Methods and systems for battery pack thermal management

Provided are methods and systems for battery pack thermal management, such as heating and cooling of individual batteries arranged into battery packs. The methods and systems use thermal control modules, specifically configured to thermally couple to the side wall and the bottom end of each battery in a battery pack. In some examples, a thermal control module comprises a thermal plate and one or two battery engagement components, connected and thermally coupled to the thermal plate. Each battery engagement component comprises a plurality of battery receiving openings. When the batteries are installed into these openings, the side wall and the bottom end of each battery are thermally coupled to the thermal control module, A thermal fluid is circulated through at least the thermal plate to provide cooling or heating to the batteries without any direct contact between the thermal fluid and the batteries,

BACKGROUND

Various powered systems (e.g., electric vehicles) use battery packs to store electrical energy. The performance of the batteries in these packs depends on their temperature. For example, most lithium-Ion batteries have a relatively narrow operating range of 0-50° C. Attempting to charge or discharge lithium-Ion batteries outside of this temperature range can cause permanent damage to the batteries and even unsafe conditions, especially when the batteries are overheated. On the other hand, thermal management of battery packs is challenging, especially of large battery packs used in electrical vehicles. In addition to environmental factors (e.g., cold or hot ambient temperatures), batteries experience internal heating during their operation, such as charge and discharge. The heat, generated inside a battery during its charge and/or discharge, is proportional to the square of the current multiplied by the internal resistance of the battery (P=I2×R). At the same time, higher charge-discharge currents are often needed for various applications, e.g., faster charging and acceleration of electric vehicles and electric grid balancing, which further complicates thermal management inside battery packs.

What is needed are methods and systems for battery pack thermal management, in particular, active battery cooling and heating.

SUMMARY

Provided are methods and systems for battery pack thermal management, such as heating and cooling of individual batteries arranged into battery packs. The methods and systems use thermal control modules, specifically configured to thermally couple to the side wall and the bottom end of each battery in a battery pack. In some examples, a thermal control module comprises a thermal plate and one or two battery engagement components, connected and thermally coupled to the thermal plate. Each battery engagement component comprises a plurality of battery receiving openings. When the batteries are installed into these openings, the side wall and the bottom end of each battery are thermally coupled to the thermal control module, A thermal fluid is circulated through at least the thermal plate to provide cooling or heating to the batteries without any direct contact between the thermal fluid and the batteries,

These and other examples are described further below with reference to the figures.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented concepts. The presented concepts may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail so as to not unnecessarily obscure the described concepts. While some concepts will be described in conjunction with the specific examples, it will be understood that these examples are not intended to be limiting.

Reference herein to “one example” or “one aspect” means that one or more feature, structure, or characteristic described in connection with the example or aspect is included in at least one implementation. The phrase “one example” or “one aspect” in various places in the specification may or may not be referring to the same example or aspect.

Introduction

Large battery packs, such as packs having capacities of at least 5 kWh, at least 20 kWh, or larger, are used for many different applications, such as electric vehicles, electrical grid storage/balancing, and the like. Some of these applications are associated with large charge and/or discharge currents passing through the battery pack. For example, large charge currents (e.g., over 100 A, or even over 300 A) may be used to expedite the charging of the battery pack in an electrical vehicle. Similarly, large discharge currents (e.g., over 1000 A) may be used during rapid accelerations of the vehicle. These electrical currents cause heating (e.g., resistive heating) of batteries inside the battery pack due to the internal resistance of these batteries. The generated heat is proportional to the square of the electrical current (P=I2×R), which illustrates the significant effect of the current on the heating of the batteries.

At the same time, the performance of lithium-ion batteries as well as other types of batteries is greatly impacted by the temperature of the batteries. The operating temperature range of a battery may depend on active materials used for battery electrodes, electrolyte composition, and overall battery design. Many types of batteries (e.g., nickel cadmium, nickel metal hydride, lithium ion) are designed to operate between about 0° C. and 50° C. For example, charging a lithium ion battery at temperatures below 0° C. may result in irreversible plating of metallic lithium because of limited diffusion at the negative electrode at low temperatures. This lithium plating can result in capacity losses and potentially unsafe conditions. Furthermore, charging a lithium ion battery at temperatures above 50° C., especially for prolonged periods of time, may result in internal gas generation and capacity losses. Overall, environment conditions (e.g., ambient temperature) and operating conditions (charge/discharge currents) impact the battery temperature and, if not managed, can result in temperature going outside of the operating range.

Various thermal management methods have been used for battery packs with different levels of success. Some examples include passive or forced air convection around individual batteries, flooding batteries in dielectric fluids (e.g., oils), extending cooling passages through an array of batteries, and positioning a cooling plate on one side of a battery array. However, air cooling is generally not sufficient, especially for high current applications. Air has a much lower heat transfer coefficient and heat capacity than liquids. Furthermore, flooded cooling, wherein a battery case is in direct contact with a cooling liquid, requires very specific non-conductive liquids to prevent battery shorting through the cooling liquid. Another issue comes from non-uniform flow of cooling liquids through complex paths formed by batteries arranged inside the battery packs. Stagnant fluid with minimal or no flow may cause undesirable hot and cold pockets in the battery pack, which should be avoided. However, flow paths are difficult to control due to the preset design of the batteries (e.g., all batteries having a cylindrical shape and being the same size) and the need to pack as many batteries as possible into a given space (e.g., to maximize the energy density of the battery pack).

Another method involves extending cooling passages through a battery array such that these passages contact side walls of cylindrical batteries. A cooling liquid flows through these cooling passages, while the passages provide heat transfer between the battery side walls and the cooling liquid. However, these passages occupy space significant amount of space inside the battery pack thereby reducing the energy density of the pack. Furthermore, these passages are typically very long and non-straight, which presents various challenges with establishing uniform flow of cooling liquids through these passages. Finally, cooling passages often cannot contact the entire perimeter of battery side walls thereby limiting the thermally coupling between the batteries and the cooling passages.

Another approach involves positioning a cooling plate at one side of a battery array. This approach relies on internal heat transfer with batteries along the height of the batteries. Furthermore, this approach may allow direct heat transfer among batteries through their side walls. Finally, a thermal coupling to a small end of a battery may not provide sufficient heat transfer between this battery and the cooling plate and can cause internal hot zones, e.g., away from the cooling plate.

Provided are methods and systems for thermal management of battery packs, which address various deficiencies of conventional systems, described above. Specifically, a thermal control module is used and specifically configured to thermally couple to at least a portion of the side wall and the bottom end of each battery in a battery pack. For example, an 18650 battery has top and bottom circular ends, each having a surface area of about 254 mm2, and a cylindrical side, having a surface area of about 3673 mm2(about 14.5 times greater than each of the circular ends). While the bottom end may be beneficial for thermal coupling because of its accessibility and because of the internal heat transfer within the battery, the cylindrical side has a large available surface for heat transfer. Overall, thermally coupling to the side wall, in addition to the bottom end of each battery in the battery pack, provides more uniform heat transfer between the batteries and the thermal control module.

Furthermore, the methods and systems utilize thermal fluids (e.g., liquids, gases, and combinations thereof) as heat carriers. A thermal fluid is flown through a thermal control module without directly contacting any of batteries positioned and thermally coupled to the thermal control module. While the batteries are thermally coupled to the thermal fluid (by the thermal control module), the batteries are physically separated and electrically isolated from the thermal fluid (also by the thermal control module). As such, there are no concerns about the batteries being electrically shortened by the thermal fluid or the thermal fluid causing corrosion of the batteries.

FIG. 1Ais a schematic illustration of battery pack100, in accordance with some examples. Battery pack100comprises batteries200and electrical interconnect module110, interconnecting batteries200. As further described below with reference toFIG. 13B, electrical interconnect module110may be connected to various electrical components of a system utilizing battery pack100. Electrical interconnect module110may be connected first and second contacts of each battery200in battery pack100. For example, electrical interconnect module110comprises bus bars, contact leads, and other like components to form these electrical connections. Various forms of electrical connections of batteries200by electrical interconnect module110are within the scope, e.g., individual connection of each battery, parallel connections, in-series connections, various combinations of parallel and in-series connections.

Battery pack100also comprises thermal control module120, thermally coupled to batteries200and controlling the temperature of batteries200during operation of battery pack100. For example, thermal control module120is used to prevent excessive heating of batteries200during rapid charging and/or discharging. In some examples, thermal control module120is used for heating batteries200, e.g., when battery pack100is operated in a cold environment. Various examples of thermal control module120are further described below.

Battery pack100also comprises battery pack controller195, which controls the operation of one or both electrical interconnect module110and thermal control module120. For example, battery pack controller195controls the flow rate (e.g., by controlling the operation of a pump) and/or the temperature of the thermal fluid supplied to thermal control module120(e.g., by controlling the operation of a thermostat, heater, pump, and/or other components of the overall system). In some examples, battery pack controller195monitors the temperature of the thermal fluid inside thermal control module120and/or leaving thermal control module120. Various operating examples of battery pack controller195are described below with reference toFIG. 12.

In some examples, battery pack100comprises multiple thermal control modules120as, for example, is shown inFIG. 1B. Specifically,FIG. 1Billustrates two thermal control modules120, each thermally coupled to two arrays of batteries200, e.g., to bottom ends and side walls of each battery200in the two arrays.FIG. 18also illustrates four electrical interconnect modules110, each electrically coupled to a separate array of batteries200, e.g., to top ends of each battery200.

Referring toFIG. 1A, thermal control module120comprises thermal plate130and battery engagement component140, connected and thermally coupled to thermal plate130. In some examples, thermal plate130and battery engagement component140are monolithic (e.g., fabricated as one component). Alternatively, thermal plate130and battery engagement component140are fabricated as separate components and then joined together to form thermal control module120.

During the operation of thermal control module120, batteries200are positioned within and supported by thermal control module120. For example, first ends201, which are sometimes referred to as top ends, of batteries200are electrically coupled to electrical interconnect module110. Battery engagement component140is thermally coupled to batteries200or, more specifically, to sides203of batteries200. In some examples, second ends202, which are sometimes referred to as bottom ends, of batteries200are thermally coupled to thermal plate130, either directly or through battery engagement component140. Alternatively, second ends202are also thermally coupled to battery engagement component140, Battery engagement component140is configured to transfer heat between batteries200(e.g., sides203and, in some examples, second ends202) and thermal plate130.

Thermal fluid109is circulated through at least thermal plate130and either remove heat from thermal control module120or add heat to thermal control module120. In some examples further described below, thermal fluid109also circulates through battery engagement component140. It should be noted that, batteries200do not have direct contact with thermal fluid109, thereby eliminating the risk of electrical shorts among batteries200through thermal fluid109. As such, an electrically conductive thermal fluid may be used in thermal control module120.

Thermal plate130is configured to provide uniform flow of thermal fluid109along the entire length (X-axis) of thermal control module120thereby eliminating temperature variations /cold and hot spots at least within thermal plate130. The heat transfer along the height (Z-axis) of thermal control module120is provided by battery engagement component140and, to some extent, by batteries200. A brief description of batteries200is helpful to understand thermal dynamics inside battery pack100.

FIG. 2Ais a schematic cross-sectional view of battery200, in accordance with some examples. In these examples, battery200is a cylindrical cell, having a wound arrangement of its electrodes. Specific examples of such batteries are 18650, 20700, 21700 and 22700 cells. This battery configuration is simple to manufacture and has good mechanical stability (e.g., able to withstand high internal pressures without deforming). However, other types of batteries, such as prismatic and pouch batteries are also within the scope.

Referring toFIG. 2A, battery200comprises first electrode221, second electrode222, and electrolyte224. First electrode221and second electrode222may be referred to as a negative electrode and a positive electrode or as an anode and a cathode. Electrolyte224provides ionic communication/exchange between first electrode221and second electrode222(e.g., allowing ions to shuttle between first electrode221and second electrode222during charge and discharge of battery200).

First electrode221and second electrode222are electrically insulated from each other. For example, separator223may be disposed between first electrode221and second electrode222to provide physical separation and electrical isolation of first electrode221and second electrode222. Separator223comprises pores and is soaked with electrolyte224, thereby allowing ionic exchange through separator223.

In some examples, first electrode221, separator223, and second electrode222are wound into cylindrical structures, often referred to as a “jelly-roll”. In other examples, first electrode221, separator223, and second electrode222are arranged into a stack. First electrode221, separator223, second electrode222, and electrolyte224may be referred to as internal components of battery200.

Battery200also comprises case230and cover232, which isolate the internal components from the environment. For example, some internal components may be sensitive to moisture and other environmental conditions. In some examples, case230and cover232are electrically isolated from each other, e.g., by seal233positioned between case230and cover232. In these examples, case230is electrically connected to first electrode221(e.g., a positive electrode or a cathode), while cover232is connected to second electrode222(e.g., a negative electrode or an anode). Furthermore, in these examples, case230is operable as first contact211of battery200, while cover232is operable as second contact212.

Case230and cover232form first end201, second end202, and side203of battery200. Referring toFIG. 2B, which shows a top view of battery200, cover232forms at least a portion of first end201(e.g., an inside portion). Case230forms another portion of first end201(e.g., an outside rim), As such, both electrical connections to battery200can be formed at first end201as, for example, shown inFIG. 1A. In other words, first contact211and second contact212of battery200are available at first end201, at least in this example. As noted above, electrical interconnect module110forms electrical connections to first contact211and also to second contact212. When these electrical connections are formed at first end201, second end202and side203remain available, e,g., for thermal coupling.

Referring toFIG. 2A, first electrode221and second electrode222extend along the height (the Z-axis) of battery200and are wound around the center axis (coinciding or parallel to the Z-axis) of battery200. Each of first electrode221and second electrode222comprises a metal current collector (e.g., a metal foil), which provides good thermal conductivity. Without being restricted to any particular theory, it is believed that the heat transfer, at least within wound cylindrical cell, is higher along its height (along the Z-axis) than along its diameter (along the X-axis and along the Y-axis). Furthermore, first electrode221and second electrode222are generally positioned closer to second end202than to first end201due to various design considerations associate with sealing battery200as well as providing first contact211and second contact212. As such, second end202is an effective thermal coupling location. However, the surface area of second end202is generally smaller than that of side203(e.g., about14.5times greater for18650-cell as noted above). As such, side203is also an effective coupling location. As described below, thermal control module120is thermally coupled to both second end202and side203of each battery200.

In some examples, battery200is a lithium ion battery. In these examples, first electrode221comprises a lithium containing material, such as Lithium Cobalt Oxide(LiCoO2), Lithium Manganese Oxide (LiMn2O4), Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2or NMC), Lithium Iron Phosphate(LiFePO4), Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2), and Lithium Titanate (Li4Ti5O12). Second electrode222comprises a lithium-getter material, such graphite, silicon, or the like. However, other types of batteries are also within the scope.

Examples of Thermal Control Modules

FIG. 3Ais a schematic cross-sectional view of thermal control module120, in accordance with some examples, prior to installing batteries200into thermal control module120.FIG. 3Cis a similar view of thermal control module120ofFIG. 3A, after installing batteries200into thermal control module120. Once batteries200are installed, thermal control module120is used for controlling temperature of batteries200in battery pack100.

As noted above, thermal control module120comprises thermal plate130and battery engagement component140. Referring toFIG. 3C, battery engagement component140is thermally coupled to sides203of batteries, while thermal plate130is thermally coupled to second end202, either directly or through a portion of battery engagement component140. Battery engagement component140may be also referred to first battery engagement component140to distinguish from second battery engagement component170, described below with reference toFIG. 3D.

Thermal plate130comprises first side131, extending along first axis121(X-axis) and second axis122(Y-axis) of thermal control module120. As shown inFIG. 3B, first axis12.1is perpendicular to second axis122. Thermal plate130also comprises second side132, also extending along first axis121and second axis122of thermal control module120. Second side132is offset relative to first side131along third axis123(Z-axis), Third axis123is perpendicular to each of first axis121and second axis122. At least one of first side131or second side132partially defines interior129of thermal control module120. First side131and second side132may be also referred to as a first wall and a second wall.

FIG. 3Aillustrates an example, where first side131and second side132define top and bottom boundaries of interior129. In this example, interior129is positioned in its entirety within thermal plate130. However, other examples, where a portion of interior129extends to battery engagement component140, are also within the scope. Some of these other examples are shownFIGS. 4A-4Dand described below. Overall, thermal control module120is designed such that all or at least most (e.g., at least 50% based on the total flow rate or at least about 75% of the total flow rate or even at least about 90% of the total flow rate) of thermal fluid190, which is supplied to thermal control module120, flows though thermal plate130, If any portion of thermal fluid190flows through first battery engagement component140and/or second battery engagement component170, the flow rate of this portion is less than that through thermal plate130.

Referring toFIGS. 3A-3C, thermal control module120also comprises thermal fluid ports134, configured to connect to thermal fluid lines and/or other components of the overall system. Thermal fluid ports134allow circulation of thermal fluid109in and out of thermal control module120and through interior129of thermal control module120.FIG. 3Billustrates an example with two thermal fluid ports134positioned along the same end of thermal control module120along the length of thermal control module120. One thermal fluid port134is used to supply thermal fluid109to interior129and may be referred to as an inlet port. The other thermal fluid port134is used to remove thermal fluid109from interior129and may be referred to as an outlet port. In some examples, the temperature of thermal fluid109supplied to and/or removed from thermal control module120is monitored at the inlet port and/or the outlet port. The thermal fluid lines may be connected to a pump, a heat exchanger, a heater, a chiller, and other like components for controlling the flow rate and the temperature of thermal fluid109flown into interior129of thermal control module120. Some examples of thermal fluid109include but are not limited to synthetic oil, water and ethylene glycol, poly-alpha-olefin oil, and the like.

Battery engagement component140is thermally coupled and connected to first side131of thermal plate130. In some examples, battery engagement component140and thermal plate130are monolithic as, for example, is shown inFIG. 3A. Alternatively, battery engagement component140and thermal plate130are initially formed as separate components and then attached to each other as, for example, is schematically shown inFIG. 5B.

Battery engagement component140comprises plurality of battery receiving openings141, extending along third axis123of thermal control module120. Each of plurality of battery receiving openings141is configured to receive one of batteries200as, for example, shown inFIG. 3B. A set of batteries200received by the same battery engagement component140may be referred to as an array of batteries200.FIG. 3Billustrates a two-dimensional array of batteries200, extending along first axis121(X-axis) and second axis122(Y-axis). Adjacent rows of cylindrical batteries may be offset relative to each other to increase battery density. When thermal control module120comprises first battery engagement component140and second battery engagement component170, thermal control module120is configured to receive and thermally couple two separate arrays of batteries200as, for example, is schematically shown inFIG. 3D.

In some examples, the size of battery receiving openings141is such that there is a snug fit between battery receiving openings141and batteries200, providing a direct contact and thermal coupling between battery engagement component140and batteries200. For example, the diameter of battery receiving openings141may be within 1-5% of the diameter of battery200, e.g., no more than 5% of the battery diameter or, more specifically, no more than 1%. Furthermore, in some examples, battery receiving openings141are formed by a compressible material (e.g., of sleeve160, further described below) to provide conformal direct contact between battery engagement component140and batteries200.

Furthermore, in some examples, battery engagement component140provides mechanical support to batteries200. For example, battery engagement component140retains batteries200in designed positioned and maintains the orientation of batteries200in thermal control module120even when battery pack100is subjected to various forces (e.g., flipped upside down), vibration, and the like. Once battery200is installed into battery engagement component140, the force required to remove battery200from battery engagement component140may be greater than, e.g., the weight of battery200. Overall, battery engagement component140thermally couples batteries200to thermal plate130(and, in some examples, to thermal fluid109), electrically insulates batteries200from thermal plate130and, more specifically, from thermal fluid109, physically isolates batteries200from thermal fluid109, and, in some examples, mechanically supports batteries200.

Referring toFIG. 3D, in some examples, thermal control module120further comprises second battery engagement component170, thermally coupled and connected to second side132of thermal plate130. Second battery engagement component170comprises second plurality of battery receiving openings171, extending along third axis123of thermal control module120, Each of second plurality of battery receiving openings171is configured to receive one of batteries200. Second battery engagement component170thermally couples this second plurality/second array of batteries200to thermal plate130, electrically insulates batteries200from thermal plate130and physically isolates batteries200from thermal fluid109. In these examples, battery engagement component140may be referred to as first battery engagement component140, in order to distinguish it from second battery engagement component170. Alternatively, thermal control module120comprises only one battery engagement component140.

In some examples, interior129is only disposed within thermal plate130. As such, the thermal fluid is flown only within thermal plate130as, for example, shown inFIG. 3C. In other words, interior129of thermal control module120does not extend into battery engagement component140, and the thermal fluid does flow through battery engagement component140. The heat transfer between sides203of batteries200and thermal plate130is provided by the thermal conductivity of one or more materials forming battery engagement component140. It should be noted that the thermal conductivity of batteries200is also relied on for heat transfer along third axis123(Z-axis) during operation of battery pack100.

Alternatively, battery engagement component140may comprise plurality of engagement module flow channels145as, for example, is shown inFIGS. 4A-4C. Engagement module flow channels145are disposed in between adjacent ones of plurality of battery receiving openings141and form a portion of interior129of thermal control module120. At the same time, engagement module flow channels145are fluidically isolated from battery receiving openings141such that the thermal fluid, provided in engagement module flow channels145, does not come in direct contact with batteries200.

In more specific examples shown inFIGS. 4A and 4B, first side131of thermal plate130comprises a plurality of thermal plate openings320. Each thermal plate opening320may be aligned and in fluid communication with one of engagement module flow channels145, This alignment feature provides fluidic communication between a portion of interior129formed by thermal plate130and a portion of interior129formed by battery engagement component140. As such, the thermal fluid can flow between these portions during operation of thermal control module120or, more generally, during operation of battery pack100. For example, the portion of interior129formed by thermal plate130may provide the main path for the thermal fluid within thermal control module120. The fluid thermal enters, flows within, and exists individual engagement module flow channels145thereby providing convection thermal transfer within battery engagement component140, in addition to conductive thermal transfer provided by the material forming battery engagement component140.

Referring toFIGS. 4A-4B, in some examples, engagement module flow channels145is in fluidic communication with a portion of interior129within thermal plate130. This interior portion is positioned between first side131and second side132. As noted above, this interior portion (within thermal plate130) provides the primary path for the thermal fluid, at least along first axis121(X-axis) and second axis122(Y-axis). This interior portion also sends some thermal fluid into extension fluid channels155thereby establishing convective heat transfer along third axis123(Z-axis) when the thermal fluid flows within extension fluid channels155. In some examples, engagement module flow channels145may not be directly connected with each other, Instead, each engagement module flow channels145receives and discharges the thermal fluid into this portion of interior129.

Alternatively, as for examples shown inFIG. 4C, engagement module flow channels145are isolated from with this portion of interior129, positioned between first side131and second side132. Instead, extension fluid channel155extends at least along first axis121and comprises extension fluid ports156. As such, interior129may be formed by two separate portions, one within thermal plate130and one within thermal extension150. These separate interior portions may not be in fluidic communication with each other, at least directly. Fluidic separation of these portions allows for independent flow control of the thermal fluid in each portion, providing additional level of the overall process control.

Referring toFIG. 5A, in some examples, battery engagement component140comprises thermal extension150and sleeve160. In these examples, the primary function of thermal extension150may be mechanical support to batteries200and to sleeve160as well as the heat transfer, while the primary function of sleeve160may be electrical isolation of batteries200from thermal extension150. The addition of sleeve160to thermal extension150allows using various electrically conductive materials for thermal extension150, such as metals or, more specifically, copper, aluminum, and the like. These materials have high thermal conductivity.

Sleeve160is formed from a thermally-conductive polymer or coating, which is electrically insulating. Some examples of materials suitable for sleeve160are polymers with non-conductive ceramic filers, e.g., boron nitride and aluminum nitride. In some examples, the thermal conductivity of a material forming sleeve160is at least about 0.5 W/mK or even at least about 2 W/mK. The electrical conductivity of a material forming sleeve160is less than 10−10S/m or even less than 10−15S/m.

Sleeve160forms at least a portion of each battery receiving opening141. As such, in some examples, when batteries200are installed into thermal control module120, only sleeve160(out of components of thermal control module120) contacts batteries200. Sleeve160electrically insulates thermal extension150from batteries200, thereby preventing shortening of batteries200by thermal extension150. At the same time, sleeve160thermally couples thermal extension150to batteries200, thereby providing a thermal path from batteries200to thermal extension150. In some examples, the thickness of sleeve160is between about 0.5 mm and 5 mm or, more specifically, between 1 mm and 3 mm.

Referring toFIG. 5A, sleeve160may extend to thermal plate130and, in some examples, form the bottom of each battery receiving opening141. In these examples, sleeve160also electrically insulates batteries200from thermal plate130, which allows forming thermal plate130from electrically conductive materials, such as metals or, more specifically, copper, aluminum, and the like.

Also, referring toFIG. 5A, thermal extension150directly interfaces first side131of thermal plate130thereby providing direct thermal transfer and mechanical support between thermal extension150and thermal plate130. In some examples, thermal extension150is welded, braised, soldered, or otherwise attached to thermal plate130. Alternatively, thermal extension150is monolithic with thermal plate130, e.g., formed from the same initial block of material.

Referring toFIG. 5B, in some examples, battery engagement component140and thermal plate130are made from different components and later joined together to form thermal control module120. For example, battery engagement component140may be formed from a thermally conductive polymer, while thermal plate130is formed from a metal. Various examples of suitable thermally conductive polymers are listed above.

Various examples and features of thermal plate130will now be described with reference toFIGS. 6A-6E. In the illustrated example, first portion133of thermal plate130is monolithic with first battery engagement component140, while second portion137of thermal plate130is monolithic with second battery engagement component170. For example, first portion133of thermal plate130and first battery engagement component140are fabricated as a single component, which is then joined together with second portion137of thermal plate130and second battery engagement component170, e.g., during assembly of thermal control module120, e.g., welded, braised, soldered, or otherwise attached. However, various features of thermal plate130, which are shown and described with reference toFIGS. 6A-6E, are also applicable to other integration examples of thermal plate130and one or more battery engagement components, which are described above.

As noted above, thermal plate130forms at least a portion of interior129of thermal control module120. Furthermore, thermal plate130is the main carrier of thermal fluid109in thermal control module120or, in some examples, the only carrier of thermal fluid109. Thermal plate130also supports and is thermally coupled to one or two battery engagement components (or integrated with one or two battery engagement components).

Referring toFIG. 6A, in some examples, thermal plate130comprises a plurality of diffusers135disposed within interior129or at least a portion thereof. Diffusers135are supported by at least one of first side131or second side132. Diffusers135are configured to redirect the thermal fluid within interior129thereby ensuring the uniform flow of the thermal fluid and avoiding cold and hot spots, associated with the stagnant or excessively fast-slowing thermal fluid. Diffusers135are configured to redirect the thermal fluid flowing along first axis121(X-axis) at least along second axis122(Y-axis). It should be noted that the main flowing direction of the thermal fluid within interior129is along first axis121(X-axis).

In some examples, diffusers135extend between and contacts each of first side131and second side132as, for examples, is shown inFIG. 6B. For example, diffusers135may be attached to or monolithic with one of first side131or second side132and contact the other side. In these examples, diffusers135act as heat spreaders between first side131and second side132thereby ensuring temperature uniformity within interior129, in addition to the thermal fluid. Furthermore, diffusers135may provide mechanical support to first side131and second side132(e.g., relative to each other such as transfer forces between first side131and second side132). This feature allows forming first side131and second side132with thinner walls thereby reducing the weight and improving thermal transfer of thermal control module120,

Referring toFIG. 6C, in some examples, each of plurality of diffusers135comprises diffusing surface310, having an acute angle relative to first axis121. Diffusing surface310is configured to redistribute the thermal fluid within the X-Y plane, e.g., redirects the thermal fluid flowing along first axis121(X-axis).

In some examples, thermal plate130comprises divider136, extending along third axis123(Z-axis) as, for example, shown inFIGS. 6D and 6E. When thermal plate130is assembled, divider136extends between first side131and second side132. Furthermore, divider136extends, along first axis121(X-axis), most of the thermal plate length. Specifically, divider136extends to the edge of thermal plate130containing the thermal fluid ports134, but not to the opposite edge, thereby creating a gap with the opposite edge. Divider136separates at least a portion of interior129(within thermal plate130) into first part331and second part332. This separation prevents the thermal fluid to transfer between first part331and second part332, other than through the gap between divider136and the opposite edge of thermal plate130, thereby forcing the thermal fluid to travel the entire length of thermal plate130.

One of thermal fluid ports134, e.g., an inlet, is in fluidic communication with first part331, while another one of thermal fluid ports134, e.g., an outlet, is in fluidic communication with second part332. As such, when the thermal fluid is supplied through the inlet into first part331, the thermal fluid flows through first part332the entire length of thermal plate130before returning back, through the gap between divider136and the opposite edge, to the outlet. During this return, the thermal fluid flows through second part332, also the entire length of thermal plate130. Overall, divider136ensures that the thermal fluid reaches various parts of interior129.

Referring toFIGS. 7A and 7C, in some examples, thermal extension150comprises first extension portion151and second extension portion152, both extending along first axis121of thermal control module120. First extension portion151and second extension portion152may be individual components, independently connected to thermal plate130. First extension portion151and second extension portion152form extension channel153, between first extension portion151and second extension portion152. In these examples, some battery receiving openings141are positioned within extension channel153.

Sleeve160extends into channel153and prevents at least direct contact between the batteries and thermal fluid. As shown inFIGS. 7A and 7B, sleeve160comprises first sleeve portion161, disposed in extension channel153and attached to first extension portion151. Sleeve160also comprises second sleeve portion162, disposed in extension channel153and attached to second extension portion152. In this example, first extension portion151and second extension portion152provide support to first sleeve portion161and second sleeve portion162, respectively. First sleeve portion161and second sleeve portion162are optional and, in some examples, the thermal fluid directly contacts first extension portion151and second extension portion152of thermal extension150.

Referring toFIGS. 7A-7C, in some examples, sleeve160comprises third sleeve portion163, forming battery receiving openings141. In these examples, sleeve fluid channel165extends between third sleeve portion163and each of first sleeve portion161and second sleeve portion162. Sleeve fluid channel165is a specific example of module flow channels145. In more specific examples, shown inFIG. 7B, sleeve160further comprises fourth sleeve portion164, attached to first side131of thermal plate130. Sleeve fluid channel165extends between third sleeve portion162and fourth sleeve portion164.

Furthermore, extension channel153comprises bridging portion199, disposed and extending between two adjacent battery receiving openings141as, for example, schematically shown inFIGS. 7C and 7D. Bridging portion199allows positioning sleeve160that is continuous (at least within each extension channel153). The same sleeve may extend along the length of battery engagement component140, within each extension channel153, and define multiple battery receiving openings141. Furthermore, bridging portion199may be used to access sides203of batteries200during installation and removal of batteries200from thermal control module120.

Referring toFIG. 7D, in some examples, thermal extension150comprises extension fluid channel155, configured to receive the thermal fluid. Extension fluid channel155is specific examples of module flow channels145. Providing the thermal fluid within thermal extension150helps with heat transfer between batteries200and the thermal fluid. Specifically, without extension fluid channels155(and also without sleeve fluid channels165), the only heat transfer from the sides of batteries200to thermal plate130is conductive heat transfer provided by the material, forming thermal extension150. Extension fluid channel155also adds convective heat transfer when the thermal fluid flows within extension fluid channel155.

Referring toFIG. 8A, width154of extension channel153, measured along second axis122(the Y-axis) of thermal control module120, may be variable. In other words, the measurements of width154differ at different positions within extension channel153, along first axis121(the X-axis). Specifically, extension channel153comprises a plurality of channel openings198, each corresponding to one of the plurality of battery receiving openings141. Two adjacent channel openings198are separated by bridging portion199. Bridging portion199has a smaller width than channel openings198. In some examples, width154of extension channel153has the highest value at channel openings198or, more specifically, at the center of each channel opening198. Varying width154of extension channel153allows increasing thermal coupling between battery engagement component140and batteries200. Specifically, the interface area (either directly or through sleeve160) between battery engagement component140and batteries200is increased when channel openings198have the same shape as batteries200, e.g., the circular shape within the X-Y cross-section. For example, the interface portion between battery engagement component140and each battery200may represent between about 50% and 90% of the side surface area of each battery200or, more specifically, between about 60% and 80%.

Referring toFIGS. 8A and 8B, in some examples, sleeve160comprises a plurality of sleeve cups169, separated from each other. Each sleeve cup169is inserted into one of plurality of channel openings198. Once inserted, each sleeve cup169defines one of plurality of battery receiving openings141. In some examples, sleeve cup169is first installed onto battery200. Then, this assembly, including battery200and sleeve cup169, is inserted as a unit into one of channel openings198. This feature simplifies fabrication of sleeve160as well as installation of sleeve160,

Referring toFIG. 9, in some examples, thermal extension150comprises plurality of triangular extensions157, each connected or otherwise integrated to first side131of thermal plate130. At least three triangular extensions157define each battery receiving opening141as, for example, is shown inFIG. 10A. In this example, battery200, positioned into battery receiving opening141is in thermal communication with three triangular extensions157. Furthermore, the bottom end of battery200may be in direct thermal communication with first side131of thermal plate130,

FIG. 10Billustrates an example, in which six triangular extensions157define each battery receiving opening141. Specifically,FIG. 10Billustrates battery200, positioned in battery receiving opening141and in thermal communication with all six triangular extensions157. It should be also noted that some triangular extensions157, may each define multiple battery receiving openings141and may be thermally coupled to multiple batteries200. For example, triangular extension157, identified with an arrow inFIG. 10B, is thermally coupled to three batteries200,

Referring toFIGS. 10A and 10B, in some examples, each of plurality of triangular extensions157has at least two curved sides158. In more specific examples, each of plurality of triangular extensions157has three curved sides158. Each curved side158is configured to conform to side203of battery200. In some examples, the curvature radius of each of at least two curved side158of each of plurality of triangular extensions157is between 1-10% greater than radius of each of batteries200.

Referring toFIG. 10C, in some examples, sleeve160fully covers each of plurality of triangular extensions157. Furthermore, sleeve160may at least partially extend to first side131of thermal plate130, thereby forming a sleeve spacer in each of plurality of battery receiving opening141. The sleeve spacer prevents direct contact between thermal plate130and battery200when battery200is installed into battery receiving opening141. More specifically, first side131of thermal plate130comprises plurality of exposed portions139. Exposed portions139is not covered by sleeve160. It should be noted that a portion of sleeve160may cover a portion of first side131. Exposed portions139are positioned between these covered portions.

FIG. 11Ais a schematic exploded view of thermal control module120, in accordance with some examples. Similar to the example described above with reference toFIG. 6A, in this example, thermal plate130comprises first portion133and second portion137. Each of these portions comprises triangular extensions157and a corresponding sleeve block, which is inserted onto triangular extensions157. Specifically, the overall sleeve160of thermal control module120comprises first sleeve block167, which is inserted onto triangular extensions157of first portion133, when thermal control module120is assembled, and second sleeve block168, which is inserted onto triangular extensions157of second portion137. Each of these sleeve blocks comprises plurality of battery receiving openings141as, for example, more clearly shown inFIG. 11B. Battery receiving openings141are open on top surfaces of the sleeve blocks, which face away from thermal plate130. In some examples, battery receiving openings141are open on top surfaces of the sleeve blocks, which face away from thermal plate130. The bottom of each battery receiving openings141may be formed by the corresponding sleeve block to prevent direct contact between batteries200and thermal plate130. Furthermore, each of these sleeve blocks comprises plurality of extension receiving openings166as, for example, more clearly shown inFIG. 11C. Triangular extensions157extend into extension receiving openings166, when thermal control module120is assembled.

Operating Examples

FIG. 12is a process flowchart corresponding to method1200of operating of battery pack100, comprising thermal control module120, in accordance with some examples. Various examples of thermal control module120are described above. Some operations of method1200may be performed by battery pack controller195.

Method1200may commence with determining the temperature of the thermal fluid (block1210). The temperature of the thermal fluid is representative of the battery temperature because of thermal coupling between batteries200and the thermal fluid, provided by thermal control module120. The temperature of the thermal fluid may be measured inside thermal control module120(e.g., a thermocouple positioned within interior129) or at one of thermal fluid ports134, e.g., an exit thermal fluid port. This temperature determining operation may be performed continuously during operation of battery pack100.

Method1200may proceed with determining thermal fluid conditions (block1220). Some examples of these conditions are one or more flow rates of the thermal fluid through thermal control module120(or, more specifically, through individual components of thermal control module120when the thermal fluid is independently directed through multiple components) and the temperature of the thermal fluid supplied into thermal control module120. In some examples, these thermal fluid conditions are determined based on the temperature of the thermal fluid determined during the operation discussed above and represented by block1210. Furthermore, these thermal fluid conditions may be determined based on electrical operating conditions associated with battery pack100. For example, if a high current is being passed through battery pack100(e.g., during its charge or discharge) or will be passed in near future, the thermal fluid conditions may be adjusted preemptively, e.g., even before the outgoing thermal fluid temperature reflects these electrical operating conditions.

Method1200also involves flowing the thermal fluid through thermal control module120(block1230). This operation is performed in accordance with the thermal fluid conditions determined during the operation discussed above and represented by block1220. Either battery pack100or a facility (e.g., an electrical vehicle) where battery pack100is installed may be equipped with various components, such as a pump, a heater, and/or a chiller for pumping, heating, and/or cooling the thermal fluid before supplying the thermal fluid to thermal control module120. These components may form a continuous loop with thermal control module120such that the thermal fluid, existing thermal control module120, is heated or cooled and pumped back into thermal control module120. These components may be controlled by battery pack controller195and may be used for other operations, e.g., such as heating or cooling the interior of an electrical vehicle.

Electric Vehicle Examples

Some examples of thermal control module120and battery pack100, comprising one or more thermal control modules120, can be deployed in electric vehicles or, more specifically, hybrid electric vehicles, plug-in hybrid electric vehicles, and all-electric vehicles. For example,FIGS. 13A and 13Bare schematic illustration of electric vehicle250, which comprises battery pack100and vehicle modules260. Some examples of vehicle modules260are heating module262, cooling module264, inverter266, and motor268as, for example, schematically shown inFIG. 13B. Heating module262and/or cooling module264may be used for heating and cooling of the interior of electric vehicle250. In some examples, heating module262and/or cooling module264is fluidically coupled to thermal fluid ports of thermal control module120, provided in battery pack100. The heating fluid is controllably pumped between interior129of thermal control module120and one or both of heating module262and/or cooling module264. As such, heating module262and cooling module264may be used for controlling the temperature of the thermal fluid. Inverter266and motor268may be coupled to electrical interconnect module110of battery pack100, such that battery pack100is configured to supply and receive the electrical power to/from inverter266and motor268. In some examples, battery pack100also supplies electrical power to heating module262and/or cooling module264.

Further Examples

Further, the description includes examples according to the following clauses:

Clause 1. Thermal control module120for controlling temperature of batteries200in battery pack100, thermal control module120comprising:

thermal plate130, comprising:first side131, extending along first axis121and second axis122of thermal control module120, wherein first axis121is perpendicular to second axis122;second side132, extending along first axis121and second axis122of thermal control module120and being offset relative to first side131along third axis123, perpendicular to each of first axis121and second axis122, wherein at least one of first side131or second side132at least partially defines interior129of thermal control module120;thermal fluid ports134, configured to connect to thermal fluid lines and flow thermal fluid109in and out of interior129of thermal control module120; and

first battery engagement component140, thermally coupled and attached to first side131of thermal plate130and comprising plurality of battery receiving openings141, extending along third axis123of thermal control module120,wherein each of plurality of battery receiving openings141is configured to receive one of batteries200, such that first battery engagement component140thermally couples batteries200to thermal plate130, electrically insulates batteries200from thermal plate130, and fluidically isolates batteries200from thermal fluid109.

thermal plate130comprises plurality of diffusers135disposed within interior129and supported by at least one of first side131or second side132,

plurality of diffusers135are configured to redirect thermal fluid through interior129at least along second axis122.

Clause 3. Thermal control module120of clause 2, wherein each of plurality of diffusers135extends between and contacts each of first side131and second side132.

Clause 4. Thermal control module120of any one of clauses23, wherein each of plurality of diffusers135comprises a diffusing surface310, having an acute angle relative to first axis121.

Clause 5. Thermal control module120of clause 4, wherein the acute angle differs for at least two of the plurality of diffusers (135).

Clause 6. Thermal control module120of any one of clauses 1-5, wherein:

first battery engagement component140comprises plurality of engagement module flow channels145, disposed among plurality of battery receiving openings141, such that plurality of engagement module flow channels145are fluidically isolated from plurality of battery receiving openings141,

first side131comprises plurality of thermal plate openings320, each being aligned and in fluid communication with one of plurality of engagement module flow channels145such that plurality of engagement module flow channels145form portion of interior129of thermal control module120,

Clause 7. Thermal control module120of clause 6, wherein thermal plate130comprises plurality of diffusers135, each being aligned with one of plurality of thermal plate openings320and configured to direct thermal fluid into one of plurality of thermal plate openings320.

Clause 8. Thermal control module120of any one of clauses 1-7, wherein:

thermal plate130comprises divider136, extending along third axis123between first side131and second side132also along first axis121thereby separating at least a portion of interior129into first part331and second part332,

one of thermal fluid ports134is in fluidic communication with first part331, and

another one of thermal fluid ports134is in fluidic communication with second part332.

Clause 9. Thermal control module120of any one of clauses 1-8, wherein both of thermal fluid ports134are positioned on the same end of thermal plate130along first axis121.

Clause 10. Thermal control module120of any one of clauses 1-9, wherein:

thermal extension150is formed from a metal,

sleeve160is formed from a thermally-conductive polymer or a thermally conductive coating, and

sleeve160forms at least a portion of each of plurality of battery receiving openings141.

Clause 12. Thermal control module120of clause 11, wherein extension channel153extends to and at least partially formed by first side131of thermal plate130.

Cause 13. Thermal control module120of clause 12, wherein width154of extension channel153, measured along second axis122of thermal control module120, is variable.

Clause 14. Thermal control module120of clause 12, wherein extension channel153comprises plurality of channel openings155, each defining one of plurality of battery receiving openings141and each having the diameter corresponding to the highest value of to width154of extension channel153.

sleeve160comprises plurality of sleeve cups169, separated from each other; and

each of plurality of sleeve cups169is inserted into one of plurality of channel openings155and defining one of plurality of battery receiving openings141.

Clause 16. Thermal control module120of clause 10, wherein thermal extension150comprises extension fluid channel155, configured to receive thermal fluid.

Clause 17. Thermal control module120of clause 16, wherein extension fluid channel155is in fluidic communication with a portion of interior129positioned between first side131and second side132.

Clause 18. Thermal control module120of clause 16, wherein extension fluid channel155is isolated from with a portion of interior129positioned between first side131and second side132, and wherein extension fluid channel155extends along first axis121, and comprises extension fluid ports156.

Clause 19. Thermal control module120of any one of clauses 10-18, wherein thermally-conductive polymer of sleeve160comprises ceramic filler.

Clause 20. Thermal control module120of any one of clauses 10-19, wherein sleeve160entirely forms each of plurality of battery receiving openings141.

Clause 21. Thermal control module120of any one of clauses 10-20, wherein sleeve160comprises first sleeve portion161and second sleeve portion163, forming a sleeve fluid channel165, configured to receive thermal fluid.

Clause 22. Thermal control module120of clause 21, wherein sleeve fluid channel165is in fluidic communication with a portion of interior129disposed between first side131and second side132.

Clause 23. Thermal control module120of clause 21, wherein sleeve fluid channel165is isolated from a portion of interior129disposed between first side131and second side132.

thermal extension150comprises first extension portion151and second extension portion152, both extending along first axis121of thermal control module120and forming extension channel153between first extension portion151and a second extension portion152, first sleeve portion161is disposed in extension channel153and attached to first extension portion151, and

second sleeve portion162is disposed in extension channel153and attached to second extension portion152.

sleeve160further comprises third sleeve portion163, forming at least portion of each of plurality of battery receiving openings141, and

sleeve fluid channel165extends between third sleeve portion162and each of first sleeve portion161and second sleeve portion162.

sleeve160further comprises fourth sleeve portion164, attached to first side131of thermal plate130, and

sleeve fluid channel165extends between third sleeve portion162and fourth sleeve portion164.

thermal extension150comprises plurality of triangular extensions157, each connected to first side131of thermal plate130; and

at least three of plurality of triangular extensions157defining each of plurality of battery receiving openings141.

Clause 28. Thermal control module120of clause 27, wherein each of plurality of triangular extensions157has at least two curved sides158.

Clause 29. Thermal control module120of any one of clauses 27-28, wherein sleeve160fully covers each of plurality of triangular extensions157and at least partially extends to first side131of thermal plate130forming a sleeve spacer in each of plurality of battery receiving openings141.

Clause 31. Thermal control module120of any one of clauses 1-30, wherein thermal plate130and first battery engagement component140are monolithic.

Clause 32. Thermal control module120of any one of clauses 1-31, wherein each of plurality of battery receiving openings141is configured to snuggly fit one of batteries200.

Clause 33. Thermal control module120of any one of clauses 1-32, further comprising second battery engagement component170, thermally coupled and connected to second side132of thermal plate130and comprising second plurality of battery receiving openings171, extending along third axis123of thermal control module120, wherein each of second plurality of battery receiving openings171is configured to receive one of batteries200, such that second battery engagement component170thermally couples batteries200to thermal plate130, electrically insulates batteries200from thermal plate130, and fluidically isolates batteries200from thermal fluid.

thermal plate130and second battery engagement component170are monolithic, and

first side131and second side132of thermal plate130are joined together thereby forming interior129of thermal control module120.

Clause 35. Thermal control module120of clause 33, wherein each of first battery engagement component140and second battery engagement component170comprises insulating coating, electrically insulating batteries200from thermal plate130.

Conclusion

Different examples and aspects of apparatus and methods are disclosed herein that include a variety of components, features, and functionality. It should be understood that various examples and aspects of apparatus and methods disclosed herein may include any of components, features, and functionality of any of other examples and aspects of apparatus and methods disclosed herein in any combination, and all of such possibilities are intended to be within spirit and scope of present disclosure.

Many modifications and other examples of disclosure set forth herein will come to mind to one skilled in art to which disclosure pertains having benefit of teachings presented in foregoing descriptions and associated drawings,

Therefore, it is to be understood that disclosure is not to be limited to specific examples presented and that modifications and other examples and aspects are intended to be included within scope of appended claims. Moreover, although foregoing descriptions and associated drawings describe examples in context of certain illustrative combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative implementations without departing from scope of appended claims.