System for controlling battery temperature

Abstract

Provided herein is a system for regulating the temperature of a battery of cells. The system comprises a battery module [21] and a charging device [31]. The battery module [21] comprises a battery of electrochemical cells [23] and a first heat exchanger [22] comprising an endpiece [25] connected to one or more plates [24], wherein each plate [24] is in thermal communication with a face of the electrochemical cells [23]. The charging device [31] comprises a second heat exchanger [32] comprising a thermal body [33] in thermal communication with a heat source and / or heat sink [36]. The charging device [31] is connectable to the battery module [21], and when the charging device [31] is connected to the battery module [21], the endpiece [25] of the battery module [21] is in thermal communication with the thermal body [33] of the charging device [31]. The system may be used to efficiently regulate the temperature of a battery of a power tool or an electric vehicle. Also provided are a battery module and a charging device suitable for use in the system.

Description

[0001] System For Controlling Battery Temperature

[0002] Related Applications

[0003] This application claims the benefit of, and priority from, GB 2416579.7 filed 11 November 2024 (11.11 .2024), the contents and elements of which are herein incorporated by reference for all purposes.

[0004] Field of the Invention

[0005] The present invention relates to a system, battery module and charging device, for controlling battery temperature, as well as method of controlling battery temperature and uses of the system, battery module and charging device.

[0006] Background

[0007] The use of battery power has become more widespread with increased requirements for electrification due to the known detrimental environmental effects of the use of fossil fuels in applications such as vehicles. As such, batteries are available in a variety of types and sizes and are used as electrical power sources in a range of applications. However, batteries require thermal controls and protections; if heat generated by a battery is not effectively removed, the performance of the battery will decrease and in extreme cases there is an increased risk of thermal runaway, which can lead to fire or explosion.

[0008] In a high-rate battery system, significantly more heat is generated during charging and discharging than in conventional battery systems. There is therefore an increased requirement for cooling which is not provided for by conventional battery cooling systems.

[0009] Batteries, such as pouch cells or prismatic cells, are typically cooled by edge cooling, where heat is taken from a thermally conductive material arranged at the edge of a cell, or tab cooling, where heat is taken from the electrically conductive tabs connected to the current collectors. Edge cooling is increasingly common because it allows for an efficient use of space and therefore improves energy density. However, it requires specialised configurations of cells, such as thicker cells, with no seams on the edges used for cooling. Cells which are not optimised for edge cooling cannot be effectively cooled in this way. Both edge cooling and tab cooling are relatively inefficient, as the area used to transfer the heat away from the cell is limited. The tabs are also typically welded to the current collectors, giving poor thermal conductance from the cell, and are selected for their electrical conducting properties, rather than their thermal conductance - so provide relatively poor thermal transfer out of the cell.

[0010] As a result, these conventional approaches rely on high throughput air or liquid cooling, to efficiently dissipate heat from the edges or tabs. The high throughput air or liquid cooling require the battery modules to be open, and non-sealed, to allow the air / liquid to effectively

[0011] 008874653 circulate through the battery module. This open architecture reduces the Ingress Protection (IP) rating of the battery module. A reduced IP rating negatively affects the commercial and practical value of the pack.

[0012] For example, EP 1178557 A2 describes a system for regulating the temperature of a battery during charging. However, this system requires air to be blown over the cells from a fan in the charger, or the inclusion of a fan in the battery pack itself. This means that the battery pack casing must have vents, which limits the IP rating of the pack.

[0013] The present invention seeks to address these problems.

[0014] Summary of the Invention

[0015] At its most general, the present invention provides a system for regulating the temperature of a battery of cells, by providing a heat exchanger in a charging device which is in thermal communication with a heat exchanger in a battery module. The charging device can provide efficient cooling to the battery, while keeping the battery module sealed.

[0016] Accordingly, in a general aspect of the invention there is provided a system for controlling battery temperature, the system comprising a battery module and a charging device, the battery module comprising: a battery, and a first heat exchanger, wherein the first heat exchanger is in thermal communication with the battery; and the charging device comprising: a second heat exchanger, the second heat exchanger comprising a heat source and / or heat sink, wherein the first heat exchanger is in thermal communication with the second heat exchanger.

[0017] The battery module can also include a heat exchanger which is in thermal communication with the face of the cells. This improves the cooling efficiency of the heat exchanger, as the surface area of the face of the cells is larger than the edge or electrical tabs.

[0018] The combination of the face cooling provided by the battery module, and the cooling effect of the charging device provides an advantageously high level of cooling, which is needed to efficiently charge high-power cells at high rates.

[0019] In a first aspect of the invention there is provided a system for controlling battery temperature, the system comprising a battery module and a charging device, the battery module comprising: a battery comprising electrochemical cells,

[0020] 008874653 a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells; and the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or a heat sink; wherein the charging device is connectable to the battery module, and when the charging device is connected to the battery module, the endpiece of the battery module is in thermal communication with the thermal body of the charging device.

[0021] The battery module and the charging device each include a heat exchanger, which allow for thermal energy to be transferred between the battery module and the charger. For example, thermal energy from the battery module can be transferred to the charging device. During charging, the thermal energy can then be dissipated to the environment using the charging device. This differs from traditional systems where the cooling is provided in the battery module - and therefore the battery module needs to provide means to dissipate the heat itself, for example, using ventilation holes in the casing of the battery module.

[0022] By including the heat sink and / or heat source in the charging device, the battery module can include fewer components, leading to lower manufacturing costs. One charging device can also be used for a number of battery modules, thus the heat sink and / or heat source components can be provided in the charger and used to control the temperature of multiple battery modules (opposed to providing a heat sink / heat source in every battery module).

[0023] The present system also allows the temperature of a battery to be regulated without requiring ventilation holes in the casing of the battery module. This means that the battery module can be sealed against intrusion from foreign bodies, such as water, improving the IP rating of the battery module.

[0024] IP ratings are defined in international standard EN 60529 (British BS EN 60529:1992, European IEC 60509:1989). The IP rating defines the level of sealing effectiveness of electrical enclosures against intrusion from foreign bodies (tools, dirt) and moisture.

[0025] The present invention also provides a battery module comprising a heat exchanger and a battery, the battery comprising electrochemical cells. The electrochemical cells may be pouch cells or prismatic cells. Preferably, the electrochemical cells are pouch cells.

[0026] In an aspect of the invention there is provided a battery module for controlling battery temperature, the battery module comprising: a battery comprising electrochemical cells, and a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells; and

[0027] 008874653 wherein the battery module is connectable to a charging device, and when the battery module is connected to a charging device, the end piece is in thermal communication with the charging device.

[0028] In a second aspect of the invention there is provided a battery module for controlling battery temperature, the battery module comprising: a battery comprising electrochemical cells, and a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells; and wherein the battery module is connectable to a charging device of the first aspect, and when the battery module is connected to the charging device, the end piece is in thermal communication with the charging device.

[0029] The battery module is connectable to a charging device of the third aspect.

[0030] The battery module is arranged such that the heat exchanger transfers thermal energy away from the cells via face cooling. This is achieved using one or more plates, wherein each plate is in thermal communication with a face of the cells. In this way, the cells are cooled more efficiently than conventional approaches to cooling, which typically cool the edges of the cells or use the thermal conduction through current collector tabs to achieve battery cooling.

[0031] The plates of the heat exchanger are also connected to an endpiece. The configuration of the endpiece and plates means that the endpiece can conduct thermal energy from multiple plates stacked with multiple cells - and transfer the thermal energy from the battery module.

[0032] The battery module may be used independently to regulate the temperature of the cells. However, the battery module may also be used together with the charging device of the present invention.

[0033] In an aspect of the invention there is provided a charging device for controlling battery temperature, the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or heat sink, wherein the charging device is connectable to a battery module, and when the charging device is connected to a battery module, the thermal body is in thermal communication with the battery module.

[0034] In a third aspect of the invention there is provided a charging device for controlling battery temperature, the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or heat sink,

[0035] 008874653 wherein the charging device is connectable to a battery module of the first aspect, and when the charging device is connected to the battery module, the thermal body is in thermal communication with the battery module.

[0036] The charging device is connectable to a battery module of the second aspect.

[0037] In a fourth aspect of the invention there is provided a method of controlling battery temperature in a battery module with a charging device, the battery module comprising: a battery comprising electrochemical cells, a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells; the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or a heat sink; and the method comprising: connecting the battery module to the charging device; and transferring thermal energy between the endpiece of the battery module and the thermal body of the charging device to control the temperature of the battery.

[0038] In a fifth aspect of the invention there is provided a use of the system of the first aspect, the battery module of the second aspect or the charging device of the third aspect, for controlling the temperature of a battery, in a mobile charging device, a static charging device, an electric vehicle or a power tool.

[0039] Summary of the Figures

[0040] The present invention is described with reference to the figures listed below.

[0041] Figure 1 is a schematic view of an example conventional battery pack

[0011] and charger

[0012] with its cooling system.

[0042] Figure 2 is a schematic view of an example battery module

[0021] and example charging device

[0031] making up an example system according to the invention.

[0043] Figure 3 is a schematic view of an alternative example battery module

[0021] and example charging device

[0031] making up an example system according to the invention.

[0044] Figure 4 is a schematic of an example conventional heat sink system. Figure 4a shows a side view and Figure 4b shows a plan view of an example conventional heat sink system.

[0045] Figure 5 is a schematic side view of an example battery module

[0021] ,

[0046] 008874653 Figure 6 is a schematic view of two example embodiments of the first heat exchanger.

[0047] Figure 6a is an example of a linear first heat exchanger. Figure 6b is an example of a radial first heat exchanger.

[0048] Figure 7 is a schematic side view of an example embodiment of the battery module.

[0049] Figure 8 is a schematic side view of another example embodiment of the battery module.

[0050] Figure 9 is a schematic side view of an example embodiment of a single heat exchanger unit of the battery module.

[0051] Figure 10 is a schematic side view of an example embodiment of a stack of heat exchanger units making up a battery module.

[0052] Figure 11 is a graph showing the changes in charge, temperature, and charging current during rapid charging of battery cells in an example system of the invention.

[0053] Detailed Description of the Invention

[0054] The present invention provides a system for controlling the temperature of a battery, the system comprising a battery module and a charging device.

[0055] System

[0056] Generally, the present invention relates to a system for controlling the temperature of a battery. The system comprises a battery module and a charging device. The battery module and charging device are in thermal communication such that thermal energy is transferred between them.

[0057] In a first aspect of the invention, there is provided a system for controlling battery temperature, the system comprising a battery module and a charging device, the battery module comprising: a battery comprising electrochemical cells, a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells; and the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or a heat sink; wherein the charging device is connectable to a battery module, and when the charging device is connected to the battery module, the endpiece of the battery module is in thermal communication with the thermal body of the charging device.

[0058] 008874653 The charging device may be electrically connectable to a battery module. That is, the charging device and battery may be connectable such that the charging device charges the battery module. The electrical connection may be of any suitable means, such as a direct electrical connection (e.g., a plug and socket) or an indirect electrical connection (e.g., an inductive or wireless electrical connection).

[0059] The endpiece of the battery module is in thermal communication with the thermal body of the charging device when the charging device is connected to the battery module, such as when the charging device is electrically connected to the battery module. The endpiece of the battery module may be in thermal communication with the thermal body of the charging device only when the charging device is connected to the battery module, such as only when the charging device is electrically connected to the battery module.

[0060] Thermal communication refers to any connection between two bodies which allows for the transfer of thermal energy. For example, thermal communication includes connection by a thermally conductive material, a heat transfer fluid, or a combination thereof.

[0061] Thermal communication may be provided by any suitable means, using conductive heat transfer, convective heat transfer and / or radiative heat transfer. The thermal communication may be active, where external power is used to drive the heat transfer, or passive, where external power is not used to drive the heat transfer.

[0062] In some embodiments, the first heat exchanger of the battery module interfaces with the second heat exchanger of the charging device. In some embodiments, the endpiece of the battery module interfaces with the thermal body of the charging device. Preferably, when the charging device is connected to the battery module the endpiece of the battery module interfaces with the thermal body of the charging device. Preferably, the endpiece of the battery module abuts with the thermal body of the charging device, to allow for thermal conduction between the first heat exchanger and the second heat exchanger.

[0063] In some embodiments, the shape of the first heat exchanger is complementary to the shape of the second heat exchanger. In some embodiments, the shape of the endpiece is complementary to the shape of the thermal body. The shape of the endpiece and the thermal body may take any suitable shape, which allows for there to be a thermally conductive interface between the endpiece and thermal body. In some embodiments, the shape of the endpiece is substantially planar. The endpiece may be planar and many comprise one or more mating features, for mating with the thermal body of the charging device. Preferably the shape of the endpiece and the thermal body is planar - such that the interface is flat.

[0064] The endpiece and the thermal body may have shapes which are complementary to each other, wherein the endpiece has a shape which is complementary to the thermal body and wherein the thermal body has a shape which is complementary to the endpiece.

[0065] 008874653 The endpiece may comprise mating features for cooperation with corresponding mating features on a charging device, wherein the thermal body comprises mating features for cooperation with corresponding mating features on the endpiece.

[0066] Such mating features may be used to fix the heat exchangers together. Mating features may also improve the thermal communication between the heat exchangers. For example, the mating features may increase the interfacial surface area between the endpiece of the first heat exchanger and the thermal body of the second heat exchanger.

[0067] Alternatively, the endpiece and the thermal body may have a planar interface, wherein the endpiece has a planar face and the thermal body has a planar face.

[0068] In some embodiments, the endpiece of the battery module is in direct thermal communication with the thermal body of the charging device. That is, the thermal energy transferred between the endpiece and the thermal body does not pass through an intermediate body. The endpiece and the thermal body may be in direct physical contact. Preferably, a surface of the endpiece contacts the thermal body of the charging device.

[0069] In some embodiments, the surface of the endpiece which contacts the thermal body of the charging module is on the opposite side of the endpiece to the one or more plates of the first heat exchanger. Thus, the endpiece and thermal body is arranged as superposed layers positioned directly between the battery cells and the heat source or heat sink. In some embodiments, the endpiece is sandwiched between the one or more plates and the thermal body of the charging module. The endpiece may have a first surface and a second surface, wherein the first surface and second surface are on opposite sides of the endpiece, wherein the first surface is connected to the one or more plates of the first heat exchanger and the second surface is for contacting the thermal body of the charging module. In this way, the endpiece is stacked with the thermal body.

[0070] This arrangement means that thermal energy being transferred between the battery cells and the charger module travels directly across the endpiece between the one or more plates and the thermal body. The direction of travel of the thermal energy may be substantially perpendicular to the surface of the endpiece which contacts the thermal body of the charging module. The direction of travel of the thermal energy may be substantially perpendicular to the first surface and / or the second surface of the endpiece. The direction of travel of the thermal energy may be parallel with the longest dimension of the one or more plates of the first heat exchanger. In this way, the transfer of thermal energy between the battery module and the charging module is direct and efficient, and the amount of thermal energy dissipated inside the battery module during transfer is minimised. In particular, the thermal energy may travel across the shortest dimension of the endpiece. This means the rate of thermal energy transfer can be high.

[0071] 008874653 Preferably, when the charging device is connected to the battery module, a substantial portion of the surface area of the endpiece is contacting the thermal body. In some embodiments, the surface of the endpiece which contacts the thermal body is 20 % or more of the total external surface area of the endpiece on an area basis. In some embodiments, the surface of the endpiece which contacts the thermal body is 30 % or more of the total external surface area, such as 40 % or more, such as 50 % or more.

[0072] Where the endpiece is substantially planar, the endpiece may have a first surface and a second surface on the opposite side of the endpiece, wherein the first surface is connected to the one or more plates of the first heat exchanger and the second surface is for contacting the thermal body of the charging module. In some embodiments, 20 % or more of the total area of the second surface is for contacting the thermal body of the charging module, such as 40 % or more, such as 60 % or more, such as 80% or more, such as 90% or more, such as 95% or more.

[0073] Thermal energy may be transferred from the battery module to the charging device or from the charging device to the battery module. Preferably, thermal energy is transferred from the battery module to the charging device.

[0074] In some embodiments:

[0075] (i) the battery module further comprises a first power connector for releasably connecting to the charging device; and / or

[0076] (ii) the charging device further comprises a second power connector for releasably connecting to battery module.

[0077] Some charging systems are known.

[0078] DE 102011082566 describes an electrical charging system including a battery module and cooling system which is part of the charging station of the battery module. Contrary to the system of the present invention, the base plate and heat exchanger components of the battery module and cooling system are not arranged as a stack of superposed layers, and only a small area of the base plate is used for thermal energy transfer. This document also does not suggest how the cooling system may work to actively cool the battery.

[0079] US 2010 / 0008036 also describes cooling system for a portable device accommodated in a docking station. The docking station comprises a non-forced air active cooling unit which maintains a first heat sink surface at a temperature below the ambient temperature. The first heat sink surface is configured to be positioned in thermal contact with a heat spreader of a portable device during charging of the device. However, there is no suggestion of including plates between the individual cells of the portable device in order to maximise heat transfer from the cells to the cooling system.

[0080] 008874653 The battery module and the charging device are discussed in more detail below. The description of the battery module and the charging device herein also applies to the system of the first aspect.

[0081] Battery Module

[0082] The present invention also provides a battery module for controlling the temperature of a battery.

[0083] In general, the battery module, comprises: a battery comprising one or more electrochemical cells; a first heat exchanger wherein the first heat exchanger is in thermal communication with a face of the cells.

[0084] More specifically, there is provided a battery module for controlling battery temperature, the battery module comprising: a battery comprising electrochemical cells, and a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells and wherein the battery module is connectable to a charging device, and when the battery module is connected to a charging device, the end piece is in thermal communication with the charging device.

[0085] In a second aspect of the invention, there is provided a battery module for controlling battery temperature, the battery module comprising: a battery comprising electrochemical cells, and a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells and wherein the battery module is connectable to the charging device of the first aspect, and when the battery module is connected to the charging device, the end piece is in thermal communication with the charging device.

[0086] The electrochemical cells may be pouch cells or prismatic cells. The cells are preferably pouch cells.

[0087] The battery module may be electrically connectable to the charging device

[0088] In one embodiment, the battery module further comprises a power connection for reversibly connecting the battery module to the charging device.

[0089] In some embodiments, when the charging device is connected to the battery module, the endpiece is in thermal communication with the thermal body of the second heat exchanger.

[0090] 008874653 In some embodiments the endpiece is for thermally communicating with the charging device.

[0091] The battery module may be surrounded by a casing. The casing may be thermally conductive. The casing may be electrically insulating.

[0092] The battery module may be sealed. In some embodiments, the battery may be sealed from the surroundings. For example, the module casing may not include any fluid passages, such as air vent or cooling channels. The module may be sealed such that the module is airtight. The module may be sealed such that the module is watertight. In this way, the battery module separates the surroundings from the battery.

[0093] As a result, the IP rating of the module may be improved compared to a non-sealed battery module. Preferably, the IP rating of the battery module is IP55 or higher, such as IP65 or higher, such as IP66 or higher, such as IP67. The IP rating may be determined according to EN 60529 (British BS EN 60529:1992, European IEC 60509:1989).

[0094] In a preferred embodiment, the battery module may be used together with the charging device of the present invention as a system to control the temperature of the battery.

[0095] Alternatively, the battery module may be used independently of a charging device to control the temperature of the battery. For example, the first heat exchanger may transfer thermal energy from the battery to the surroundings, such as the air.

[0096] KR 2019 / 0138358 describes a battery module which is said to improve cooling efficiency by dissipating heat from the cells to a cooling plate through a highly thermally conductive plate connected to the ends of the cells. This battery module does not include plates between each cell.

[0097] US 2019 / 0081373 describes a battery module having a stacked body of batteries including heat conducting fins between the batteries. Heat is dissipated from the fins to a heat transfer device, which acts as the endpiece, and then to a cooling plate. Unlike in the present invention, the cooling plate is provided on a side of the battery stacked body (parallel to the batteries), rather than being laminated with the end piece as in the present invention. The surface area for heat transfer between the heat transfer device and cooling plate is therefore not optimised.

[0098] US 2015 / 0318523 describes a battery module including heat transfer plates between each pair of adjacent batteries. The batteries are placed in a batter holder, however, there is no system for further dissipating heat away from the batteries.

[0099] Unlike the battery module of the present invention, those described in the prior art do not appear to be suitable for use with pouch cells.

[0100] 008874653 Battery

[0101] The battery comprises one or more electrochemical cells. The battery may comprise two or more cells, such as four or more cells, such as six or more cells, such as eight or more cells. The battery may comprise from two to twelve cells, such as from four to ten cells, such as six to eight cells.

[0102] Any suitable electrochemical cell format may be used. Typically, the cell is a pouch cell or a prismatic cell. Preferably, the cell is a pouch cell.

[0103] The face of the cell typically refers to the external surface adjacent to an electrode. Typically, one face is adjacent to the anode and the opposite face is adjacent to the cathode. The faces of the cell are typically perpendicular to the direction of ion flow in the cell. The face is the surface parallel to the electrode surface. For example, where the electrodes are planar, the face is the surface parallel to the electrode surface.

[0104] In contrast, the edge of the cell typically refers to the external surface adjacent to the edges of the electrode. The edge of the cell may be adjacent to the edges of multiple electrodes, while a face is adjacent to the face of a single electrode. The edges of the cell are typically parallel with the direction of ion flow in the cell.

[0105] The electrochemical cells may be pouch cells. A pouch cell is typically rectangular, and defines two opposing faces, bordered by an edge. Each face contains the majority of the surface area of the pouch cell. The surface area of the face is greater than the edge. The face of the pouch cell is typically flat.

[0106] The electrochemical cells may be prismatic cells. A prismatic cell is typically a polygonal prism, such as a rectangular prism, and defines two opposing faces bordered by four sides. Each face has a larger surface area than any one of the sides. The sides typically comprise two opposing short sides and two opposing long sides. The faces and sides of the prismatic cell are typically flat.

[0107] Any suitable electrochemical cell format may be used. Typically, the cell is a pouch cell or a prismatic cell. Typically, the pouch cell or prismatic cell is an electrochemical cell capable of charging at a high rate, such as a rate of 3C or more, preferably as 5C or more, more preferably 8C or more, yet more preferably 12C or more. The cell is capable of charging at a high rate, such as a rate of 3C or more, preferably as 5C or more, more preferably 8C or more, yet more preferably 12C or more while maintaining a specific capacity of 80% or more, compared to the capacity measured at 1C.

[0108] In some embodiments, the cell may have a maximum operable charge rate which is 3C or more, where the capacity retention is at least 70% over 1 ,000 cycles, preferably 5 C or more,

[0109] 008874653 where the capacity retention is at least 70% over 1 ,000 cycles, more preferably 10 C or more where the capacity retention is at least 70% over 1 ,000 cycles.

[0110] The electrochemical cells typically include a working electrode, a counter electrode, an electrolyte and a separator. The working electrode and counter electrode are typically mounted on current collectors.

[0111] To improve conductivity at the working electrode, a conductive carbon material (e.g., carbon black, graphite, nanoparticulate carbon powder, carbon fiber and / or carbon nanotubes) is typically admixed with the working electrode material. Alternatively, the conductive carbon material may be coated onto the working electrode material. In one embodiment, the working electrode comprises porous carbon, such as porous reduced graphene oxide, which may wrap the larger niobium oxides particles.

[0112] Typically, the working electrode contains 1-5% by weight of binders.

[0113] The working electrode may be admixed with a binder. Some examples of binders include PVDF, PTFE, CMC, PAA, PMMA, PEO, SBR and co-polymers thereof.

[0114] The working electrode is typically fixed to a current collector, such as a copper or aluminum collector, which may be in the form of a plate.

[0115] The working electrode may be an anode or cathode during a discharge step, for example in a lithium-ion battery. Preferably, the working electrode is the anode during a discharge step. The working electrode is electrically conductive and is electrically connectable to a counter electrode.

[0116] In some embodiments, the working electrode comprises a niobium oxide or a niobium metal oxide. The niobium oxide may be selected from NbgOs polymorphs, NbCh, NbgOs or combinations thereof. The niobium metal oxide may be a compound (for example, having a crystalline structure) of a niobium oxide and an additional metal oxide. Suitable niobium metal oxides include niobium tungsten oxide (for example NbieWsOss or NbisWieOgs), a titanium niobium oxide (for example TiNb2O7), a niobium molybdenum oxide (for example Nb2Mo30i4), or combinations thereof. Suitable niobium tungsten oxides include Nbi2WO33, Nb26W4O77, Nbi4W3O44, Nb-ieWsOss, Nb-isWsOeg, NbgWOs, NbisWieOgs, NbggWggOns, Nb8WgO47, Nb54W82O38i, Nb2oW3iOi43, Nb4W7O3i, or Nb2Wi505o or combinations thereof.

[0117] In some embodiments, the working electrode comprises a niobium metal oxide material having a molar ratio of Nb2O5to WO3from 6:1 to 1 :15. Preferably, the molar ratio of Nb2O5to WO3in the working electrode is from 8:5 to 11 :20. More preferably, the molar ratio of Nb2O5to WO3 in the working electrode is 8:5 or 9:16.

[0118] 008874653 In some embodiments the working electrode active material comprises Nbi6W5O55, Nb-iaWaOeg, Nb2WO8, Nbi8Wi8O93, or Nb22W2oOn5, or combinations thereof Preferably the working electrode comprises Nbi6W5O55 or Nbi8Wi6O93, or combinations thereof.

[0119] In some embodiments, the working electrode comprises graphite, Si, SiOx(where x is typically from 0 to 2), LTO, or a mixture thereof. In some embodiments, the working electrode consists essentially of graphite Si, SiOx(where x is typically from 0 to 2), or lithium titanate (LTO). Preferably, the working electrode comprises these compounds (e.g. graphite) in particulate form.

[0120] The working electrode may comprise a mixture of niobium tungsten oxide and an additional active material. The additional active material may be an additional metal oxide. For example, the working electrode may comprise a mixture of niobium tungsten oxide and an additional active material selected from lithium titanate (LTO; Li4Ti50i2), titanium niobium oxides (for example TiNb2O7), titanium tantalum oxides (for example TiTa2O7), tantalum tungsten oxides (for example Ta8W9O47) and niobium molybdenum oxides (for example Nb2Mo3Oi4). The working electrode may comprise a mixture of niobium tungsten oxide and LTO.

[0121] The additional active material may be graphite. The working electrode may comprise a mixture of niobium tungsten oxide and graphite.

[0122] Preferably, the working electrode consists essentially of niobium tungsten oxide and an additional active material. For example, the working electrode consists essentially of a mixture of niobium tungsten oxide and LTO. Alternatively, the working electrode may consist essentially of a mixture of niobium tungsten oxide and graphite.

[0123] The electrochemical cell typically comprises a counter electrode. The counter electrode may be an anode or cathode during a discharge step, for example in a lithium ion battery. Preferably the counter electrode is the cathode during a discharge step.

[0124] In addition to the working electrode, an electrochemical cell comprises a counter electrode and an electrolyte, and optionally a separator, such as a microporous polyethylene film, between the working electrode and counter electrode.

[0125] Suitable materials for the counter electrode include lithium-containing or lithium-intercalated material, such as a lithium metal oxide, wherein the metal may be a transition metal such as Co, Fe, Ni, V, or Mn, or combination thereof. Some examples of counter electrode materials include lithium cobalt oxide (LiCo02) lithium nickel manganese cobalt oxide (NMC, LiNiMnCo02, e.g., LiNi06Co02Mn02O2), lithium vanadium fluorophosphate (LiVPO4F), lithium nickel cobalt aluminium oxide (NCA, LiNiCoAI2), lithium iron phosphate (LFP, LiFePO4) and manganese-based spinels (e.g. LiMn2O4). In one embodiment, the counter electrode is substantially free of binders. In an alternative embodiment, the counter electrode is admixed

[0126] 008874653 with a binder or adhesive. Some examples of binders or adhesives include PVDF, PTFE, CMC, PAA, PMMA, PEO, SBR and co-polymers thereof. The counter electrode may be fixed to a current collecting substrate, such as an aluminium plate.

[0127] The electrochemical cell typically comprises an electrolyte. The electrolyte facilitates ion transport between the cathode and anode.

[0128] The electrolyte comprises lithium salts, such as lithium (bis(trifluoromethane)sulfonimide (LiTFSI), LiPF6, LiBF4, l_iCIO4, lithium triflate (LiTF), or lithium bis(oxalate)borate (LiBOB). The electrolyte may be a liquid electrolyte, such as a liquid at ambient temperature, for example at 25°C. The electrolyte may be a non-aqueous electrolyte. The electrolyte may comprise a polar aprotic solvent, such a cyclic or linear carbonate, such as ethylene carbonate, dimethyl carbonate, or ethyl methyl carbonate.

[0129] Suitable solvents include carbonate solvents. For example, propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), chloroethylene carbonate, fluorocarbonate solvents (e.g., fluoroethylene carbonate and trifluoromethyl propylene carbonate), as well as the dialkylcarbonate solvents, such as dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC), methyl propyl carbonate (MPC), and ethyl propyl carbonate (EPC).

[0130] Suitable solvents also include sulfone solvents. For example methyl sulfone, ethyl methyl sulfone, methyl phenyl sulfone, methyl isopropyl sulfone (MiPS), propyl sulfone, butyl sulfone, tetramethylene sulfone (sulfolane), phenyl vinyl sulfone, allyl methyl sulfone, methyl vinyl sulfone, divinyl sulfone (vinyl sulfone), di phenyl sulfone (phenyl sulfone), dibenzyl sulfone (benzyl sulfone), vinylene sulfone, butadiene sulfone, 4-methoxyphenyl methyl sulfone, 4- chlorophenyl methyl sulfone, 2-chlorophenyl methyl sulfone, 3,4-dichlorophenyl methyl sulfone, 4-(methylsulfonyl)toluene, 2-(methylsulfonyl) ethanol, 4-bromophenyl methyl sulfone, 2-bromophenyl methyl sulfone, 4-fluorophenyl methyl sulfone, 2-fluorophenyl methyl sulfone, 4-aminophenyl methyl sulfone, a sultone (e.g., 1 ,3-propanesultone), and sulfone solvents containing ether groups (e.g., 2-methoxyethyl(methyl)sulfone and 2- m eth oxy eth oxy ethyl (et hy I) s u Ifo n e) .

[0131] Suitable solvents also include silicon-containing solvents such as a siloxane or silane. For example, hexamethyldisiloxane (HMDS), 1 ,3-divinyltetramethyldisiloxane, the polysiloxanes, and polysiloxane-polyoxyalkylene derivatives. Some examples of silane solvents include methoxytrimethy Isilane, ethoxytrimethy Isilane, dimethoxydimethylsilane, methyltrimethoxysilane, and 2-(ethoxy)ethoxytrimethylsilane.

[0132] Typically, an additive may be included in the electrolyte to improve performance. For example vinylene carbonate (VC), vinyl ethylene carbonate, allyl ethyl carbonate, t-butylene carbonate, vinyl acetate, divinyl adipate, acrylic acid nitrile, 2-vinyl pyridine, maleic anhydride, methyl cinnamate, ethylene carbonate, halogenated ethylene carbonate, a-bromo-y-

[0133] 008874653 butyrolactone, methyl chloroformate, 1 ,3-propanesultone, ethylene sulfite (ES), propylene sulfite (PS), vinyl ethylene sulfite (VES), fluoroethylene sulfite (FES), 12-crown-4 ether, carbon dioxide (CO2), sulfur dioxide (SO2), and sulfur trioxide (SO3).

[0134] The electrochemical cell may also include a separator, such as a solid porous membrane positioned between the working and counter electrodes. The solid porous membrane may partially or completely replace the liquid electrolyte. The solid porous membrane may comprise a polymer (e.g., polyethylene, polypropylene, or copolymer thereof) or an inorganic material, such as a transition metal oxide (e.g., titania, zirconia, yttria, hafnia, or niobia) or main group metal oxide, such as silicon oxide, which can be in the form of glass fiber.

[0135] The solid non-porous membrane may comprise a lithium-ion conductor. For example, LLZO (garnet family), LSPO (LISICON family), LGPS (thio-LISICON family), LATP / LAGP (NASICON family), LLTO (perovskite family) and phosphide / sulfide glass ceramics.

[0136] First Heat Exchanger

[0137] The first heat exchanger comprises an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells.

[0138] A heat exchanger is a component which permits the transfer of thermal energy between one body and another body. Where there is a temperature difference across the heat exchanger, thermal energy is transferred down the temperature gradient, from the “hot side” to the “cold side”. For example, the heat exchanger may transfer thermal energy between a battery (hot side) and a heat transfer fluid (cold side), or may transfer thermal energy from a heat transfer fluid (hot side) to the surroundings (cold side), or may transfer thermal energy from a heat transfer fluid (hot side) to a battery (cold side).

[0139] Each of the heat exchangers may be of any suitable configuration. For example, the heat exchangers may be a plate heat exchanger, a shell and plate heat exchanger, or a direct contact heat exchanger. Each of the heat exchangers typically include a thermally conductive interface which comprises any suitable material having high thermal conductivity. Preferably, the thermally conductive interface comprises a metal, such as aluminium, copper, steel, nickel, Inconel, or cupronickel. Preferably, the heat exchanger is a plate heat exchanger.

[0140] The endpiece and the plates of the first heat exchanger are in thermal communication, such that thermal energy is transferable between the plates and the endpiece. Preferably, the endpiece and the plates of the first heat exchanger are in direct thermal communication. In other words, thermal energy is transferred directly between the endpiece and the plates, and the thermal energy does not pass through another medium between the endpiece and the plates.

[0141] In some embodiments the endpiece is connected to two or more plates, such as four or more plates, such as six or more plates. In some embodiments the endpiece is connected to ten or

[0142] 008874653 less plates, such as eight or less plates, such as six or less plates. Typically, the endpiece is connected to from two or ten plates, such as from four to eight plates, such as from five to six plates.

[0143] In an alternative embodiment, the endpiece is connected to one plate.

[0144] In some embodiments the endpiece and the plates of the first heat exchanger are integrally formed. In other words, the endpiece and the plates may be unitary. That is, the first heat exchanger is of unitary construction, such that the endpiece and the one or more plates are constructed as a single unit and made from a single material.

[0145] The first heat exchanger may have a thermal conductivity of 100 Wnr1K'1or more, preferably 150 Wm'1K'1or more, more preferably 200 Wnr1K'1or more, yet more preferably 300 Wnr1K'1or more. The first heat exchanger may have a thermal conductivity of from 100 to 500 Wnrr1K-1, such as from 200 to 400 Wnr1K'1. The first heat exchanger may be aluminium, having a thermal conductivity of about 237 Wnr1K'1. The first heat exchanger may be copper, having a thermal conductivity of about 398 Wm1K'1. Thermal conductivity may be measured using any suitable means, such as ISO 22007-2:2022.

[0146] The first heat exchanger may have a specific heat capacity of 100 Jkg_1K_1or more, preferably 300 Jkg_1K'1or more, more preferably 500 Jkg_1K_1or more, yet more preferably 800 Jkg_1K_1or more. The first heat exchanger may have a specific heat capacity of from 100 to 1200 Jkg_1K'1, such as from 500 to 1000 Wnr1K'1, such as from 850 to 950 Jkg_1K'1. The first heat exchanger may be aluminium, having a specific heat capacity of about 902 Jkg-1K-1. The first heat exchanger may be copper, having a specific heat capacity of about 385 Jkg-1K-1.

[0147] Specific heat capacity may be measured using any suitable means, such as ISO 19935- 2:2020.

[0148] The first heat exchanger may be made from a metal, such as aluminium, copper, steel, nickel, Inconel, or cupronickel. Preferably, the metal is aluminium or copper, more preferably aluminium.

[0149] In some embodiments the endpiece and the plates of the first heat exchanger have a uniform cross-section along one axis. In other words, the endpiece and the plates are prismatic. This allows the first heat exchanger to be formed by extrusion. The first heat exchanger may be extrudable.

[0150] The endpiece and plates may form a heat exchanger unit. The first heat exchanger may comprise two or more heat exchanger units. The heat exchanger units may be separable. The heat exchanger units may form a stack of two or more heat exchanger units. Each heat exchanger unit may be integrally formed.

[0151] 008874653 Where the first heat exchanger comprises a stack of heat exchanger units, each heat exchanger unit may be integrally formed. The one or more plates and the endpiece of each heat exchanger unit may be integrally formed. In such embodiments, the plates and the endpiece are made from the same material.

[0152] In some embodiments, the endpieces of the heat exchanger units may include mating features to stack with adjacent heat exchanger units. The mating features may be a lip and groove. The mating features are typically for securing the heat exchanger unit to the endpiece of adjacent heat exchanger units. The adjacent endpieces in the stack of heat exchanger units may form a planar surface. Preferably, adjacent endpieces in the stack of heat exchanger units are in thermal communication.

[0153] In some embodiments, in the heat exchanger unit the endpiece is connected to two or more plates, such as four or more plates, such as six or more plates. In some embodiments the endpiece is connected to ten or fewer plates, such as eight or fewer plates, such as six or fewer plates. Typically, the endpiece is connected to from two or ten plates, such as from four to eight plates, such as from five to six plates. Preferably, in the heat exchanger unit the endpiece is connected to one plate.

[0154] In some embodiments the first heat exchanger comprises two or more heat exchanger units, such as four or more heat exchanger units, such as six or more heat exchanger units. In some embodiments the first heat exchanger comprises ten or fewer heat exchanger units, such as eight or fewer heat exchanger units, such as six or fewer heat exchanger units. Typically, the first heat exchanger comprises from two or ten heat exchanger units, such as from four to eight heat exchanger units, such as from five to six heat exchanger units.

[0155] The heat exchanger may have one endpiece, which is connected to an end of the one or more plates. In this embodiment, the endpiece and plate together may have a T-shaped cross-section or an L-shaped cross-section. Preferably, the endpiece and plate together have a T-shaped cross-section.

[0156] The heat exchanger may comprise a first endpiece connected to a first end of the one or more plates and a second endpiece connected to a second end of the one or more plates. The first end of the plate is different to the second end of the plate. The first end is preferably opposite to the second end. The first endpiece, second endpiece and plate may together have a U-shaped cross section. The first endpiece, second endpiece and plate may together have an H-shaped cross-section.

[0157] In some embodiments, an endpiece connected to one or more plates forms a heat exchanger unit, wherein the first heat exchanger comprises a stack of heat exchanger units. Preferably, an endpiece connected to one plate forms a heat exchanger unit. In some embodiments, a plate, a first endpiece connected to a first end of the plate and a second endpiece connected to a second end of the plate together form a heat exchanger unit.

[0158] 008874653 In this way, the number of heat exchanger units in the first heat exchanger may be varied, so that the size of the first heat exchanger may be adjusted for use with batteries comprising different numbers of cells. Additionally, a heat exchanger comprising a stack of heat exchanger units may be easily disassembled, for example for maintenance or repair.

[0159] The battery module is arranged such that each plate of the first heat exchanger is in thermal communication with the face of one or two cells. The cells of the present invention are therefore cooled by face cooling.

[0160] In some embodiments, each plate is in thermal communication with 50% or more of the face of the cell, calculated on an area basis, preferably 70% or more, more preferably 90% or more. In some embodiments, each plate is in thermal communication with 50% to 100% of the face of the cell, calculated on an area basis, preferably 70% to 95%, more preferably 80% to 90%.

[0161] Typically the plate is in thermal communication with only one face of the cell, in which case the plates are in thermal communication with 50% or more of the surface area of that face, preferably 70% or more, and more preferably 90% or more. In some embodiments, the plate is in thermal communication with only one face of the cell, in which case each plate is in thermal communication with 50% to 100% of the face of the cell, calculated on an area basis, preferably 70% to 95%, more preferably 80% to 90%.

[0162] In some embodiments, the plates overlap with 50% or more of the face of the cells, calculated on an area basis, preferably 70% or more, and more preferably 90% or more. In some embodiments, the plates overlap with 50% to 100% of the face of the cell, calculated on an area basis, preferably 70% to 95%, more preferably 80% to 90%.

[0163] Typically the plates overlap with only one face of the cell, in which case the plates are in overlap with 50% or more of the surface area of that face, preferably 70% or more, and more preferably 90% or more. Typically the plates overlap with only one face of the cell, in which case the plates are in overlap with 50% to 100% of the face of the cell, calculated on an area basis, preferably 70% to 95%, more preferably 80% to 90%.

[0164] Overlap refers to the amount of one object which is covered by another object. In this context, overlap refers to the percentage of the face of the cell which is covered by an adjacent plate. Only the faces of cells which are facing a plate are included in this calculation.

[0165] The plates may have a complimentary shape to the face of the cells.

[0166] In some embodiments, the plates are arranged perpendicular to the endpiece.

[0167] 008874653 In some embodiments, the endpiece is planar. In these embodiments, the plates may be arranged in parallel to one another.

[0168] In some embodiments, the endpiece is cylindrical. In these embodiments, the plates may be arranged radially.

[0169] The electrochemical cells may be arranged between the plates.

[0170] Where the plates are arranged in parallel, they form a row of plates in the battery module. In some embodiments, there is a plate at the end of the row which has only one face in thermal communication with a cell.

[0171] Alternatively, there may be a cell at the end of the row, such that the plate at the end of the row has both faces in thermal communication with a cell. In this way, each plate may be sandwiched between the face of two cells.

[0172] There may be one or more cells sandwiched between two adjacent plates. There may be two or more cells sandwiched between two adjacent plates. Preferably, there are no more than two cells sandwiched between two adjacent plates.

[0173] There may be one cell between the plates. In this way, each cell has at least one face in thermal communication with a plate, and optionally both faces in thermal communication with different plates.

[0174] There may be two cells between the plates. In this way, each has at least one face in thermal communication with a plate.

[0175] Two cells may be separated by a deformable material, such that the two cells sandwich a layer of the deformable material. In some embodiments, the two or more cells are separated by a resiliently deformable layer.

[0176] The deformable material is intended to allow the cells to expand and contract during charging and discharging. The deformable material may be used to secure the cells in the battery module. For example, the deformable material may force the cells against the plates. This may serve to secure the cells and improve the thermal communication between the cells and the plates.

[0177] The deformable material may be a resiliently deformable material. The deformable material may be a packaging material. The deformable material may be foam, rubber or plastic for example. The deformable material is preferably a foam.

[0178] In some embodiments, the battery module comprises an electrically insulating layer. The electrically insulating layer may be sandwiched between each cell and the plate. The plate

[0179] 008874653 typically refers to a plate which is in thermal communication with the face of the cell. In other words, the plates and the face of the electrochemical cells (e.g., which are in thermal communication with the plate) are separated by an electrically insulating layer. The electrically insulating layer is typically thermally conductive. That is, the electrically insulating layer allows for thermal communication between the face of the cell and the plates, but does not allow for electrical communication between the face of the cell and the plates.

[0180] The endpiece is in thermal communication with the plates. The endpiece is typically connected to an end of the plates.

[0181] In some embodiments, the endpiece comprises a first layer and a second layer. The first layer joins the one or more plates and the second layer is in thermal communication with the first layer. The second layer may be laminated with the first layer. The first layer may be integrally formed with the plates.

[0182] In some embodiments, the endpiece comprises a first layer connected to the one or more plates, and a second layer which is in thermal communication with the first layer.

[0183] Where the first heat exchanger comprises a stack of heat exchanger units, the endpiece of each unit may comprise a first layer and a second layer, wherein the first layer is connected to the plate and the second layer is in thermal communication with the first layer. The first layer may be integrally formed with the plate.

[0184] The first layer of an endpiece may be in thermal communication with adjacent first layers. The second layer of an endpiece may be in thermal communication with adjacent second layers.

[0185] Alternatively, where the first heat exchanger comprises a stack of heat exchanger units, the second layer may be a continuous layer which is not separated into units. In this embodiment, the endpieces of adjacent heat exchange units together form a first layer. The second layer may be laminated with the first layer.

[0186] Where the endpiece comprises a first layer and a second layer, the first layer may be made from a first material and the second layer may be made from a second material. In some embodiments, the plates are also made from the first material. In such embodiments, the first layer may be integrally formed with the plates.

[0187] In some embodiments the first layer, and optionally the plates, are made from a first material, and the second layer is made from a second material which is different from the first material.

[0188] The first material may have a thermal conductivity of 100 Wm1K'1or more, preferably

[0189] 150 Wnr1K'1or more, more preferably 200 Wnr1K'1or more, yet more preferably 300 Wnr1K'1or more. The first material may have a thermal conductivity of from 100 to 500 Wnr1K'1, such as from 200 to 400 Wnr1K'1. The first material may be aluminium, having a thermal

[0190] 008874653 conductivity of about 237 Wnr1K'1. The first material may be copper, having a thermal conductivity of about 398 Wnr1K'1. Thermal conductivity may be measured using any suitable means, such as ISO 22007-2:2022.

[0191] Where present, the second material may be different from the first material. The second material may have a heat conductivity which is different to the first material. Preferably, the second material may have a heat conductivity which is less than the first material. The second material may have a thermal conductivity of 100 Wm-1K'1or more, preferably 150 Wnr1K-1or more, more preferably 200 Wnr1K'1or more, yet more preferably 300 Wnr1K'1or more. The first material may have a thermal conductivity of from 100 to 500 Wnr1K'1, such as from 200 to 400 Wnr1K'1. Thermal conductivity may be measured using any suitable means, such as ISO 22007-2:2022.

[0192] The first material may have a specific heat capacity of 100 Jkg_1K_1or more, preferably 300 Jkg_1K'1or more, more preferably 500 Jkg_1K_1or more, yet more preferably 800 Jkg_1K_1or more. The first material may have a specific heat capacity of from 100 to 1200 Jkg_1K_1, such as from 500 to 1000 Wnr1K'1, such as from 850 to 950 Jkg-1K-1. The first material may be aluminium, having a specific heat capacity of about 902 Jkg_1K_1. The first material may be copper, having a specific heat capacity of about 385 Jkg-1K-1. Specific heat capacity may be measured using any suitable means, such as ISO 19935-2:2020.

[0193] Where present, the second material may have a specific heat capacity which is different to the first material. The second material may have a specific heat capacity which is greater than the first material. The second material may have a specific heat capacity of 100 Jkg-1K-1or more, preferably 300 Jkg-1K-1or more, more preferably 500 Jkg-1K-1or more, yet more preferably 800 Jkg_1K_1or more. The second material may have a specific heat capacity of from 100 to 1200 Jkg-1K-1, such as from 500 to 1000 Wnr1K'1, such as from 850 to 950 Jkg_1K'1Specific heat capacity may be measured using any suitable means, such as ISO 19935-2:2020.

[0194] The first material may be a metal, such as aluminium, copper, steel, nickel, Inconel, or cupronickel. The second material may also be a metal, such as aluminium, copper, steel, nickel, Inconel, or cupronickel. Preferably, the first material is aluminium or copper, more preferably aluminium. Preferably, the second material is aluminium or steel, more preferably aluminium. The second material may be different from the first material.

[0195] Where the battery module is connected to a charging device, the second layer is in thermal communication with the charging device.

[0196] The second layer may be planar, such that the interface between the second layer of the endpiece and the second heat exchanger is planar.

[0197] 008874653 Where the endpiece is cylindrical, the second layer may form a core, wherein the first layer circumscribes the core.

[0198] The second layer may have a shape which is complementary to the thermal body. For example, the second layer may have mating features for cooperation with corresponding mating features on the thermal body of the charging device. The mating features may comprise a pin and hole feature, or a lip and groove feature.

[0199] Alternatively, the second layer may be used without the charging device, such that the second layer is in thermal communication with the surroundings. In this case, thermal energy is transferred from the second layer to the surroundings or vice versa. The surroundings may be a fluid, such as air, or a solid external surface. In this way, the battery module may be used independently to control the temperature of the cells.

[0200] Also described is an embodiment where the second layer is a heat sink, the heat sink comprising two or more fins protruding from a thermal body. Fluid may pass over the fins. Fluids include air or liquid coolant. In this way, thermal energy may be transferred from the first heat exchanger into the surroundings. For example, thermal energy may be transferred from an EV battery into the air.

[0201] Charging Device

[0202] The present invention also provides a charging device for controlling the temperature of a battery, such as the battery of the battery module. The charging device is also for charging the battery module.

[0203] In general, the charging device comprises: a second heat exchanger, wherein the second heat exchanger is for thermally communicating with the battery module.

[0204] More specifically, there is provided a charging device for controlling battery temperature, the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or heat sink, wherein the charging device is connectable to a battery module, and when the charging device is connected to a battery module, the thermal body is in thermal communication with the battery module.

[0205] In a third aspect of the invention, there is provided a charging device for controlling battery temperature, the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or heat sink,

[0206] 008874653 wherein the charging device is connectable to the battery module of the first aspect, and when the charging device is connected to the battery module, the thermal body is in thermal communication with the battery module.

[0207] The charging device may be electrically connectable to a battery module.

[0208] In one embodiment, the charging device further comprises a power connection for reversibly connecting the charging device to the battery module.

[0209] In some embodiments, when the charging device is connected to the battery module, the thermal body is in thermal communication with the endpiece of the first heat exchanger.

[0210] In some embodiments, when the power connector of the battery module is connected to the power connector of the charging device, then the second heat exchanger is in thermal communication with the first heat exchanger. For example, the thermal body is in thermal communication with the endpiece.

[0211] Charging devices which are also able to reduce the temperature of a battery are known in the art. However, there are differences and draw backs compared to the charging module of the present invention.

[0212] JPH06150978 describes a charging unit for a battery pack which reduces temperature rise of the battery during charging. Cool air is provided from a fan which is directed either onto a heat pipe which is in thermal communication with the battery pack, or directly on to the battery pack.

[0213] US 2006 / 0232929 describes a battery charger comprising a heat dissipation module, which includes a heat-transfer element, a heat-dissipation element, and a heat pipe. However, the surface area for thermal conduction provided between the heat-transfer element and the device being charged is small compared to the total contact area between the charger and device. Furthermore, there is no active cooling of the heat dissipation module, so the heat dissipation effect is limited.

[0214] CN210074847 describes a charging device having a silicone thermal pad which dissipates heat from charging into a refrigerant stored in a cavity in the charging device. The silicone thermal pad comprises a single flat layer and does not include the second layer as used in the charging device of the invention, or a heat sink having fins for increasing the dissipation of heat into the refrigerant.

[0215] US 6313987 describes a thermal connector for joining mobile electronic devices to docking stations. A second heat transfer element on the docking station mates with a first heat transfer element which is coupled to the electronic component. Heat is dissipated from the second heat transfer element with the help of a set of heat dissipation fins and a fan. Unlike

[0216] 008874653 the charging device of the present invention, there is no layered structure between the heat transfer elements and the heat sink. There is therefore less surface area for heat transfer and the use of space inside the charging module is less efficient.

[0217] US 6181553 describes an arrangement for cooling a portable computer. The computer includes a heat spreader thermally attached to an end of a heat pipe, which is attached at another end to a receiving socket. The docking module includes a plug for docking into the socket. The plug is connected to a heat pipe which is thermally attached to a heat sink. Again, this document does not describe a layered structure between thermal bodies on the device and docking module and the heat sink. There is also no indication that the docking module also charges the device.

[0218] Second Heat Exchanger

[0219] The charging device comprises a second heat exchanger. The second heat exchanger comprises a thermal body in thermal communication with a heat source and / or a heat sink. Preferably, the thermal body and the heat source and / or a heat sink of the second heat exchanger are in direct thermal communication. In other words, thermal energy is transferred directly between the thermal body and the heat source and / or a heat sink, and the thermal energy does not pass through another medium between the thermal body and the heat source and / or a heat sink.

[0220] A heat exchanger is a component which permits the transfer of thermal energy between one body and another body. Where there is a temperature difference across the heat exchanger, thermal energy is transferred down the temperature gradient, from the “hot side” to the “cold side”. For example, the heat exchanger may transfer thermal energy between a battery (hot side) and a heat transfer fluid (cold side), or may transfer thermal energy from a heat transfer fluid (hot side) to the surroundings (cold side), or may transfer thermal energy from a heat transfer fluid (hot side) to a battery (cold side).

[0221] The heat exchanger may be of any suitable configuration. For example, the heat exchangers may be a plate heat exchanger, a shell and plate heat exchanger, or a direct contact heat exchanger. The heat exchanger includes a thermal body which comprises any suitable material having high thermal conductivity. Preferably, the thermal body comprises a metal, such as aluminium, copper, steel, nickel, Inconel, or cupronickel.

[0222] The thermal body may have a thermal conductivity of 100 Wm1K'1or more, preferably 150 Wnr1K'1or more, more preferably 200 Wnr1K'1or more, yet more preferably 300 Wnr1K'1or more. The thermal body may have a thermal conductivity of from 100 to 500 Wm-1K'1, such as from 200 to 400 Wm1K'1. The thermal body may be aluminium, having a thermal conductivity of about 237 Wnr1K'1. The first material may be copper, having a thermal conductivity of about 398 Wnr1K'1. Thermal conductivity may be measured using any suitable means, such as ISO 22007-2:2022.

[0223] 008874653 The thermal body may have a specific heat capacity of 100 Jkg-1K-1or more, preferably 300 Jkg-1K-1or more, more preferably 500 Jkg-1K-1or more, yet more preferably 800 Jkg-1K-1or more. The thermal body may have a specific heat capacity of from 100 to 1200 Jkg_1K_1, such as from 500 to 1000 Wnr1K'1, such as from 850 to 950 Jkg-1K-1. The thermal body may be aluminium, having a specific heat capacity of about 902 Jkg_1K_1. The thermal body may be copper, having a specific heat capacity of about 385 Jkg-1K-1. Specific heat capacity may be measured using any suitable means, such as ISO 19935-2:2020.

[0224] In some embodiments, the thermal body comprises a single layer.

[0225] Alternatively, the thermal body may comprise a first layer and a second layer, wherein the first layer is laminated with the second layer. In this embodiment, the first layer is in thermal communication with the first heat exchanger, such as the endpiece, and the second layer is in thermal communication with the first layer and with the heat source and / or heat sink. The first layer may be made from a material as described above, in relation to the thermal body.

[0226] The second layer may actively control the temperature of the first layer.

[0227] In one embodiment, the second layer comprises a thermoelectric cooler. This may also be known as a Peltier device. A Peltier has a hot side and a cold side. The Peltier may heat or cool the first layer, that is, the Peltier may transfer thermal energy into or away from the first layer.

[0228] A Peltier device can be used for cooling or heating. When a voltage is applied across the Peltier device, a temperature difference builds up between the two sides. Thus, the device has a hot side and a cold side.

[0229] Where the charging device comprises a heat sink, the hot side of the Peltier is in thermal communication with the heat sink, and the cold side of the Peltier is in thermal communication with the first layer of the thermal body.

[0230] Alternatively, where the charging device comprises a heat source, the cold side of the Peltier is in thermal communication with the heat source and the hot side of the Peltier is in thermal communication with the first layer of the thermal body.

[0231] In some embodiments, the first layer is made from a first material and the second layer is made from a second material, wherein the second material is different from the first material. The second material may have a different specific heat capacity than the first material and / or a different heat conductivity than the first material.

[0232] The second material may be different from the first material. The second material may have a specific heat capacity which is different than the first material, such as greater than the first

[0233] 008874653 material. The second material may have a heat conductivity which is different than the first material, such as less than the first material.

[0234] The first material may have a thermal conductivity of 100 Wnr1K'1or more, preferably 150 Wm'1K'1or more, more preferably 200 Wnr1K'1or more, yet more preferably 300 Wnr1K'1or more. The first material may have a thermal conductivity of from 100 to 500 Wnr1K'1, such as from 200 to 400 Wnr1K'1. The first material may be aluminium, having a thermal conductivity of about 237 Wnr1K'1. The first material may be copper, having a thermal conductivity of about 398 Wnr1K'1. Thermal conductivity may be measured using any suitable means, such as ISO 22007-2:2022.

[0235] Where present, the second material may be different from the first material. The second material may have a heat conductivity which is different to the first material. Preferably, the second material may have a heat conductivity which is less than the first material. The second material may have a thermal conductivity of 100 Wnr1K'1or more, preferably 150 Wnr1K-1or more, more preferably 200 Wnr1K'1or more, yet more preferably 300 Wnr1K'1or more. The first material may have a thermal conductivity of from 100 to 500 Wnr1K'1, such as from 200 to 400 Wnr1K'1. Thermal conductivity may be measured using any suitable means, such as ISO 22007-2:2022.

[0236] The first material may have a specific heat capacity of 100 Jkg_1K_1or more, preferably 300 Jkg-1K-1or more, more preferably 500 Jkg-1K-1or more, yet more preferably 800 Jkg-1K-1or more. The first material may have a specific heat capacity of from 100 to 1200 Jkg_1K_1, such as from 500 to 1000 Wnr1K'1, such as from 850 to 950 Jkg-1K-1. The first material may be aluminium, having a specific heat capacity of about 902 Jkg-1K-1. The first material may be copper, having a specific heat capacity of about 385 Jkg_1K_1. Specific heat capacity may be measured using any suitable means, such as ISO 19935-2:2020.

[0237] Where present, the second material may have a specific heat capacity which is different to the first material. The second material may have a specific heat capacity which is greater than the first material. The second material may have a specific heat capacity of 100 Jkg_1K_1or more, preferably 300 Jkg-1K-1or more, more preferably 500 Jkg-1K-1or more, yet more preferably 800 Jkg_1K_1or more. The second material may have a specific heat capacity of from 100 to 1200 Jkg-1K-1, such as from 500 to 1000 Wnr1K'1, such as from 850 to 950 Jkg-1K-1Specific heat capacity may be measured using any suitable means, such as ISO 19935-2:2020.

[0238] The first material may be a metal, such as aluminium, copper, steel, nickel, Inconel, or cupronickel. Preferably the first material is aluminium or copper, such as aluminium.

[0239] The second material may also be a metal, such as aluminium, copper, steel, nickel, Inconel, or cupronickel. Preferably the first material is aluminium or copper, such as aluminium.

[0240] 008874653 The first and second layers may be laminated together. The first and second layers may be joined by welding or glueing.

[0241] The thermal body is in thermal communication with a heat sink or a heat source.

[0242] In some embodiments the second heat exchanger comprises a thermal body and a heat sink. The heat sink may be for dissipating heat to the environment.

[0243] In some embodiments the second heat exchanger comprises a thermal body and a heat sink, wherein the heat sink is for dissipating thermal energy from the thermal body to a fluid.

[0244] The heat sink comprises a base and two or more fins which protrude from the base. Thermal energy is transferred from the thermal body into the heat sink. The fins of the heat sink are arranged such that fluid can flow over the fins, such that thermal energy is transferred from the fins into the fluid. Suitable fluids include air or liquid coolant.

[0245] In some embodiments the second heat exchanger comprises a thermal body and a heat source. Where the heat exchanger comprises a heat source, this may be configured to receive thermal energy from a fluid, such as air or liquid. The fluid may be heated by another component of the charger, such as power electronics.

[0246] In some embodiments, the second heat exchanger comprising a thermal body and a heat source, wherein the heat source is for transferring thermal energy to the thermal body.

[0247] In some embodiments: the second heat exchanger comprises a heat sink, and the heat sink is for transferring thermal energy from the thermal body to a heat transfer fluid, and / or the second heat exchanger comprises a heat source, and the heat source is for transferring thermal energy to the thermal body from a heat transfer fluid.

[0248] In some embodiments, the heat sink and / or heat source may be actively cooled or heated. That is, power is used to apply or remove thermal energy to the heat source.

[0249] In some embodiments, the charging device may comprise a pump for moving the heat transfer fluid over the heat source or heat sink. The charging device may include a pump for moving liquid over the heat sink or the heat source. The pump may be a fan for moving air or a pump for moving liquid. The heat transfer fluid may be for dissipating the thermal energy to the environment.

[0250] The charging device may comprise a fan. The fan is configured to blow air over the fins of the heat sink. In this embodiment, there may be ventilation holes in the body of the charging device to allow the free circulation of air.

[0251] 008874653 Alternatively, the charging device may comprise a pump, which moves liquid over the fins of the heat sink or the heat source. The pump may circulate liquid from the fins of the heat sink or heat source to a third heat exchanger.

[0252] In some embodiments, the pump is controllable. The pump may be controllable to adjust the rate of heat transfer from the heat sink or heat source. For example, a higher flow rate of heat transfer fluid over the heat sink or heat source may increase the rate of thermal energy transfer.

[0253] In alternative embodiments, the heat sink and / or heat source may be actively cooled or heated. That is, the heat sink and / or heat source are not actively cooled or heated. In this way, no power is used to circulate heat transfer fluid. Instead, the heat transfer fluid may circulate by convection.

[0254] The third heat exchanger may dissipate thermal energy to the surroundings. Alternatively, the third heat exchanger may receive thermal energy, such as from power electronics or a heater.

[0255] Method

[0256] The present invention also provides a method of charging and controlling the temperature of a battery.

[0257] In a fourth aspect of the invention there is provided a method of controlling battery temperature in a battery module with a charging device, the battery module comprising: a battery comprising electrochemical cells, a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells; the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or a heat sink; and the method comprising: connecting the battery module to the charging device; and transferring thermal energy between the endpiece of the battery module and the thermal body of the charging device to control the temperature of the battery.

[0258] The step of connecting the battery module to the charging device may be known as the connection step.

[0259] In the connection step, a releasable power connector on the battery module is typically connected to a releasable power connector on the charging device. In this way, the battery module and the charging device are in electrical communication.

[0260] 008874653 The step of transferring thermal energy between the endpiece of the battery module and the thermal body of the charging device is known as the heat transfer step.

[0261] In some embodiments the second heat exchanger comprises a thermal body and a heat sink. The heat sink may be for dissipating heat to the environment or to a heat transfer fluid. In some embodiments, the heat transfer step comprises transferring thermal energy from the endpiece of the battery module, to the thermal body. The heat sink then dissipates the thermal energy from the thermal body. In this way, the charging device cools the battery module. As a result, the temperature of the battery may be controlled and maintained at an optimal temperature for charging.

[0262] In some embodiments the second heat exchanger comprises a thermal body and a heat source. The heat source may be for receiving heat from the environment or from a heat transfer fluid. In some embodiments, the heat transfer step comprises transferring thermal energy from the heat source to the thermal body, and onto the endpiece of the battery module. The endpiece in turn transfers the thermal energy to the plates and to the cells. In this way, the charging device heats the battery module. As a result, the temperature of the battery may be controlled and maintained at an optimal temperature for charging.

[0263] The method may further comprise a step of charging the battery module from the charging device. This may be known as the charging step. The charging step occurs after the connection step and before the disconnection step.

[0264] In the charging step, power is transferred to the cells at a high rate, such as a rate of 3C or more, preferably as 5C or more, more preferably 8C or more, yet more preferably 12C or more.

[0265] The method may further comprise a step of disconnecting the battery module to the charging device. This may be known as the disconnection step.

[0266] In the disconnection step, a releasable power connector on the battery module is typically disconnected from a releasable power connector on the charging device. In this way, the battery module and the charging device are disconnected.

[0267] Use

[0268] In another aspect of the invention, there is provided a use of the system for controlling the temperature of a battery.

[0269] In a fifth aspect of the invention there is provided a use of the system of the first aspect, the battery module of the second aspect or the charging device of the third aspect, for controlling

[0270] 008874653 the temperature of a battery, in a mobile charging device, a static charging device, an electric vehicle or a power tool.

[0271] In some embodiments, the use is for heating or cooling the battery. Preferably, the use is for cooling the battery.

[0272] The system may be used to control the temperature of a battery of a mobile charging device, a static charging device, an electric vehicle or a power tool. Preferably, the system may be used to control the temperature of a battery of an electric vehicle or a power tool

[0273] The system may be used to control the temperature of a battery of an electric bicycle (e-bike), a drone, an electric aircraft, and an electric or hybrid boat. Similarly, the system may be used to control the temperature of a battery of a power tool such as powered drills or saws, garden tools such as lawnmowers, hedge trimmers, or grass trimmers, or home appliances such as toothbrushes, vacuum cleaners or hair dryers. The system may be used to control the temperature of a battery of a camera. The system may be used to control the temperature of a battery of a robot, such as a delivery robot or a warehouse automation robot..

[0274] The system may be used to simultaneously control the temperature of and charge the battery of a mobile charging device, a static charging device, an electric vehicle or a power tool.

[0275] The battery module of the present invention may be used to control the temperature of a battery independently of a charging device. For example, the battery module may be used to control the temperature of the battery of an electric vehicle or a power tool independently of a charging device.

[0276] The charging device of the present invention may be used to charge and control the temperature of a battery which is not the battery module of the present invention. For example, the charging device of the present invention may be used to simultaneously charge and cool a battery which is cooled by edge cooling.

[0277] In some embodiments there is provided a use of the system of the first aspect, the battery module of the second aspect or the charging device of the third aspect, for improving heat transfer to or from a battery. The use may be for improving heating or cooling of a battery.

[0278] In some embodiments there is provided a use of the system of the first aspect, the battery module of the second aspect or the charging device of the third aspect, for improving heat transfer to or from a sealed battery. The use may be for improving heating or cooling of a sealed battery.

[0279] 008874653 Other Preferences

[0280] Each and every compatible combination of the embodiments described above is explicitly disclosed herein, as if each and every combination was individually and explicitly recited.

[0281] Various further aspects and embodiments of the present invention will be apparent to those skilled in the art in view of the present disclosure.

[0282] “and / or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example “A and / or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein.

[0283] Unless context dictates otherwise, the descriptions and definitions of the features set out above are not limited to any particular aspect or embodiment of the invention and apply equally to all aspects and embodiments which are described.

[0284] Certain aspects and embodiments of the invention will now be illustrated by way of example and with reference to the figures described above.

[0285] Examples

[0286] The following examples are provided to further illustrate the present invention and are not intended to limit the scope of the invention.

[0287] Figure 1 shows a conventional battery pack

[0011] and charger

[0012] with its cooling system. The battery pack

[0011] comprises a collection of battery cells

[0013] , a power connection

[0015] , and a pair of air vents [19, 110] which can be used to pass air from one side of the battery pack

[0011] to the other to cool the battery cells

[0013] ,

[0288] The charger

[0012] comprises a power connection

[0014] and air vents [17, 18] on either side of a fan

[0016] , which is used to draw air into the charger

[0012] and blow it into the battery pack

[0011] ,

[0289] During charging, the battery pack

[0011] is mated to the charger

[0012] such that the power connection

[0014] on the charger

[0012] is connected to the power connection

[0015] on the battery pack

[0011] so that electrical power can be carried from a power source, for example a mains connection but in some implementations the power source may be another battery. The electrical power is then used to charge the battery cells

[0013] in a conventional way. While charging, the battery cells

[0013] produce heat and therefore require cooling not only to improve the efficiency of charging but also for safety, as it is easy for battery cells to overheat, and this may lead to fire or explosion. The system therefore also includes cooling.

[0290] 008874653 The cooling system in Figure 1 consists of the fan

[0016] and vent system [17, 18] of the charger

[0012] and the vent system [19, 110] of the battery pack

[0011] , When the battery pack

[0011] is docked with the charger

[0012] for charging, the input vent

[0019] of the battery pack

[0011] and the output vent

[0110] of the charger

[0012] are also mated to facilitate airflow from one to the other. The fan

[0016] draws air through the charger input vent

[0017] and blows it through the output vent

[0018] of the charger

[0012] and therefore through the input vent

[0019] of the battery pack

[0011] , The air passes over and around the battery cells

[0014] , allowing them to dissipate heat to the air before it is exhausted through the output vent

[0110] of the battery pack

[0011] ,

[0291] This system is problematic due to the presence of vents [19, 110] in the battery pack

[0011] , which are a point of weakness in the casing and also provide an access point for liquids and foreign bodies, which may damage the battery cells

[0013] and their related circuitry.

[0292] Figure 2 shows a battery module

[0021] and charging device

[0031] with a cooling system according to the invention. As in the conventional system of Figure 1 , the battery module

[0021] comprises a collection of cells

[0023] , connected to a power connection

[0028] , The charging device

[0031] , likewise, includes a power connection

[0038] arranged to mate with the power connection

[0028] on the battery module

[0021] and transfer electrical power to the power connection

[0028] on the battery module

[0021] for charging of the battery cells

[0023] ,

[0293] Unlike in the conventional system of Figure 1 , there are no vents in the battery module

[0021] , The charging device

[0031] includes a fan

[0310] with input and output vents, here shown as a single vent

[0311] on the side of the charging device

[0031] that does not mate with the battery module

[0021] , since there is no requirement for the output vent

[0311] to mate with a vent on the battery module

[0021] , Instead, the charging device

[0031] comprises a second heat exchanger

[0032] comprising a heat sink

[0036] connected to a thermal body

[0033] on the mating side of the charging device

[0031] and a fan

[0310] that passes air over the heat sink

[0036] , Heat is carried from the thermal body

[0033] to the heat sink

[0036] and the fan

[0310] blows air over the heat sink

[0036] to remove the heat through radiation. This air may be cooled by a separate device not shown here, for example a Peltier cooler which may be entirely separate or may be colocated with the charger in the same casing such that they appear to be a single device, or it may be at ambient temperature, though cooled air will lead to more effective cooling.

[0294] The part of the cooling system incorporated into the battery module

[0021] comprises a first heat exchanger

[0022] comprising plates

[0024] connected to an endpiece

[0025] , The plates are interleaved between the battery cells

[0023] and absorb heat from the battery cells

[0023] , then carry it to the first layer

[0026] of the endpiece

[0025] via conduction. The first layer

[0026] of the endpiece

[0025] is then thermally connected to a second layer

[0027] of the endpiece and is therefore able to transfer the heat from the battery cells

[0023] to the second layer

[0027] via conduction.

[0295] When the battery module

[0021] is mated with the charging device

[0031] , the second layer

[0027] comes into contact with the thermal body

[0033] of the second heat exchanger

[0032] of the

[0296] 008874653 charging device

[0031] and is therefore able to transfer the heat to the thermal body

[0033] , cooling the battery module

[0021] without any requirement for vents in the casing of the battery module

[0021] ,

[0297] Figure 3 shows an alternative embodiment of the invention arranged similarly to the system in Figure 2 but the thermal body

[0033] of the second heat exchanger

[0032] has two layers [34, 35], In this embodiment, the second layer is a Peltier cooler

[0035] , The Peltier cooler

[0035] generates a temperature gradient across its body due to the Seebeck effect. If the hot side of the cooler

[0035] - the side away from the first layer

[0034] of the thermal base - is kept at ambient temperature the cold side - the side associated with the first layer

[0034] of the thermal body

[0033] - can be tens of degrees cooler than the ambient temperature, in turn leading to a significant cooling effect on the first layer

[0034] , The larger the temperature difference between the first layer

[0034] of the thermal body

[0033] and the battery module

[0021] , the faster the heat will be conducted away, so this embodiment results in faster cooling than the embodiment in Figure 2.

[0298] In both these embodiments, the second layer

[0027] of the endpiece

[0025] of the battery module

[0021] can also be used to cool the battery module

[0021] in use if it is arranged appropriately. For example, if the battery module

[0021] is set on a cool surface such as a stone worktop during use, the cool surface will cool the second layer

[0027] in the battery module

[0021] , cooling the battery cells

[0023] in the same way as the second heat exchanger in the charging device.

[0299] To maximise the rate of transfer the thermal contact between the battery module

[0021] and the charging device

[0031] must be as low resistance as possible. This could be achieved by having the surface completely flat, or with both surfaces having mating features such as corrugations to increase the contact surface area. The face-on interaction between the second layer

[0027] and the thermal body

[0033] provides a large surface area for the efficient transfer of thermal energy. The direct movement of thermal energy across the series of superposed layers comprising the first layer

[0026] and second layer

[0027] or the endpiece

[0025] and the thermal body

[0033] also makes the transfer of thermal energy highly efficient.

[0300] Figure 4 shows two views of the operation of a conventional heat sink system. The upper view (Figure 4a) is a view from the side showing the heat source

[0045] and fins

[0042] , The lower view (Figure 4b) is a view from above showing airflow through the fins

[0042] ,

[0301] The side view shows a heat sink

[0041] with a heat-absorbent base

[0043] and five fins

[0042] , thermally connected to a heat source

[0045] , which may be a battery, electronics, or a mechanical device such as a motor. Heat is absorbed from the heat source

[0045] by the base

[0043] and transferred up the fins

[0042] by conduction, indicated by the solid arrows. It is then radiated to air passing through the channels

[0044] between the fins

[0042] , the air flow indicated by the dashed lines in the upper view and dashed arrows in the lower view.

[0302] 008874653 This conventional system is bulky, since the channels

[0044] between the fins

[0042] cannot be obstructed and the heat sink

[0041] takes up space in addition to the space required for the heat source

[0045] , Furthermore, it is unsuitable for face cooling of a battery cell since only one cell could be placed against the base

[0043] at a time, making it less efficient for battery cooling.

[0303] Figure 5 shows a side view of a battery module

[0021] arranged according to the invention, comprising a first heat exchanger

[0022] and eight cells

[0023] , The cells

[0023] are inserted in pairs between the plates

[0024] , The cells

[0023] are thermally connected to the plates

[0024] such that the plates

[0024] absorb heat generated by the cells

[0023] , The heat is then passed to the endpiece

[0025] via conduction, indicated by the solid arrows. In this embodiment, the endpiece

[0025] of the first heat exchanger comprises just one layer.

[0304] The endpiece

[0025] may then be actively cooled, for example by being placed against a cool surface, by air or liquid cooling, or by a device such as a Peltier cooler.

[0305] This system takes advantage of the greater surface area of the battery cell faces and the fins to provide more efficient cooling.

[0306] Unlike conventional face-cooling systems such as that described in US 2024 / 0030518 A1 , the first heat exchanger of the present invention can be manufactured through extrusion. This allows manufacture as a single piece that can be produced at high volumes relatively cheaply while other face-cooling systems require multiple complex parts to achieve the same function. This provides cost savings at manufacture and assembly and reduces the chance of part failure.

[0307] Figure 6 shows two example alternative embodiments of the first heat exchange system according to the invention.

[0308] Figure 6a shows an example embodiment which uses air cooling, as previously mentioned. The upper part of the heat exchange system comprises four plates

[0024] interspersed with pairs of battery cells

[0023] , as described in Figure 5. The lower part of the heat exchanger is a conventional heat sink

[0041] such as that described in Figure 4, comprising four fins with airflow

[0042] between them. This system could be used where the heat exchange system can be exposed to a coolant in use, such as a vent on the outside of an electric vehicle (EV) which is exposed to airflow when the EV is in motion.

[0309] Figure 6b shows an example embodiment with a tubular configuration, arranged such that the plates

[0024] radiate from a central tube. As previously described, battery cells

[0023] are placed between the plates

[0024] , and in this case the cells

[0023] may be shaped for the most efficient use of the shape. The operation of the system is the same; heat is transferred from the battery cells

[0023] to the plates

[0024] and then to the first layer

[0026] of the endpiece and to the second layer

[0027] which forms a central tube, which is cooled by the flow of coolant through the centre

[0029] ,

[0310] 008874653 Figure 7 shows another embodiment of the first heat exchanger

[0022] of the present invention. As previously described, a pair of cells

[0023] are arranged between two adjacent plates

[0024] which are joined to an endpiece

[0025] , In this embodiment, a layer of electrically insulating film

[0210] is sandwiched between the face of each cell

[0023] and plate

[0024] , The electrically insulating film prevents electrical conduction between the cells and the plates, in order to improve efficiency and safety. A layer of deformable material

[0211] is sandwiched between the two cells. This deformable material

[0211] allows for variation in cell size during charging and discharging.

[0311] Figure 8 shows another embodiment of the first heat exchanger

[0022] of the present invention. In this embodiment, the heat exchanger

[0022] comprises a single plate

[0024] sandwiched between two cells

[0023] and attached to an endpiece

[0025] at one end, such that the plate

[0024] and endpiece

[0025] together have an L-shaped cross section. The arrow shows the direction of thermal energy transfer from the plate

[0024] to the endpiece

[0025] ,

[0312] Figure 9 shows a single heat exchange unit

[0221] comprising a plate

[0024] with a first endpiece

[0025] attached to a first end of the plate and a second endpiece

[0025] attached to a second end of the plate. The first endpiece, second endpiece and plate together have a U-shaped crosssection. In some embodiments, the first heat exchanger comprises a stack of two or more heat exchange units

[0221] , The arrow shows the direction of thermal energy transfer from the plate

[0024] to the endpiece

[0025] ,

[0313] Figure 10 shows an embodiment of the first heat exchanger

[0022] wherein the first heat exchanger

[0022] comprises a stack of three heat exchanger units

[0221] as shown in Figure 9. Three electrochemical cells

[0023] are interleaved with the plates

[0024] of the heat exchanger units

[0221] , The endpieces

[0025] of the heat exchanger units

[0221] comprise mating features

[0251] which allow the endpieces of adjacent heat exchanger units to securely stack together. The arrow shows the direction of thermal energy transfer from the plate

[0024] to the endpiece

[0025] ,

[0314] Figure 11 shows the changes in charge, temperature, and charging current during rapid charging of battery cells in a system according to the invention. A battery pack comprising a first heat exchanger arranged according to the invention was charged at 12C using a CC-CV method, comprising a constant current of 600A for the first 180s which then falls in the conventional way. For the first 180s the battery charge rises steadily to slowly plateau after 180s. The battery pack temperature also rises steadily for the first 180s and peaks after around 250s, after which it begins to slowly fall. The maximum temperature peaks at around 59°C and the minimum temperature peaks at around 57°C, which is higher than the optimal temperature range for lithium-ion batteries (this range lying on average between 15°C and 45°C) but is not dangerously high. Furthermore, for other battery chemistries such as cells comprising a niobium-containing metal oxide such as those disclosed in GB2592341 , the optimal range may be larger.

[0315] 008874653 This demonstrates the relationship between the charging current and battery charge and the temperature: while the current is high and the battery is charging rapidly, the temperature rises rapidly. However, the cooling system of the invention controls the rise in temperature and causes it to start falling while charging is ongoing. Comparative data for rapid charging of similar battery cells in a conventional system is not available for safety reasons; cooling offered by the conventional system is insufficient, leading to a risk of thermal runaway if a battery cell is charged at the same high rate as that used for the above experiment.

[0316] References

[0317] A number of publications are cited above in order to more fully describe and disclose the invention and the state of the art to which the invention pertains. The entirety of each of these references is incorporated herein.

[0318] EP 1178557 A2

[0319] DE 102011082566 A1

[0320] US 2010 / 0008036 A1

[0321] JPH06150978 A

[0322] KR 2019 / 0138358 A

[0323] US 2019 / 0081373 A1

[0324] US 2015 / 0318523 A1

[0325] US 2006 / 0232929 A1

[0326] CN 210074847U

[0327] US 6313987 B1

[0328] US 6181553 B1

[0329] 008874653

Claims

Claims1 . A system for controlling battery temperature, the system comprising a battery module and a charging device, the battery module comprising: a battery comprising electrochemical cells, a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells; and the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or a heat sink; wherein the charging device is connectable to the battery module, and when the charging device is connected to the battery module, the endpiece of the battery module is in thermal communication with the thermal body of the charging device.

2. The system of claim 1 , wherein when the charging device is connected to the battery module the endpiece of the battery module interfaces with the thermal body of the charging device, preferably wherein the shape of the endpiece is complementary to the shape of the thermal body.

3. The system of claim 1 or claim 2, wherein the endpiece is substantially planar, such as wherein a surface of the endpiece for contacting the thermal body is substantially planar.

4. The system of any one of claims 1 to 3, wherein the endpiece has a first surface and a second surface, wherein the first surface and the second surface are on opposite sides of the endpiece, and wherein the first surface is connected to the one or more plates of the first heat exchanger and the second surface is for contacting the thermal body of the charging module.

5. The system of claim 4, wherein 20 % or more of the total area of the second surface is for contacting the thermal body of the charging module, such as 40 % or more, such as 60 % or more, such as 80% or more, such as 90% or more, such as 95% or more.

6. The system of any preceding claim, wherein the endpiece is connected to two or more plates, such as four or more plates, such as six or more plates.

7. The system of any preceding claim, wherein the endpiece and the plates of the first heat exchanger are integrally formed.

8. The system of any of claims 1 to 5, wherein the endpiece is connected to one plate, and forms a heat exchanger unit, wherein the first heat exchanger comprises two or more heat exchanger units, such as a stack of two or more heat exchanger units.0088746539. The system of claim 8, wherein each heat exchanger unit is integrally formed.

10. The system of any preceding claim, wherein the endpiece is connected to a first end of the one or more plates and a second endpiece is connected to a second end of the one or more plates.

11. The system of any preceding claim, wherein each plate is in thermal communication with 50% or more of the face of the cell, calculated on an area basis, preferably 70% or more, more preferably 90% or more.

12. The system of any preceding claim, wherein the endpiece comprises a first layer connected to the one or more plates, and a second layer which is in thermal communication with the first layer.

13. The system of claim 10, wherein the first layer, and optionally the plates, are made from a first material, and the second layer is made from a second material which is different from the first material.

14. The system of claim 11 , wherein the first material has a higher thermal conductivity than the second material.

15. The system of any preceding claim, wherein two or more cells are sandwiched between two adjacent plates, preferably wherein two cells are sandwiched between two adjacent plates.

16. The system of claim 13, wherein:(i) the two or more cells are each separated by a resiliently deformable layer; and / or(ii) the plates and the face of the electrochemical cells are separated by an electrically insulating layer.

17. The system of any preceding claim, wherein the electrochemical cells are pouch cells or prismatic cells, preferably wherein the electrochemical cells are pouch cells.

18. The system of any preceding claim wherein the battery is sealed from the surroundings.

19. The system of any preceding claim, wherein the charging device is electrically connectable to the battery module, and optionally(i) the battery module further comprises a first power connector for releasably connecting to the charging device; and(ii) the charging device further comprises a second power connector for releasably connecting to the battery module.00887465320. The system of any preceding claim, wherein: the second heat exchanger comprises a heat sink, and the heat sink is for transferring thermal energy from the thermal body to a heat transfer fluid, and / or the second heat exchanger comprises a heat source, and the heat source is for transferring thermal energy to the thermal body from a heat transfer fluid.

21. The system of claim 20, further comprising a pump for moving the heat transfer fluid over the heat source or heat sink.

22. The system of claim 20 or claim 21 , wherein the heat transfer fluid is for dissipating the thermal energy to the environment.

23. The system of any preceding claim, wherein the thermal body comprises a first layer and a second layer, wherein when the charging device is connected to a battery module, the first layer is in thermal communication with the battery module; and wherein the second layer is in thermal communication with the first layer and the heat source and / or heat sink.

24. The system of claim 23, wherein the second layer comprises a thermoelectric cooler, such as a Peltier device.

25. A battery module for controlling battery temperature, the battery module comprising: a battery comprising electrochemical cells, and a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells, and wherein the battery module is connectable to a charging device as defined in claim 1 , and when the battery module is connected to the charging device, the end piece is in thermal communication with the charging device.

26. A charging device for controlling battery temperature, the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or heat sink, wherein the charging device is connectable to a battery module as defined in claim 1 , and when the charging device is connected to the battery module, the thermal body is in thermal communication with the battery module.

27. A method of controlling battery temperature in a battery module with a charging device, the battery module comprising: a battery comprising electrochemical cells, a first heat exchanger comprising an endpiece connected to one or more plates, wherein each plate is in thermal communication with a face of the electrochemical cells;008874653the charging device comprising: a second heat exchanger comprising a thermal body in thermal communication with a heat source and / or a heat sink; and the method comprising: connecting the battery module to the charging device; and transferring thermal energy between the endpiece of the battery module and the thermal body of the charging device to control the temperature of the battery.

28. Use of the system according to any of claims 1 to 24, the battery module of claim 25 or the charging device of claim 26, for controlling the temperature of a battery, in a mobile charging device, a static charging device, an electric vehicle or a power tool.008874653

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