

[0020] Fig. 17 shows a plan view of a printed temperature sensor of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0021] Fig. 18 shows a top perspective view of conductive joints of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0022] Fig. 19 shows a top perspective view of a ramp of the conductive joints of Fig. 18;

[0023] Fig. 20 shows a top perspective view of a thermistor of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0024] Fig. 21 shows a top plan view of conductive joints of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0025] Fig. 22 shows a top plan view of portions of the conductive circuit of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0026] Fig . 23 shows a top perspective view of the portions of the conductive circuit shown in Fig. 22, wherein the insulating layers are transparent other than their outlines;

[0027] Fig. 24 shows a bottom perspective view of conductive joints of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0028] Fig. 25 shows a sectional view of a portion of the conductive joints of Fig. 24, wherein the insulating layers are shown in solid form;

[0029] Fig. 26 shows a bottom perspective view of a ramp of the conductive joints of Fig. 24;

[0030] Fig. 27 shows a top perspective view of a portion of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are transparent other than their outlines;

[0031] Fig. 28 show a top perspective view of conductive joints of the portion of the hybrid monitoring circuit structure shown in Fig. 27;

[0032] Fig. 29 shows a bottom perspective view of conductive joints of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0033] Figs 30 and 31 show perspective views of conductive joints of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are removed;

[0034] Fig. 32 shows a top perspective view of portions of the hybrid monitoring circuit structure of Fig. 11 , wherein the insulating layers are transparent other than their outlines;

[0035] Fig. 33 shows a top plan view of an intermediate monitoring circuit structure, in accordance with some embodiments, wherein a top insulating layer has been removed; and

[0036] Fig. 34 shows a top plan view of a final hybrid monitoring circuit structure formed from the intermediate monitoring circuit structure of Fig. 33DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0037] It should be noted that in the detailed descriptions that follow, identical components have the same reference numerals, regardless of whether they are shown in different embodiments of the present disclosure. It should also be noted that for purposes of clarity and conciseness, the drawings may not necessarily be to scale, and certain features of the disclosure may be shown in somewhat schematic form.

[0038] Spatially relative terms, such as "top", "bottom", "lower", "above", "upper", and the like, are used herein merely for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as they are illustrated in (a) drawing figure(s) being referred to. It will be understood that the spatially relative terms are not meant to be limiting and are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings.

[0039] The present disclosure is directed to a battery module and method of forming the same. The battery module may be for use in a battery system for a vehicle, such as an electric vehicle ("EV") or a hybrid electric vehicle ("HEV"). In some embodiments, a battery module 10 may generally include a housing 12 enclosing a plurality of battery cells 14, a battery interconnect system (BIS) 16 and a hybrid monitoring circuit structure 18, as is shown in schematic form in Fig. 1.

[0040] An example of a housing 12 that may be used is shown in Figs. 2 and 3. The housing 12 may include a body 20 and a lid 22, one or both of which may be formed from a thermoplastic resin. The thermoplastic resin may have good electrical insulating properties and is heat resistant. The body 20 and the lid 22 may each be constructed to have latch structures 24 that secure the lid 22 to the body 20 to form a seal therebetween, whereby an interior holding space 26 of the body 20 is sealed from the outside environment. The body 20 includes a plurality of exterior walls 28. An opposing pair of the exterior walls 28 may include projections for receipt in mounting rails, which are used to mount a plurality of battery modules to a structure, such as a chassis of a vehicle. The housing 12 may accomodate a male power connector 30 that protrudes from a side exterior wall 28 and a female power connector (not shown) that is accessible through an opening in an opposing exterior wall 28.

[0041] The battery cells 14 may be rechargeable lithium ion (LI-ION) batteries or other type of rechargeable battery. The battery cells 14 may be cylindrical cells, prismatic cells or pouch cells. Cylindrical cells have a rigid housing that is cylindrical, while prismatic cells have a rigid housing that is prismatic, typically in the form of a rectangular prism. Cylindrical cells may have terminals at their opposing ends or at only one end. Prismatic cells typically have spaced-apart terminals at one end. Pouch cells do not have a rigid housing and, instead, have a sealed flexible foil as a cell container. The terminals of pouch cells are typically located along one sealed edge.

[0042] An example of a prismatic embodiment of the battery cell 14 is shown in Fig. 4 and may be designated by the reference numeral 114. Each of the battery cells 114 has a housing or case that is a rectangular cuboid. Terminals 132, 134 protrude from a top wall of the case. The terminals 132, 134 are spaced-apart, such that the terminal 132 is disposed toward a first end of the case 130 and the terminal 134 is disposed toward a second end of the case 130. One of the terminals 132, 134 is positive and one of the terminals 132, 134 is negative. The battery cells 114 are part of a battery module 100.

[0043] An example of a cylindrical embodiment of the battery cell 14 is shown in Fig.5 and may be designated by the reference numeral 214. The battery cell 214 may be an 18650 type LI-ION battery, having a cylindrical shape with a diameter of about 18 mm and a length of about 65 mm. In some embodiments, each battery cell 214 may have a cylindrical case 230 with first and second ends. A center positive terminal 232 and a surrounding annular negative terminal 234 are located at the first end. Once again, other rechargeable battery form factors may be used, as well as different chemistries.

[0044] The BIS 16 may have one or more layers of conductor structures 50 that connect together the battery cells 14 in series, parallel and / or combinations thereof. For example, the BIS 16 may form a circuit arrangement in which a plurality of groups of battery cells 14 are electrically connected in series, wherein in each group, the battery cells 14 are electrically connected in parallel.

[0045] In some embodiments, the BIS 16 may have two or more layers of interconnect panels, wherein each interconnect panel is formed in a stamping operation from a single sheet of conductive metal. Each interconnect panel may be a single, unitary or monolithic structure, or may comprise a plurality of sections, which are separated from each other by gaps or spaces. A unitary interconnect panel would comprise a single conductor structure 50, whereas a sectioned interconnect panel would comprise a plurality of conductor structures 50, with each section being a conductor structure 50. Thus, in a BIS 16 having layers of interconnect panels, each layer may comprise one or more conductor structures 50.

[0046] The interconnect panels may each include positive and negative contacts, which are disposed in and / or extend through openings in the interconnect panels to connect to terminals of the battery cells 14. One or more insulating layers may be disposed between the two interconnect panels, and one or more insulating layers may be disposed between the battery cells 14 and a bottom conductor structure 50. The interconnect panels and insulating layers may be supported on a tray formed from a polymer, such as polycarbonate.

[0047] In other embodiments, the BIS 16 may have two or more layers of conductorstructures 50, with a plurality of conductor structures 50 being disposed in each layer. The conductor structures 50 may be busbar type of structures, each of which is configured for connection to a plurality of the battery cells 14. One or more insulating layers may be disposed between the two layers of conductor structures 50, and one or more insulating layers may be disposed between the battery cells 14 and a bottom layer of the conductor structures 50.

[0048] In still other embodiments, the BIS 16 may have a single layer of conductor structures 50, each of which is configured for connection to a plurality of the battery cells 14. One or more insulating layers may be disposed between the battery cells 14 and the conductor structures 50.

[0049] An example of a single layer embodiment of the BIS 16 is shown in Fig. 4 and may be designated by the reference numeral 116. The BIS 116 has busbars 150 that are an embodiment of the conductor structures 50. The busbars 150 interconnect the terminals 132, 134 of the battery cells 114 to form a series circuit or a parallel circuit, depending on the arrangement of the battery cells 114. For example, the battery cells 114 may be arranged in a stack in which adjacent battery cells 114 have their positive terminals connected together (and their negative terminals connected together) or have their positive terminals connected to the negative terminals of the other battery cell 114. In the first arrangement (the positive terminals are connected together, etc.), the arrangement would form a parallel circuit, and in the second arrangement, the (positive terminals are connected to the negative terminals), the arrangement would form a series circuit. The arrangement shown in Fig. 4 would form a series circuit.

[0050] Another example of a single layer embodiment of the BIS 16 is shown in Fig.3 and is designated by the reference numeral 216. The BIS 216 has conductor structures 250 that are an embodiment of the conductor structures 50 and are disposed in a single layer. Each conductor structure 250 may be unitary or monolithic and may be formed (such as by stamping) from a conductive metal, such as copper or a copper alloy. In addition, each conductor structure 250 may have an irregular shape with positive tabs 252 and / or negative tabs 254 joined to and extending from arms. Theconductor structures 250 are connected (such as through laser welding) to the battery cells 214 to form a desired circuit arrangement for the battery module 10. The circuit arrangement may have the battery cells 214 connected together in series, parallel and / or combinations thereof. For example, the circuit arrangement may have a plurality of the groups of battery cells 214 electrically connected in series, wherein in each group, the battery cells 214 are electrically connected in parallel.

[0051] A first or positive conductor structure 250a has only positive tabs 252 connected to positive terminals of battery cells 214; a last or negative conductor structure 250h has only negative tabs 254 connected to negative terminals of battery cells 214; and other ones of the conductor structures 250 each have positive tabs 252 connected to positive terminals of battery cells 214 and negative tabs 254 connected to negative terminals of battery cells 214. The positive conductor structure 250a is the most positive conductor structure 250 and has a positive terminal 260. A negative conductor structure 250h is the most negative conductor structure 250 and has a negative terminal 262. Current flows from the positive terminal 260, up through a first plurality of groups of battery cells 214, across a bridging group of battery cells 214 and thence down through a second plurality of groups of battery cells 214 to the negative terminal 262. In this manner, current flows in an approximately U-shaped path from the positive terminal 260 to the negative terminal 262.

[0052] Referring now to Figs. 6 and 7, the hybrid monitoring circuit structure 18 includes a main circuit structure 70 connected to one or more branch circuit structures 72. While the main circuit structure 70 and the branch circuit structures 72 may share some components, the main circuit structure 70 overall has a different construction than the branch circuit structures 72. In particular, a conductive main circuit 74 of the main circuit structure 70 has a different construction than a conductive branch circuit 82 of the branch circuit structure 72. The main circuit structure 70 is electrically and physically connected to a terminal connector 60 configured for connection to a corresponding terminal connector in a battery monitoring module (BMM) 62. The main circuit structure 70 may have its main circuit 74 disposed in one or more layers, which is / are disposedbetween insulating layers 76. An insulating layer 76 may also be disposed between layers of the main circuit 74. The main circuit 74 may comprise aluminum, titanium, nickel, copper, steel, and / or alloys comprising these metals. The insulating layers 76 may comprise polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), ethyl vinyl acetate (EVA), polyethylene (PE), polypropylene (PP), polyvinyl fluoride (PVF), polyamide (PA), and polyvinyl butyral (PVB), an aramid polymer (such NOMEX), cloth, paper, or any other electrically insulating material. The insulating layers 76 may have different compositions, respectively, and may be laminated or adhesively bonded to, or otherwise disposed over, the conductor circuit 74. Ends of the main circuit 74 may be uncovered, as shown.

[0053] The main circuit 74 is for transmitting data to the BMM 62 for physical properties of the battery module 10, such as voltages, currents and temperatures. The main circuit 74 may have conductive lines that include voltage detection lines, current detection lines, sensor detection lines and other types of conductive lines. These conductive lines may have a thickness greater than 10 pm, such as from about 10 pm to about 50 pm. The voltage detection lines may be connected to the conductor structures 50 of the BIS 16 to convey voltage data of individual and / or groups of battery cells 14 to the BMM 62. The current detection lines may be connected to the conductor structures 50 of the BIS 16 to convey current data of individual and / or groups of battery cells 14 to the BMM 62. The sensor detection lines may be connected to sensors (such as temperature sensors and / or humidity sensors) that are strategically placed within the battery module 10 to convey sensor data to the BMM 62.

[0054] The voltage detection lines may be connected directly to the conductor structures 50 or may be indirectly connected to the conductor structures 50 through conductive lines in the branch circuit structures 72. Similarly, the current detection lines may be connected directly to the conductor structures 50 or may be indirectly connected to the conductor structures 50 through conductive lines in the branch circuit structures 72. The sensor detection lines are indirectly connected to the sensors throughconductive lines in the branch circuit structures 72, as described more fully below.

[0055] In some embodiments, the main circuit structure 70 may be a flexible die cut circuit (FDC) in which the main circuit 74 is formed using a rotating die to cut the main circuit 74 (e.g., the voltage detection lines, the current detection lines and the sensor detection lines) from a sheet of a conductive metal, such as copper or a copper alloy. The conductive metal sheet may be part of a continuous composite sheet comprising the conductive metal sheet bonded or laminated to an insulating sheet (which may form one of the insulating layers 76). The insulating sheet may comprise PI, PEN, PET, PMMA, EVA, PE, PP, PVF, PA, PVB, an aramid polymer (such NOMEX), cloth, or paper. In some embodiments, the insulating sheet may be PI.

[0056] The composite sheet may be fed through the rotating die in a reel-to-reel process in which the rotating die kiss cuts the composite sheet to cut the conductive metal sheet and leave the insulating sheet intact and untouched. Later the cut composite sheet may be unwound from the take-up reel and cut to form a plurality of main circuits 70.

[0057] In some embodiments, the main circuit structure 70 may be a flexible printed circuit (FPC) in which the main circuit 74 is formed through chemical etching, electrochemical etching, laser cutting, and / or laser ablation. In these processes, a conductive metal layer may be deposited on, or adhesive bonded or laminated to an insulating substrate (which may form one of the insulating layers 76) to form a multilayer composite. The conductive metal layer may comprise aluminum, titanium, nickel, copper, steel, and / or alloys comprising these metals. In some embodiments, the conductive metal layer may be copper or a copper alloy. The insulating substrate may comprise PI, PEN, PET, PMMA, EVA, PE, PP, PVF, PA, PVB, an aramid polymer (such NOMEX), cloth or paper. In some embodiments, the insulating substrate may be PI.

[0058] Chemical etching is a multi-stage batch process in which a protective mask is disposed over the conductive metal layer of the multilayer composite to cover retained portions of the conductive metal layer. The retained portions comprise the main circuit 74, i.e., the voltage detection lines, the current detection lines, the sensor detectionlines and other conductive lines. The masked multilayer composite is then submerged in an etching solution, which may by way of example be a ferric chloride solution, an ammonium persulfate solution, or a hydrogen peroxide solution. The etching solution reacts with the unmasked (exposed) portions of the conductive metal layer, thereby removing them and leaving the masked portions. The protective mask is then removed from the multilayer composite, such by using a solvent, leaving the retained portions of the conductive metal layer on top of the insulating substrate, i.e., a main circuit structure 70.

[0059] An electrochemical etching process is a variation of chemical etching process described above in which the conductive metal layer is connected to a positive terminal of a DC power source and the masked multilayer composite is submerged in an electrolyte solution, which contains an electrode connected to a negative terminal of the DC power source. The applied voltage supplied by the DC power source dissolves the metal in the unmasked (exposed) portions of the conductive metal layer, thereby removing them and leaving the masked portions.

[0060] In laser cutting, a laser beam from a laser cutting head may be moved along a cutting path that outlines the main circuit 74 in the conductive metal layer of the multilayer composite. The laser beam causes metal in its path to melt and vaporize, which may be carried away by gas flowing around the laser cutting head. The laser beam may be controlled to form kiss cuts in the multilayer composite, i.e., to leave the underlying insulating substrate (which may form the insulating layer 76) uncut and otherwise untouched. Laser ablation may be used to remove larger portions or areas of the conductive metal layer around the main circuit 74.

[0061] In some embodiments, the main circuit structure 70 may be a flexible flat cable (FFC) in which the conductor circuit 74 comprises a plurality of thin rectangular copper conductors laminated or adhesive bonded between two insulation layers. The insulation layers may comprise PI, PEN, PET, PMMA, EVA, PE, PP, PVF, PA, PVB, an aramid polymer (such NOMEX), cloth or paper. In some embodiments, the insulating layers may be PI. Ends of the copper conductors may be uncovered and tin plated. Astiffener may be bonded to one or both ends of the cable to provide mechanical stability for the copper conductor during connection and disconnection.

[0062] Each branch circuit structure 72 may have its branch circuit 82 disposed in one or more layers, which is / are disposed between insulating layers 84. An insulating layer 84 may also be disposed between layers of the branch circuit 82. The insulating layers 84 may be separate from or comprise portions of the insulating layers 76 of the main circuit structure 70. Each branch circuit 82 is printed with conductive ink on an insulating layer 84 and includes one or more conductive lines, which may have a thickness of from about 1 pm to about 10 pm, more usually from about 2 pm to about 4 pm. As such, the branch circuit 82 has a thickness that is less than the thickness of the main circuit 74. In some embodiments, the main circuit 74 is at least twice as thick as the branch circuit 82, and in some embodiments, the main circuit 74 is more than five times as thick as the branch circuit 82. The conductive ink may comprise nanoparticles of copper, silver, gold or a combination thereof, or graphene or carbon nanotubes, together with organic dispersants and solvents. The insulating layers 84 may comprise PI, PEN, PET, PMMA, EVA, PE, PP, PVF, PA, PVB, an aramid polymer (such NOMEX), cloth or paper. In some embodiments, the insulating layers 84 may be PET. The insulating layers 84 may have different compositions, respectively, and may be laminated or adhesively bonded to, or otherwise disposed over, the branch circuit 82.Ends of the branch circuit 82 may be uncovered, as shown. Each branch circuit 82 may include electronic components, such as resistors, thermistors, humidity sensors and fuses, which are also printed using a conductive ink. The conductive ink used to form electronic components may be the same or different from the conductive ink used to form the conductive lines, which connect to them.

[0063] Each branch circuit 82 may be printed on an insulating layer 84 or other substrate using an inkjet printer controlled by a processor executing program instruction stored in associated memory. The program instructions may be for printing a specific conductive circuit. During printing, the insulating layer(s) 84 is / are held on a printing platform. Afterwards, the printed branch circuit 82 is sintered to remove the organicdispersants and solvents, which increases the metal density of the branch circuit 82, thereby increasing its conductivity. The printing of the branch circuit 82 on the insulating layer 84 may be performed in a reel-to-reel process in which the printing platform is disposed between the reels.

[0064] At least a portion of the printing of the branch circuit 82 of a branch circuit structure 72 may be performed when the branch circuit structure 72 is connected to or being connected to the main circuit structure 70. In addition, the printing of the branch circuit 82 of a branch circuit structure 72 may be performed when the main circuit structure 70 and / or the branch circuit structure(s) 72 are connected to or being connected to the BIS 16 and / or the battery cells 14.

[0065] The branch circuit(s) 82 of the branch circuit structure(s) 72 may be electrically joined to the main circuit 74 of the main circuit structure 70 using different joining types. In some embodiments, the main circuit 74 may be joined to the branch circuit(s) 82, with a conductive glue, such as conductive polyurethane glue. In other embodiments, the main circuit 74 may be joined to the branch circuit(s) 82, with solder, such as a low-temperature solder. In such solder embodiments, the insulating layer 84 may comprise high temperature PET or NOMEX. The soldering of the circuits may be performed at a temperature of about 65°C. In still other embodiments, the main circuit 74 may be joined to the branch circuit(s) 82 using copper pads or mechanical crimps.

[0066] The main circuit structure 70 and the branch circuit structure(s) 72 may be connected together using different types of conductive joints. In some embodiments, conductive joints with ramps may be used to connect together conductive lines of the main circuit structure 70 and the branch circuit structure(s) 72. For example, Fig. 8 shows a sectional view of a portion of the main circuit structure 70 connected to a portion of a branch circuit structure 72 by a joint 87 comprising a ramp 88. The insulating layer 76 of the main circuit structure 70 may be coplanar with and abut an insulating layer 84 of the branch circuit structure 72. A conductive line 86 of the main circuit 74 of the main circuit structure 70 is disposed over the insulating layer 76. Proximate to an end of the conductive line 86, the ramp 88 may be formed on theinsulating layer 84 of the branch circuit structure 72. The ramp 88 may have the configuration of a right triangle, with a first side of the ramp 88 disposed at a right angle to a second side of the ramp 88. The first side of the ramp 88 abuts the conductive line 86 of the main circuit structure 70. A sloping side (hypotenuse) of the ramp 88 slopes upwardly from the direction of the branch circuit structure 72 toward the main circuit structure 70 so that at the juncture with the main circuit structure 70, a top of the first side of the ramp 88 is at least mostly flush with a top surface of the conductive line 86 of the main circuit structure 70. The ramp 88 may be formed of a non-conductive ink using the inkjet printer. After the ramp 88 is formed, at least a portion of a conductive line 90 of the branch circuit 82 of the branch circuit structure 72 may be printed over the sloping side of the ramp 88 and over the conductive line 86 of the main circuit structure 70. After the conductive line 90 is fully printed, an insulating layer 92 may be adhesive bonded, laminated or otherwise disposed over the conductive lines 86, 90 and any other exposed conductive lines. The insulating layer 92 may be separate from or comprise a portion of an insulating layer 76 of the main circuit structure 70 and / or a portion of an insulating layer 84 of the branch circuit structure 72.

[0067] In some embodiments, the branch circuit structure(s) 72 may utilize a portion of an insulating layer 76 of the main circuit structure 70 as at least a portion of its insulating layer. For example, the conductive line 86 of the main circuit structure 70 may stop short of an end portion of the insulating layer 76. The ramp 88 may be printed on the insulating layer 76 in this end portion. The conductive line 90 of the branch circuit structure 72 may then be printed over the end portion of the insulating layer 76, as well as the ramp 88 and a portion of the conductive line 86 of the main circuit structure 70.

[0068] In some embodiments, a base one of the insulating layers 76 of the main circuit structure 70 may have a different thickness than a base one of the insulating layers 84 of a branch circuit structure 72. For example, Fig. 9 shows a sectional view of a portion of the main circuit structure 70 connected to a portion of a branch circuit structure 72 by a conductive joint 89, wherein a base insulating layer 84 of the branch circuit structure 72 is thicker than a base insulating layer 76 of the main circuit structure70 by an amount that is about equal to the thickness of the conductive line 86 of the main circuit structure 70. In this manner, the top surface of the conductive line 86 of the main circuit structure 70 is coplanar or flush with the top surface of the base insulating layer 84 of the branch circuit structure 72. A conductive line 90 of the branch circuit structure 72 may be printed over the insulating layer 84 of the branch circuit structure 72 and over at least a portion of the conductive line 86 of the main circuit structure 70. After the conductive line 90 is fully printed, an insulating layer 92 may be disposed over the conductive lines 86, 90 and any other exposed conductive lines. The insulating layer 92 may be hot laminated over the conductive line 90.

[0069] In some embodiments, conductive lines of the main circuit structure 70 and the branch circuit structures 72 that are to be connected together may have end portions that are tortuous and configured to fit together to form an interconnected joint. Such an interconnected joint has an increased joining area and is more robust than more simple joints. An example of end portions of conductive lines configured to form such an interconnected joint is shown in Fig. 10. An end portion 96 of a conductive line of the main circuit 74 of the main circuit structure 70 is shown spaced from an end portion 98 of a conductive line of the branch circuit 82 of the branch circuit structure 72. The end portions 96, 98 are tortuous and configured to fit together to form an interconnected joint.

[0070] Referring back to Fig. 4, the battery module 100 includes an embodiment of the hybrid monitoring circuit structure 18 that may be designated by the reference numeral 118. The hybrid monitoring circuit structure 118 includes an embodiment of the main circuit structure 70, designated by the reference numeral 170, and embodiments of the branch circuit structures 72, designated by the reference numeral 172. The main circuit structure 170 includes a plurality of voltage detection lines 180, portion(s) of one or more current detection lines 182 and portion(s) of one or more sensor detection lines 184. The voltage detection lines 180, the current detection line(s) 182 and the sensor detection line(s) 184 are connected to the terminal connector 60.

[0071] In some embodiments, all of the voltage detection lines 180 may be locatedsolely in the main circuit structure 170 (except for their end connections to the busbars 150 and the terminal connector 60), as is shown in Fig. 4. The voltage detection lines 180 are physically and electrically connected to the busbars 150 that interconnect the battery cells 114, as described above. The voltage detection lines 180 may be connected to the busbars 150 by soldering, conductive glue or mechanical crimping. The voltages between the terminals 132, 134 of the battery cells 114 of connected battery cells 114 are transmitted to the BMM 62 through the terminal connector 60.

[0072] In some embodiments, a first section of one or more voltage detection lines 180 may be is located in the main circuit structure 170 and a second section of such voltage detection line(s) 180 may be located in a branch circuit structure 172. The first and second sections of the voltage detection line(s) 182 may be connected together using ramps 88 and / or insulating layers of different thicknesses, as described above.

[0073] A first section of each current detection line 182 is located in the main circuit structure 170 and a second section of each current detection line 182 is located in a branch circuit structure 172. The first and second sections of the current detection line 182 may be connected together using conductive joints comprising ramps 88 and / or insulating layers of different thicknesses, as described above. The conductive joints between the first and second sections of the current detection line 182 may be formed using soldering, conducive glue or mechanical crimping, as described above. Each second section of a current detection line 182 may include a shunt resistor 186 printed with a conductive ink, which may be the same or different from the conductive ink used to print the current detection lines 182. The shunt resistor 186 causes a voltage drop that may be used to calculate current flow. Reduced voltages caused by the voltage drops are transmitted to the BMM 62 through the terminal connector 60.

[0074] A first section of each sensor detection line 184 is located in the main circuit structure 170 and a second section of each sensor detection line 184 is located in a branch circuit structure 172. The first and second sections of each sensor detection line 184 may be connected together using conductive joints comprising ramps 88 and / or insulating layers of different thicknesses, as described above. The conductive jointsbetween the first and second sections of each sensor detection line 184 may be formed using soldering, conducive glue or mechanical crimping, as described above. Each second section of a sensor detection line 184 may be electrically connected to a sensor 188, such as an NTC (Negative Temperature Coefficient) thermistor, which may be printed using the same or different inks. Alternately, the sensor 188 may be soldered or otherwise secured to a copper pad that is electrically connected to the sensor detection line 184.

[0075] Referring now to Fig. 11 , a hybrid monitoring circuit structure 300 is shown for use in a battery module that may have a BIS with two or more layers of interconnect panels, wherein each interconnect panel has a plurality of sections, which are separated from each other by gaps or spaces. The hybrid monitoring circuit structure 300 is an embodiment of the monitoring circuit structure 18 and includes an embodiment of the main circuit structure 70, designated by the reference numeral 302, and embodiments of the branch circuit structures 72, designated by the reference numerals 304, 306, 308, 310, 312. For purposes of providing better clarity, portions of the hybrid monitoring circuit structure 300 have been removed and are not shown or described.

[0076] The main circuit structure 302 is elongated and extends between first and second ends. The main circuit structure 302 includes a conductive main circuit 316. The main circuit 316 may be disposed in one or more layers, which is / are disposed between insulating layers 318. An insulating layer 318 may also be disposed between layers of the main circuit 316. In some embodiments, there may be three insulating layers 318: a top insulating layer 318a, a middle insulating layer 318b and a bottom insulating layer 318c, as shown in Figs. 14, 25. In these embodiments, the main circuit 316 is formed on the middle insulating layer 318b. In some embodiments, the main circuit 316 may comprise copper or a copper alloy and be formed through chemical etching or electrochemical etching, and the insulating layers 318 may comprise PI. In other embodiments, the main circuit 316 may have a different composition and be formed by other processes, and the insulating layers 318 may have a different composition.

[0077] In some embodiments, the branch circuit structures 304, 306, 308, 310, 312may all utilize the same insulating layers 318 as the main circuit structure 302. In these embodiments, although the insulating layers 318 are the same, the insulating layers 318 in the main circuit structure 302 may be considered as main insulating layers and the insulating layers 318 in the branch circuit structures may be considered branch insulating layers. Although they may have the same insulating layers 318, the branch circuit structures 304, 306, 308, 310, 312 have conductive circuits that are different from those of the main circuit structure 302. More specifically, the conductive circuits of the branch circuit structures 304, 306, 308, 310, 312 comprise conductive lines that are printed with a conductive ink that may comprise nanoparticles of copper, silver, gold or a combination thereof, or graphene or carbon nanotubes, together with organic dispersants and solvents. The conductive lines may be printed using an inkjet printer. After the conductive lines are printed, they may be cured, such as by laser sintering, oven sintering, electrical sintering or chemical sintering. The conductive lines of the branch circuit structures 304, 306, 308, 310, 312 formed by printing may be secured to the conductive lines of the main circuit 316 formed by etching, etc. using conductive glue and / or mechanical crimping.

[0078] The conductive circuits of the branch circuit structures 304, 306, 308, 310, 312 include devices and / or structures for obtaining information about the operation of battery cells of the battery module, which is then transmitted to a battery monitoring module, such as the BMM 62. As will be described more fully below, the branch circuit structure 304 may include a temperature sensor 346; the branch circuit structure 306 may include an NTC thermistor 380; the branch circuit 308 may include a voltage tab connector 400; the branch circuit 310 may include a voltage tab connector 402; and the branch circuit 312 may include an NTC thermistor 468 and a pair of leg structures 483, 485 that include voltage tab connectors 500, 502.

[0079] Referring now also to Figs. 12-14, the main circuit 316 may include a terminal arrangement 320 located toward the first end of the main circuit structure 302. The terminal arrangement 320 may be configured for surface mounting to a connector, which connects to the BMM 62. The terminal arrangement 320 may include a row ofsurface mount first terminals 322 and a row of surface mount second terminals 324. The row of first terminals 322 and the row of second terminals 324 are arranged in a staggered manner such that the first terminals 322 are at least partially disposed between the second terminals 324. The first terminals 322 are disposed inward from the second terminals 324 in the longitudinal direction. The second terminals 324 may each have an upper portion 326 joined by one or more hollow columns 327 to a lower portion 328. The upper portions 326 of the second terminals 324 may be disposed between the middle insulating layer 318b and the top insulating layer 318a, while the lower portions 328 of the second terminals 324 may be disposed between the middle insulating layer 318b and the bottom insulating layer 318c. The first terminals 322 may be accessed through the top insulating layer 318a, while the second terminals 324 may be accessed through either the top insulating layer 318a or the bottom insulating layer 318c. More specifically, the upper portions 326 of the second terminals 324 may be accessed through the top insulating layer 318a, while the lower portions 328 of the second terminals 324 may be accessed through the bottom insulating layer 318c.

[0080] The first terminals 322 may be formed on a top surface of the middle insulating layer 318b. The upper portions 326 of the second terminals 324 may be formed on the top surface of the middle insulating layer 318b and the lower portions 328 of the second terminals 32 may be formed on a bottom surface of the middle insulating layer 318b. The columns 327 may be formed by coating holes extending through the middle insulating layer 318b. More specifically, in each second terminal 324, the upper portion 326 and the lower portion 328 may be formed over holes in the middle insulating layer 318b and during their formation, conductive material is injected into the holes to thereby form the columns 327.

[0081] The staggered arrangement of the first and second terminals 322, 224 and the ability of the second terminals 324 to be accessed through either the top or bottom insulating layers 318a,c enable the terminal arrangement 320 to have a high density of connections in a limited amount of space.

[0082] Referring now to Figs. 12, 15,16, first terminals 322a, b may be connected tosensor lines 330, 332, which are formed on the top surface of the middle insulating layer 318b and extend linearly over the top surface of the middle insulating layer 318b, toward the second end of the main circuit structure 302. Proximate to the second end, the sensor lines 330, 332 may bend at a right angle and terminate at end portions, which abut ramps 334, 336, respectively. The ramps 334, 336 each have a crosssection at least approximating a right triangle and have a sloping surface joined to an end surface that abuts the end portion of the sensor line 330 or the sensor line 332, as the case may be. The ramps 334, 336 may be printed on the top surface of the middle insulating layer 318b with non-conductive ink using the inkjet printer. End portions of sensor lines 340, 342 of the branch circuit structure 304 are printed over the sloping surfaces of the ramps 334, 336 and over the end portions of the sensor lines 330, 332 with conductive ink using the inkjet printer, thereby forming conductive joints 337, 339 which may be secured with conductive glue and / or mechanical crimping.

[0083] From their end portions, the printed sensor lines 340, 342 extend across the main circuit structure 302 and thence down the length of the branch circuit structure 304 to an end portion thereof, which projects at about a right angle to the length of the branch circuit structure 304. The printed sensor lines 340, 342 may be inkjet printed on the top surface of the middle insulating layer 318b in the main circuit structure 302 and the branch circuit structure 304.

[0084] Referring now to Fig. 17, the printed sensor lines 340, 342 are shown physically and electrically connected to a temperature sensor 346 in the end portion of the branch circuit structure 304. The temperature sensor 346 may be printed on the middle insulating layer 318b with conductive ink using the inkjet printer. For compactness, the temperature sensor 346 may have a serpentine configuration, as shown.

[0085] Referring now to Figs. 12, 18, 19, first terminals 322c, d may be connected to sensor lines 350, 352, which extend linearly toward the second end of the main circuit structure 302. Toward the second end, the sensor lines 350, 352 may terminate at rectangular plates 354, 356, respectively. Two sides of the plate 354 abut an angledramp 358 and two sides of the plate 356 abut an angled ramp 360. The angled ramps 358, 360 each have a pair of arms 362 joined together at a right angle. Each arm 362 has a sloping outer surface, a vertical inner surface and a cross-section at least approximating a right triangle. The inner surfaces of the arms 362 of the angled ramp 358 adjoin the sides of the plate 354, while the inner surfaces of the arms 362 of the angled ramp 360 adjoin the sides of the plate 360. The angled ramps 358, 360 may be printed on the middle insulating layer 318b with non-conductive ink using the inkjet printer.

[0086] End portions 368, 370 of sensor lines 372, 374 of the branch circuit structure 306 are printed over the sloping outer surfaces of the angled ramps 358, 360 and over the plates 354, 356 of the sensor lines 350, 352 with conductive ink using the inkjet printer. The end portions 368, 370 of the sensor lines 372, 374 may each have a rectangular frame shape. In this manner two sides of the end portion 368 of the sensor line 372 extend over the sloping outer surfaces of the angled ramp 358, and two sides of the end portion 370 of the sensor line 374 extend over the sloping outer surfaces of the angled ramp 360. This arrangement makes the connections between the sensor lines 350, 352 and the printed sensor lines 372, 374 redundant, thereby making them more robust. The connections between the sensor lines 350, 352 and the printed sensor lines 372, 374 comprise conductive joints 353, 355 that include the plates 354, 356, the end portions 368, 370 and the angled ramps 358, 360.

[0087] From their end portions, the printed sensor lines 372, 374 extend across the main circuit structure 302 and thence down the length of the branch circuit structure 306 to an end portion thereof, which projects at about a right angle to the length of the branch circuit 306. The printed sensor lines 372, 374 may be inkjet printed on the top surface of the middle insulating layer 318b in the main circuit structure 302 and the branch circuit structure 306.

[0088] Referring now to Fig. 20, the printed sensor lines 372, 374 are shown physically and electrically connected to an NTC thermistor 380 in the end portion of the branch circuit structure 306. The thermistor 380 may be an electronic component that isnot printed and is soldered to the sensor lines 372, 374. A stiffener plate 382 may be disposed below the thermistor 380 and the middle insulating layer 318b to provide support to the thermistor 380 and its soldered connections to the sensor lines 372, 374. The stiffener plate 382 may extend through the bottom insulating layer 318a.

[0089] Referring now to Figs. 12 and 21-23, first terminals 322e,f may be connected to voltage lines 384, 386, which are formed on the top surface of the middle insulating layer 318b and extend linearly toward the second end of the main circuit structure 302. Toward the second end, the voltage lines 384, 386 may bend at right angles and terminate at end portions, which abut ramps 388, 390, respectively. The ramps 388, 390 each have a cross-section at least approximating a right triangle and have a sloping surface joined to an end surface that abuts the end portion of the voltage line 384 or the voltage line 386, as the case may be. The ramps 388, 390 may be printed on the top surface of the middle insulating layer 318b with non-conductive ink using the inkjet printer. End portions of voltage lines 392, 394 of the branch circuit structures 308, 310 are printed over the sloping surfaces of the ramps 388, 390 and over the end portions of the voltage lines 384, 386 with conductive ink using the inkjet printer, thereby forming conductive joints 383, 385, which may be secured with conductive glue and / or mechanical crimping.

[0090] From their end portions, the printed voltage lines 392, 394 extend across the main circuit structure 302 and thence down the lengths of the branch circuit structures 308, 310 to end portions thereof, respectively. In the end portions, the printed voltage lines 392, 394 are secured to tab connectors 400, 402, respectively, such as by soldering. The tab connectors 400, 400 comprise a conductive metal, such as nickel. The tab connectors 400, 402 are configured for securement to sections of BIS interconnect panels, which are embodiments of the conductor structures 50. These sections of interconnect panels are connected to a group of battery cells, such as battery cells 214. In this manner, each of the printed voltage lines 392, 394 may be electrically connected to a group of the battery cells 214, via the tab connectors 400, 402, and may transmit the voltages of the groups of battery cells 214 to the voltage lines384, 386 and thence the first terminals 322e,f, which provides them to the BMM 62.

[0091] The printed voltage lines 392, 394 may be inkjet printed on the top surface of the middle insulating layer 318b in the main circuit structure 302 and on the top surfaces of the middle insulating layers 318b in the branch circuit structures 308, 310, respectively. During printing, a fuse 410 is formed in the printed voltage line 392, and a fuse 412 is formed in the printed voltage line 394. Each of the fuses 410, 412 may have a sinusoidal shape with thin curves that cannot carry as much current as the rest of the printed voltage line 392 or the printed voltage line 394, as the case may be. In this manner, the fuses 410, 412 will break when they receive a current exceeding a predetermined level. In addition to having an electric function, the fuses 410, 412 also have a mechanical function by permitting more flex in the printed voltage lines 392, 394 above the end portions of the branch circuit structures 308, 310. The fuses 410, 412, however, are located away from the end portions so as to not be damaged when the end portions are manipulated during the mounting of the monitoring circuit structure 300 to the BIS.

[0092] Initially, the end portions of the branch circuit structures 308, 310 are connected by sacrificial isthmuses 414, 416 to an island 418 of the insulating layers 318, thereby connecting the end portions together. This configuration helps prevent undue movement of the end portions of the branch circuit structures 308, 310 during the mounting of the hybrid monitoring circuit structure 300 to the BIS. After the hybrid monitoring circuit structure 300 has been mounted to the BIS, the isthmuses 414, 416 may be severed and the island 418 may be removed.

[0093] Referring now to Figs. 12 and 24-28, first terminals 322g, h may be connected to sensor lines 420, 422, which extend linearly toward the second end of the main circuit structure 302. The sensor lines 420, 422 terminate at upper plates 424, 426, which are joined to lower plates 428, 430 by hollow columns 432, 433. The upper plates 424, 426 are formed on a top surface of the middle insulating layer 318b, while the lower plates 428, 430 are formed on a bottom surface of the middle insulating layer 318b. Both the upper plates 424, 426 and the lower plates 428, 430 are formed over holes extendingthrough the middle insulating layer 318b. During the formation of the upper plates 424, 426 and the lower plates 428, 430, a conductive metal composition is injected into the holes in the middle insulating layer 318b, thereby forming the columns 432, 433 that physically and electrically connect together the upper plates 424, 426 and the lower plates 428, 430.

[0094] On the bottom surface of the middle insulating layer 318b, angled ramps 434, 436 (shown in Fig. 26) are printed with non-conductive ink to adjoin the lower plates 428, 430, respectively. Two sides of the lower plate 428 abut the angled ramp 434 and two sides of the lower plate 430 abut the angled ramp 436. The angled ramps 434, 436 each have a pair of arms 438 joined together at a right angle. Each arm 438 has a sloping outer surface, a vertical inner surface and a cross-section at least approximating a right triangle. The inner surfaces of the arms 438 of the angled ramp 434 adjoin the sides of the lower plate 428, while the inner surfaces of the arms 438 of the angled ramp 436 adjoin the sides of the lower plate 430.

[0095] First end portions 440, 442 of lower sensor lines 444, 446 of the branch circuit structure 312 are printed over the sloping outer surfaces of the angled ramps 434, 436 and over the lower plates 428, 430 of the sensor lines 420, 422 with conductive ink using the inkjet printer. The end portions 440, 442 of the printed lower sensor lines 444, 446 may each have a rectangular frame shape. In this manner two sides of the end portion 440 of the printed lower sensor line 444 extend over the sloping outer surfaces of the angled ramp 434, and two sides of the end portion 442 of the printed sensor line 446 extend over the sloping outer surfaces of the angled ramp 436. This arrangement makes the connections between the sensor lines 420, 422 and the printed lower sensor lines 444, 446 redundant, thereby making them more robust. The connections between the sensor lines 420, 422 and the printed lower sensor lines 444, 446 comprise conductive joints 445, 447 that include the upper plates 424, 426, the lower plates 428, 430, the angled ramps 434, 436 and the first end portions 440, 442.

[0096] From their first end portions 440, 442, the printed lower sensor lines 444, 446 extend over the bottom surface of the middle insulating layer 318b in the main circuitstructure 302 and thence over the bottom surface of the middle insulating layer 318b in the branch circuit structure 312. In the branch circuit structure 312, the printed lower sensor lines 444, 446 make 90° bends and then extend laterally to second end portions 450, 452, which connect to first end portions 454, 456 of upper sensor lines 458, 460 that are printed on the upper surface of the middle insulating layer 318b.

[0097] Both the second end portions 450, 452 of the printed lower sensor lines 444, 446 and the first end portions 454, 456 of the printed upper sensor lines 458, 460 are formed over holes extending through the middle insulating layer 318b. During the printing of the second end portions 450, 452 and the first end portions 454, 456, the conductive ink is injected into the holes in the middle insulating layer 318b, thereby forming hollow columns 462, 464 that physically and electrically connect together the second end portions 450, 452 and the first end portions 454, 456 and, thus, the printed lower sensor lines 444, 446 and the printed upper sensor lines 458, 460. These connections comprise conductive joints 461 , 463 that form composite sensor lines that transition from being below the middle insulating layer 318b to being above the middle insulating layer 318b.

[0098] From their first end portions 454, 456, the printed upper sensor lines 458, 460 extend to an NTC thermistor 468. The thermistor 468 may be an electronic component that is not printed and is soldered to the printed upper sensor lines 458, 460. A stiffener plate 470 may be disposed below the thermistor 468 and the middle insulating layer 318b to provide support to the thermistor 468 and its soldered connection to the printed upper sensor lines 458, 460. The bottom insulating layer 318a may disposed below the stiffener plate 470. The stiffener plate 470 may extend through the bottom insulating layer 318a.

[0099] Referring now to Figs. 12, 27 and 29-32, second terminals 324a, b may be connected to voltage lines 472, 474, which are formed on the bottom surface of the middle insulating layer 318b and extend linearly toward the second end of the main circuit structure 302. The voltage lines 472, 474 terminate at end portions, which abut ramps 476, 478, respectively. The ramps 476, 478 each have a cross-section at leastapproximating a right triangle and have a sloping surface joined to an end surface that abuts the end portion of the voltage line 472 or the voltage line 474, as the case may be. The ramps 476, 478 may be printed on the bottom surface of the middle insulating layer 318b with non-conductive ink using the inkjet printer. First end portions of lower voltage lines 480, 482 of the branch circuit structure 312 are printed over the sloping surfaces of the ramps 476, 478 and over the end portions of the voltage lines 472, 474 with conductive ink using the inkjet printer, thereby forming conductive joints 475, 477 which may be secured with conductive glue and / or mechanical crimping. The printed lower voltage lines 480, 482 are printed on the bottom surface of the middle insulating layer 318b. As shown in Fig. 27, the printed lower voltage lines 480, 482 extend under the printed upper sensor lines 458, 460.

[0100] From their first end portions, the printed lower voltage lines 480, 482 extend over the bottom surface of the middle insulating layer 318b in the main circuit structure 302 and thence over the bottom surface of the middle insulating layer 318b in an upper portion of the branch circuit structure 312. In the branch circuit structure 312, the printed lower voltage lines 480, 482 extend into the leg structures 483, 485, respectively, and then terminate at second end portions 484, 486, which connect to first end portions 490, 492 of upper voltage lines 494, 496 that are printed on the upper surface of the middle insulating layer 318b.

[0101] Both the second end portions 484, 486 of the printed lower voltage lines 480, 482 and the first end portions 490, 492 of the printed upper voltage lines 494, 496 are formed over holes extending through the middle insulating layer 318b. During the printing of the second end portions 484, 486 and the first end portions 490, 492, the conductive ink is injected into the holes in the middle insulating layer 318b, thereby forming hollow columns 493, 495 that physically and electrically connect together the second end portions 484, 486 and the first end portions 490, 492 and, thus, the printed lower voltage lines 480, 482 and the printed upper voltage lines 494, 496. These connections comprise conductive joints 497, 499 that form composite voltage lines that transition from being below the middle insulating layer 318b to being above the middleinsulating layer 318b.

[0102] From their first end portions, the printed upper voltage lines 494, 496 extend down the lengths of the two leg structures 483, 485 of the branch circuit structure 312 to end portions thereof, respectively. In the end portions, the printed upper voltage lines 494, 496 are secured to tab connectors 500, 502, respectively, such as by soldering. The tab connectors 500, 502 comprise a conductive metal, such as nickel. The tab connectors 500, 502 are configured for securement to sections of BIS interconnect panels, which are embodiments of the conductor structures 50. These sections of interconnect panels are connected to groups of battery cells, such as battery cells 214. In this manner, each of the printed upper voltage lines 494, 496 may be electrically connected to a group of the battery cells 214, via the tab connectors 500, 502, and may transmit the voltages of the groups of battery cells 214 to the voltage lines 472, 474 and thence the second terminals 324a, b which provides them to the BMM 62.

[0103] The printed upper voltage lines 494, 496 may be inkjet printed on the top surface of the middle insulating layer 318b in the two leg structures 483, 485, respectively. During printing, a fuse 510 is formed in the printed upper voltage line 494, and a fuse 512 is formed in the printed upper voltage line 496. Each of the fuses 510, 512 may have a sinusoidal shape with thin curves that cannot carry as much current as the rest of the printed upper voltage line 494 or the printed upper voltage line 496, as the case may be. In this manner, the fuses 510, 512 will break when they receive a current exceeding a predetermined level. In addition to having an electric function, the fuses 510, 512 also have a mechanical function by permitting more flex in the printed upper voltage lines 494, 496 above the end portions of the leg structures 483, 485 of the branch circuit structure 312. The fuses 510, 512, however, are located away from the end portions so as to not be damaged when the end portions are manipulated during the mounting of the hybrid monitoring circuit structure 300 to the BIS.

[0104] Initially, the end portions of the leg structures 483, 485 of the branch circuit structure 312 are connected by sacrificial isthmuses 514, 516 to an island 518 of the insulating layers 318, thereby connecting the end portions together. This configurationhelps prevent undue movement of the end portions of the leg structures 483, 485 of the branch circuit structure 312 during the mounting of the mounting circuit structure 300 to the BIS. After the mounting circuit structure 300 has been mounted to the BIS, the isthmuses 514, 516may be severed and the island 518 may be removed.

[0105] The hybrid monitoring circuit structure may be formed in a continuous process or a series of continuous and / or semi-continuous processes using one or more reel-to- reel systems. For example, the conductive main circuit 316 may be formed by etching or otherwise on top and bottom surfaces of a first sheet of insulating material (from which the middle insulating layer 318b is formed) in one or more processes. The top surface of the first sheet of insulating material with the main circuit 316 formed thereon may then be printed with conductive ink using an inkjet printer disposed above the first sheet of insulating material, with the first sheet of insulating material being moved by a reel-to- reel system. Subsequently, a bottom surface of the first sheet of insulating material with the main circuit 316 formed thereon may then be printed with conductive ink using an inkjet printer disposed below the first sheet of insulating material, with the first sheet of insulating material being moved by another reel-to-reel system. Alternately, conductive ink may be printed on the top and bottom surfaces of the first sheet of insulating material with the main circuit 316 formed thereon at the same time, using a single reel- to-reel system and using two inkjet printers located above and below the first sheet of insulating material. Second and third sheets of insulating material (from which the top and bottom insulating layers 318a,c are formed) may be laminated over the top and bottom surfaces of the first sheet with the conductive circuits formed thereon in one or more subsequent reel-to-reel laminating processes.

[0106] In some embodiments, the sheets of insulating material may be large enough to permit a hybrid monitoring circuit structure (such as the hybrid monitoring circuit structure 300) to be formed in its final configuration, i.e., with its branch circuit structures (such as the branch circuit structures 304-312) extending perpendicular from its main circuit structure. In these embodiments, upon completion of the etching, printing and laminating, large portions of the insulating layers are removed and discarded. In order toreduce the amount of scrap insulating material that is produced and to permit smaller machinery to manufacture a hybrid monitoring circuit structure with a desired configuration, an intermediate monitoring circuit structure having an intermediate configuration may first be produced. This intermediate monitoring circuit structure may then be further processed to form the final hybrid monitoring circuit structure, with the desired configuration. An example of this procedure is described more fully below with reference to Figs. 33-34.

[0107] Fig. 33 shows a schematic of a nascent or intermediate monitoring circuit structure 600 and Fig. 34 shows a schematic of a final hybrid monitoring circuit structure 650 that has been formed from the intermediate monitoring circuit structure 600. The final hybrid monitoring circuit structure 650 may be for use in a battery module that may have a BIS with two or more layers of interconnect panels, wherein each interconnect panel has a plurality of sections, which are separated from each other by gaps or spaces.

[0108] The intermediate monitoring structure 600 is formed from a plurality of unitary sheets of insulating material (such as PI) that are arranged in insulating layers 606, such as bottom, middle and top insulating layers 606. In Figs. 33 and 34, the top one of the insulating layers 606 has been removed to facilitate illustration. The intermediate monitoring circuit structure 600 is elongated and may have a rectangular shape. The intermediate monitoring circuit structure 600 includes a main circuit structure 602 and an intermediate branch circuit structure 604. The main circuit structure 602 and the intermediate branch circuit structure 604 are arranged serially in a longitudinal direction. An area 608 delineated below the main circuit structure 602 and the intermediate branch circuit structure 604 represents the approximate additional width of insulating layers that would be required to form the final hybrid monitoring circuit structure 650 without using the method of first forming the intermediate monitoring circuit 600.

[0109] The main circuit structure 602 may comprise a conductive main circuit 610 that has been formed from layers of copper or a copper alloy by etching, kiss cutting using a rotary die, or some other process. The main circuit 610 includes a terminalarrangement 611 located toward a first end of the main circuit structure 602. The terminal arrangement 612 may include first terminals 322 and second terminals 324 described above and may be configured for surface mounting to a connector, which connects to the BMM 62. The main circuit 610 may further include upper main lines (such as upper main lines 612, 614) formed on a top surface of the middle one of the insulating layers 606, and lower main lines (such as lower main lines 616, 618) formed on a bottom surface of the middle one of the insulating layers 606. The first terminals 322 may be connected to the upper main lines 612, 614 et al and the second terminals 324 may be connected to the lower main lines 616, 618 et al. In Figs. 33 and 34, the upper main lines 612, 614 are shown in solid to indicate that they are on the top surface of the middle one of the insulating layers 606, while the lower main lines 616, 618 are shown in dashed lines to indicate that they are on the bottom surface of the middle one of the insulating layers 606.

[0110] The intermediate branch circuit structure 604 includes conductive circuits formed by printing conductive ink on the middle one of the insulating layers 606. The conductive ink may comprise nanoparticles of copper, silver, gold or a combination thereof, or graphene or carbon nanotubes, together with organic dispersants and solvents. The conductive circuits may be printed using an inkjet printer. After the conductive circuits are printed, they may be cured, such as by laser sintering, oven sintering, electrical sintering or chemical sintering. The conductive circuits include upper branch lines (such as upper branch lines 620, 622) printed on a top surface of the middle one of the insulating layers 606, and lower branch lines (such as lower branch lines 624, 626) printed on a bottom surface of the middle one of the insulating layers 606. Similar to the upper and lower main lines, the upper branch lines 620, 622 are shown in solid to indicate that they are on the top surface of the middle one of the insulating layers 606, while the lower branch lines 624, 626 are shown in dashed lines to indicate that they are on the bottom surface of the middle one of the insulating layers 606.

[0111] The upper main lines may be connected to the upper branch lines byconductive joints and the lower main lines may be connected to the lower branch lines by conductive joints. For instance, the upper main lines 612, 614 may be connected to the upper branch lines 620, 622 by conductive joints 630, 632, which may have substantially the same construction as the conductive joints 337, 339 described above or the conductive joints 353, 355 described above. In addition, the lower main lines 616, 618 may be secured to the lower branch lines 624, 626 by conductive joints 634, 636, which may have substantially the same construction as the conductive joints 445, 447 described above or the conductive joints 475, 477 described above. The conductive joints may be secured together using conductive glue and / or mechanical crimping.

[0112] The intermediate branch circuit structure 604 is transformed into individual branch circuit structures (such as branch circuit structures 640, 642) by making longitudinal and other cuts in the insulating layers 606 to form nascent branch circuit structures that are separated from each other. In connection with these cuts, portions of the insulating layers 606 may be removed. The nascent branch circuit structures are then manipulated to make folds that change the shapes and directions of the nascent branch circuits, thereby forming the branch circuit structures.

[0113] For example, the branch circuit structure 640 is formed by making a first fold 644 in a nascent branch circuit structure that comprises the lower branch lines 624, 626. The first fold 644 is formed along a diagonal fold line such that the branch circuit structure 640 has an angled configuration with a first portion extending from and being disposed parallel to the main circuit structure 602 and a second portion extending downwardly from the first portion and being disposed perpendicular to the main circuit structure 602. The first fold 644 inverts the orientation of the middle one of the insulating layers 606 in the second portion such that its original bottom surface is now its top surface. As a result, the lower branch lines 624, 626 in the second portion face upward (as indicated by the solid lines).

[0114] For another example, the branch circuit structure 642 is formed by making a first fold 646 and a second fold 648 in a nascent branch circuit structure that comprises the upper branch lines 620, 622. The first fold 646 is formed along a diagonal fold lineso as to provide the branch circuit structure 642 with a first portion and a second portion. The first portion extends from and is disposed parallel to the main circuit structure 602 and the second portion extends downwardly from the first portion and is disposed perpendicular to the main circuit structure 602. The second fold 648 is formed along a diagonal fold line so as to provide the branch circuit structure 642 with a third portion that extends from the second portion toward the main circuit structure 602 and is disposed parallel to the main circuit structure 602. In this manner, the first and second folds 646, 648 provide the branch circuit structure 642 with a general C-shape.

[0115] The first fold 646 inverts the orientation of the middle one of the insulating layers 606 in the second portion such that its original top surface is now its bottom surface. As a result, the upper branch lines 620, 622 in the second portion face downward (as indicated by the dashed lines). The second fold 648 inverts the orientation of the middle one of the insulating layers 606 back to its original position. As a result, the upper branch lines 620, 622 in the third portion face upward (as indicated by the solid lines).

[0116] Devices and / or structures for conveying information about the operation of battery cells of the battery module may be secured to the printed conductive circuits of the branch circuit structures. For example, the lower branch lines 624, 626 in the second portion of the branch circuit structure 640 may be connected to a temperature sensor, a voltage tab connector or a current sensor. Similarly, the upper branch lines 620, 622 in the third portion of the branch circuit structure 642 may be connected to a temperature sensor, a voltage tab connector or a current sensor.

[0117] Although not shown, additional branch circuit structures may be formed from the intermediate branch circuit structure 604.

[0118] It is to be understood that the description of the foregoing exemplary embodiment(s) is (are) intended to be only illustrative, rather than exhaustive. Those of ordinary skill will be able to make certain additions, deletions, and / or modifications to the embodiment(s) of the disclosed subject matter without departing from the spirit of the disclosure or its scope.

Claims

What is claimed is:1 . A battery module comprising: a plurality of battery cells, each battery cell comprising a pair of terminals; a battery interconnect system connecting together the terminals of the battery cells to form a circuit arrangement; and a monitoring circuit structure connected to the battery interconnect system and configured to collect and transmit operating data for monitoring operation of the battery module, the monitoring circuit comprising: a terminal arrangement; a main circuit structure secured to the terminal arrangement and comprising a conductive main circuit adjoining a main insulating layer, the main circuit comprising at least one main section of a conductive line; and a branch circuit structure connected to the main circuit structure and comprising a conductive branch circuit at least partially adjoining a branch insulating layer, the branch circuit comprising at least one branch section of the conductive line; wherein the at least one main section of the conductive line is joined to the at least one branch section of the conductive line by at least one conductive joint to form the conductive line; and wherein the branch circuit comprises a conductive ink that is printed on at least the branch insulating layer.

2. The battery module of claim 1 , wherein the main circuit is at least twice as thick as the branch circuit.

3. The battery module of claim 2, wherein the conductive ink comprises silver or copper nanoparticles.

4. The battery module of claim 3, wherein the main circuit comprises copper or a copper alloy that: (a.) has been kiss cut by a rotary die from a sheet of copper or the copper alloy, or (b.) has been etched from a layer of copper or the copper alloy; or (c.) is in the form of rectangular copper conductors.

5. The battery module of claim 1 , wherein the at least one main section of the conductive line comprises an upper main section joined to a lower main section by a connection extending through the main insulating layer, wherein the upper main section of the conductive line adjoins a top surface of the main insulating layer and the lower main section of the conductive line adjoins a bottom surface of the main insulating layer.

6. The battery module of claim 1 , wherein the at least one branch section of the conductive line comprises an upper branch section joined to a lower branch section by a connection extending through the branch insulating layer, wherein the upper branch section of the conductive line adjoins a top surface of the branch insulating layer and the lower branch section of the conductive line adjoins a bottom surface of the branch insulating layer.

7. The battery module of claim 1 , wherein the conductive line comprises a voltage detection line that connects the battery interconnect system to the terminal arrangement to convey voltage data from one or a group of the battery cells.

8. The battery module of claim 1 , wherein the conductive line comprises a current detection line that connects the battery interconnect system to the terminal arrangement to convey current data from one or a group of the battery cells.

9. The battery module of claim 8, wherein the current detection line is connected across a resistor, which drops the voltage to produce a reduced voltage that is used to calculate current flow, the current data comprising the reduced voltage; andwherein the resistor comprises a second conductive ink that is inkjet printed on the branch insulating layer.

10. The battery module of claim 1 , further comprising one or more sensors; and wherein the conductive line comprises a sensor detection line that connects the one or more sensors to the terminal arrangement to convey sensor data.11 . The battery module of claim 10, wherein the one or more sensors comprises an NTC thermistor; and wherein the sensor detection line is electrically connected to a copper pad to which the NTC thermistor is mounted.

12. The battery module of claim 1 , wherein the battery interconnect system comprises conductor structures arranged in a single layer, and wherein the circuit arrangement comprises battery cells or groups of battery cells connected in series, parallel or combinations thereof.

13. The battery module of claim 12, wherein the battery cells are prismatic, and the conductor structures comprise bus bars, each bus bar connecting together terminals of adjacent battery cells such that the battery cells are connected in series.

14. The battery module of claim 12, wherein the battery cells are cylindrical and the conductor structures each have an irregular shape with positive tabs and / or negative tabs joined to and extending from arms, and wherein the conductor structures are connected to the battery cells such that the circuit arrangement has a plurality of groups of the battery cells electrically connected in series, wherein in each group of the battery cells, the battery cells are electrically connected in parallel.

15. The battery module of claim 1 , wherein the at least one conductive jointcomprises: a ramp disposed on the main insulating layer or the branch insulating layer, the ramp being non-conductive and having first, second and third sides, wherein the first side is disposed at a right angle to the second side and the third side slopes from the first side to the second side, and wherein the first side defines a height of the ramp and abuts an end portion of the at least one main section of the conductive line; and wherein an end portion of the at least one branch section of the conductive line is disposed over the third side of the ramp and over the end portion of the at least one main section of the conductive line.

16. The battery module of claim 1 , wherein the main insulating layer and the branch insulating layer are a unitary middle insulating layer; wherein the monitoring circuit structure further comprises a top insulating layer disposed above the middle insulating layer and a bottom insulating layer disposed below the middle insulating layer; and wherein the top insulating layer is disposed over the main circuit and the branch circuit, and the bottom insulating layer is disposed below the main circuit and the branch circuit.

17. The battery module of claim 16, wherein the at least one branch section of the conductive line comprises a lower branch section connected to an upper branch section, wherein the lower branch section is printed on a bottom surface of the middle insulating layer and the upper branch section is printed on a top surface of the middle insulating layer.

18. The battery module of claim 17, wherein the at least one main section of the conductive line comprises an upper main section connected to a lower main section, wherein the upper main section is formed on a top surface of the middle insulating layer and the lower main section is formed on a bottom surface of the middle insulating layer;and wherein the at least one conductive joint comprises a ramp disposed on the bottom surface of the middle insulating layer, the ramp being non-conductive and having first, second and third sides, wherein the first side is disposed at a right angle to the second side, and the third side slopes from the first side to the second side, and wherein the first side defines a height of the ramp and abuts an end portion of the lower main section of the conductive line; and wherein an end portion of the lower branch section of the conductive line is disposed over the third side of the ramp and over an end portion of the lower main section of the conductive line.

19. The battery module of claim 18, wherein the ramp comprises first and second arms joined at a right angle; wherein the first, second and third sides of the ramp are located in the first arm; wherein the end portion of the lower branch section of the conductive line has a rectangular frame shape and includes first and second members disposed at a right angle to each other, the first member being disposed over the third side of the first arm of the ramp and over the end portion of the lower main section of the conductive line; wherein the second arm has fourth, fifth and sixth sides, wherein the fourth side is disposed at a right angle to the fifth side, and the sixth side slopes from the fourth side to the fifth side, and wherein the fourth side abuts the end portion of the lower main section of the conductive line; and wherein the second member of the end portion of the lower branch section of the conductive line is disposed over the sixth side of the second arm of the ramp and over the end portion of the lower main section of the conductive line.

20. A method of forming a monitoring circuit structure for a battery module, comprising:(a.) forming a nascent monitoring circuit structure comprising:forming a conductive main circuit on an insulating layer to form a main circuit structure, the main circuit comprising main sections of conductive lines; printing a conductive branch circuit on the insulating layer using a conductive ink to form an intermediate branch circuit structure, the branch circuit comprising branch sections of the conductive lines; and joining the main sections of the conductive lines to the branch sections of the conductive lines to form the conductive lines; and wherein the main circuit structure and the intermediate branch circuit structure are arranged serially in a longitudinal direction;(b.) forming the monitoring circuit structure from the nascent monitoring circuit structure, comprising: cutting away portions of the insulating layer in the intermediate branch circuit structure to form nascent branch circuit structures that are separated from each other; and making a diagonal fold in each of the nascent branch circuit structures to form branch circuit structures, each of the branch circuit structures having a first portion that extends from the main circuit structure and a second portion that extends at a right angle to the first portion.

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