SYSTEM AND METHOD FOR SECURING BONDED POUCH CELLS

An energy storage device. The energy storage device includes a first pouch battery including a first terminal, a first pouch, and a first cell disposed in the first pouch; a second pouch battery positioned beneath the first pouch battery, the second pouch battery including a second terminal, a second pouch, and a second cell disposed in the second pouch; and a battery management system (BMS) positioned between the first cell and the second cell, wherein the BMS is coupled to the first terminal and to the second terminal; wherein each pouch has a top foil and a bottom foil, each foil including a first edge, a second edge, a third edge, and a fourth edge; wherein each edge of the bottom foil of the first pouch is bonded to a corresponding edge of the top foil of the second pouch.

TECHNICAL FIELD

The present disclosure relates generally to rechargeable batteries, and in particular to pouch batteries.

BACKGROUND

With modern advances in electronics technology, battery life has become increasingly important. As a result, batteries that are simple, flexible, and lightweight have become highly desirable. Batteries including cells disposed in pouches (“pouch batteries”) provide high packaging efficiencies that allow designers and engineers to create devices which are not limited by the form factor of the energy element of the electronic device. A pouch cell typically includes conductive foil tabs welded to electrodes, thereby allowing for electrical connections outside of the pouch for transferring electricity while the battery remains fully sealed. The pouch provides a soft pack that allows for reducing weight of the battery.

As pouch batteries are useful and relatively expensive, there is a market for repurposing such batteries, for example by attempting to bypass battery management systems and accessing the cells directly. Thus, pouch batteries are frequent targets of tampering attempts.

It would therefore be advantageous to provide a battery system which would be resistant, if not impervious, to at least some of these repurposing techniques.

SUMMARY

Certain embodiments disclosed herein include a secure energy storage device. The secure energy storage device comprises: a first pouch battery including a first terminal, a first pouch, and a first cell disposed in the first pouch; a second pouch battery positioned beneath the first pouch battery, the second pouch battery including a second terminal, a second pouch, and a second cell disposed in the second pouch; and a battery management system (BMS) positioned between the first cell and the second cell, wherein the BMS is coupled to the first terminal and to the second terminal; wherein each pouch has a top foil and a bottom foil, each foil including a first edge, a second edge, a third edge, and a fourth edge; wherein the first edge of the bottom foil of the first pouch is bonded to the first edge of the top foil of the second pouch, the second edge of the bottom foil of the first pouch is bonded to the second edge of the top foil of the second pouch, the third edge of the bottom foil of the first pouch is bonded to the third edge of the top foil of the second pouch, and the fourth edge of the bottom foil of the first pouch is bonded to the fourth edge of the top foil of the second pouch.

DETAILED DESCRIPTION

The various disclosed embodiments include a secure energy storage device. In an embodiment, the secure energy storage device includes a first pouch battery, a second pouch battery positioned beneath the first pouch battery, and a battery management system (BMS). The first pouch battery further comprises a first terminal, a first pouch, and a first cell disposed in the first pouch. The second pouch battery further comprises a second terminal, a second pouch, and a second cell disposed in the second pouch. The BMS is positioned between at least the first cell and the second cell. The BMS is coupled to the first terminal of the first battery and to the second terminal of the second battery.

Each pouch includes a top foil and a bottom foil, where a first edge of the bottom foil and a first edge of the top foil are bonded together, a second edge of the bottom foil and a second edge of the top foil are bonded together, a third edge of the bottom foil and a third edge of the top foil are bonded together, and a fourth edge of the bottom foil and a fourth edge of the top foil are bonded together. The top foil of the second pouch is bonded to the bottom foil of the first pouch.

FIG. 1Ais an example cross-sectional view of a bonded secured pouch battery100A utilized according to an embodiment. The pouch battery100includes a cell110disposed in a cavity150between a bottom foil120and a top foil130. Each foil120or130may be, but is not limited to, a polymer laminate.

In an embodiment, the top foil130and the bottom foil120are bonded together, for example by using an adhesive. To this end, the bottom foil120includes first and second excess portions122and124, respectively, and the top foil130includes first and second excess portions132and134, respectively. This results in a pouch structure with the cavity150in which the cell110, for example a rechargeable cell, may be disposed and protected from external elements. The rechargeable cell may be, but is not limited to, a Lithium-ion (Li-ion) cell, a Lithium polymer (LIPo) cell, and the like.

Each excess portion extends from the respective foil120or130and includes an edge of the foil120or130. The excess portion of one foil120or130may be bonded to a corresponding excess portion of the other foil120or130(e.g., by bonding at least the edge of the excess portion of one foil to the edge of the corresponding excess portion of the other foil), thereby collectively bonding the top foil130to the bottom foil120. Specifically, the first top excess portion132is bonded with the first bottom excess portion122, resulting in a first bonded sheet142. The second top excess portion134is bonded with the second bottom excess portion124, resulting in a second bonded sheet144. A third and a fourth bonding may each be performed perpendicular to the first and second bonded sheets142and144such that bonded sheets (not shown inFIGS. 1A-1B) formed by the third and fourth bondings are parallel to each other, and the first and second bonded sheets142and144are similarly parallel to each other.

FIG. 1Bis an example cross-sectional view of a bonded secured pouch battery100B utilized according to another embodiment. The first bonded sheet142and the second bonded sheet144may each be rolled, for example onto themselves. In some embodiments, an adhesive or other bonding agent may be deposited on the top portion146of the first bonded sheet142and on a top portion148of the second bonded sheet144to cause bonding as each bonded sheet142or144is rolled (or, in some embodiments, folded), thereby preventing the bonded sheet142or144from unraveling during storage, normal use, or both.

FIG. 2is an example cross-sectional view of a secure energy storage device200according to an embodiment. The secure energy storage device200includes a first pouch battery100-1and a second pouch battery100-2. The second pouch battery100-2is positioned beneath the first pouch battery100-1. In the example implementation shown inFIG. 2, each pouch battery100-1or100-2is as described herein with respect toFIG. 1B.

In an embodiment, the top foil130and the bottom foil120of each pouch battery100-1or100-2may each include a third excess portion and a fourth excess portion (not shown inFIG. 2), each excess portion corresponding to a side of a rectangular shape of the foil, such that the third excess portion of the top foil130corresponds to a third excess portion of the respective bottom foil120and the fourth excess portion of the top foil130corresponds to a fourth excess portion of the respective bottom foil120. In an example implementation, the excess portions may resemble a substantially cross-shaped foil.

The bonded sheets142and144of the pouch batteries100-1and100-2may be rolled together such that the top portion148-1of the bonded sheet144-1of the first pouch battery100-1is beneath the top portion148-2of the second bonded sheet144-2of the second pouch battery100-2(the bonded sheets142-1and142-2may be collectively referred to as bonded sheets142and the bonded sheets144-1and144-2may be collectively referred to as bonded sheets144merely for simplicity purposes).

FIG. 3is an example cross-sectional view of a secured energy storage device300including a battery management system (BMS)160according to an embodiment. The BMS160is positioned between a first pouch battery100-1and a second pouch battery100-2. In some implementations, more than two pouch batteries may be used, and one or more battery management systems may be placed between any two of the pouch batteries.

The BMS160is coupled with terminals including at least an anode (not shown inFIG. 3) of the first pouch battery100-1and a cathode (not shown) of the second pouch battery100-2. The BMS160manages the pouch batteries100-1and100-2, and may monitor, for example but not limited to, total voltage, voltage of each cell, temperature, state of charge, depth of charge, current, and the like. The BMS160may further include an over-voltage protection circuit, an under-voltage protection circuit, an over-current protection circuit, an over-discharge protection circuit, and the like. The BMS160may further be coupled to a communication bus (not shown) to allow communication between the BMS160and a load powered by either or both of the pouch batteries100-1and100-2. An example schematic diagram of the BMS160is described further herein below with respect toFIG. 9.

In an example implementation, the BMS160may include an authentication module (not shown) for authenticating commands to ensure that only commands received from authorized sources are executed. This may ensure, for example, that the pouch batteries100-1and100-2only serve one or more intended uses. In some implementations, a protection circuit module (PCM, not shown) may be utilized instead of the BMS160.

It should be noted thatFIGS. 2-3are described herein with respect to use of pouch batteries100B ofFIG. 1Bmerely for example purposes, and that the pouch battery100A ofFIG. 1Amay be equally utilized without departing from the scope of the disclosure.

FIG. 4is an example top-frontal isometric view of the secure energy storage device300. In this example embodiment, the first bonded sheet142and the second bonded sheet144are rolled towards the top surface of the top foil130. A third edge170of the top foil130is bonded to a third edge (not shown) of the bottom foil120. In an embodiment, the top foil130and bottom foil120each include a third excess portion corresponding to the third edge, such that the bonding results in a third bonded sheet. The third bonded sheet may be rolled (rolling of the third bonded sheet not shown inFIG. 4) towards the top surface of the top foil130, or towards the bottom surface of the bottom foil120.

FIG. 5is an example cross-sectional view of a secure energy storage device500according to yet another embodiment. The secure energy storage device500includes the components described herein above with respect toFIG. 3in addition to a first filament182and a second filament184.

The first bonded sheet142-1of the first pouch battery100-1and the second bonded sheet144-1of the first pouch battery100-1may each be rolled towards the top surface of the top foil130-1of the first pouch battery100-1. In some embodiments, an adhesive, or other bonding agent, may be placed on the top portion146-2of the first bonded sheet142-1and on the top portion148-2of the second bonded sheet144-1.

The first filament182is positioned such that the first bonded sheet142-2of the second pouch battery100-2is rolled onto the first bonded sheet142-1of the first pouch battery100-1, which in turn is rolled onto the first filament182. The second filament184is positioned such that the second bonded sheet144-2of the second pouch battery100-2is rolled onto the first bonded sheet144-1of the first pouch battery100-1, which in turn is rolled onto the second filament184. In an embodiment, each filament may be cylindrical. In some implementations, each filament may be a hollow or solid rod.

By rolling the bonded sheets142and144of the pouch batteries100-1and100-2around the filaments182and184, respectively, the pouches100-1and100-2are provided with an additional layer of security. For example, accessing the BMS160(shown inFIG. 5) in order to manipulate the rechargeable cells110-1and110-2becomes a difficult task. Specifically, attempts to access either of the rechargeable cells110-1or110-2requires separating the bonded sheets142and144of the pouch batteries100-1and100-2from each other (i.e., separating each bonded sheet142or144from the corresponding bonded sheet142or144of the other pouch100-1or100-2) and from the respective filaments182and184. Separation of the bonded sheets142and144from each other or from the filaments182and184(for example, to access the cells110directly) may result in tearing of the pouch100-1,100-2, or both, thereby resulting in cell degradation. The cell degradation may be severe, particularly when the cells then come into contact with moisture.

In the example embodiment shown inFIG. 5, the first bonded sheet142-1and the second bonded sheet144-1are rolled towards the top foil130-1. In another embodiment, the first bonded sheet142-1, the second bonded sheet144-1, or both, may be rolled towards the bottom foil120-2. In such an embodiment, the filaments are positioned accordingly.

FIG. 6is a top-frontal isometric view of the secure energy storage device500. The BMS160is secured between two rechargeable cells112and114. Typically, in order to repurpose a rechargeable cell, access is required to an anode and a cathode of the rechargeable cell. If a plurality of rechargeable cells are to be repurposed, then access is required to at least an anode of a first rechargeable cell, and at least a cathode of a second rechargeable cell, assuming the cathode of the first rechargeable cell is connected to the anode of the second rechargeable cell. A plurality greater than two rechargeable cells may of course be implemented. In some of the embodiments discussed herein, an anode and a cathode of one or more rechargeable cells are connected to a BMS (e.g., the BMS160,FIG. 5). The BMS includes at least two terminals protruding from the pouch. The terminals are operative to connect batteries (e.g., the pouch batteries100-1and100-2) to a load.

It should be noted that components ofFIG. 6other than the filaments182and184are shown in broken lines merely for illustrative purposes and without limitation on the disclosed embodiments. The broken lines are utilized to demonstrate an example positioning of the filaments182and184unobscured by the bonded sheets142and144.

FIG. 7is a top-frontal isometric view of a secure energy storage device700according to yet another embodiment. A first terminal cathode192and a second terminal anode194protrude from the first bonded sheet142such that a BMS (not shown inFIG. 7) may be coupled with an external load, power source, or both, to charge the rechargeable cells of the battery (not shown inFIG. 7) disposed in the secure energy storage device700and managed by the BMS.

FIG. 8is a front cross-sectional view of the secure energy storage device700including a BMS and an outgoing terminal according to yet another embodiment. In the example implementation shown inFIG. 8, the BMS160is placed between the top foil130and the bottom foil120. In some embodiments, the BMS160may be further placed between a first rechargeable cell112and a second rechargeable cell114. In an embodiment (not shown), only a single rechargeable cell (e.g. either the first rechargeable cell112or the second rechargeable cell114) is placed between the top foil130and the bottom foil120. The BMS160may be coated with an insulated material to protect a circuit (not shown inFIG. 8) of the BMS160from the rechargeable cells112and114.

In the example implementation shown inFIG. 8, an anode112-A of the rechargeable cell112is connected (for example via a wire210) to a cathode114-C of the rechargeable cell114. An anode114-A of the rechargeable cell114is connected to the BMS160(for example via a wire214), and a cathode112-C of the rechargeable cell112is connected to the BMS160(for example via a wire212). A wire215may connect a terminal (not shown) of the BMS160to the terminal192, which protrudes from the pouch. In a similar fashion, another terminal (not shown) of the BMS160may be connected to the other terminal194. In some embodiments, three or more pouch batteries may be used, each having its own BMS (or PCM, in another example).

FIG. 9is an example schematic diagram of the battery management system (BMS)160according to an embodiment. The BMS160includes a processing circuitry910coupled to a memory920, and a storage930. In an embodiment, the components of the BMS160may be communicatively connected via a bus940.

The memory920may be volatile (e.g., RAM, etc.), non-volatile (e.g., ROM, flash memory, etc.), or a combination thereof. The storage930may be magnetic storage, optical storage, and the like, and may be realized, for example, as flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVDs), or any other medium which can be used to store the desired information.

In an embodiment, computer readable instructions to monitor and control battery access as discussed herein may be stored in the storage930. In another embodiment, the memory920is configured to store software. Software shall be construed broadly to mean any type of instructions, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Instructions may include code (e.g., in source code format, binary code format, executable code format, or any other suitable format of code).

It should be understood that the embodiments described herein are not limited to the specific architecture illustrated inFIG. 9, and other architectures may be equally used without departing from the scope of the disclosed embodiments.

It should be noted that various embodiments described herein with respect to using a BMS, but that other embodiments including protection circuit modules (PCMs) may be equally utilized without departing from the scope of the disclosure. Specifically, each BMS as described with respect to the disclosed embodiments may be replaced with a PCM.