Cellular fusible link and battery module configuration

Implementations described and claimed herein provide a battery unit having a first plurality of cells oriented in a first direction and a second plurality of cells oriented in a second direction. The first plurality of cells have a corresponding first plurality of terminals with a first polarity, and the second plurality of cells have a corresponding second plurality of terminals having a second polarity that is an opposite polarity of the first polarity. A conducting surface electrically connects the first and second pluralities of terminals and has a plurality of fuses, each fuse associated with one of the second plurality of terminals. Each fuse has an elongated perforation defining an enclosed surface having a resistive aperture. In general, each resistive aperture is oriented relative to resistive apertures of at least one adjacent fuse such that a substantially even current path is provided to each of the second plurality of terminals.

TECHNICAL FIELD

Aspects of the present disclosure involve a cellular fusible link and more particularly involve a battery module configuration having cellular fusible links.

BACKGROUND

Large, complex battery systems provide high voltage and power for a variety of modern uses, including, but not limited to, electric vehicles, hybrid vehicles, backup power supplies for computing centers, homes, and neighborhoods, and power storage for alternative energy generation platforms. Such battery systems generally include one or more cells in parallel that may be connected in series configurations to provide higher voltage and power. Regardless of the configuration, however, cells and modules are susceptible to failure for a variety of reasons. For example, if the temperature of a cell exceeds the upper limit of the functional temperature range of the cell, the pressure from the high temperature may cause a cell to burst, may increase shorts, and can even cause a fire. Further, an internal short in one of the cells may result in thermal runaway, which occurs when an increase in temperature increases the current through the cell, resulting in a further increase in temperature until the cell fails. Failure of one cell often triggers a similar failure in adjacent cells.

It is with these and other issues in mind that various aspects of the present disclosure were developed.

SUMMARY

Implementations described and claimed herein address the foregoing problems by providing a battery unit having a first plurality of cells oriented in a first direction and a second plurality of cells oriented in a second direction. The first plurality of cells have a corresponding first plurality of terminals with a first polarity, and the second plurality of cells have a corresponding second plurality of terminals having a second polarity that is an opposite polarity of the first polarity. The first plurality of terminals are positioned relative to the second plurality of terminals such that the first plurality of terminals and the second plurality of terminals may be electrically connected to a conducting surface. The conducting surface has a plurality of fuses, each fuse associated with one of the second plurality of terminals. Each fuse has an elongated perforation that defines an enclosed surface having a resistive aperture (fusible link). In general, each resistive aperture is oriented relative to resistive apertures of at least one other adjacent fuse such that a substantially even current path is provided to each of the second plurality of terminals.

DETAILED DESCRIPTION

Aspects of the presently disclosed technology involve a battery system including one or more modules connected in series configurations to provide higher voltage and power, each module having one or more cells connected in parallel. In general, excessive current flow through and particularly from one cell often results in the failure of that cell, sometimes catastrophically. For example, if the temperature of a cell exceeds the upper limit of the functional range of the cell or the cell experiences a short, the cell may fail. Moreover, excessively high currents can cause failures or malfunction of related systems. In one example, failure of one cell often triggers a similar failure in adjacent cells, which may impair the operation of the battery system or render it inoperative. Accordingly, the presently disclosed technology provides a battery module configuration and fusible links at the cell level, sometimes referred to as cellular fusible links, to isolate failed cells from adjacent cells. Aspects of the presently disclosed technology provide a fuse associated with a terminal, such as a negative terminal, of each cell of the same polarity, wherein the fuse blows to isolate the cell when the current through the fuse exceeds a threshold discharge corresponding to one cell.

FIG. 1illustrates a side view of an example battery unit100having fusible links. The battery unit100may be used in a variety of systems, including, but not limited to, electric vehicles, hybrid vehicles, backup power supplies for computing centers, homes, and neighborhoods, and power storage for alternative energy generation platforms. The battery unit100includes a plurality of modules104and106involving one or more cells114stacked in parallel. The battery unit100may be connected to additional battery units in series to provide higher voltage and power. A battery system includes one or more of the battery units100. In one very particular exemplary implementation used to illustrate the various concepts described herein, a battery system provides approximately 330 Volts, with each of the battery units100in the battery system providing approximately 36 Volts and each cell114providing 3.25 to 3.8 Volts. However, other battery unit arrangements, cell types, and cell voltages are contemplated. A battery system may experience a short or other failure on the system level, battery unit100level, and/or individual cell114level. Accordingly, the battery system may include fuses to provide overcurrent protection at each of these levels. For example, if there is a high voltage short at the battery system level, a system fuse may blow and split the voltage approximately in half (e.g., from 330 Volts to approximately 160 Volts), thereby interrupting the overcurrent. Additionally, the battery unit100may include fuses to isolate a failed battery unit100from adjacent battery units100. Further, the battery unit100may include a fuse for each individual cell114, as illustrated inFIG. 1A, to isolate failed cells from adjacent cells, wherein the fuse blows to isolate the cell when the current through the fuse exceeds a threshold discharge corresponding to one cell. For example, the fuse for each 3.25 to 3.8 Volt cell114may be configured to allow passage of a nominal current of approximately 6.67 Amps with a peak current discharge of approximately 16.67 Amps and to blow if the current reaches or exceeds approximately 200 Amps.

An implementation of the battery unit100includes one or more conducting surfaces102. In the illustrated example, the conducting surfaces102are arranged in two parallel planes at either end of a stacked set of cells114. However, the conducting surfaces102may be arranged in other formats. The present arrangement, however, may provide ease of assembly and module104and106replacement. In the illustrated example, representative conducting surfaces102on the opposite plane are depicted in dotted lines. For clarity ofFIG. 1, only two of the conducting surfaces102on the opposite plane are shown inFIG. 1, but it should be understood that there may be a conducting surface102on the opposite plane corresponding to each of the conducting surfaces102on the plane in view.

Generally speaking, each conducting surface102electrically connects a plurality of cells114arranged in a first module104and a second module106. For clarity ofFIG. 1, the modules104and106are only shown with respect to one conducting surface102; however, it should be understood that each conducting surface102may correspond to a first module104and a second module106. The conducting surface102electrically inter-connects modules104and106at a positive or negative terminal (e.g., terminal116) of the cells114of the respective modules104and106. Stated differently, the conducting surface102is a common conducting plane between adjacent cells114whereby the voltage potential of the conducting surface102is substantially the same as an individual cell114of the modules104and106. In the same arrangement, however, the modules104and106may source current about equal to the sum of the currents available from the individual cells114. The first module104includes a discrete set of stacked cells114oriented in a first direction such that a positive terminal of each cell114may be electrically connected to the conducting surface102. Each positive terminal has a positive electrical polarity. Similarly, the second module106includes a discrete set of stacked cells114oriented in a second direction such that a negative terminal116of each cell may be electrically connected to the conducting surface102. Each negative terminal has a negative electrical polarity. In this respect, the conducting surface102provides a series connection between the modules104and106.

Each of the conducting surfaces102may be electrically connected in series to provide higher voltage and power to the battery unit100. In a particular example implementation, the battery unit100provides 36 Volts from the series connection of 10 sets of modules104and106having a plurality of cells114stacked in parallel, each cell114providing a nominal voltage of approximately 3.6 Volts. An implementation of the battery unit100further includes a circuit board108, which includes conductive pathways to electrically connect the electric components of the battery unit100. In one example, each of the conducting surfaces102includes a conducting tab124to electrically connect each conducting surface102to a conductive pathway on the circuit board108, which connects the conducting surfaces102via the conductive pathways. The circuit board108may also be configured to monitor the level of power capacity or other performance characteristics of the battery unit100and to react to those characteristics. For example, the circuit board108may monitor the current output of the modules104and106during recharging and compare the measured current to a set cutoff current. If a module104or106meets or exceeds the cutoff current, the circuit board108may react to reduce the current output from the module104or106. However, the battery unit100may include further mechanisms for protecting against overcurrent.

To provide overcurrent protection at the cellular level, failed cells are isolated from adjacent cells using fusible links. Each conducting surface102has a plurality of fuses F, which may be an integral feature of the conducting surface102, corresponding to individual cell terminals116of the same polarity. In one implementation, the fuses are positioned on the conducting surface102relative to each of the terminals116having a negative polarity. For clarity ofFIG. 1, the fuses F are only shown on one of the conducting surfaces102; however, it should be understood that each of the conducting surfaces102may have a plurality of fuses F.

Referring toFIG. 1A, each fuse has an elongated perforation118defining an enclosed conducting surface120in electrical communication with one of terminals116. In one implementation, the elongated perforation118forms a generally arced shape. More particularly, the elongated perforation118may define a semi-circular arc. The enclosed conducting surface120includes a resistive aperture122(fusible link). The elongated perforation118of each fuse focuses the current path on the conducting surface102to flow through the resistive aperture122. Stated differently, the conducting pathway through the elongated perforation118and into the enclosed conducting surface120provide a fusible link between the terminal116of the associated cell114and the surrounding conducting material of the conducting surface102around the elongated perforation118. As discussed herein, the resistive aperture122represents an aperture of conducting material from the enclosed conducting surface120through the elongated perforation118to the surrounding conducting material of the conducting surface102. Thus, the term “resistive aperture” is used herein in conjunction with the term “fusible link,” as the conducting or resistive aperture is a material link that breaks under certain current conditions.

Specifically, the resistive aperture122(fusible link) is configured to allow passage of nominal current up to a peak current discharge and allow excessive current for short durations. The resistance of the resistive aperture122generates heat due to the current flow, and as the current rises, the material of the resistive aperture122rises to a higher temperature. When the current flowing through the resistive aperture122is below the peak current discharge, the resistive aperture122is conductive with negligible resistance or impedance. Accordingly, the temperature of the resistive aperture122remains relatively low under these conditions. However, if excessive current flows through the resistive aperture122, the resistive aperture122becomes increasingly resistive, and the generated heat melts the resistive aperture122, physically separating the terminal116of the cell114from the conducting surface102. Separating the terminal116of the cell114from the conducting surface102isolates the cell114from adjacent cells and effectively removes the cell114from electrical communication with the battery unit100. In other words, current flow is concentrated into this conductive pathway in a controlled manner whereby the fusible link will fail under predictable conditions (e.g., excessively high current), thereby isolating a failed cell from other cells, etc.

In one implementation, the battery unit100further includes an electrical insulation layer110, which has a plurality of holes112. The electrical insulation layer110electrically insulates the conducting layer102from the plurality of cells114. Each of the plurality of holes112are positioned relative to either a positive terminal or a negative terminal (e.g., terminal116) of a particular cell114. The conducting surface102is in electric communication with the positive and/or negative terminals at each of the holes112. In one implementation, the enclosed conducting surface120of each of the fuses is in electric communication with one of the negative terminals116through one of the holes112, and the electrical insulation layer110separates the surface area of the negative terminal116from the surface area of the conducting surface102outside the enclosed conducting surface120. Thus, the electrical insulation layer110provides a barrier between the plurality of cells114and the conducting layer102except at the point of connection between a particular cell terminal116and the conducting surface102. In the event a particular cell type does not have an integral raised terminal, then a conducting plate may be fabricated with a conducting bump, such as a solder ball or other mechanism to extend through the holes112and engage the terminal116of the cell114. If there is an overcurrent and a fuse blows, the electrical insulation layer110prevents a failed cell from accidental electrical communication with the conducting layer102. Specifically, even if a fuse blows removing the point of connection between the cell terminal116and the conducting surface102, the surrounding conducting material of the conducting surface102around the elongated perforation118may accidentally come into contact with the cell terminal116. Accordingly, the electrical insulation layer110provides a barrier between the surrounding conducting material of the conducting layer102from coming into electrical communication with the cell terminal116.

FIG. 2illustrates a detailed view of an example battery module configuration200having fusible links. For clarity of the illustration, the fuses are not shown inFIG. 2. However, it should be understood that the battery module configuration200may include one or more fuses as described herein. An implementation of the battery module configuration200includes a plurality of cells arranged in modules. Each of the cells has a shape, including, but not limited to, cylindrical, hexahedral, pyramidal, etc. Most commonly, the cells are each cylindrical, and when cells of the same type are used, then the cylindrical dimensions are consistent between the cells. The cells may be stacked, for example, in a vertically staggered configuration or a vertically orthogonal configuration. Further, the cells may be potted in a module. For example, the cells may be potted with a high temperature insulator (e.g., silicon). Potting the cells electrically isolates the cells and reduces vibration and overcurrent. Further, potting the cells provides an even stress distribution around the outside of the cells, which provides uniform loading to the cells. Without potting, a cell may be in physical contact with adjacent cells, which creates point loading locations. If the battery module configuration200experiences a shock load, the point loading may damage the cell internally, which may result in a short circuit or a failure of the cell. Potting the cells substantially eliminates point loading to the cells, thereby providing uniform loading to the cells.

In one implementation, a first module202comprises a first plurality of cells oriented in a first direction and a second module204comprises a second plurality of cells oriented in a second direction, which is different from the first direction. As shown inFIG. 2, the cells of the first module202are stacked in one direction such that a collection of terminals of the same polarity are adjacent, and the cells of the second module204are stacked in the opposite direction such that a collection of terminals of the same polarity opposite the polarity of terminals of the first module202are adjacent. The first module202is positioned relative to the second module204. In one implementation, the first module202and the second module204each have a shape comprising a series of triangular relationships206and208with vertices210and212oriented in opposite directions. For example, in an exemplary implementation illustrated inFIG. 2, the cells in the first module202are arranged in a series of triangular relationships206having a vertex210oriented vertically upward, and the cells of the second module204are arranged in a series of triangular relationships208having a vertex212oriented vertically downward. It should be understood the terms upward and downward are used in conjunction with the orientation ofFIG. 2for illustrative purposes only and should not be used to infer such relationships or be otherwise limiting. In another implementation, the first module202and the second module204each have a shape comprising a series of rectangular relationships. However, other module configurations are contemplated. Further, additional modules may be connected to increase power and voltage.

The first plurality of cells included in the first module202have a corresponding first plurality of terminals with a first polarity, and the second plurality of cells included in the second module204have a corresponding second plurality of terminals with a second polarity, which is an opposite polarity of the first polarity. In one implementation, the first plurality of cells has a corresponding plurality of positive terminals, each having a positive electrical polarity, and the second plurality of cells has a corresponding plurality of negative terminals, each having a negative electrical polarity. An electrical connection between the positive and negative terminals represents a voltage potential of a cell or a plurality of cells. The first plurality of terminals is positioned relative to the second plurality of terminals, such that the first terminals and the second terminals may be electrically connected to a conducting surface214. In one implementation, the first terminals and the second terminals are substantially coplanar. The coplanarity may provide ease of assembly and module replacement. However, the terminals may be arranged in other formats relative to the conducting surface214and adjacent terminals.

The conducting surface214creates an electrical connection between the first plurality of cells in the first module202and the second plurality of cells in the second module204in a serial configuration. Thus, through a plurality of conducting surfaces, a serial chain of cells may be established at a desired module voltage. Stated differently, the stacked cells alternate across the modules202and204with the conducting surface214electrically connecting positive and negative terminals to provide a series chain of stacked (physically parallel) cell groups. The conducting surface214is in electrical communication with each of the first plurality of terminals and the second plurality of terminals. The conducting surface214may be connected to each of the terminals through various processes, including, but not limited to, simple contact, with or without biasing pressure such as in a detent, resistance welding, soldering, and brazing. Once in electrical communication with each of the first plurality of terminals in the first module202and the second plurality of terminals in the second module204, the conducting surface214has a first conducting surface and a second conducting surface. The first conducting surface corresponds to the first plurality of terminals, and the second conducting surface corresponds to the second plurality of terminals. Accordingly, the conducting surface214provides a conductive path between a portion of the conducting surface214in electrical communication with the first plurality of terminals (the first conducting surface) and a portion of the conducting surface214in electrical communication with the second plurality of terminals (the negative conducting surface). The conducting surface214thus, while providing a contiguous conductive surface, provides a conductive path between the first module202and the second module204. The conducting surface214may further include a conducting tab216to electrically connect the conducting surface214to a device, such as a circuit board, that electrically connects the conducting surface214to other conducting surfaces and electrical components.

To isolate a failed cell from adjacent cells, the conducting surface214may include a plurality of fuses corresponding to terminals of the same polarity. For example, the plurality of fuses may correspond to the second plurality of terminals included in the second module204. In a particular example, the fuses are positioned on the conducting surface214relative to negative terminals. The fuses may comprise an elongated perforation, enclosed conducting surface, and resistive aperture (fusible link), as described with respect toFIG. 1.

In one implementation, an electrical insulating layer218electrically insulates the conducting layer214from the cells in the first module202and the second module204. The electrical insulation layer218may have a plurality of holes positioned relative to the first plurality of terminals and the second plurality of terminals. The conducting surface214is in electrical communication with each of the first plurality of terminals and the second plurality of terminals at the holes of the electrical insulation layer218. In one implementation, the enclosed conducting surface of each of the fuses is in electric communication with one of the second plurality of terminals through one of the holes.

Referring now toFIG. 3, one particular example of a conducting surface300with an integrated fusible link configuration is illustrated. In this particular example, the conducting surface300electrically connects the positive terminals of six cells with the negative terminals of six adjacent cells.

The cylindrical shape of each of the cells lends itself naturally to stacking the cells in triangular relationships such that each module may be considered two sets of three cells with the terminals of each set arranged in a triangular relationship. In the particular example illustrated inFIG. 3, the positive module has six cells arranged in two positive triangular relationships, one of which is shown with dotted lines as positive triangular relationship302. With respect to the positive terminals, the positive triangular relationship302is merely one way to visualize the relationships between the cells in the positive module. However, in the particular example illustrated inFIG. 3, the positive terminals are not fused, so besides the convenience of positioning the cells, the positive triangular relationship302is not relevant to the connection with the conducting surface300. For example, alternatively or additionally, the conducting surface300may include a plurality of terminal locating perforations306and/or a plurality of alignment perforations308. The terminal locating perforations306indicate the approximate center of a cell terminal, for example, to assist in orienting the fuses during manufacturing. Similarly, the alignment perforations308indicate the vacant spots between the cells, to assist in orienting the fusible links configuration during manufacturing.

With respect to the negative module, the particular example illustrated inFIG. 3shows a fusible link configuration for six cells arranged in two negative triangular relationships, one of which is shown with dotted lines as negative triangular relationship304. Each of the negative terminals of the cells in the negative module is associated with a fuse. Accordingly, for the negative module, the negative triangular relationships (e.g., the negative triangular relationship304) work in conjunction with the individual fuses to provide a current path between the positive terminals and the negative terminals.

As discussed herein, each fuse may have an elongated perforation312defining an enclosed conducting surface314in electrical communication with a negative cell terminal. The elongated perforation312has a generally arced shape, including, but not limited to, curved, U-shaped, semi-circular, semi-elliptical, semi-rectangular, and semi-triangular. The enclosed conducting surface314includes a resistive aperture316(fusible link), as described with respect toFIG. 1. In one implementation, the resistive aperture316has a width ranging from approximately 4 to 4.5 mm. This width corresponds to the separation between perforation holes326at either end of the elongated perforation312that partially surrounds the negative cell terminal. However, other widths are contemplated depending on the size and type of cells used. As described herein, if excessive current flows through the resistive aperture316, generated heat melts the resistive aperture316(fusible link), physically separating the enclosed conducting surface314from the conducting surface300, as illustrated inFIG. 3with broken lines.

Even if a battery system does not include a failed cell, the battery system is limited by the weakest cell in the amount of current that the battery system can supply. A battery system having cells that remain as close to equal charge as possible generally provides the best performance. Accordingly, each fusible link is oriented relative to the fusible links of at least two adjacent fuses, such that a substantially even current path is provided to each of the corresponding cell terminals. For example, the resistive aperture316is oriented relative to resistive apertures318and320. Similarly, the fusible links in the negative triangular relationship304are positioned relative to each other. As shown by the example current paths322illustrated inFIG. 3, the current flows from the positive terminals into the negative triangular relationships, and the orientation of the fusible links provides a substantially even current path to each of the negative terminals in the negative triangular relationships. A substantially even current path taxes each of the cells generally equally, so the cells have as close to equal charge as possible. For example, in one implementation, for a battery system using cells providing 3.25 to 3.8 Volts, the resistive apertures316,318, and320may be oriented to provide a current path of approximately 6.67 Amps per cell with a peak discharge of approximately 16.67 Amps per cell. If the current reaches or exceeds the threshold discharge for one cell, the resistive aperture of that cell will blow to isolate the cell from the adjacent cells quickly. For example, once the current reaches or exceeds the threshold discharge (e.g., approximately 200 Amps), the fuse may blow in approximately 1 second.

The conducting surface300may further include one or more linear perforations310and/or a perforation bridge324to direct the current paths322through an opening in each of the negative triangular relationships. The opening of each of the negative triangular relationships faces cells in the positive module. For example, as illustrated inFIG. 3, the opening of the negative triangular relationship304faces the cells in the positive triangular relationship302. The perforation bridge324prevents the current paths322from entering the negative triangular relationships outside of the openings in the negative triangular relationships. Accordingly, a substantially even current path is provided to each of the negative triangular relationships. Additionally, the perforation bridge324may promote fusing between the positive triangular relationships and the negative triangular relationships. In other words, the perforation bridge324reduces the conducting surface area of the conducting surface300, which creates a fusing location with respect to the positive module and the negative module.

FIG. 4illustrates a detailed view400of a portion of the example fusible link configuration introduced inFIG. 3. Specifically, the detailed view400shows the negative triangular relationship304ofFIG. 3. The negative triangular relationship304includes plurality of cells402,404, and406, each having a first terminal408,410, and412, respectively, having a first polarity. As described with respect toFIG. 3, the conducting surface300has a plurality of integrated fuses corresponding to the negative triangular relationship304. Specifically, the conducting surface300includes a fuse positioned relative to each of the terminals408,410, and412. Each of these fuses includes a resistive aperture414,416, and418(fusible link), as described with respect toFIG. 3.

In one implementation, the resistive apertures414,416, and418are oriented relative a point area420, which is defined by lines422,424, and426emanating from the approximate center of the resistive apertures414,416, and418(fusible links), respectively. The orientation of the resistive apertures414,416, and418provides a substantially even current flow from the conducting surface300to each of the first terminals408,410, and412. For example, a current path enters the negative triangular relationship304at an opening near the point area420. Due to the positioning of the cells402,404, and406relative to the opening to the negative triangular relationship304, the current path has a relatively shorter distance to travel to the first terminals408and412than the first terminal410. However, the orientation of the resistive apertures414,416, and418results in a curved current path to reach the first terminals408and412and a straight current path to reach the first terminal410, which results in a substantially even current flow to each of the first terminals408,410, and412.

FIG. 5illustrates a section view500of the battery module configuration ofFIG. 2along the length of a cell. Specifically, the section view500shows a cell502in the first module202, as shown inFIG. 2. An implementation of the battery cell502includes a first terminal504of a first polarity and a second terminal506of a second polarity, opposite the first polarity. For example, the first terminal504may be a positive terminal having a positive electrical polarity, and the second terminal506may be a negative terminal having a negative electrical polarity.

The battery cell includes a case508, which may be cylindrical, hexahedral, pyramidal, etc. in shape and closed by a cap510. The case508holds an electrode-wound package, including anode and cathode rolled and packed into the case508. An electrolyte solution may also be injected into the case508. In general, as the temperature of the battery cell502rises, so does the pressure inside the case508. An internal short in the battery cell502may result in thermal runaway, which may increase the temperature of the battery cell502outside the upper limit of the functional temperature range of the battery cell502. The functional temperature range of the battery cell502depends on the chemistry of the electrode-wound package, the electrolyte solution, and other chemicals contained within the case508. For example, a practical upper limit for a Lithium Ion battery cell may be approximately 50° C.

If the temperature of the battery cell502exceeds the upper limit of the functional temperature range, the pressure from the high temperature may cause the battery cell502to burst, may create shorts, and may even cause a fire. To prevent this, the battery cell502may include a vent512to release some of the pressure in the case508. If the pressure inside the case508reaches a predetermined threshold, a disk in the vent512mechanically ruptures and safely releases gases out of the battery cell502, thereby decreasing the pressure. Often, the gases released are highly flammable. Accordingly, to avoid any fires or explosions, any materials that may reach a high temperature, such as the fusible links described herein, should be disposed away from the vent512.

In one implementation, the vent512is disposed near the first terminal504, which is in electrical communication with a first conducting surface, the conducting surface214, as illustrated inFIG. 2, at a conductive link514. The conducting surface214may include a perforation at the conductive link514that is oriented relative to the vent512to allow any released gases to escape safely. The second terminal506is in electrical communication with a second conducting surface516at a fusible link518. As described with respect toFIG. 2and elsewhere in the present disclosure, the fusible link518generates heat due to current flow between the second conducting surface516and the second terminal506, and there is excessive current flow, the fusible link518will physically sever from the second conducting surface616, illustrated inFIG. 5by dotted lines, thereby isolating the battery cell502.

The section view500further illustrates the electrical insulating layer218disposed between the conducting surface214and the battery cell502. As described herein, the electrical insulating layer218may include a hole522positioned relative to the first terminal504, such that the battery cell502is not in electrical communication with the conducting surface214outside the hole522. Further, the positioning of the hole522allows any gases released from the vent512to safely escape through the electrical insulating layer218. Similarly, a second electrical insulating layer520is disposed between the second conducting surface516and the battery cell502. The second electrical insulating layer520may include a hole524positioned relative to the second terminal506, such that the battery cell502is not in electrical communication with the second conducting surface516outside the hole524.

The electrical insulating layer218and the second electrical insulating layer520may be made, for example, from mica sheets, a paraffinic polymer, and/or a thermoplastic polymer, including, but not limited to, polytetrafluoroethylene. In one implementation, the electrical insulating layer218and the second electrical insulating layer520are each approximately 0.0001 inches thick. However, other electric insulating materials and thicknesses are contemplated. Polytetrafluoroethylene is thermally conductive and resistant, as well as chemically resistant, which further protects against unsafe conditions that may result when a cell releases corrosive and flammable chemicals. The conductive surface214and the second conducting surface516may be made, for example, from electrically conductive metals and metallic alloys, including without limitation, nickel and nickel alloys. In one implementation, the conductive surface214and the second conducting surface516are each approximately 0.006 inches thick. However, other electric insulating materials and thicknesses are contemplated.

When the fusible link518severs, the material of the second conducting surface516reaches substantially high temperatures. Specifically, the molten temperature of the second conducting surface516is substantially higher than the melting point of the second electrical insulating layer520. For example, nickel has a molten temperature of approximately 1,453° C. and polytetrafluoroethylene has a melting point of approximately 327° C. Thus, the melting point of polytetrafluoroethylene counsels against its use in the presently disclosed technology. However, through experimentation and research, the presently disclosed technology recognizes that when the fusible link528severs, the molten temperature of the second conducting surface516is relatively short lived such that the second electrical insulating layer520does not liquefy or break.

FIG. 6illustrates an example vehicle system600that may be useful in implementing the presently disclosed technology. An implementation of the vehicle system600includes a battery602, a motor604, and a computer606.

The battery602provides electric power to various components and devices included in the vehicle600. In one implementation, the battery602includes a plurality of cells arranged in modules, which are electrically connected by a conducting surface. The battery602may include additional modules to provide higher voltages and power. One of the plurality of cells may fail for a variety of reasons. Failure of one cell often triggers a similar failure in adjacent cells, which may impair the operation of the battery602or render the vehicle600inoperative.

As described herein, to isolate failed cells from adjacent cells, the conducting surface has a plurality of fuses corresponding to individual cell terminals having the same polarity. Each fuse has an elongated perforation defining an enclosed conducting surface in electrical communication with one of the terminals. The enclosed conducting surface includes a resistive aperture, which generates heat due to current flow, and if excessive current flows between one of the terminals and the second conductive surface, the resistive aperture will melt, physically separating the failed cell from the second conducting surface, thereby isolating it from adjacent cells.

The motor604may be an electric motor that uses power from the battery602to propel the vehicle600. The vehicle600may be a pure electric vehicle or a hybrid electric vehicle. An electric vehicle may include an inverter between the battery602and the motor604to convert DC electric power into a three-phase AC electric power to drive the motor604. A hybrid vehicle may include an internal combustion engine or hydrogen fuel cell to supply power to a transmission to propel the vehicle600and to turn a generator to provide power to charge the battery602. The computer606is powered by the battery602and controls the operation of the vehicle600and additional components such as an audio system, a navigation system, lighting, etc.

Embodiments of the present disclosure may be provided as a computer program product, which may include a machine-readable medium having stored thereon instructions, which may be used to program a computer (or other electronic devices) to perform a process. The machine-readable medium may include, but is not limited to, floppy diskettes, optical disks, compact disc read-only memories (CD-ROMs), and magneto-optical disks, ROMs, random access memories (RAMs), erasable programmable read-only memories (EPROMs), electrically erasable programmable read-only memories (EEPROMs), magnetic or optical cards, flash memory, or other type of media/machine-readable medium suitable for storing electronic instructions.