Ultra high-performance battery module with active and dynamic management of operating temperature and pressure

Abstract

The invention discloses a system and a method for managing the operating temperature and pressure of a battery. Battery cells are housed in cylindrical modules in which there circulates a heat-transfer fluid under pressure and temperature. A fluidic unit has a return reservoir that collects the oil leaving the modules, and cooling and heating reservoirs containing the oil pumped from the return reservoir at predefined hot and cold temperatures. The oil is transmitted to the modules at a temperature and a pressure that are obtained almost instantaneously by regulated mixing and flowrate of hot and cold oil. The mixing and the flowrate are controlled by controllers connected to a BMS which manages the oil pressure and temperature setpoints to be applied to the cells as a function of a power and energy demand received by the BMS and of pressure and temperature measurements taken by sensors in the system.

Description

[0001] ULTRA-PERFORMANCE BATTERY MODULE WITH ACTIVE AND DYNAMIC MANAGEMENT OF OPERATING PRESSURE AND TEMPERATURE

[0002] FIELD OF THE INVENTION

[0003] A system and method for actively and dynamically managing operating pressure and temperature of cells of one or more battery modules is disclosed.

[0004] CONTEXT

[0005] The operating pressure and temperature values ​​of Li-Ion cells cannot be used as a reference for optimal operation of cells in a new generation battery, including a solid-state battery. According to current knowledge, precise, active and dynamic management of battery operating pressure and temperature values ​​is likely to be critical for:

[0006] - minimize / eliminate the appearance of dynamic porosities or "voids" during rapid discharge ("stripping" phase), which subsequently promote the formation of dendrites during rapid charging;

[0007] - increase the charging speed while limiting / eliminating the process of formation and propagation of dendrites during plating;

[0008] - increase battery life (maintain capacity, minimize "dead" or inactive lithium);

[0009] - limit the rate of increase in battery cell impedance over cycles;

[0010] - work hardening the dendrite areas / tips (increase in the diffusion / transport of lithium or other metal constituting the anode);

[0011] - ensure that the quality of contacts at the cathode-electrolyte-anode interfaces of the cells is maintained;

[0012] - minimize / eliminate damage to cells in case of extraordinary stress;

[0013] - exploit the potential of new generation batteries to the maximum. Known in the art, application WO 2019 / 017994 (Hettrich) proposes active and passive pressure management of a battery and a battery module in which a fluid maintains an isostatic pressure on at least one electrochemical cell in the module.

[0014] US Application 2020 / 0259232 (Ge et al.) proposes a stable, high-performance battery on demand, in which a battery cell includes a heating element such as a resistor to raise the temperature of the battery and improve its performance.

[0015] US 2016 / 0380315 (Weicker et al.) proposes battery systems having independently controlled battery cell assemblies based on specialized and complementary battery modules, e.g., a power-specialized module and an energy-specialized module. The specificity of the modules may be related to the use of different chemistries from one module to another.

[0016] US Application 2014 / 0227568 (Hermann) proposes battery systems with selective thermal management including battery modules working cooperatively so that one module heats the other as needed.

[0017] US 2013 / 0330577 (Kristofek et al.) proposes dynamic pressure control in a battery pack using a fluid that can also be used to manage temperature. The fluid is not in direct contact with the battery cells but rather is contained in pouches that are in contact with the cells and allow them to be cooled and pressure applied to the cells.

[0018] US 2021 / 0167414 (Torres Martinez) proposes a pressurized electrochemical battery and a corresponding manufacturing method. A dynamic pressure and temperature management system is implemented using a fluid that plays both roles, similarly to what is proposed in US 2013 / 0330577.

[0019] Application DE 102019211729 (Jahnke et al.) proposes a vehicle battery module comprising a dynamic pressure management system. Mechanisms applying pressure to cells of a battery can be passive or active by means of springs, piezoelectrics or small fluid-filled pouches.

[0020] Application DE 102018203050 (Hoffmann) proposes a dynamic pressure management system for a battery based on a fluid injected into pockets applied against battery cells.

[0021] None of the systems proposed in the art is capable of actively and dynamically managing significant pressure and temperature variations at the level of cells of a battery with a quasi-instantaneous response time depending on given operating or stress conditions, in order to exploit the possible performance characteristics of such a battery.

[0022] SUMMARY

[0023] An object of the present invention is to provide a system for managing the operating pressure and temperature of cells of one or more battery modules, which makes it possible to exploit the possible performance characteristics of such a battery.

[0024] According to one aspect of the present invention, there is provided a system for managing the operating pressure and temperature of a battery, the system comprising: at least one battery module having a chamber housing cells of the battery, and at least one on-board circuit connected to the cells and configured to control their operation and monitor their state of charge, the chamber having opposite fluid inlets and outlets for receiving and discharging a heat transfer fluid applied to all the cells;a fluidic unit having a return reservoir in communication with the fluidic outlet of each battery module, a cooling reservoir for holding a quantity of the heat transfer fluid pumped from the return reservoir at a predefined cold temperature, a heating reservoir for holding a quantity of the heat transfer fluid pumped from the return reservoir at a predefined hot temperature, and a temperature and pressure control device having inlets in communication with the cooling and heating reservoirs and at least one outlet in communication with the fluidic inlet of each battery module so as to transmit the heat transfer fluid at a temperature and pressure by controlled mixing and flow of the heat transfer fluid from the cooling and heating reservoirs; temperature and pressure sensors of the heat transfer fluid circulating between the fluidic unit and the at least one battery module;at least one controller having inputs for receiving temperature and pressure setpoint signals of the heat transfer fluid in the at least one battery module, inputs for receiving temperature and pressure measurement signals produced by the temperature and pressure sensors, and outputs for producing signals controlling the mixing and flow rate of the heat transfer fluid transmitted by the fluidic unit according to the setpoint signals and the temperature and pressure measurement signals; and a BMS connected to the at least one controller and to the at least one on-board circuit, the BMS being configured to produce the temperature and pressure setpoint signals of the heat transfer fluid and a request setpoint intended for the at least one battery module according to an energy and power demand received at the input and the state of charge provided by the at least one on-board circuit.;

[0025] According to another aspect of the invention, there is provided a method of managing operating pressure and temperature of a battery, the method comprising the steps of: housing cells of the battery in a chamber defined by at least one battery module, the chamber having opposed fluid inlets and outlets for receiving and discharging a heat transfer fluid applied to all of the cells; monitoring a state of charge of the cells in the at least one battery module; collecting the heat transfer fluid discharged from the fluid outlet of each battery module in a return tank; separately cooling and heating quantities of the heat transfer fluid pumped from the return tank in cooling and heating tanks to predefined cold and hot temperatures;conveying the heat transfer fluid to the fluid inlet of the at least one battery module at regulated temperature and pressure by controlled mixing and flow rate of the heat transfer fluid from the cooling and heating tanks; taking temperature and pressure measurements of the heat transfer fluid conveyed to and discharged by the at least one battery module; controlling the mixing and flow rate of the heat transfer fluid conveyed to the at least one battery module according to the temperature and pressure measurements and setpoints; and adjusting the temperature and pressure setpoints of the heat transfer fluid and a demand setpoint intended for the at least one battery module according to an energy and power demand and the state of charge of the cells in the at least one battery module.;

[0026] In a non-limiting manner, the present invention proposes a system for managing the pressure and operating temperature of cells of one or more battery modules, which make it possible, at the same time or separately: to achieve a precise value of pressure applied to the cells as a function of stress conditions of the battery; to apply a uniform pressure to the cells of the battery; to apply significant values ​​of pressure, for example up to 2,000 psi; to vary very quickly a value of pressure applied to the cells as a function of changes in stress or operating conditions; to allow a variation in the volume of the cells during a charge and discharge cycle; to achieve a precise value of temperature of the cells as a function of stress or operating conditions of the battery;to vary a temperature value of the cells very quickly according to changes in stress or operating conditions; to apply significant temperature values ​​and variations, for example from 0 to 80°C; to obtain a uniform temperature on each of the cells, over their entire surface area; to adjust pressure and temperature regulation strategies according to the health status of the battery and specificities linked to use of the battery by means of varied and / or evolving algorithms; in the case of use of the battery in a vehicle, to minimize a transfer of vibrations from the vehicle to the battery cells in order to preserve the integrity of the electrical contacts; to minimize energy consumption dedicated to cooling or heating a heat transfer fluid and to the application of significant pressure;to cost-effectively integrate the various system assemblies into a vehicle body; and to neutralize chemical reactions in the event of defective cells or an accident.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] A detailed description of preferred embodiments of the invention will be given hereinafter with reference to the following drawings:

[0029] Figure 1 is a schematic diagram illustrating a battery operating pressure and temperature management system according to one embodiment of the invention.

[0030] Figure 2 is a schematic diagram illustrating a pressure and temperature control arrangement according to one embodiment of the invention.

[0031] Figure 3 is a flowchart illustrating a system control and monitoring process according to one embodiment of the invention. Figure 4 is a flowchart illustrating pressure and temperature management and operation parameters of a battery module according to one embodiment of the invention.

[0032] Figures 5A, 5B, 5C and 5D are graphs illustrating examples of pressure and temperature management protocols implemented in the system according to one embodiment of the invention.

[0033] Figure 6 is an exploded schematic diagram of a battery module with button-type cells according to one embodiment of the invention.

[0034] Figures 7A and 7B are partial perspective views of an internal structure of a battery module according to one embodiment of the invention.

[0035] Figures 8A, 8B, 8C and 8D are schematic diagrams of possible arrangements of several battery modules according to one embodiment of the invention.

[0036] Figures 9A and 9D are exploded schematic diagrams of a battery module with prismatic type cells according to one embodiment of the invention.

[0037] DETAILED DESCRIPTION OF FAVORITE ACHIEVEMENTS

[0038] For the purposes of this disclosure, a battery is formed from cells that are composed of two electrodes - a positive pole (or cathode) and a negative pole (or anode) - separated by a medium acting as an ionic conductor, called an electrolyte. The cells can be of different architectures, formats and dimensions. The anodes, cathodes and electrolytes can be made of different materials. The electrolyte can be liquid, solid, hybrid (polymer, ceramic, liquid, etc.). As used in this disclosure, the expression near instantaneous or "instantaneous" means a time lapse or response time of approximately 15 s or less, unless the context implies a different interpretation.

[0039] With reference to Figure 1, a system for managing the operating pressure and temperature of a battery according to one embodiment of the invention is illustrated. The system comprises at least one battery module 2. In the illustrated case and for the remainder of the disclosure, for the purposes of simplification only, reference will be made to a system comprising three battery modules 2. It should be understood that the number of battery modules in the system may be different from one or three, for example two or more than three if desired. The invention presents a solution to the problem of optimally operating a battery by managing the operating pressures and temperatures of the cells it comprises in an active, dynamic, precise and almost instantaneous manner by means of a heat transfer fluid circulating in the system according to control modes which will be described below.In Figure 1, the dotted lines represent heat transfer fluid flow lines while the solid lines represent signal communication lines.

[0040] Referring to Figure 6, each battery module 2 has a chamber 4 housing cells 6 of the battery, and at least one on-board circuit 8 connected to the cells 6 and configured to control their operation and monitor their state of charge. The at least one on-board circuit 8 may include power units, energy dissipaters, current limiters and a smart charger (not shown), making it possible to generate the relevant conditions of pressure, temperature and current density to obtain the optimal performance of the battery modules 2. The chamber 4 has opposite fluid inlets and outlets 10, 12 (illustrated eg in Figure 2) to receive and evacuate a heat transfer fluid applied to all the cells 6.Preferably, the heat transfer fluid is a liquid, advantageously an oil, and more advantageously a mineral oil to neutralize potential chemical reactions in the event of a defective or damaged cell. In the remainder of the disclosure, the term hydraulic may be used instead of "fluidic" in connection with an oil serving as a heat transfer fluid, without limiting the heat transfer fluid to an oil and oil pressure and temperature control devices only.

[0041] Referring again to Figure 1, the system comprises a fluidic unit 14 having a return tank 16 in communication with the fluidic outlet 12 (illustrated eg in Figure 2) of each battery module 2, a cooling tank 18 for containing a quantity of the heat transfer fluid pumped from the return tank 16 at a predefined cold temperature, a heating tank 20 for containing a quantity of the heat transfer fluid pumped from the return tank 16 at a predefined hot temperature, and a temperature and pressure control device 22, 24 having inlets 26 in communication with the cooling and heating tanks 18, 20 and at least one outlet 28 in communication with the fluidic inlet 10 of each battery module 2 so as to transmit the heat transfer fluid at a desired temperature and pressure by controlled mixing and flow of the heat transfer fluid from the cooling and heating tanks 18, 20.According to one embodiment, the predefined hot temperature is 100°C while the predefined cold temperature is -30°C, so that the heat transfer fluid supplied to the battery modules 2 by the fluidic unit 14 can have a temperature varying almost instantaneously from -30°C to 100°C for their dynamic management. Other cold and hot temperature values ​​may be suitable depending on the chemistries of the battery modules 2 used and their operating temperature ranges, for example and preferably at most 0°C and 80°C.

[0042] Referring to Figure 2, the system comprises temperature sensors 31 (Ti, T2, T3) and pressure sensors 33 (Pi, P2, P3) of the heat transfer fluid circulating between the fluidic unit 14 and the battery modules 2. According to one embodiment of the invention, the system comprises controllers 34, 36, 38 (hereinafter also referred to as controllers #1, #2, #3) having inputs 40, 42, 44 for receiving temperature and pressure setpoint signals of the heat transfer fluid in the battery modules 2, inputs 46, 48 for receiving temperature Ti, T2, T3 and pressure Pi, P2, P3 measurement signals produced by the temperature sensors 31 and pressure sensors 33, outputs 50 for producing signals controlling the mixing and the flow rate of the heat transfer fluid transmitted by the fluidic unit 14 according to the setpoint signals and temperature and pressure measurement signals. The functions of controllers 34, 36, 38 can be performed by a single controller if desired.Other types of sensors for monitoring, measuring, informing, controlling, adjusting, and evolving can be added to the system, for example sensors for measuring current, measuring voltage, analyzing gases dissolved in the oil or other heat transfer fluid used (not shown).

[0043] Referring again to Figure 1, the system comprises a BMS 52 connected to the controllers 34, 36, 38 (illustrated eg in Figure 2) and to the on-board circuits 8 (illustrated eg in Figure 6) of the battery modules 2. The BMS 52 is configured to produce the temperature and pressure setpoint signals of the heat transfer fluid and one or more demand setpoints 54 intended for the battery modules 2 as a function of an energy and power demand received at input 56 and the state of charge provided by the on-board circuits 8.

[0044] The BMS 52 can be configured to store and execute algorithms for controlling operating parameters of the battery modules 2 as a function of load conditions, the state of charge and a state of health of the battery modules 2, and as a function of an ambient temperature and a pre-established vocation of a battery module among the battery modules 2. The load conditions, the state of charge and the state of health can be transmitted to the BMS 52 via a controller 88 of load instructions for the battery modules and the states of charge and health provided by a monitoring module 90 processing the signals produced by the on-board circuits 8 (illustrated eg in Figure 6) of the battery modules 2.The pre-established vocation of a battery module 2 can be programmed into the BMS 52 so that the BMS 52 generates the appropriate command and control signals to dynamically and actively manage its pressure, temperature, load and states according to its vocation via the controller 88 and the circuit 54 in communication with the on-board circuits 8 of the battery modules 2, as well as via the pressure control controllers 36 and temperature control controllers 34, 38. The vocation of a battery module 2 can, for example, consist of making it operate in a different way than that for which its cells 6 have been normally designed. The operating parameters include the pressure and temperature of the heat transfer fluid circulating in the battery modules 2, and can also include a power admitted by each battery module 2.The stress conditions can be, for example, rapid charging, a power demand, for example acceleration, a load draw, sudden braking in the case of an electric vehicle.

[0045] The system may be equipped with a heat exchanger 92 with the reservoirs 16, 18, 20 of the fluidic unit 14 and peripheral devices (not shown) generating thermal energy, such as a heater, an air conditioner, a brake motor, a smart charger, for minimizing energy consumption for heating / cooling the heat transfer fluid.

[0046] Referring again to Figure 2, according to one embodiment, the fluidic unit 14 is provided with a pump 94 and an accumulator 100 making it possible to dynamically adjust and manage the pressure to be applied to the battery modules 2 to a desired value. The pump 94 has an inlet 96 communicating with the return tank 16 and an outlet 98 for transmitting a quantity of the heat transfer fluid pumped from the return tank 16. The accumulator 100 has an inlet 102 communicating with the outlet 98 of the pump 94 and an outlet 104 communicating with the cooling and heating tanks 18, 20. The accumulator 100 produces a servo signal 106 controlling the pump 94 according to a pressure measurement provided by a pressure sensor 103 (PO) at the outlet 104 of the accumulator 100 so that a pressure of the heat transfer fluid in the cooling and heating tanks 18, 20 is slightly higher than the pressure setpoint 44.A pressure relief valve 108 is preferably added in parallel to the pump 94. Referring again to Figure 6, each battery module 2 may be formed of a tubular element 58 and end elements 60, 62 closing the tubular element 58 to define the chamber 4 which is similar to a reservoir. A structure 64 for supporting and spacing the cells 6 in an axial direction of the cylindrical element 58 may advantageously ensure appropriate spacing of the cells 6 to allow their volume variation during charge-discharge cycles and minimize transmission of mechanical vibrations to the cells 6 immersed in the heat transfer fluid. A heat transfer fluid distributor arrangement 66 is in communication with the fluid inlet 10 and has openings 68 (illustrated eg in Figure 7B) aligned with spaces between the cells 6. An arrangement 70 of electrical connections connects the cells 6 and the on-board circuit(s) 8 together.The tubular element 58 may be cylindrical in shape as illustrated in Figure 6, being particularly suitable for button-type cells 6 as also illustrated in the Figure. The end members 60, 62 may advantageously be dome-shaped projecting at opposite ends of the tubular element 58 and defining interior spaces housing the embedded circuit(s) 8. In the case where there are two embedded circuits 8 (only one being visible in Figure 6), the embedded circuits 8 may be respectively housed in the end members 60, 62 and isolated from the reservoir or chamber 4 by sealing washers 110, 112. The tubular element in cylindrical form may also be used with prismatic-type cell arrangements 6 as illustrated in Figure 9B.The structure 64 for supporting and spacing the cells 6, the distributor arrangement 66 and the arrangement 70 of electrical connections (as illustrated in Figure 6) are then modified accordingly, for example by suitable elements (not illustrated) arranged between successive stacks of the cells 6 and at the opposite ends of the tubular element 58. The tubular element 58 may have a parallelepiped shape as illustrated in Figure 9B which may advantageously be suitable for prismatic type cells 6, or another shape such as an oblong shape if desired. Similarly, shapes other than a dome may be used for the end elements 60, 62 if desired. The end elements 60, 62 and the opposite ends of the tubular element 58 may advantageously have bolted assembly flanges 59 (not illustrated) allowing the battery module 2 to be dismantled if necessary. Other types of fittings and joints can be used if desired.

[0047] Referring to Figures 7A and 7B, according to one embodiment, the support and spacing structure 64 comprises elongated bars 72 having external surfaces substantially matching an internal surface of the cylindrical element 58 (illustrated e.g. in Figure 6), and internal surfaces having transverse notches 74 distributed in the axial direction of the cylindrical element 58 and in which peripheral rims 76 of the cells 6 engage. The distributor arrangement 66 may comprise conduits 78 extending into the bars 72 and in communication with the fluid inlet 10 (illustrated e.g. in Figure 6), the openings 68 of the distributor arrangement 66 being provided in the internal surfaces of the bars 72 so that the heat transfer fluid applies an isostatic (uniform) pressure on the cells 6 immersed in and directly in contact with the heat transfer fluid.The arrangement 70 of electrical connections may be formed of upper and lower series of plates 80, 82 electrically connected to each other and in contact with terminals of the cells 6. The upper series of plates 80 may extend between the bars 72. The configuration described above of a battery module 2 allows optimal circulation of the heat transfer fluid (rapid variation in temperature, uniform temperature of the cells).

[0048] Referring again to Figure 2, the heat transfer fluid circulates between the fluidic unit 14 and the battery modules 2 through a pipe circuit (illustrated by the thick black lines) provided with flow control members of the heat transfer fluid, controlled by the controllers 34, 36, 38 so as to adjust a temperature and a pressure of the heat transfer fluid circulating in the pipe circuit. The flow control members can advantageously be, for each battery module 2, a distributor Di, D2, D3 of the heat transfer fluid conveyed to the battery module 2, and a proportional pressure regulator Li, L2, L3 of the heat transfer fluid discharged by the battery module 2.

[0049] According to one embodiment, the controller 34 (#1) serves as a temperature management controller for the heat transfer fluid in the system in general by controlling flow regulating members formed for example by distributors D4 and D5 on fluid lines 30, 32 associated with the cooling and heating tanks 18, 20 according to the temperature setpoint signal received at the input 40. The controller 34 may have an input 84 for receiving and taking into account a temperature adjustment signal coming from a temperature sensor 35 (T o) indicative of the temperature of the heat transfer fluid transmitted by the fluidic unit 14. The controller 36 (#2) serves as a pressure management controller for the heat transfer fluid conveyed to and discharged by the battery modules 2 by controlling the distributors Di, D2, D3 and the proportional pressure limiters Li, L2, L3 according to the pressure setpoint signal 44 and the pressure measurement signals (Pi, P2, P3) provided by the sensors 33. The controller 36 is thus responsible for regulating the pressure of the heat transfer fluid in the battery modules 2. The controller 36 may have an input 86 for receiving and taking into account a signal from a pressure sensor 37 (Pc) indicative of the overall pressure of the heat transfer fluid transmitted by the fluidic unit 14.The controller 38 (#3) serves as a temperature management controller for the heat transfer fluid circulating specifically in the battery modules 2 by controlling the distributors Di, D2, D3 conveying the heat transfer fluid to the battery modules 2 according to the temperature setpoint signal 42 at the level of the cells 6 of the battery modules 2 and the temperature measurement signals (Ti, T2, T3) provided by the temperature sensors 31. The controller 38 also provides the temperature setpoint to the controller 34 which manages the fluidic unit 14.

[0050] With reference to Figures 8A, 8B, 8C and 8D, the battery modules 2 may be arranged to form an independent, complementary or combined arrangement depending on whether their fluidic inlets and outlets 10, 12 are paired or separate and depending on a chemistry of their cells. For example, each battery module 2 may be operated in pressure and temperature independently as illustrated in Figure 8A. The battery modules 2 may be operated at a common pressure but at different temperatures as illustrated in Figure 8B. Some battery modules 2 may be operated at a common pressure different from the pressure of another battery module 2, and at different temperatures for each battery module 2 as illustrated in Figure 8C.Some battery modules 2 may be operated at common pressure and temperature different from the operating pressure and temperature of another battery module 2, as illustrated in Figure 8D. The design of the battery modules 2 may be chosen according to certain operating conditions, for example extremely fast recharging, strong acceleration or a large payload to be pulled in the case of an electric vehicle (not illustrated), storage, extreme outside temperature, and according to a use for which they are intended, for example, car, truck, bus, airplane, train, boat, energy storage. As many battery modules 2 as desired may be used, in complementarity or not, with variable capacities and dimensions, paired or not. The pressure and temperature values ​​of the battery modules 2 may be regulated in real time or be fixed.One of the battery modules 2 may be intended to play a special role (i.e. its purpose), for example to operate at fixed pressure and in particular at a very high pressure to support extreme operating conditions such as extremely rapid recharging or to be used as a priority during strong acceleration in the case of an electric vehicle, even if it means having to replace the battery module 2 after a certain time (e.g. prematurely). Such a battery module 2 may be likened to a sacrificial battery module for increased performance. In one embodiment of the invention, the system may include battery modules 2 whose pressure regulation is achieved solely by varying the temperature of the heat transfer fluid, in particular if an increased pressure value is necessary for increased temperature values, using the effect of the thermal expansion coefficient of the heat transfer fluid.Referring again to Figure 1, in short, according to an embodiment of the invention, the system includes at least one battery module 2 (or several working in collaboration) with variable operating conditions (variable role) or fixed (dedicated role), the active and dynamic management of which of the operating temperature and the pressure applied to the cells 6 (illustrated e.g. in Figure 6) is carried out via a pressurized liquid (or fluid) in which the cells 6 are immersed. The various mechanical, hydraulic, electrical and logical systems described above are controlled by processors (not illustrated, but which can be integrated into the BMS 56 or the controllers 34, 36, 38) controlled by scalable algorithms and coordinated via master software implemented in the BMS 56.The BMS 56 can execute an intelligent charge management algorithm including an efficient and optimal management strategy for energy-consuming systems (pressure and temperature regulation) during fast charging or during sudden braking. The scalable algorithms can be based on an implementation of artificial intelligence. The active and dynamic management of the operating temperature and the pressure applied to the cells 6 allows optimal exploitation of the cells of a battery. The cylindrical reservoir formed by the elements 58, 60, 62 (illustrated e.g. in Figure 6) of the battery module 2 makes it possible to apply a variable isostatic pressure of significant value (e.g. up to 2,000 psi) to the cells 6, while being compact and easy to integrate into a vehicle (not shown).

[0051] According to one embodiment of the invention, a method for managing the operating pressure and temperature of a battery consists of housing cells 6 of the battery in a chamber 4 defined by at least one battery module 2, the chamber 4 having opposite fluid inlets and outlets 10, 12 for receiving and discharging a heat transfer fluid applied to all the cells 6.The method also involves monitoring a state of charge of the cells 6 in each battery module 2, collecting the heat transfer fluid discharged through the fluid outlet 12 of each battery module 2 in a return tank 16, separately cooling and heating quantities of the heat transfer fluid pumped from the return tank 16 in cooling and heating tanks 18, 20 to predefined cold and hot temperatures, and delivering the heat transfer fluid to the fluid inlet 10 of each battery module 2 at regulated temperature and pressure by controlled mixing and flow of the heat transfer fluid from the cooling and heating tanks 18, 20.The method further involves taking temperature and pressure measurements of the heat transfer fluid conveyed to and discharged by each battery module 2, controlling the mixing and flow rate of the heat transfer fluid conveyed to each battery module 2 according to the temperature and pressure measurements and setpoints, and adjusting the temperature and pressure setpoints of the heat transfer fluid and a load setpoint intended for each battery module 2 according to an energy and power demand and the state of charge of the cells 6 in each battery module 2. According to one embodiment, the flow rate of the heat transfer fluid conveyed to each battery module 2 is maintained as long as the pressure and temperature measurements are different from the pressure and temperature setpoints.The method may involve performing an evolutionary process of controlling operating parameters of each battery module 2 as a function of load conditions, state of charge and a state of health of each battery module 2 and as a function of an ambient temperature and a pre-established vocation of a battery module 2 among all the battery modules 2 used.

[0052] In the following description, the heat transfer fluid will be considered to be oil. It should nevertheless be understood that another fluid suitable for the invention may be used with a different temperature range if desired.

[0053] With reference to Figure 3, according to one embodiment, the oil (mixture) temperature setpoint value 114 is based on the operating temperature setpoint value (eg -30°C to 100°C or other preferred temperature range) of the cells 6 (illustrated eg in Figure 6), taking into account thermal losses, thermal inertia, the volume of oil involved, an acceptable time to reach a new operating temperature value and material considerations (eg permissible thermal transitions). The strategy for quickly reaching the oil temperature setpoint can be based on algorithms developed in the laboratory on the necessary hot-cold mixture (flow rates) 116, 118, 120, 122. Prioritization by the BMS 52 can be made on the ordering of the achievement of the setpoints if different operating temperatures are required from one battery module 2 to another.A dimensioning of the system components (tanks 16, 18, 20, pump 94, accumulator 100, battery module 2 illustrated eg in Figure 2) is preferably optimized in order to maximize the speed to vary the temperature of the cells 6. With regard to the pressure regulation, the oil can first be brought to the right temperature, and the pressure setpoint 124 can be achieved simultaneously for all the battery modules 2, even in the case of different setpoints from one battery module 2 to another. Controller #2 36 can operate the pressure limiters Li, L2, L3 and the servovalves Di, D2, D3 of the battery modules 2 (illustrated eg in Figure 2) to regulate their pressure 126, 128. An interaction of the oil temperature and pressure adjustment processes may involve maintaining the oil flow until both setpoints (temperature and pressure) are reached.Achieving the pressure setpoint can also take into account the effect of two other factors on the pressure value, namely the oil temperature and the variable volume of the cells (state of charge) 130. A battery module 2 is considered compatible with the requirements when the temperature and pressure setpoints are reached 132, otherwise the temperature of the battery module 2 is rectified again 116.

[0054] Referring again to Figure 2, when the BMS 52 (illustrated eg in Figure 1) sends operating pressure and temperature regulation instructions to adequately adjust the operating conditions of the cells 6 (illustrated eg in Figure 6) according to the stress conditions of the latter, pressure limit value instructions are sent to the pressure limiters Li, L2, L3 via the controller #2 36 in order to build the target operating pressures Pi, P2, P3 in the battery modules 2 (#1, #2 and #3). If the new pressure instruction for a given battery module 2 is higher than the pressure measured in the battery module 2, the distributor Di, D2, OR D3 associated with the battery module 2 (#1, #2 or #3), via the controller 36 (#2), authorizes the admission of oil to reach this new pressure value. The new pressure value is reached instantly.The pressure P in the accumulator 100 makes it possible to build up a pressure P. o in the cold and hot oil tanks 18, 20. When the oil mixture is made, a pressure P o ' is built upstream of the distributors Di, D2, D3. To allow instantaneous building of a desired pressure in the battery modules 2, at any time P min > Po > Po' > Pi, P2, P3. For example, if the maximum pressure of the modules is set at 1000 psi, the minimum acceptable pressure in accumulator 100 could be 1500 psi. When the value of P Amin will fall below the threshold of 1,500 psi, pump 94 will start and inject oil into accumulator 100 until it reaches the value of P max(2,500 psi for example). When an operating temperature setpoint T1, T2, T3 of cells 6 is sent by the BMS 52, the controller 34 (#1) manages the cold and hot oil line distributors D4, D5 according to flow management algorithms so as to generate an oil mixture at temperature T o . To increase the operating temperature value of cells 6, then T o > T1, T2, T3. Conversely, to decrease the operating temperature value of the cells, then T o < T1, T2, T3. The difference in values ​​between the temperature of the oil mixture T oand the operating temperature T1, T2, T3 of the cells 6 depends on the speed to reach the new operating temperature, taking into account the thermal inertia of the system as a whole and the thermal transition limits allowed by the materials constituting the cells 6. Even if the operating pressure value Pi, P2, P3 is reached for a given battery module 2, the controller 38 (#3) allows the admission of oil at T o via distributor D1, D2, D3 associated with battery module 2 as long as the target operating temperature value T1, T2, T3 of battery module 2 is not reached.

[0055] With reference to Figure 4, an example of high-level management that the system according to the invention can implement according to different pressure and temperature management and operation parameters of a battery module 2 is illustrated. An event 134 such as a power demand, rapid braking or rapid charging is reported to the BMS 52 (illustrated e.g. in Figure 1). As illustrated by block 136, the BMS 52 performs an analysis of the system parameters versus operating requirements. For this purpose, the BMS 52 can consider certain conditions such as a state of charge (SOC), a state of health (SOH), pressure and temperature of the cells 6 (illustrated e.g. in Figure 6), their life history (calendar) and a number of cycles experienced by the cells 6 of a battery module 2 as illustrated by block 138.Similarly, the BMS 52 may consider various parameters such as an ambient temperature, an expected charging duration, an expected charging power, peripheral devices in operation, a terrain morphology to be traveled, a driving habit, a driving mode selection, a traffic condition, charging options on a route, as illustrated by block 140. A check 142 is then performed to determine whether a battery module 2 is compatible with the requirements with respect to the system parameters. If so, power instructions are transmitted to the compatible battery modules 2, as illustrated by block 144. Otherwise, the BMS 52 transmits instructions to the regulation mechanisms as illustrated by block 146. A temperature regulation 148, a pressure regulation 150 and a current density management 152 are performed, so that a battery module 2 is possibly compatible 154.Surplus power management 156 may be performed for heating or cooling of the oil 158, for operating a battery module 2 as a sacrificial module at the expense of its nominal operating parameters 160, or for power dissipation 162 if desired.

[0056] With reference to Figures 5A, 5B, 5C and 5D, examples of pressure and temperature management protocols implemented in the system according to an embodiment of the invention are illustrated in graphical form. Figure 5A shows a possible protocol for regulating the pressure of the cells 6 of a battery module 2 (illustrated e.g. in Figure 6) as a function of a recommended charging or discharging speed. Figure 5B shows a possible protocol for regulating the pressure of the cells 6 of a battery module 2 as a function of its state of charge (SOC). Figure 5C shows a possible protocol for regulating the operating temperature with respect to a recommended charging or discharging speed. Figure 5D shows a possible protocol for regulating the operating pressure with respect to the number of charging and discharging cycles experienced by a battery module 2.

[0057] Referring again to Figure 1, certain considerations relating to the system according to the invention may be relevant. In addition, the value of the oil pressure in a pressure tank will tend to vary depending on the following factors: the pressure setpoint dictated to the fluidic unit 14 by the BMS 52, the variation in the temperature of the oil, the variation in the volume of the cells 6. The pressure regulation control algorithm may include coordinated inputs related to these factors, based on a model integrating an interaction of the pressure and temperature setpoints, as well as feedback on the state of charge of the cells 6, therefore their volume at a specific time. The BMS 52 can coordinate and direct a request for the different battery modules 2 according to an energy and power demand.Proximity management of each of the battery modules 2 may be carried out on board each battery module 2 by an onboard BMS or a BMS-module implemented by the onboard circuits 8. Oil monitoring, involving for example monitoring of chemical elements or dissolved gases, may make it possible to identify symptoms of deterioration of the components constituting a battery module 2. Mineral oil used as a heat transfer fluid may make it possible to neutralize potential chemical reactions in the event of a defective or damaged cell 6. An implementation of evolutionary algorithms e.g. artificial intelligence in the BMS 52 may represent a strategic aspect of the operation of the system according to the invention. Such algorithms may be responsible for managing the operating parameters of the battery modules 2 (current, pressure, temperature). Programming (e.g.in industry) of the initial algorithms in the BMS 52 can be made according to the use of the battery modules 2 (e.g. car, bus, truck, airplane, boat, storage, etc.). A modification of such algorithms can be made over time, according to different factors such as a type of driving (e.g. acceleration, braking, load draw), terrain morphology, external temperatures, charging patterns, usage patterns (frequency, duration). Evolutionary algorithms can lead to a decision to overuse a battery module 2 in case of extreme usage conditions (e.g. sacrifice module).

[0058] They can also lead to a particular charging scheme (depending on electricity demand / tariff, reduced performance of battery modules 2, suspected presence of dendrite initiation zone), including a dendritic damage repair procedure ("self-healing") by strategically combining temperature-pressure-current values ​​and charging current schemes known for their beneficial effects on battery condition.

[0059] Although embodiments of the invention have been illustrated in the accompanying drawings and described above, it will be apparent to those skilled in the art that modifications may be made to these embodiments without departing from the invention.

Claims

CLAIMS:

1. Battery operating pressure and temperature management system, the system comprising: at least one battery module having a chamber housing battery cells, and at least one on-board circuit connected to the cells and configured to control their operation and monitor their state of charge, the chamber having opposing fluid inlets and outlets to receive and discharge a heat transfer fluid applied to all the cells;a fluidic unit having a return tank in communication with the fluidic outlet of each battery module, a cooling tank to hold a quantity of the heat transfer fluid pumped from the return tank at a predefined cold temperature, a heating tank to hold a quantity of the heat transfer fluid pumped from the return tank at a predefined hot temperature, and a temperature and pressure control device having inlets in communication with the cooling and heating tanks and at least one outlet in communication with the fluidic inlet of each battery module so as to transmit the heat transfer fluid at a temperature and pressure by controlled mixing and flow of the heat transfer fluid from the cooling and heating tanks; temperature and pressure sensors of the heat transfer fluid circulating between the fluidic unit and at least one battery module;at least one controller having inputs to receive temperature and pressure setpoint signals from the heat transfer fluid in at least one battery module, inputs to receive temperature and pressure measurement signals produced by the temperature and pressure sensors, and outputs to produce signals controlling the mixing and flow rate of the heat transfer fluid transmitted by the fluidic unit according to the setpoint signals and the temperature and pressure measurement signals; and a BMS connected to at least one controller and at least one on-board circuit, the BMS being configured to produce the temperature and pressure setpoint signals of the heat transfer fluid and a demand setpoint intended for at least one battery module according to a demand in; - 23 - energy and power received at input and the state of charge supplied by at least one on-board circuit.

2. The system according to claim 1, wherein the cells of at least one battery module are immersed in and directly in contact with the heat transfer fluid which applies isostatic pressure on the cells.

3. The system according to claim 1, wherein the heat transfer fluid is an oil.

4. The system according to claim 1, wherein at least one battery module comprises: a tubular element and end elements closing the tubular element to define the chamber; a cell support and spacing structure in an axial direction of the tubular element; a heat transfer fluid distribution arrangement in communication with the fluidic inlet and having openings aligned with spaces between the cells; and an electrical connection arrangement connecting the cells and at least one on-board circuit together.

5. The system according to claim 4, wherein the end elements are in the form of domes projecting from opposite ends of the tubular element and defining internal spaces housing at least one embedded circuit.

6. The system according to claim 4, wherein: the support and spacing structure comprises elongated bars having external surfaces substantially conforming to an internal surface of the cylindrical element, and internal surfaces having transverse notches distributed in the axial direction of the cylindrical element and into which peripheral edges of the cells engage; The distributor arrangement includes conduits extending into the bars and communicating with the fluidic inlet, the openings of the distributor arrangement being provided in the internal surfaces of the bars so that the heat transfer fluid exerts an isostatic pressure on the cells; and the electrical connection arrangement includes upper and lower series of plates electrically connected to each other and in contact with cell terminals, the upper series of plates extending between the bars, with at least one on-board circuit comprising two on-board circuits housed in the end elements.

7. The system according to claim 1, wherein the heat transfer fluid circulates between the fluidic unit and at least one battery module through a piping circuit equipped with heat transfer fluid flow control devices, controlled by at least one controller so as to adjust a temperature and pressure of the heat transfer fluid circulating in the piping circuit.

8. The system according to claim 7, wherein the flow control elements comprise, for each battery module, a distributor of the heat transfer fluid delivered to the battery module, and a proportional pressure limiter of the heat transfer fluid discharged by the battery module.

9. The system according to claim 1, wherein at least one controller comprises: a first temperature management controller for the heat transfer fluid, controlling flow control devices on fluid lines associated with the tanks, cooling and heating according to the temperature setpoint signal; a second pressure management controller for the heat transfer fluid circulating in at least one battery module, controlling flow control devices for the heat transfer fluid supplied to and discharged by at least one battery module according to the pressure setpoint signal and the pressure measurement signal; and a third temperature management controller for the heat transfer fluid circulating in at least one battery module, controlling the flow regulation unit of the heat transfer fluid delivered to at least one battery module according to the temperature setpoint signal and the temperature measurement signal.

10. The system according to claim 1, wherein at least one battery module comprises several battery modules forming an independent, complementary or combined arrangement depending on whether their fluidic inlets and outlets are paired or separate and according to a chemistry of their cells.

11. The system according to claim 1, wherein the BMS is configured to store and execute a scalable algorithm for controlling operating parameters of at least one battery module as a function of stress conditions, state of charge and health status of at least one battery module and as a function of ambient temperature and a pre-established purpose of one battery module among the at least one battery module.

12. The system according to claim 11, wherein: the operating parameters include the pressure and temperature of the heat transfer fluid circulating in at least one battery module and a power admitted by at least one battery module; and the stress conditions include a rapid charge and a power demand.

13. The system according to claim 1, further comprising a heat exchanger with the fluidic unit tanks and peripheral devices generating thermal energy.

14. The system according to claim 1, wherein the predefined hot temperature is from 80°C to 100°C and the predefined cold temperature is from -30°C to 0°C. - 26 - 15. The system according to claim 1, wherein the fluidic unit comprises: a pump having an inlet communicating with the return tank and an outlet for transmitting a quantity of the heat transfer fluid pumped from the return tank; and an accumulator having an inlet communicating with the outlet of the pump and an outlet communicating with the cooling and heating tanks, the accumulator producing a servo signal controlling the pump according to a pressure measurement provided by a pressure sensor at the outlet of the accumulator so that a pressure of the heat transfer fluid in the cooling and heating tanks is slightly higher than the pressure setpoint.

16. A method for managing the operating pressure and temperature of a battery, the method comprising the steps of: housing battery cells in a chamber defined by at least one battery module, the chamber having opposing fluidic inlets and outlets for receiving and expelling a heat transfer fluid applied to all the cells; monitoring a state of charge of the cells in at least one battery module; collecting the heat transfer fluid expelled by the fluidic outlet of each battery module into a return tank; separately cooling and heating quantities of the heat transfer fluid pumped from the return tank into cooling and heating tanks at predetermined cold and hot temperatures; conveying the heat transfer fluid to the fluidic inlet of at least one battery module at temperature and pressure regulated by controlled mixing and flow of the heat transfer fluid from the cooling and heating tanks;take temperature and pressure measurements of the heat transfer fluid supplied to and discharged by at least one battery module; - 27 - control the mixing and flow rate of the heat transfer fluid delivered to at least one battery module according to temperature and pressure measurements and setpoints; and adjust the temperature and pressure setpoints of the heat transfer fluid and a stress setpoint intended for at least one battery module according to energy and power demand and the state of charge of the cells in at least one battery module.

17. The method according to claim 16, wherein the flow rate of the heat transfer fluid delivered to at least one battery module is maintained as long as the pressure and temperature measurements are different from the pressure and temperature setpoints.

18. The method according to claim 16, further comprising the step of executing an evolving process of controlling operating parameters of at least one battery module as a function of stress conditions, state of charge and health status of at least one battery module and as a function of ambient temperature and a pre-established purpose of one battery module among the at least one battery module.

19. The method according to claim 16, wherein the cells of at least one battery module are immersed in and directly in contact with the heat transfer fluid which applies isostatic pressure to the cells. - 28 -

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