Cooling techniques for battery packages

Abstract

The method comprises forming a cooling plate containing a conductive material and having a plurality of openings, and coating the cooling plate with a dielectric coating. The method further comprises placing the cooling plate in the vicinity of a metal plate containing one or more metals, and exposing the cooling plate to moisture and / or water. In the example, the minimum lateral distance between the cooling plate and the metal plate is at most 0.5 inches. The method further comprises applying a voltage across both ends of the cooling plate and the metal plate while the cooling plate is exposed to moisture and / or water, and measuring the resulting leakage current passing through the cooling plate. The thickness of the dielectric coating on the edges of the openings among the plurality of openings is at least 0.003 inches.

Description

Technical Field

[0001]

[0001] This disclosure generally relates to batteries, and more particularly to the cooling of battery assemblies.

Background Art

[0002]

[0002] A battery is a common power source that provides direct current (DC) to a load, for example. A battery has a positive terminal or cathode and a negative terminal or anode. Multiple batteries can be connected in series and / or in parallel to form a high-voltage and / or high-power DC power source.

[0003]

[0003] Rechargeable batteries can be charged and discharged, and such charge and discharge cycles can occur multiple times over the life of the battery. For example, when a battery is discharged during use, it can be recharged using an applied current, during which the original composition of the battery electrodes can be fully or at least partially restored by the reverse current. Examples of such rechargeable batteries include lead-acid batteries and lithium-ion batteries. Batteries can be used in a number of applications such as household electronic devices, wearable devices, computers, electric and non-electric vehicles, and / or many other devices or systems that use DC power. Several important issues remain regarding the design and operation of battery packs.

Brief Description of the Drawings

[0004] [Figure 1A]

[0004] Various figures of an exemplary battery assembly in accordance with embodiments of the present disclosure are illustrated. [Figure 1B] Various figures of an exemplary battery assembly in accordance with embodiments of the present disclosure are illustrated. [Figure 1C] Various figures of an exemplary battery assembly in accordance with embodiments of the present disclosure are illustrated. [Figure 1D] Various figures of an exemplary battery assembly in accordance with embodiments of the present disclosure are illustrated. [Figure 2]

[0005] Figures 1A to 1D illustrate battery assemblies according to embodiments of the present disclosure, and further schematically illustrate condensates deposited on the cooling plates of the battery assemblies. [Figure 3]

[0006] The dielectric material coating on the cooling plate of the battery assembly shown in Figures 1A-1D and 12, according to embodiments of the present disclosure, is illustrated to further illustrate exemplary locations that are susceptible to electrical short circuits between conductive lines(s) of the battery assembly and the cooling plate(s). [Figure 4]

[0007] An embodiment of the present disclosure illustrates another dielectric material coating on the cooling plate(s) of the battery assembly shown in Figures 1A-1D and 1D, wherein the coating has at least a threshold thickness T1 on the edges of the openings of the cooling plate. [Figure 5]

[0008] A flowchart illustrating a method for testing a cooling plate (such as any of the cooling plates shown in Figures 1A-1D, 2, and 4) and manufacturing a battery assembly including a cooling plate, in such a way that the opportunity for electrical short circuits between the conductive lines(s) of the battery assembly and the cooling plate(s) is eliminated or at least reduced, according to embodiments of the present disclosure. [Figure 6A]

[0009] An example of a test apparatus for testing a cooling plate (or more) according to the method system shown in Figure 5, based on an embodiment of this disclosure, is provided. [Figure 6B] An example of a test apparatus for testing a cooling plate (or more) according to the method system shown in Figure 5, based on an embodiment of this disclosure, is provided. [Figure 7A]

[0010] An exemplary type of battery cell according to an embodiment of the present disclosure is illustrated. [Figure 7B] Another exemplary battery assembly comprising the multiple battery cells shown in Figure 7A, according to an embodiment of the present disclosure, is illustrated. [Figure 7C]

[0011] The following illustrates a typical location of water droplets within the battery assembly shown in Figure 7B, according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0005]

[0012] The drawings illustrate various embodiments of the present disclosure for illustrative purposes only and are not necessarily drawn to scale. Numerous variations, configurations, and other embodiments will become apparent from the detailed discussion below.

[0006]

[0013] Battery assemblies including cooling devices are described herein. In an example, the cooling device includes one or more cooling plates comprising a conductive material coated with one or more layers of dielectric material, wherein each cooling plate has a plurality of openings to allow ventilation of outgassing from the corresponding one or more battery cells, for example, during a malfunction of a battery cell. Furthermore, each of the one or more cooling plates may have a sufficiently thick dielectric coating on the side walls and edges of the openings to prevent or reduce the opportunity for electrical short circuits between the edges of the individual openings of the cooling plate and conductive lines coupled to the battery terminals. Such coatings may help reduce electrical short circuits caused, for example, by condensation accumulation in the cooling plate (where condensed water tends to accumulate on the side walls of the openings of the cooling plate).

[0007]

[0014] In one embodiment, the battery assembly comprises a first cooling plate comprising a conductive material and coated with a dielectric coating, wherein the first cooling plate includes an array of first openings within it. The first battery has a first positive terminal adjacent to and substantially aligned with the first opening in the array of first openings. A conductive line is coupled to the first positive terminal of the first battery. In this example, the distance between the conductive line and the edge of the first opening is at most 0.4 inches. A second cooling plate is substantially parallel to the first cooling plate, wherein the second cooling plate comprises a conductive material and coated with a dielectric coating. The second cooling plate includes an array of second openings within it. The second battery has a second positive terminal adjacent to and substantially aligned with the second opening in the array of second openings.

[0008]

[0015] In the example, the first battery is configured to vent outgass from or near its positive terminal during a malfunction of the first battery, so that the outgass is vented out of the battery assembly through a first opening in the array of openings in the first cooling plate. Similarly, the second battery is configured to vent outgass from or near its positive terminal during a malfunction of the second battery, so that the outgass is vented out of the battery assembly through a second opening in the array of openings in the second cooling plate.

[0009]

[0016] In another example, a method for forming and testing a cooling plate for a battery assembly is also disclosed. For example, a cooling plate is formed, wherein the cooling plate comprises a conductive material and has a plurality of openings. The cooling plate is coated with a dielectric coating. The cooling plate is placed in proximity to a metal plate comprising one or more metals, and the cooling plate and the metal plate are exposed to moisture and / or water. For example, the cooling plate and the metal plate are exposed to moisture and / or water by immersing the cooling plate and the metal plate in water. In another example, the cooling plate and the metal plate are exposed to moisture and / or water by spraying water onto the cooling plate and / or operating a water humidifier located close to the cooling plate. In the example, the minimum lateral distance between the cooling plate and the metal plate is at most 0.5 inches. A voltage is applied across both ends of the cooling plate and the metal plate, and the resulting leakage current through the cooling plate is measured. In response to a leakage current exceeding a threshold, the cooling plate is recoated with a dielectric coating and retested for leakage current again, and this process is repeated until the leakage current falls below the threshold. In the example, the thickness of the dielectric coating on the edges of the openings among the multiple openings in the cooling plate is at least 0.003 inches. Numerous variations and embodiments will become apparent in light of this disclosure. General Overview

[0010]

[0017] As indicated above, several important issues remain regarding the design and operation of the battery pack. For example, the battery pack may generate heat during operation, and a cooling device may be deployed to cool the battery pack in order to keep the battery temperature within acceptable limits. Due to the relatively low temperature of the cooling device (e.g., compared to the ambient temperature), water may condense on one or more sections of the cooling device, which can increase the chance of an electrical short circuit in the battery assembly. Furthermore, during battery cell malfunction (e.g., during thermal runaway or for other reasons), gas may be released by the battery cell, which may be referred to herein as "outgassing" of the battery cell. For example, a pressure relief valve or membrane of the battery cell may rupture during such an outgassing event (e.g., due to a rise in pressure within the battery cell resulting from battery cell malfunction), thereby releasing such gas.

[0011]

[0018] Therefore, techniques for forming a battery assembly including a cooling device comprising one or more cooling plates are described herein, where each cooling plate has a plurality of openings to allow ventilation of outgassing, for example, during a malfunction of a battery cell. Furthermore, in order to avoid the opportunity for electrical short circuits due to condensate accumulation (where condensed water tends to accumulate on the side walls of the openings of the cooling plate), each cooling plate may have dielectric coatings on the side walls and edges of the openings sufficient to prevent or reduce the opportunity for electrical short circuits between the edges of the individual openings of the cooling plate and conductive lines coupled to the battery terminals.

[0012]

[0019] In one embodiment, the battery assembly described herein has one or more cooling plates, such as two substantially parallel cooling plates, e.g., a first cooling plate and a second cooling plate. Battery cells are arranged laterally between the first and second cooling plates. The battery cells are arranged alternately. In the example, some battery cells have a positive terminal facing the first cooling plate and a negative terminal facing the second cooling plate, while some other battery cells have a positive terminal facing the second cooling plate and a negative terminal facing the first cooling plate. Each cooling plate comprises a conductive material (such as a metal and / or metal alloy) coated with one or more layers of dielectric material coating.

[0013]

[0020] The positive terminal of each battery cell is adjacent to and substantially aligned with the corresponding opening of the corresponding cooling plate. For example, the first battery cell has a first positive terminal facing the first cooling plate, so that the first positive terminal of the first battery cell is adjacent to and substantially aligned with the corresponding first opening of the first cooling plate. Similarly, the second battery cell has a second positive terminal facing the second cooling plate, so that the second positive terminal of the second battery cell is adjacent to and substantially aligned with the corresponding second opening of the second cooling plate.

[0014]

[0021] In the example, the openings in the first and second cooling plates are for venting outgassing that may be released by the battery cell, for example, during a malfunction of the battery cell. For example, a pressure relief valve or membrane may be on or near the cathode or positive terminal of the battery cell, for example, on or near the surface of the battery cell including the positive terminal. The pressure relief valve or membrane may rupture during such an outgassing event (for example, due to a pressure increase inside the battery cell resulting from a malfunction of the battery cell), thereby releasing such gas.

[0015]

[0022] For the ventilation of such gases from or near the positive terminal of the battery cell, the positive terminal of each battery cell is adjacent to and substantially aligned with a corresponding opening, for example, so that the vented outgas from the battery cell can pass through the corresponding opening of the cooling plate and out of the battery assembly. From this, the opening in the cooling plate forms a safe outlet path for the outgas. The ventilation of the outgas through the corresponding opening in the cooling plate prevents or at least reduces the propagation of the outgas to the battery cell itself or adjacent battery cells, thereby preventing or at least reducing the risk of fire in the battery assembly.

[0016]

[0023] Note that since the outgas may not exit the battery cell from or near the corresponding negative terminal of the battery cell, the negative terminal of the battery cell may not have a corresponding adjacent opening in the cooling plate. For example, negative side discharge may be possible, but may be unlikely, for example, considering the way individual battery cells are manufactured. In some examples, for example, instead of or in addition to the positive terminal of the battery cell being adjacent to the opening, the negative terminal of the battery cell may be adjacent to the opening.

[0017]

[0024] In one embodiment, the battery cell is held in place by a honeycomb-like structure. This structure prevents or reduces the movement of individual battery cells and comprises a rigid material such as aluminum, epoxy resin, and / or another suitable material, with holes or slots machined therein to allow the battery cell to be fitted into the corresponding slots.

[0018]

[0025] In one embodiment, the battery assembly comprises a plurality of conductive busbars or connection lines for coupling, for example, the corresponding positive or negative terminals of the battery cells to adjacent battery cells (or other components of the battery assembly). In one embodiment, the lines comprise a conductive material such as one or more metals and / or their alloys.

[0019]

[0026] In one embodiment, the battery assembly comprises a flame-retardant dielectric material, such as a dielectric foam, adjacent to the junction between the battery terminals and the lines. The foam functions as a flame retardant and thermal barrier to prevent or reduce the opportunity for fire propagation and / or heat transfer from one battery cell to an adjacent battery cell, for example. A thermal pad (also referred to herein as a gap pad) is located between the cooling plate and the conductive lines. The thermal pad functions as a thermal interface material between the cooling plate and the battery cells. For example, during the operation of the battery assembly, the thermal pad transfers heat from the battery cells to the cooling plate to prevent or reduce the opportunity for the battery cells to overheat, for example. The thermal pad comprises a dielectric material having a relatively high thermal conductivity. In this example, the thermal pad is also used to fill gaps created by the imperfectly flat (or smooth) surface of the conductive lines. As illustrated in Figure 1D, each thermal pad (e.g., one adjacent to the first cooling plate and the other adjacent to the second cooling plate) has a corresponding array of openings substantially aligned with the array of openings of the adjacent cooling plate, for example, to allow ventilation of outgassing from the positive terminal of the aligned battery cell.

[0020]

[0027] As illustrated in Figure 1D, a portion of the conductive line and the cooling plate are separated by an empty space or air, with the minimum distance between the line and the opening in the first cooling plate being L1, and the minimum distance between the other line and the opening in the second cooling plate being L2 (see Figure 1D). In the example, lengths L1 and L2 are at most 1 inch, or at most 0.8 inches, or at most 0.4 inches, or at most 0.2 inches, or at most 0.1 inches, or at most 0.08 inches, or at most 0.06 inches, or at most 0.05 inches, or at most 0.04 inches.

[0021]

[0028] In this example, the first and second cooling plates are relatively cool, for example, cooler than the ambient air in which the battery assembly operates. Therefore, moisture condensation may be present on the walls of the cooling plates (see, for example, Figure 2). For example, water droplets may accumulate on the cooling plates. These droplets may be on the sides of the cooling plates and may adhere to the sides due to, for example, surface tension. Furthermore, water tends to drip down onto the bottom sidewalls of the openings in the cooling plates and accumulate or collect (see, for example, Figure 2). For example, water from the sides of the cooling plates tends to drip downwards (for example, due to gravity) and accumulate on the bottom sidewalls of the individual openings.

[0022]

[0029] As described above, each of the first and second cooling plates has one or more layers of dielectric material coating. In the example, the dielectric coating is thicker on the non-edge surfaces of the cooling plate and thinner on the edges of the openings of the cooling plate. For example, the coating on the non-edge surfaces can have a thickness of 0.005 to 0.01 inches, for example, at least 0.003 inches, or at least 0.005 inches, or at least 0.008 inches, or at least 0.01 inches, or at least 0.015 inches, or at least 0.02 inches. In contrast, the thickness of the dielectric coating on the edges of the openings may be, for example, less than 0.003 inches, or less than 0.002 inches, or less than 0.001 inches. Exemplary differences in dielectric coating thickness are illustrated in Figures 3 and 4. The thinner dielectric material coating on the edges may be due to the deposition technique used to deposit the coating on the cooling plate. For example, after a coating is deposited on a cooling plate, the retention of the coating on the edges is relatively lower compared to the retention of the coating on the non-edge surfaces of the cooling plate. For instance, the coating may not adhere sufficiently to the edges compared to the adhesion of the coating on the non-edge surfaces of the cooling plate.

[0023]

[0030] Furthermore, in the example, the battery assembly may be installed inside the aircraft, for example, in a pressurized section of the aircraft or in an unpressurized section of the aircraft. In the example, as the aircraft gains altitude, and may as such, the air pressure inside the aircraft and consequently adjacent to the battery assembly decreases, which can increase the air conductivity (for example, air conducts more readily at lower pressures). Additionally or alternatively, conductivity at higher altitudes is higher than conductivity at sea level due to the presence of higher-energy particles from space at higher altitudes (which decrease as you get closer to the Earth's surface).

[0024]

[0031] In this example, this could mean that (i) water droplets accumulate on or near the edge of the opening in the cooling plate, (ii) the thickness of the coating on or near the edge of the opening in the cooling plate may be relatively small (e.g., less than the thickness on the non-edge surface of the cooling plate), (iii) the distance between the line and the edge of the opening in the cooling plate may be relatively small (e.g., length L1 in Figure 2), (iv) the battery assembly may have a relatively high operating voltage at the positive terminal of the battery, and / or (v) during the operation of the battery assembly, the air conductivity at higher altitudes may be greater than the air conductivity at sea level (e.g., when the aircraft on which the battery assembly is installed is flying at high altitude). In this example, one or more of the above factors could contribute to an electrical arc or short circuit between the line and the edge of the cooling plate, as schematically illustrated in Figure 3.

[0025]

[0032] In the example, to prevent or at least reduce the opportunity for such short circuits, the dielectric coating may have at least a threshold thickness T1 on the edges of individual openings in the cooling plate (see Figure 4). In the example, the thickness T1 is, for example, at least 0.002 inches, or at least 0.003 inches, or at least 0.004 inches, or at least 0.005 inches, or at least 0.006 inches, or at least 0.007 inches, or at least 0.008 inches, or at least 0.01 inches, or at least 0.012 inches, or at least 0.015 inches. Also, the average thickness T2 of the coating on the non-edge surface of the cooling plate (see Figure 4) is, for example, at least 0.005 inches, or at least 0.007 inches, or at least 0.009 inches, or at least 0.01 inches, or at least 0.02 inches, or at least 0.025 inches, or at least 0.03 inches. In this example, the opportunity for an electrical short circuit between the cooling plate and the line can be eliminated or at least reduced due to an increase in the thickness T1 of the coating at or near the edge of the opening, and / or due to a sensible selection of the dielectric material used for the coating.

[0026]

[0033] In an example, the cooling plate may be rigorously tested to ensure that the dielectric coating on the cooling plate is sufficient to eliminate or reduce the opportunity for the electrical short circuit described above. For example, one or more layers of dielectric material coating are first applied to the cooling plate. Then, a metal plate is placed in close proximity to the cooling plate (see Figures 6A and 6B). The lateral distance D between the metal plate and the cooling plate may be, for example, at most 1 inch, at most 0.8 inches, at most 0.7 inches, at most 0.5 inches, at most 0.3 inches, at most 0.1 inches, at most 0.05 inches, or at most 0.03 inches. In one example, the distance D is substantially zero (D ≈ 0), in which case at least sections of the cooling plate and at least sections of the metal plate are in contact with each other.

[0027]

[0034] Next, the cooling plate and metal plate are exposed to moisture and / or water. In one example, the cooling plate is sprayed with water and / or placed in a humid environment (see Figure 6A). In another example, the cooling plate and metal plate are immersed in water (see Figure 6B). In both examples, water droplets (Figure 6A) or water (Figure 6B) are present on the side walls and edges of the opening of the cooling plate. This mimics the conditions described above that are caused by condensation during the normal operation of the cooling plate (e.g., water droplets on the side walls and edges of the opening of the cooling plate).

[0028]

[0035] Subsequently, a voltage V1 is applied across both ends of the cooling plate and the metal plate, and the leakage current I is measured. If the dielectric material coating is satisfactorily applied (e.g., the edges of the opening have a sufficiently thick coating of at least T1), the coating will prevent substantial current I between the metal plate and the cooling plate. However, if the dielectric material coating is not satisfactorily applied (e.g., the edges of the opening do not have a sufficiently thick coating), the coating may not be able to prevent leakage current between the metal plate and the cooling plate. Therefore, in this example, a high value of current I (e.g., current I exceeds the threshold current value) is an indicator of an electrical short circuit between the metal plate and the cooling plate, which in turn is an indicator of a weak coating on the cooling plate (e.g., insufficient coating thickness at the edges of the opening).

[0029]

[0036] It should be noted that the test voltage V1 may be higher than the operating voltage Va of the battery assembly to account for, for example, the altitude at which the battery assembly is rated to operate. For example, the battery assembly may be installed inside an aircraft, for example, in a pressurized section of the aircraft or in an unpressurized section of the aircraft. In this example, as the aircraft gains and may gain altitude, the air pressure inside the aircraft and consequently adjacent to the battery assembly may decrease, which may increase the air conductivity (for example, air conducts more readily at lower air pressures). Additionally or alternatively, due to the presence of higher-energy particles from space at increased altitudes (which decrease as they approach the Earth's surface), conductivity at higher altitudes may be higher than conductivity at sea level. Therefore, in this example, to compensate for the increased air conductivity at higher altitudes at which the battery assembly is rated to operate, and to maintain a safety margin in the test process, the test voltage V1 is higher than the operating voltage Va of the battery assembly, as described below.

[0030]

[0037] As described above, the example determines whether the leakage current I is greater than the threshold current value. If the leakage current I is greater than the threshold current value, one or more additional layers of coating are reapplied to the cooling plate, and the cooling plate is tested again. This testing and recoating process continues until the cooling plate passes the test, for example, until the leakage current I is less than the threshold current value. For example, a leakage current I being less than the threshold current value implies that the coating at the edges of the openings in the cooling plate is sufficient to prevent or at least reduce the opportunity for an electrical short circuit.

[0031]

[0038] Subsequently, the battery assembly is formed using the cooling plates coated and tested according to the process described above. In one example, the battery assembly may be installed in an aircraft, while in another example, the battery assembly may also be installed for other suitable applications.

[0032]

[0039] According to some embodiments of the present disclosure, these various techniques may be used individually or in combination to operate the cooling system of a battery assembly while allowing outgassing and preventing or at least reducing the opportunity for electrical short circuits caused by condensate buildup in the cooling system.

[0033]

[0040] Where used herein, the term “approximately” indicates that the listed values ​​may be modified to some extent, or otherwise within acceptable tolerances, provided that the modification does not result in a nonconformity of the process or device. For example, for some elements, the term “approximately” may refer to a variation of ±0.1%, while for other elements, the term “approximately” may refer to a variation of ±1%, ±10%, or any point within that range. Also, where used herein, a term defined in the singular is intended to include a term defined in the plural, and vice versa.

[0034]

[0041] Any reference to a numerical range in this specification explicitly includes each number (including fractions and integers) that is encompassed by that range. For example, a reference to the range "at least 50" or "at least about 50" in this specification includes integers such as 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, and fractions such as 50.1, 50.2, 50.3, 50.4, 50.5, 50.6, 50.7, 50.8, 50.9, and so on. In further examples, references to the range “less than 50” or “about less than 50” in this specification include integers such as 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, etc., and fractions such as 49.9, 49.8, 49.7, 49.6, 49.5, 49.4, 49.3, 49.2, 49.1, 49.0, etc.

[0035]

[0042] As used herein, the terms “substantially” or “substantial” are equally applicable when used in a negative sense to refer to the complete or near-complete absence of an action, characteristic, feature, state, structure, item, or result. For example, a “substantially” flat surface would be either perfectly flat or nearly flat, with the same effect as if it were perfectly flat. architecture

[0036]

[0043] Figures 1A, 1B, 1C, and 1D illustrate various diagrams of an exemplary battery assembly 100 according to embodiments of the present disclosure.

[0037]

[0044] Figure 1A illustrates a perspective view of the battery assembly 100 (also simply called assembly 100), illustrating the cooling system of the battery assembly 100, which comprises cooling plates 104a and 104b and coolant tubes 112a and 112b on the cooling plates 104a and 104b, respectively, but does not illustrate other components of assembly 100. Figure 1B illustrates another perspective view of the battery assembly 100, illustrating the cooling plates 104a and 104b and exemplary battery cells 116a, 116b, 118a, and 118b, but does not illustrate other components of assembly 100. Figure 1C illustrates a section of cooling plate 104a. Figure 1D illustrates a cross-sectional view of the battery assembly 100, for example, along line A-A' in Figure 1B.

[0038]

[0045] Referring to Figure 1A, the assembly 100 comprises two cooling plates 104a, 104b that are substantially parallel to each other. In this example, the cooling plates 104a, 104b comprise one or more thermally conductive materials, such as metals and / or alloys thereof, and are coated with one or more layers of dielectric coating material. The cooling plates 104 provide cooling of the battery assembly 100, for example, by transferring heat from the assembly 100 to the surroundings and / or coolant flowing through coolant tubes (also simply called tubes) 112a and 112b. One or more thermally conductive metals, such as copper and / or aluminum, may be used to form the cooling plates 104a, 104b.

[0039]

[0046] Each cooling plate 104 is associated with a corresponding coolant tube 112 that is in contact with or very close to the cooling plate. For example, the coolant tube 112 may meander around the corresponding cooling plate 104 to cover a large area of ​​the cooling plate. An exemplary layout of coolant tubes 112a, 112b is illustrated in Figure 1A, but the coolant tubes 112a, 112b may have any other suitable layout configuration. The coolant tube 112b of cooling plate 104b is illustrated using a dotted line in Figure 1A because the coolant tube 112b is installed on or close to the surface of the cooling plate, which is not visible in Figure 1A, and therefore the coolant tube 112b will not be visible in Figure 1A. In the example, the coolant tubes 112a, 112b may be machined or brazed into the corresponding cooling plates 104a, 104b, respectively, so that the coolant tubes are sealed by the surface of the corresponding cooling plate.

[0040]

[0047] The tubes 112a and 112b of the cooling plates 104a and 104b are schematically illustrated using thick lines. Each of the tubes 112a and 112b receives relatively cool coolant (for example, the arrow labeled "Coolant In" in Figure 1A), and the cool coolant flows from one end of the tube to the other. The cooling plates 104a and 104b transfer heat generated from the batteries 116 and 118 to the coolant in the tubes 112a and 112b, respectively, which increases the temperature of the coolant. The relatively hot coolant exits the tubes 112a and 112b, is cooled by an external cooling device, and the cooled coolant is then recirculated back into the tubes 112a and 112b.

[0041]

[0048] As illustrated in Figures 1A and 1B, the cooling plate 104a has an array of openings 108a, and the cooling plate 104b has an array of openings 108b. In each cooling plate 104, the corresponding openings 108 are arranged in rows and columns. In the example, the openings 108a of cooling plate 104a are offset (e.g., not aligned) from the openings 108b of cooling plate 104b. For example, if cooling plate 104a is aligned (e.g., so that the boundary of cooling plate 104a is substantially aligned with the boundary of cooling plate 104) and placed on the top of cooling plate 104a, the openings 108a and 108b will not be aligned, but will be offset from each other. Figure 1D also illustrates openings 108a1 of cooling plate 104a and openings 108b1 of cooling plate 104b that are offset from each other.

[0042]

[0049] From this, for example, a hypothetical line passing through opening 108a1 and extending toward cooling plate 104b (where the hypothetical line is substantially perpendicular to one or both of cooling plates 104a and 104b) will not contact or pass through the opening in cooling plate 104b. Similarly, for example, a hypothetical line passing through opening 108b1 and extending toward cooling plate 104a (where the hypothetical line is substantially perpendicular to one or both of cooling plates 104a and 104b) will not contact or pass through the opening in cooling plate 104a. Note that in Figures 1A and 1B, the side walls of the openings are not illustrated for the purpose of clarifying the illustration (see Figure 1D for a portion of the side wall of the opening).

[0043]

[0050] In one embodiment, multiple battery cells 116, 118 are arranged laterally between cooling plates 104a and 104b. Several such exemplary battery cells 116a, 116b, 118a, 118b are illustrated in Figure 1B.

[0044]

[0051] In the example, each battery cell 116, 118 is substantially orthogonal to one or both of the cooling plates 104a, 104b (note that in the example, the cooling plates 104a, 104b are parallel to each other). For example, each battery cell 116, 118 extends from near one cooling plate to near the opposing cooling plate.

[0045]

[0052] Each battery cell 116, 118 has a cathode or positive terminal and an anode or negative terminal. As illustrated in Figure 1B, battery cells 116 (e.g., battery cells 116a, 116b) have corresponding positive terminals facing the cooling plate 104b, and battery cells 118 (e.g., battery cells 118a, 118b) have corresponding positive terminals facing the cooling plate 104a.

[0046]

[0053] For example, the cathode or positive terminal of each battery cell is adjacent to a corresponding opening in either the cooling plate 104a or the cooling plate 104b. For example, battery cell 116a has a positive terminal adjacent to and substantially aligned with the corresponding opening 108b1 of the cooling plate 104b, and battery cell 116b has a positive terminal adjacent to and substantially aligned with the corresponding opening 108b2 of the cooling plate 104b (see Figure 1B). Thus, the positive terminals of battery cells 116a and 116b face the cooling plate 104b and are substantially aligned with the respective openings of the cooling plate 104b.

[0047]

[0054] On the other hand, for example, battery cell 118a has a positive terminal adjacent to and substantially aligned with the corresponding opening 108a1 of the cooling plate 104a, and battery cell 118b has a positive terminal adjacent to and substantially aligned with the corresponding opening 108a2 of the cooling plate 104a. Thus, the positive terminals of battery cells 118a and 118b face the cooling plate 104a and are substantially aligned with the respective openings of the cooling plate 104a.

[0048]

[0055] Assembly 100 contains numerous other battery cells not illustrated in Figure 1B for the purpose of clarifying the illustration. For example, there is one battery cell for each corresponding opening. Thus, each opening 108b of the cooling plate 104b has the corresponding positive terminal of the corresponding battery cell 116 adjacent to the corresponding opening. Similarly, each opening 108a of the cooling plate 104a has the corresponding positive terminal of the corresponding battery cell 116 adjacent to the corresponding opening.

[0049]

[0056] In the example, openings 108a and 108b are for venting outgassing that may be released by the battery cell, for example, during a malfunction of the battery cell. For example, during a malfunction of the battery cell (such as during a thermal runaway condition or for other reasons), gas may be released by the battery cell, which is referred to herein as “outgassing” of the battery cell. For example, a pressure relief valve or membrane may be on or near the cathode or positive terminal of the battery cell, for example, on or near the surface of the battery cell including the positive terminal. The pressure relief valve or membrane may rupture during such an outgassing event (for example, due to a pressure increase within the battery cell resulting from a malfunction of the battery cell), thereby releasing such gas.

[0050]

[0057] For the ventilation of such gases from or near the positive terminal of a battery cell, the positive terminal of each battery cell is adjacent to and substantially aligned with a corresponding opening, for example, so that the vented outgass can exit the assembly 100 through the opening. Thus, the opening forms a safe exit path for outgass. Ventilation of outgass through the corresponding opening prevents or at least reduces the propagation of outgass to the battery cell itself or adjacent battery cells, thereby preventing or at least reducing the risk of fire in the assembly 100.

[0051]

[0058] Referring now to Figure 1C, a section of the opening 108a1 within the illustrated section of the cooling plate 104a is illustrated. Note that the entire opening 108a1 is not illustrated in Figure 1C. The opening 108a1 has a side wall 109a that extends from the left side of the cooling plate 104a to the right side of the cooling plate 104a. The right edge 109a of the opening 108a1 is located between the side wall 109a of the opening 108a1 and the right side of the cooling plate 104a. The left edge 109b of the opening 108a1 is located between the side wall 109a of the opening 108a1 and the left side of the cooling plate 104a.

[0052]

[0059] Similarly, each of the other openings in assembly 100 also includes one or more side walls, a left edge, and a right edge. In the examples in Figures 1A-1C, the opening 108 is illustrated to have a circular or oval cross-section, but the opening 108 may have another suitable cross-section, such as a square, rectangle, or rhombus.

[0053]

[0060] Referring now to Figure 1D, a cross-sectional view of assembly 100 along line A-A' in Figure 1B is illustrated. Note that only the section of assembly 100 containing two exemplary battery cells 116a and 118a is illustrated in Figure 1D.

[0054]

[0061] As described with respect to Figures 1A and 1B, and also illustrated in Figure 1D, the cooling plates 104a and 104b are arranged parallel to each other, and the battery cells 116 and 118 are arranged laterally between the cooling plates 104a and 104b. For example, each battery 116, 118 extends laterally from near one of the cooling plates to near the other. In this example, each battery cell 116, 118 is arranged substantially perpendicular to one or both of the cooling plates 104a and 104b.

[0055]

[0062] As described above, each of the cooling plates 104a and 104b includes corresponding openings 108a and 108b, respectively. For example, the opening 108a1 in the cooling plate 104a and the opening 108b1 in the cooling plate 104b are illustrated in Figure 1D.

[0056]

[0063] As described above, each battery cell 116, 118 has a cathode or positive terminal and an anode or negative terminal. For example, as illustrated in Figure 1D, battery cell 116a has a corresponding positive terminal facing the cooling plate 104b (marked by a "+" sign in Figure 1D) and a corresponding negative terminal facing the cooling plate 104a (marked by a "-" sign in Figure 1D). Similarly, battery cell 118a has a corresponding positive terminal facing the cooling plate 104a (marked by a "+" sign in Figure 1D) and a corresponding negative terminal facing the cooling plate 104b (marked by a "-" sign in Figure 1D).

[0057]

[0064] As illustrated in Figure 1D, the positive terminal of battery cell 116a is located proximal to, for example, adjacent to, the opening 108b1. For example, the positive terminal of battery cell 116a is substantially aligned with the opening 108b1 so that, for example, an outgassing event of battery cell 116a releases outgass through a valve or membrane at or near the positive terminal of battery cell 116a, and such gas exits the assembly 100 through the opening 108b1. In this example, the positive terminal of battery cell 116a and the opening 108b1 are separated by at most 2 inches, or at most 1.5 inches, or at most 1 inch, or at most 0.8 inches, or at most 0.4 inches, or at most 0.2 inches, or at most 0.1 inches, or at most 0.08 inches, or at most 0.06 inches, or at most 0.05 inches, or at most 0.04 inches.

[0058]

[0065] Similarly, as illustrated in Figure 1D, the positive terminal of battery cell 118a is located proximal to, for example, adjacent to, the opening 108a1. For example, the positive terminal of battery cell 118a is substantially aligned with the opening 108a1 so that, for example, an outgassing event of battery cell 118a releases outgass through a valve or membrane at or near the positive terminal of battery cell 118a, and such gas exits the assembly 100 through the opening 108a1. In this example, the positive terminal of battery cell 118a and the opening 108a1 are separated by at most 2 inches, or at most 1.5 inches, or at most 1 inch, or at most 0.8 inches, or at most 0.4 inches, or at most 0.2 inches, or at most 0.1 inches, or at most 0.08 inches, or at most 0.06 inches, or at most 0.05 inches, or at most 0.04 inches.

[0059]

[0066] It should be noted that the negative terminal of a battery cell may not have an adjacent opening in the cooling plate, as illustrated in Figure 1D, because outgassing may not occur from or near the corresponding negative terminal of the battery cell. For example, negative side exhaust may be possible, but unlikely, given, for example, the way in which individual battery cells are manufactured. In some examples, for example, the negative terminal of a battery cell may be adjacent to an opening instead of, or in addition to, the positive terminal of the battery cell being adjacent to an opening.

[0060]

[0067] In one embodiment, battery cells 116a and 118a are held in place by a honeycomb structure 122. The structure 122 is located on the sidewalls of the battery cells, where the sidewalls extend from their positive terminals to their negative terminals, as illustrated in Figure 1D. The structure 122 prevents or reduces movement of the individual battery cells 116 and 118 in the z-axis direction (e.g., the vertical direction in Figure 1D) and the y-axis direction (e.g., the direction in which the battery cells move in and out of the plane of the paper in Figure 1D). In one example, the structure 122 comprises a rigid material having a dielectric material such as a relatively rigid plastic. In another example, the structure 122 comprises a rigid material such as aluminum or another suitable material, with holes or slots machined inside to allow the battery cells to be fitted into the corresponding slots. Note that the structure 122 is illustrated in Figure 1D, but is not illustrated in Figures 1A and 1B for the purpose of clarifying the illustration.

[0061]

[0068] In one embodiment, the assembly 100 comprises a capture or retaining plate 124 adjacent to a cooling plate 104a and another capture or retaining plate 124 adjacent to a cooling plate 104b. The plates 124 hold the corresponding battery cells 116, 118 in place. For example, each plate 124 has finger-like projections that at least partially restrict the movement of the battery cells 116, 118 in the x-axis direction in the exemplary orientation of the assembly 100 in Figure 1D. In the example, the plates 124 are made of a dielectric material. In the example, the plates 124 are made of epoxy resin or another suitable dielectric material. Each plate 124 has openings or holes inside which they are aligned with the corresponding positive terminals of the battery cells and aligned with the openings of the corresponding adjacent cooling plates, as illustrated in Figure 1D.

[0062]

[0069] In one embodiment, the assembly 100 comprises a plurality of conductive busbars or connecting lines 132, such as busbars or lines 132a, 132b, and 132c shown in Figure 1D. For example, line 132a connects the positive terminal of battery cell 118a to the negative terminal of battery cell 116a. Line 132b connects the negative terminal of battery cell 118a to another component not illustrated in Figure 1D (for example, connecting the negative terminal of battery cell 118a to the positive terminal of another battery cell). Similarly, line 132c connects the positive terminal of battery cell 116a to another component not illustrated in Figure 1D (for example, connecting the positive terminal of battery cell 116a to the negative terminal of another battery cell).

[0063]

[0070] Therefore, in Figure 1D, battery cells 118a and 116a are connected in series through lines 132a, 132b, and 132c. However, in another example, another suitable connection of battery cells 116a and 118a (e.g., parallel connection) may also be possible.

[0064]

[0071] In one embodiment, lines 132a, 132b, and 132c comprise one or more conductive materials such as metals and / or alloys thereof. Exemplary metals for lines 132a, 132b, and 132c include copper, aluminum, nickel, and / or one or more other metals and / or metal alloys used in the busbars or lines of the battery assembly.

[0065]

[0072] In one embodiment, the assembly includes a flame-retardant dielectric material 130, such as a dielectric foam 130, adjacent to the joint between the battery terminals and line 132. The foam 130 functions, for example, as a flame retardant to prevent or reduce the opportunity for fire to propagate from the battery cell to the outside of the battery cell.

[0066]

[0073] The thermal pad (also referred to herein as a gap pad) 126 is located between (i) the cooling plate and (ii) the plate 124, lines 132a, 132b, 132c, and foam 130. The thermal pad 126 functions as a thermal interface material between the cooling plate and the battery cells 116, 118. For example, during the operation of the battery assembly 100, the thermal pad 126 transfers heat from the battery cells 116, 118 to the cooling plates 104a, 104b to prevent or reduce the opportunity for the battery cells 116, 118 to overheat. The thermal pad 126 comprises a dielectric material having relatively high thermal conductivity. In this example, the thermal pad 126 is also used to fill gaps created by the imperfectly flat (or smooth) surfaces of the lines 132 and plate 124. In this example, the heating pad is relatively hard at room temperature but becomes soft at relatively high temperatures, allowing it to fill the gap between (i) the cooling plate 104 and (ii) the line 132 and plate 124.

[0067]

[0074] As illustrated in Figure 1D, each thermal pad 126 has an array of openings substantially aligned with the array of openings of the adjacent cooling plate. For example, the space between a portion of line 132a (e.g., it is coupled to the positive terminal of battery cell 118a) and cooling plate 104a cannot be filled with thermal pad 126 to allow for possible ventilation of outgassing from the positive terminal of battery cell 118a, for example. Similarly, the space between a portion of line 132c (e.g., it is coupled to the positive terminal of battery cell 116a) and cooling plate 104b cannot be filled with thermal pad 126 to allow for possible ventilation of outgassing from the positive terminal of battery cell 116a, for example.

[0068]

[0075] As illustrated in Figure 1D, a portion of line 132a and the cooling plate 104a are separated by an empty space or air, and the minimum distance between line 132a and the cooling plate 104a is L1. Similarly, a portion of line 132c and the cooling plate 104b are separated by an empty space or air, and the minimum distance between line 132c and the cooling plate 104b is L2.

[0069]

[0076] Lengths L1 and L2 are, in this example, at most 1 inch, at most 0.8 inches, at most 0.4 inches, at most 0.2 inches, at most 0.1 inches, at most 0.08 inches, at most 0.06 inches, at most 0.05 inches, or at most 0.04 inches. Note that a portion of line 132b illustrated in Figure 1D is not adjacent to the cooling plate 104b and is completely separated from the cooling plate 104b by the thermal pad 126 (equipped with dielectric material).

[0070]

[0077] Figure 2 illustrates the battery assembly 100 of Figure 1D according to an embodiment of the present disclosure, and further schematically illustrates the condensation deposited on the cooling plates 104a and 104b of the battery assembly 100. For example, the cooling plates 104a and 104b are relatively cold, for example, colder than the ambient air in which the assembly 100 operates. Therefore, there is moisture condensation on the walls of the cooling plates 104a and 104b. For example, Figure 2 illustrates water droplets on the cooling plates 104a and 104b. The water droplets are on the sides of the cooling plates 104a and 104b and may adhere to the sides due to surface tension, for example. Furthermore, as illustrated in Figure 2, water tends to drip, accumulate, or accumulate on the bottom side walls of the openings 108a1 and 108b1. For example, water from the sides of the cooling plates 104a and 104b tends to drip downwards (for example, due to gravity) and accumulate on the bottom side walls of the openings 108a1 and 108b1.

[0071]

[0078] Figure 3 illustrates the dielectric material coating 308 on the cooling plates 104a and 104b of the battery assembly 100 in Figures 1D and 1D and 2 according to an embodiment of the present disclosure, and further schematically illustrates the weaknesses regarding electrical short circuits between the conductive lines 132a and 132c of the battery assembly 100 and the cooling plates 104a and 104b.

[0072]

[0079] For example, an enlarged view of section 304 of the cooling plate 104a is illustrated in Figure 3. As illustrated, the cooling plate 104a has one or more layers of a dielectric material coating 308. The cooling plate 104b has a similar dielectric material coating.

[0073]

[0080] As illustrated, the coating 308 is thicker on the non-edge surface of the cooling plate 104a and thinner on the edges of the openings in the cooling plate 104a. For example, the edge 312 of the opening 108a1 is labeled in Figure 3, where the edge 312 is also illustrated as edges 109a and 109b in Figure 1C. In the example, the coating 308 is relatively thin on the edges of the openings (compared to, for example, the thickness of the coating 308 on the non-edge surface of the plate 104a). For example, the coating 308 on the non-edge surface can have a thickness of 0.005 to 0.01 inches, for example, at least 0.003 inches, or at least 0.005 inches, or at least 0.008 inches, or at least 0.01 inches, or at least 0.015 inches, or at least 0.02 inches. In contrast, the thickness of the coating 308 on the edge 312 of the opening 108a1 may be, for example, less than 0.003 inches, less than 0.002 inches, or less than 0.001 inches. This difference in thickness is illustrated in section 304 of the cooling plate in Figure 3.

[0074]

[0081] The thinner dielectric material coating on the edge 312 may be due to the deposition technique used to deposit the coating 308 on the cooling plate 104a. For example, when coating the cooling plate 104a (e.g., using any suitable paint deposition technique), the thickness of the coating 308 on the non-edge surface is inherently greater than the thickness of the coating 308 on the edge 312, for example, due to unintended limitations on the coating deposition process. For example, after the coating has been deposited on the cooling plate 104a, the retention of the coating 308 on the edge 312 is relatively low compared to the retention of the coating 308 on the non-edge surface of the cooling plate 104a. For example, the coating may not adhere sufficiently to the edge 312 compared to the adhesion of the coating 308 on the non-edge surface of the cooling plate 104a.

[0075]

[0082] Furthermore, in the example, the battery assembly 100 is installed inside the aircraft, for example, in a pressurized section of the aircraft or in an unpressurized section of the aircraft. In the example, as the aircraft gains altitude, and may gain altitude, the air pressure inside the aircraft and consequently adjacent to the battery assembly may decrease, which may increase the air conductivity (for example, air has higher conductivity at lower air pressures). Additionally or alternatively, due to the presence of higher-energy particles from space at higher altitudes (where the presence of such higher-energy particles decreases as one approaches the Earth's surface), conductivity at higher altitudes may be higher than conductivity at sea level.

[0076]

[0083] In this example, this means that (i) water droplets accumulate on or near the edge 312 of the opening 108a1 of the cooling plate 104a, (ii) the thickness of the coating 308 at or near the edge is relatively small, (iii) the distance between line 132a and the edge 312 of the cooling plate 104a (e.g., length L1 in Figure 2) is relatively small, (iv) the battery assembly 100 may have a relatively high voltage at the positive terminal of the battery 118a (e.g., it may be about 800V in an exemplary implementation), and / or (v) the battery assembly 100 may be rated to operate at higher altitudes where air is more conductive than sea level (e.g., when the aircraft on which the battery assembly is installed is flying high in the air).

[0077]

[0084] In the example, one or more of the above factors may contribute to an electrical arc or short circuit 320 between line 132a and cooling plate 104a, as schematically illustrated by line 320 in Figure 3. In the example, although not illustrated in Figure 3, a similar electrical arc or short circuit may also occur between line 132c and cooling plate 104b.

[0078]

[0085] Figure 4 illustrates another dielectric material coating 408 on the cooling plates 104a, 104b of the battery assembly 100 of Figures 1D and 2 according to an embodiment of the present disclosure, wherein the coating 408 has at least a threshold thickness T1 on the edge 312 of the opening 108a1 of the cooling plate 104a. In this example, the thickness T1 of the coating 408 on the edge 312 of the cooling plate 104a is, for example, at least 0.002 inches, or at least 0.003 inches, or at least 0.004 inches, or at least 0.005 inches, or at least 0.006 inches, or at least 0.007 inches, or at least 0.008 inches, or at least 0.01 inches, or at least 0.012 inches, or at least 0.015 inches.

[0079]

[0086] Furthermore, the average thickness T2 of the coating 408 on the non-edge surface of the cooling plate 104a is, for example, at least 0.005 inches, or at least 0.007 inches, or at least 0.009 inches, or at least 0.01 inches, or at least 0.02 inches, or at least 0.025 inches, or at least 0.03 inches.

[0080]

[0087] In the example, in Figure 4, the opportunity for an electrical short circuit between the cooling plate 104a and the line 132a is eliminated or at least reduced due to the increased thickness of the coating 408 at or near the edge 312 of the cooling plate 104a (compared to the thickness illustrated in Figure 3, for example) and / or due to the sensible selection of dielectric material used for the coating 408. Thus, even if (i) water droplets accumulate on or near the edge 312 of the opening 108a1 of the cooling plate 104a, (ii) the distance between line 132a and the edge 312 of the cooling plate 104a (e.g., length L1 in Figure 2) is relatively small, (iii) a relatively high voltage is present at the positive terminal of the battery 118a (e.g., it may be about 800V in an exemplary implementation), and / or (iv) the battery assembly 100 may be rated to operate at a higher altitude where air is more conductive than sea level, the thickness T1 and T2 and / or selection of the dielectric material coating 408 eliminates or at least reduces the opportunity for an electrical short circuit between the cooling plate 104a and line 132a. Similarly, the thickness and / or selection of the dielectric material coating 408 eliminates or at least reduces the opportunity for an electrical short circuit between the cooling plate 104b and line 132c (and between either of the cooling plates 104a, 104b and any of the lines of the assembly 100). Therefore, in contrast to Figure 3, electrical short circuits may not occur in the battery assembly shown in Figure 4.

[0081]

[0088] Coating 408 may include a suitable dielectric material that satisfactorily adheres to the edges of the openings of the cooling plate and has sufficient dielectric properties. Examples of coating 408 include ethylene chlorotrifluoroethylene (ECTFE), semi-crystalline melt-workable partially fluorinated polymers, thermoplastic powder coatings, and / or other suitable types of dielectric material coatings.

[0082]

[0089] Figure 5 illustrates a flowchart illustrating a method 500 for manufacturing a battery assembly 100 including a cooling plate (such as any of the cooling plates 104a, 104b in Figures 1A, 1B, 1C, 1D, 2, and 4) so ​​as to eliminate or at least reduce the opportunity for an electrical short circuit between the conductive lines 132 of the battery assembly 100 and the cooling plate, according to embodiments of the present disclosure. Figures 6A and 6B illustrate a test apparatus for testing the cooling plate according to the method system 500 of Figure 5, according to embodiments of the present disclosure. Figures 5, 6A, and 6B are discussed together.

[0083]

[0090] Referring to Figure 5, in method 504 of method 500, one or more layers of dielectric material coating (e.g., coating 408 in Figure 4) are applied to a cooling plate (such as cooling plate 104a). The coating may be applied using a suitable technique used for applying the coating to the cooling plate.

[0084]

[0091] As described herein, the coating may not adhere to or adhere to the edges of the openings of the cooling plate compared to the non-edge surfaces of the cooling plate. For example, the coating on the edges of the openings of the cooling plate may be smaller than T1 (see Figure 4), as described with respect to Figure 3, which may consequently increase the chance of an electrical short circuit between the cooling plate and line 132 (see Figure 3). Therefore, after the coating has been applied, the cooling plate may be tested to confirm satisfactory performance of the cooling plate, as described below.

[0085]

[0092] Method 500 proceeds from 504 to 508. In 508, the cooling plate is sprayed with water and / or placed in a humid environment, for example as illustrated in Figure 6A. Alternatively, the cooling plate is immersed in water, for example as illustrated in Figure 6B. Furthermore, a metal plate 604 is placed in close proximity to the cooling plate, as illustrated in Figures 6A and 6B. Thus, the cooling plate and the metal plate 604 are exposed to moisture and / or water.

[0086]

[0093] For example, in Figure 6A, the cooling plate 104 is sprayed with water from a water sprayer 612. The water sprayer 612 may be a water spray bottle, a sprayer attached to a water supply pipe, or a water tap, which may be operated manually or automatically to spray water onto the cooling plate 104, in this example. In this example, in addition to or instead of spraying water, a water humidifier 608 is operated near the cooling plate 104a. The water humidifier 608 humidifies the environment by, for example, releasing water vapor or steam, thereby increasing the moisture level in the air near the cooling plate 104a. Thus, as a result of the water spraying and / or the operation of the water humidifier 608, water droplets are formed on the surface of the cooling plate 104a and on the side walls of the openings of the cooling plate 104a, as schematically illustrated in Figure 6A.

[0087]

[0094] As illustrated in Figure 6A, the metal plate 604 is placed proximal to the cooling plate 104a. In this example, the metal plate 604 has no dielectric material coating on it. The metal plate 604 is separated from the cooling plate 104a by a lateral distance D. In this example, the distance D is, for example, at most 1 inch, at most 0.8 inches, at most 0.7 inches, at most 0.5 inches, at most 0.3 inches, at most 0.1 inches, at most 0.05 inches, or at most 0.03 inches. In one example, the distance D is substantially zero (D≈0), in which case at least a section of the cooling plate 104a and at least a section of the metal plate 604 are in contact with each other.

[0088]

[0095] In Figure 6B, the cooling plate 104 and the metal plate 604 are separated by the distance D described above, and the combination of the cooling plate 104 and the metal plate 604 is immersed in the water in the container 616.

[0089]

[0096] Therefore, in Figures 6A and 6B, the water droplets (Figure 6A) or water (Figure 6B) are located on the side walls and edges of the opening of the cooling plate 104a. This mimics the conditions described above with respect to Figures 3 and 4 (for example, water droplets on the side walls and edges of the opening of the cooling plate 104a).

[0090]

[0097] Method 500 then proceeds to steps 508 through 512. In step 512, a voltage V1 is applied across both ends of the cooling plate 104a and the metal plate 604, as illustrated in Figures 6A and 6B, and a leakage current I is measured. If the dielectric material coating is satisfactorily applied in process 504 (for example, the edges of the opening have a sufficiently thick coating of at least T1 thickness, see Figure 4), the coating 408 will prevent substantial current I between the metal plate 604 and the cooling plate 104a, for example, as described above with respect to Figure 4. However, if the dielectric material coating is not satisfactorily applied in process 504 (for example, the edges of the opening do not have a sufficiently thick coating, see Figure 3), the coating may not be able to prevent leakage current between the metal plate 604 and the cooling plate 104.

[0091]

[0098] Therefore, in the example, a high value of current I in process 512 (e.g., current I exceeding the threshold current value) is an indicator of an electrical short circuit between the metal plate 604 and the cooling plate 104a, which in turn is an indicator of a weak coating on the cooling plate 104a (e.g., insufficient coating thickness at the edges of the openings).

[0092]

[0099] When the battery assembly 100 is operational, it is assumed that the battery assembly 100 outputs a voltage Va. In the example, the voltage V1 applied for testing in process 512 is greater than Va. In the example, the test voltage V1 is greater than the operating voltage Va of the battery assembly 100 in order to maintain a safety margin and to take into account the fact that the battery assembly 100 is rated to operate at higher altitudes where the air is more conductive (for example, due to the presence of higher energy particles from space and / or reduced air pressure, which contribute to higher air conductivity).

[0093]

[0100] For example, the tests in Figures 6A and 6B may be carried out in a test facility with ground surface air pressure (which may differ slightly from sea surface air pressure depending on the elevation of the physical facility where the test is being performed). However, the battery assembly 100 may, in example, be installed in an aircraft that can reach high altitudes during its flight, during which time the air conductivity may be less than that of the ground surface for the reasons described above.

[0094]

[0101] Therefore, the “rated altitude” of the battery assembly can be substantially higher than the “test altitude” (e.g., the altitude at which the tests in Figures 6A and 6B are performed). For example, the rated altitude of the battery assembly can be at least 1,000 ft, or at least 2,000 ft, or at least 5,000 ft, or at least 10,000 ft, or at least 15,000 ft, or at least 20,000 ft higher than the test altitude, depending on the altitude at which the aircraft is rated to fly. Also, as explained above, an increase in altitude results in a corresponding increase in the conductivity of the air, which in turn increases the opportunity for electrical short circuits as explained above.

[0095]

[0102] Therefore, in order to compensate for the rated altitude of the battery assembly which is higher than the test altitude, and to maintain a safety margin in the test process, the test voltage V1 in Figures 6A and 6B is higher than the operating voltage Va of the battery assembly 100. For example, the test voltage V1 is at least 1.2 times, 1.5 times, 2 times, 2.5 times, 2.8 times, 3 times, 3.5 times, 4 times, 4.5 times, or 5 times the operating voltage Va (where at least 1.2 times implies, for example, that V1 is at least 1.2 times Va). Just as an example, the operating voltage Va of the battery assembly 100 may be about 800V, and the test voltage V1 of the battery assembly 100 may be, for example, about 3,000V, 3,500V, or 3,550V, although the actual voltage may be specific to the implementation configuration.

[0096]

[0103] In the example, the voltage may be applied for at least a threshold time period. For example, the test may be formed for at least 60 seconds, but such a threshold time period may be specific to the implementation.

[0097]

[0104] Method 500 proceeds from 512 to 516. In 516, a determination is made as to whether the leakage current I (see Figures 6A and 6B) is greater than the threshold current value. In the example, the threshold current value may be 0.2 milliamperes (mA), or 0.5 mA, or 0.7 mA, or 1 mA, or 1.2 mA, or 1.5 mA, or 2 mA, or 5 mA, or 10 mA. In the example, the threshold current value may depend on the sensitivity of the battery assembly 100 to leakage current between the cooling plate and the conductive line 132, and / or on the critical operation at which the battery assembly 100 should be deployed.

[0098]

[0105] If the answer to 516 is yes (for example, if the leakage current I is greater than the threshold current value), this implies that the coating in process 504 is not sufficient to avoid the electrical short circuit described above. For example, the coating at the edge 312 may be insufficient, as described above with respect to Figure 3. Therefore, if the answer to 516 is yes, method 500 proceeds from 516 to 520. In 520, one or more additional layers of coating are reapplied onto the cooling plate. Method 500 then returns to 508, where water is resprayed onto the cooling plate and / or the cooling plate is placed in a humid environment or immersed in water, and the test of the cooling plate in 512 is performed again between the cooling plate and the metal plate.

[0099]

[0106] On the other hand, if the answer to 516 is "No" (for example, if the leakage current I is less than the threshold current value), this implies that the coating in process 504 is sufficient to avoid the electrical short circuit described above. For example, as described above with respect to Figure 4, the coating on the edge 312 is sufficient. Therefore, if the answer to 516 is "No", method 500 proceeds from 516 to 524. In 524, the battery assembly 100 is formed using cooling plates coated and tested according to processes 504 to 520. For example, each cooling plate 104a, 104b used in the battery assembly 100 may be coated and tested according to processes 504 to 520. The structure of the battery assembly 100 is described above with respect to Figures 1A to 1D. The battery assembly 100 may be formed using appropriate techniques for forming such a battery assembly.

[0100]

[0107] Method 500 proceeds to 524 to 528. In 528, the battery assembly 100 described above may be installed in an aircraft, in this example. In other examples, the battery assembly 100 may also be installed for other suitable applications.

[0101]

[0108] It should be noted that the processes in Method 500 are presented in a specific order for the sake of clarity. However, one or more of the processes may be performed in a different order or not at all, according to some embodiments (i.e., they may be optional). Based on this disclosure, numerous variations of Method 500 and the techniques described herein will become apparent.

[0102]

[0109] Figure 7A illustrates an exemplary type of battery cell 718 according to an embodiment of the present disclosure, and Figure 7B illustrates another exemplary battery assembly 700 comprising a plurality of battery cells 718 of Figure 7A according to an embodiment of the present disclosure.

[0103]

[0110] Referring to Figure 7A, the positive terminal 703 of the battery cell 718 is on one side of the battery cell 718 (marked with a "+" sign), and the negative terminal 707 of the battery cell 718 is on the other side of the battery cell 718 (marked with a "-" sign). The battery cell 718 further comprises a conductive shell 705 that is at least partially wrapped around the battery cell 718 and coupled to the negative terminal 707 of the battery cell 718. The conductive shell 705 is also referred to herein as the conductive outer surface 705 of the battery cell 718.

[0104]

[0111] The conductive outer surface 705 comprises one or more conductive materials, such as metals and / or alloys thereof. The conductive outer surface 705 forms an extension of the negative terminal 707. For example, conductive lines coupled to any portion of the conductive outer surface 705 are electrically coupled to the negative terminal 707. Note that the conductive outer surface 705 wraps at least partially around the side wall between the positive and negative terminals of the battery cell 718 and conducts current.

[0105]

[0112] As illustrated, both the positive terminal 703 and a portion of the conductive outer surface 705 are located on the same side of the battery cell 718 (e.g., the left side in the orientation of Figure 7A). Therefore, both the positive and negative terminals of the battery cell 718 can be accessed from the same side of the battery cell 718.

[0106]

[0113] Referring here to Figure 7B, the battery assembly 700 comprises a single cooling plate 704a. In this example, the cooling plate 704a comprises one or more thermally conductive materials, such as metals and / or alloys thereof, coated with one or more layers 708 of dielectric coating material (see Figure 7C). The cooling plate 704 provides cooling of the battery assembly 700, for example, by transferring heat from the assembly 700 to a coolant flowing through coolant tubes and / or to the surroundings. The coolant tubes are not illustrated in Figure 7B and may be similar to the coolant tubes 112a, 112b described above with respect to the battery assembly 100.

[0107]

[0114] In one embodiment, a plurality of battery cells 718 are arranged to extend laterally from the cooling plate 704. Several such exemplary battery cells 718a, 718b, 718c, and 718d are illustrated in Figure 7B.

[0108]

[0115] In the example, each battery cell 718 is substantially perpendicular to the cooling plate 704. Each battery cell 718 has a cathode or positive terminal 703 and an anode or negative terminal 707. The battery cell 718 has a corresponding negative terminal 707 facing the cooling plate 704, as illustrated. Thus, unlike the battery assembly 100, in the battery assembly 700, the negative terminal 707 of each battery 718 faces the cooling plate 704. Since the negative terminal 707 of the battery cell 718 faces the cooling plate 704, the cooling plate 704 does not need to have openings for outgassing.

[0109]

[0116] The thermal pad (also referred to herein as a gap pad) 726 is located between the cooling plate 704 and the battery cell 718. Note that the cooling plate 704 is on one side of the battery cell 718, and therefore the thermal pad 726 is also on the same side of the battery cell 718. The thermal pad 726 functions as a thermal interface material between the cooling plate and the battery cells 116, 118. For example, during the operation of the battery assembly 700, the thermal pad 726 transfers heat from the battery cell 718 to the cooling plate 704 to prevent or reduce the opportunity for the battery cell 718 to overheat. The thermal pad 726 comprises a dielectric material having a relatively high thermal conductivity.

[0110]

[0117] In one embodiment, the battery cells 718 are held in place by a honeycomb structure 722. The structure 722 is located on the sidewalls of the battery cells 718, where the sidewalls of the battery cells extend from their positive terminal to their negative terminal, as illustrated in Figure 7B. The structure 722 prevents or reduces movement of the individual battery cells 718 in the z-axis direction (e.g., the vertical direction in Figure 7B) and the y-axis direction (e.g., the direction in which the paper enters and exits in Figure 7B). In this example, the structure 722 also includes finger-like projections near the positive terminals 703 of the battery cells, such projections prevent or at least reduce movement of the individual battery cells 718 toward the left along the x-axis direction relative to the orientation in Figure 7B. Thus, unlike the battery assembly 100 in Figure 1 (e.g., it had a capture plate or retaining plate 124), the battery assembly 700 in Figure 7B does not have a capture plate or retaining plate. In this example, the structure 722 also functions as a capture plate. However, in another example, a separate capture plate may exist in the battery assembly 700, similar to the battery assembly 100.

[0111]

[0118] In one example, structure 722 comprises a rigid material having a dielectric material such as a relatively rigid plastic. In another example, structure 722 comprises a rigid material such as aluminum or another suitable material.

[0112]

[0119] In one embodiment, the assembly 700 comprises a plurality of conductive busbars or connecting lines 732, such as busbars or lines 732a, 732b, 732c, and 732d in Figure 7B. Note that, as discussed with respect to Figure 7A, the negative terminal 707 of the battery cell 718 is electrically extended to the same side as the positive terminal 703 by a conductive shell or outer surface 705. Therefore, both the positive and negative terminals are tapped from the same side of the battery cell 178, such as the left side in the orientation of Figure 7B.

[0113]

[0120] Thus, conductive line 732b connects the negative terminal of battery cell 718a to the positive terminal of battery cell 718b, conductive line 732c connects the negative terminal of battery cell 718b to the positive terminal of battery cell 718c, conductive line 732d connects the negative terminal of battery cell 718c to the positive terminal of battery cell 718d, and so on. In this way, battery cells 718a, 718b, 718c, and 718d are connected in series through lines 732a, 732b, 732c, and 732d. However, in another example, another suitable connection of battery cell 718 (e.g., parallel connection) may also be possible.

[0114]

[0121] In one embodiment, line 732 comprises one or more conductive materials such as metals and / or alloys thereof. Exemplary metals for line 732 include copper, aluminum, nickel, and / or one or more other metals and / or metal alloys used in the busbars or lines of the battery assembly.

[0115]

[0122] In one embodiment, the assembly 700 includes a flame-retardant dielectric material 730, such as a dielectric foam 730, adjacent to the junction between the battery terminals and the line 732. The foam 730 functions as a flame retardant and thermal barrier, for example, to prevent or reduce the opportunity for fire to propagate from the battery cells to the outside of the battery cells.

[0116]

[0123] In Figure 7B, the foam 730 is illustrated as a continuous foam with conductive lines 732 extending inside it. However, the foam 730 may be discontinuous and / or have openings, as with the foam 130 of the battery assembly 100 described earlier.

[0117]

[0124] It should be noted that since the negative terminal 707 of the battery cell 718 faces the cooling plate 704, the cooling plate 704 does not need to have an opening for outgassing. The foam 730 is not rigid, and outgassing from the positive terminal 703 of the battery assembly 718 can be vented through the foam 730. For example, during such a venting process, the foam 730 may burst to form a path for outgassing. In another example, although not illustrated in Figure 7B, the foam 730 may have an opening for outgassing (similar to, for example, the opening in the foam 130 of the battery assembly 100 described above).

[0118]

[0125] In one embodiment, the assembly 700 comprises a plurality of mounting brackets 711, such as bolts or screws. The mounting brackets 711 attach the heating pad 726 and the cooling plate 704 to the structure 722, as illustrated. For example, the mounting brackets 711 hold the heating pad 726 and the cooling plate 704 in place relative to the structure 722. For example, the mounting brackets 711 have a first end on the outer surface of the cooling plate 704 and a second side which is screwed or bolted into the structure 722 to secure the cooling plate 704 in place.

[0119]

[0126] In one embodiment, the cooling plate 704 has openings 708 (example openings 708a, 708b, etc.) through which mounting brackets 711 are inserted into the cooling plate 704. Unlike the battery assembly 100, in the battery assembly 700 the openings 708 are not aligned with the battery cells 718. Rather, the openings are aligned with the structure 722. The number of openings 708 in the cooling plate 704 is based on the desired number of mounting brackets 711 to be used to secure the cooling plate 704 to the structure 722.

[0120]

[0127] In the example, water can enter the opening 708 through capillary action or wicking action, for example, due to surface tension and / or gravity. Figure 7C illustrates an exemplary location of water droplets in the battery assembly 700 of Figure 7B according to an embodiment of the present disclosure. Note that, unlike the battery assembly 100, in the battery assembly 700, the opening 708 of the cooling plate 704 is not close to any of the conductive lines 732. Rather, the opening 708 of the cooling plate 704 is here close to the conductive shell or outer surface 705 of the battery cell 718. For example, water droplets can increase the opportunity for an electrical short circuit between the edge of the opening 708 and the conductive shell or outer surface 705 of the adjacent battery cell 718.

[0121]

[0128] Figure 7C also illustrates a dielectric material coating 708 on a cooling plate 704 of the battery assembly 700, where the coating 708 has at least a threshold thickness T1 on the edge 712 of the opening 708 of the cooling plate 704. In the example, the thickness T1 of the coating 708 is as described above with respect to Figure 4. For example, the thickness T1 of the edge 712 of the cooling plate 704 is, for example, at least 0.002 inches, or at least 0.003 inches, or at least 0.004 inches, or at least 0.005 inches, or at least 0.006 inches, or at least 0.007 inches, or at least 0.008 inches, or at least 0.01 inches, or at least 0.012 inches, or at least 0.015 inches. Furthermore, the average thickness T2 of the coating 708 on the non-edge surface of the cooling plate 704 is, for example, at least 0.005 inches, or at least 0.007 inches, or at least 0.009 inches, or at least 0.01 inches, or at least 0.02 inches, or at least 0.025 inches, or at least 0.03 inches.

[0122]

[0129] In the example, in Figure 7C, the opportunity for an electrical short circuit between the cooling plate 704 and the conductive outer surface 705 is eliminated or at least reduced, due to the increased thickness of the coating 708 at or near the edge 712 of the cooling plate 704 (compared to, for example, the thickness illustrated in Figure 3), and / or due to the sensible selection of the dielectric material used for the coating 708, as described above, for example, with respect to the battery assembly 100.

[0123]

[0130] In the example, the cooling plate 704 is tested and the battery assembly 700 is manufactured, at least in part, according to method 500 in Figure 5 described above. Further exemplary embodiments

[0124]

[0131] The following examples illustrate further embodiments, from which numerous substitutions and configurations will become apparent.

[0125]

[0132] Example 1. A battery assembly comprising a cooling plate having a conductive material and coated with a dielectric coating, wherein the cooling plate comprises an array of openings inside, a battery adjacent to the cooling plate, and a conductive line coupled to the positive terminal of the battery, wherein the distance between (i) the edge of an opening in the array of openings and (ii) one or both of the conductive line and the battery is at most 0.4 inches.

[0126]

[0133] Example 2. The battery assembly according to Example 1, wherein the cooling plate is a first cooling plate, the battery is a first battery, the positive terminal is a first positive terminal, the array of openings is an array of first openings, the first positive terminal of the first battery is adjacent to and substantially aligned with the first opening in the array of first openings, and the battery assembly further comprises a second cooling plate substantially parallel to the first cooling plate, wherein the second cooling plate comprises a conductive material and is coated with a dielectric coating, the second cooling plate comprises a second array of openings inside, and the second battery has a second positive terminal adjacent to and substantially aligned with the second opening in the array of second openings.

[0127]

[0134] Example 3. The battery assembly according to Example 2, wherein the first negative terminal of the first battery faces the second cooling plate and is not aligned with any of the openings in the array of the second openings, and the second negative terminal of the second battery faces the first cooling plate and is not aligned with any of the openings in the array of the first openings.

[0128]

[0135] Example 4. The battery assembly according to Example 2 or 3, further comprising a structure made of aluminum, the structure including at least a first slot and a second slot, wherein a first battery is located in the first slot and a second battery is located in the second slot.

[0129]

[0136] Example 5. The battery assembly according to any one of Examples 1 to 4, wherein the battery is configured to allow outgassing from or near the positive terminal of the battery during battery malfunction, so that the outgassing is vented out of the battery assembly through an opening in an array of openings in the cooling plate.

[0130]

[0137] Example 6. The battery assembly according to any one of Examples 1 to 5, wherein the cooling plate comprises a first surface facing the battery and a second surface opposite to the first surface, and the battery assembly further comprises coolant tubes disposed on the second surface of the cooling plate.

[0131]

[0138] Example 7. The battery assembly according to any one of Examples 1 to 6, wherein the array of openings is a first array of openings, and the battery assembly further comprises a thermal pad between the conductive lines and the cooling plate, the thermal pad having a second array of openings substantially aligned with the first array of openings of the cooling plate.

[0132]

[0139] Example 8. A battery assembly according to any one of Examples 1 to 7, further comprising a structure including a slot, wherein the battery is located within the slot and extends through an opening in an array of openings in a cooling plate and extends within the structure.

[0133]

[0140] Example 9. A battery assembly according to any one of Examples 1 to 8, wherein the thickness of the dielectric coating on the edge of the opening is at least 0.003 inches.

[0134]

[0141] Example 10. A method comprising: forming a cooling plate comprising a conductive material and having a plurality of openings; coating the cooling plate with a dielectric coating; placing the cooling plate proximal to a metal plate comprising one or more metals and exposing the cooling plate to moisture and / or water, wherein the minimum lateral distance between the cooling plate and the metal plate is at most 0.5 inches; applying a voltage across both ends of the cooling plate and the metal plate while the cooling plate is exposed to moisture and / or water and measuring the resulting leakage current passing through the cooling plate; and recoating the cooling plate with a dielectric coating in response to the leakage current being higher than a threshold.

[0135]

[0142] Example 11. The method according to Example 10, wherein exposing the cooling plate to moisture and / or water comprises immersing the cooling plate and metal plate in water.

[0136]

[0143] Example 12. The method of Example 10, wherein exposing the cooling plate to moisture and / or water comprises spraying water onto the cooling plate and / or operating a water humidifier adjacent to the cooling plate.

[0137]

[0144] Example 13. The method according to Example 10 or 11, further comprising: recoating the cooling plate with a dielectric coating; placing the recoated cooling plate in the vicinity of a metal plate; exposing the recoated cooling plate to moisture and / or water; and reapplying a voltage across both ends of the recoated cooling plate and the metal plate while the recoated cooling plate is exposed to moisture and / or water; and measuring the resulting leakage current through the recoated cooling plate.

[0138]

[0145] Example 14. The method according to any one of Examples 10-13, further comprising determining that the cooling plate formation process is complete in response to the leakage current being below a threshold.

[0139]

[0146] Example 15. The method according to Example 14, wherein, upon completion of the forming process, the thickness of the dielectric coating on the edges of the openings among the multiple openings is at least 0.003 inches.

[0140]

[0147] Example 16. The method according to any one of Examples 10-15, wherein the battery assembly on which the cooling plate is to be used is rated to operate at a first voltage, and the voltage applied across the ends of the cooling plate and the metal plate is at least three times the first voltage rating of the battery assembly to take into account the altitude of at least 10,000 ft on which the battery assembly is rated to operate.

[0141]

[0148] Example 17. The method according to any one of Examples 10-16, wherein applying a voltage comprises applying a voltage across both ends of the cooling plate and the metal plate for at least a threshold time period.

[0142]

[0149] Example 18. A system comprising an aircraft and a battery assembly installed inside the aircraft, the battery assembly comprising a cooling plate comprising a conductive material and coated with a dielectric coating, wherein the cooling plate comprises a first array of openings inside therein, wherein the thickness of the dielectric coating on the edges of the openings of the plurality of openings is at least 0.003 inches, and a battery having terminals adjacent to and substantially aligned with the openings of the first array of openings, conductive lines coupled to the terminals of the battery, and a thermal pad between the conductive lines and the cooling plate, wherein the thermal pad has a second array of openings substantially aligned with the first array of openings of the cooling plate.

[0143]

[0150] Example 19. The battery assembly is installed within a section of the aircraft, and the air pressure within the section of the aircraft is not adjusted when the aircraft is flying at a certain altitude, as described in Example 18.

[0144]

[0151] Example 20. The system described in Example 18 or 19, wherein the distance between the conductive line and the edge of the opening is at most 0.4 inches.

[0145]

[0152] The foregoing description of exemplary embodiments has been presented for illustrative and explanatory purposes only. It is not intended to be exhaustive or to limit this disclosure to the very forms disclosed. Many modifications and variations are possible based on this disclosure. The scope of this disclosure is intended to be limited not by the forms for carrying out the invention, but rather by the claims appended to this specification. Future applications claiming priority to this application may assert the disclosed subject matter in different ways and may generally include any set of one or more limitations as variously disclosed or otherwise demonstrated herein.

Claims

1. It is a battery assembly, A cooling plate comprising a conductive material and coated with a dielectric coating, wherein the cooling plate comprises an array of openings inside, The battery adjacent to the cooling plate, A conductive line connected to the positive terminal of the aforementioned battery and A battery assembly comprising (i) the edge of an opening in the array of openings and (ii) the distance between one or both of the conductive line and the battery is at most 0.4 inches.

2. The cooling plate is a first cooling plate, the battery is a first battery, the positive terminal is a first positive terminal, the array of openings is an array of first openings, the first positive terminal of the first battery is adjacent to and substantially aligned with the first opening in the array of first openings, and the battery assembly is A second cooling plate substantially parallel to the first cooling plate, wherein the second cooling plate comprises a conductive material and is coated with a dielectric coating, and the second cooling plate comprises an array of second openings inside thereof. A second battery having a second positive terminal adjacent to and substantially aligned with a second opening in the array of the second openings, The battery assembly according to claim 1, further comprising:

3. The first negative terminal of the first battery faces the second cooling plate and is not aligned with any of the openings in the array of the second openings. The second negative terminal of the second battery faces the first cooling plate and is not aligned with any of the openings in the array of the first openings. The battery assembly according to claim 2.

4. The structure further comprises aluminum, the structure including at least a first slot and a second slot, the first battery being located in the first slot and the second battery being located in the second slot. The battery assembly according to claim 2.

5. The battery is configured to allow outgassing from or near the positive terminal of the battery during a malfunction, so that the outgassing is vented out of the battery assembly through the openings in the array of openings of the cooling plate. The battery assembly according to claim 1.

6. The cooling plate comprises a first surface facing the battery and a second surface opposite to the first surface, and the battery assembly is The battery assembly according to claim 1, further comprising a cooling material tube disposed on the second surface of the cooling plate.

7. The array of openings is a first array of openings, and the battery assembly is The battery assembly according to claim 1, further comprising a thermal pad between the conductive line and the cooling plate, wherein the thermal pad has a second array of openings substantially aligned with the first array of openings of the cooling plate.

8. A structure including a slot, wherein the battery is located within the slot. Mounting brackets extending through the openings in the array of openings of the cooling plate and extending within the structure The battery assembly according to claim 1, further comprising:

9. The battery assembly according to claim 1, wherein the thickness of the dielectric coating on the edge of the opening is at least 0.003 inches.

10. It is a method, To form a cooling plate that is made of a conductive material and has multiple openings, Coating the cooling plate with a dielectric coating, The cooling plate is placed near a metal plate comprising one or more metals, and the cooling plate is exposed to moisture and / or water, wherein the minimum lateral distance between the cooling plate and the metal plate is at most 0.5 inches. While the cooling plate is exposed to the moisture and / or water, a voltage is applied across both ends of the cooling plate and the metal plate, and the resulting leakage current passing through the cooling plate is measured. In response to the leakage current being higher than the threshold, the cooling plate is recoated with the dielectric coating. A method that includes [a certain feature].

11. Exposing the cooling plate to moisture and / or water is, The method according to claim 10, further comprising immersing the cooling plate and the metal plate in water.

12. Exposing the cooling plate to moisture and / or water is, The method according to claim 10, further comprising spraying water onto the cooling plate and / or operating a water humidifier adjacent to the cooling plate.

13. Following the recoating of the cooling plate with the dielectric coating, The recoated cooling plate is placed near the metal plate, and the recoated cooling plate is exposed to moisture and / or water. While the recoated cooling plate is exposed to the moisture and / or water, a voltage is reapplied across both ends of the recoated cooling plate and the metal plate, and the resulting leakage current passing through the recoated cooling plate is measured. The method according to claim 10, further comprising:

14. In response to the leakage current being lower than the threshold, it is determined that the cooling plate formation process is complete. The method according to claim 10, further comprising:

15. The method according to claim 14, wherein, upon completion of the forming process, the thickness of the dielectric coating on the edges of the openings among the plurality of openings is at least 0.003 inches.

16. The battery assembly on which the cooling plate is to be used is rated to operate at a first voltage, and the voltage is applied across both ends of the cooling plate and the metal plate. The method according to claim 10, further comprising applying a voltage at least three times the first voltage rating of the battery assembly to both ends of the cooling plate and the metal plate, in order to take into account an altitude of at least 10,000 ft at which the battery assembly is rated to operate.

17. Applying the aforementioned voltage means The method according to claim 10, further comprising applying the voltage to both ends of the cooling plate and the metal plate for at least a threshold time period.

18. It is a system, Aircraft and The battery assembly installed inside the aircraft and The battery assembly comprises, A cooling plate comprising a conductive material and coated with a dielectric coating, wherein the cooling plate comprises an array of first openings inside, and the thickness of the dielectric coating on the edges of the openings is at least 0.003 inches. A battery having terminals adjacent to and substantially aligned with the openings in the array of the first openings, A conductive line connected to the terminal of the battery, The heat pad between the conductive line and the cooling plate A system comprising, wherein the heating pad has a second array of openings substantially aligned with the first array of openings of the cooling plate.

19. The system according to claim 18, wherein the battery assembly is installed within a section of the aircraft, and the air pressure within the section of the aircraft is not adjusted when the aircraft is flying at a certain altitude.

20. The system according to claim 18, wherein the distance between the conductive line and the edge of the opening is at most 0.4 inches.

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