Lithium battery with broad cold / hot temperature range

Abstract

A battery and method of operating a battery are described. The battery includes one or more battery cells, a sensor configured to measure a temperature of one or both of a space exterior to the battery and the one or more battery cells, and a battery management system (BMS) electrically coupled to the sensor. The BMS is configured to determine a temperature value based on the measured temperature, determine whether the temperature value is within an extended temperature range, and select a battery operating mode based on a predetermined charge / discharge rate (C-rate) and whether the temperature value is within the extended temperature range.

Description

[0001] LITHIUM BATTERY WITH BROAD COLD / HOT TEMPERATURE RANGE

[0002] TECHNICAL FIELD

[0003] This disclosure relates to a method and system for a battery such as a lithium-ion battery that is operable within an extended temperature range.

[0004] BACKGROUND

[0005] Motor-powered and / or electrically powered vehicles tend to rely on using one or more battery or battery systems for providing at least a portion of a motion power for the vehicle and, some cases, a starting power (e.g., power used to crank and start an engine). Such vehicles may include one or more of an air- or watercraft, a rail-guided vehicle, a street vehicle, etc., where a street vehicle may refer to, for example, cars, trucks, buses, recreational vehicles, etc. In some cases, batteries may operate when the outside temperature or temperature of the battery is within a temperature range. However, when the battery is operated at a temperature that is lower or higher than the operating temperature range of the battery, battery components may be damaged, which may render the battery unusable and / or create a hazardous condition.

[0006] SUMMARY

[0007] Some embodiments advantageously provide a method and system for a battery, such as a lithium-ion battery, that is operable within an extended temperature range, i.e., a temperature range larger than a typical battery. The battery may include one or more battery cells that support operation within the extended temperature range. The extended temperature range may include a first subrange, a second subrange, and a third subrange. The first subrange may include temperature values that are lower than temperature values of a typical temperature range, and the third subrange may include temperature values that are greater than temperature values of the typical temperature range.

[0008] In some embodiments, the battery cells are lithium iron phosphate (LFP) (or LiFePO4) battery cells. In some other embodiments, the battery cells are arranged to provide supercapacitor functions, e.g., provided at least by an LFP element (such as cathode) that has active carbon.

[0009] In some embodiments, the battery may include battery management system (BMS) that is configured to enable or disable battery operation based at least on temperature of the battery and / or temperature of a battery component and / or ambient temperature and / or a charge / discharge rate (i.e., C-rate). In some embodiments, the BMS may enable battery operation when the temperature is within the extended temperature range, e.g., the first subrange and / or the second subrange, and allow the battery to provide voltage / energy at a charge / discharge rate that is equal to or exceeds a predetermined charge / discharge rate threshold.

[0010] In accordance with one aspect, a battery is provided. The battery comprises one or more battery cells, a sensor configured to measure a temperature of one or both of a space exterior to the battery and the one or more battery cells and a battery management system (BMS) electrically coupled to the sensor. The BMS is configured to determine a temperature value based on the measured temperature, determine whether the temperature value is within an extended temperature range and select a battery operating mode based on a predetermined charge / discharge rate, C-rate, and whether the temperature value is within the extended temperature range.

[0011] In accordance with an embodiment of this aspect, the BMS is further configured to one or both of cause the battery to enable or disable battery operation based on the selected battery operating mode and cause the battery to operate in a predetermined operating mode to discharge and warm the battery in preparation for a discharge event predetermined to be at or exceed the C-rate.

[0012] In accordance with an embodiment of this aspect, the extended temperature range comprises a first subrange, a second subrange having a temperature range greater than the first subrange, and a third subrange having a temperature range greater than the second temperature range, wherein the second subrange is a typical temperature range of the battery based on one or more conditions / factors associated with an environment where the battery is going to be used.

[0013] In accordance with an embodiment of this aspect, the selected operating mode includes operating the battery by discharging the battery at or above the C-rate when the temperature value is within the first temperature subrange or the third temperature subrange.

[0014] In accordance with an embodiment of this aspect, the one or more battery cells are lithium iron phosphate, LFP, battery cells and are arranged to provide supercapacitor functions. In accordance with an embodiment of this aspect, the LFP battery cells comprise an anode and a cathode, and wherein at least one of the anode and cathode comprise active carbon, and wherein the supercapacitor functions are provided by one of both of the anode and cathode having the active carbon. In accordance with an embodiment of this aspect, the BMS is further configured to limit operation of the battery to a predetermined amount of time when the battery is operating in one or more of the first subrange, the second subrange and the third subrange. In accordance with an embodiment of this aspect, the BMS is further configured to limit operation of the battery to a predetermined amount of time when the battery is operating in the third subrange. In accordance with an embodiment of this aspect, the BMS is further configured to allow the battery to discharge to a predetermined charge level or state of charge, SOC, to increase the internal temperature of the battery in preparation for a discharge event that occurs within the first or third temperature subranges. In accordance with an embodiment of this aspect, the BMS is further configured prepare the battery for future discharge events by causing warming of the battery to a typical operating temperature range, the typical temperature range of the battery based on one or more conditions / factors associated with an environment where the battery is going to be used.

[0015] In accordance with another aspect, a method of operating a battery having one or more battery cells is provided. The method comprises measuring a temperature of one or both of a space exterior to a battery and the one or more battery cells, determining a temperature value based on the measured temperature, determining whether the temperature value is within an extended temperature range and selecting a battery operating mode based on a predetermined charge / discharge rate (C-rate) and whether the temperature value is within the extended temperature range.

[0016] In accordance with an embodiment of this aspect, the method further comprises causing the battery to enable or disable battery operation based on the selected battery operating mode and causing the battery to operate in a predetermined operating mode to discharge and warm the battery in preparation for a discharge event predetermined to be at or exceed the C-rate.

[0017] In accordance with an embodiment of this aspect, the extended temperature range comprises a first subrange, a second subrange having a temperature range greater than the first subrange, and a third subrange having a temperature range greater than the second temperature range, wherein the second subrange is a typical temperature range of the battery based on one or more conditions / factors associated with an environment where the battery is going to be used. In accordance with an embodiment of this aspect, the selected operating mode includes operating the battery by discharging the battery at or above the C-rate when the temperature value is within the first temperature subrange or the third temperature subrange.

[0018] In accordance with an embodiment of this aspect, the one or more battery cells are lithium iron phosphate, LFP, battery cells and are arranged to provide supercapacitor functions. In accordance with an embodiment of this aspect, the LFP battery cells comprise an anode and a cathode, and wherein at least one of the anode and cathode comprise active carbon, and wherein the supercapacitor functions are provided by one of both of the anode and cathode having the active carbon.

[0019] In accordance with an embodiment of this aspect, the method further comprises limiting operation of the battery to a predetermined amount of time when the battery is operating in one or more of the first subrange, the second subrange and the third subrange. In accordance with an embodiment of this aspect, the method further comprises limiting operation of the battery to a predetermined amount of time when the battery is operating in the third subrange. In accordance with an embodiment of this aspect, the method further comprises allowing the battery to discharge to a predetermined charge level or state of charge, SOC, to increase the internal temperature of the battery in preparation for a discharge event that occurs within the first or third temperature subranges. In accordance with an embodiment of this aspect, the method further comprises preparing the battery for future discharge events by causing warming of the battery to a typical operating temperature range, the typical temperature range of the battery based on one or more conditions / factors associated with an environment where the battery is going to be used.

[0020] BRIEF DESCRIPTION OF THE DRAWINGS

[0021] A more complete understanding of embodiments described herein, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

[0022] FIG. 1 is a diagram of an example system according to principles disclosed herein;

[0023] FIG. 2 shows an example battery constructed in accordance with the principles of the present disclosure;

[0024] FIG. 3 is a block diagram of a battery management system according to some embodiments of the present disclosure; FIG. 4 is a method of operating a battery in accordance with the principles of the present disclosure;

[0025] FIG. 5 shows an example thermal runaway process according to some embodiments of the present disclosure; and

[0026] FIG. 6 shows an example of state of health percentages versus floating charge time according to some embodiments of the present disclosure.

[0027] DETAILED DESCRIPTION

[0028] Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to battery that is operable within an extended temperature range. Accordingly, the system and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0029] As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0030] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. In some other embodiments, “in communication with” indicates the transmission and / or of signaling by the components that are in communication with each other. The signaling may cause one or more components to perform one or more actions based on the signaling. The term “in communication with” may also refer to being in fluid communication, such as where two spaces are in fluid communication with each other. One having ordinary skill in the art will appreciate that multiple components may interoperate, and modifications and variations are possible of achieving the electrical and data communication.

[0031] In some embodiments, the general description elements in the form of “one of A and B” corresponds to A or B. In some embodiments, at least one of A and B corresponds to A, B or AB, or to one or more of A and B. In some embodiments, at least one of A, B and C corresponds to one or more of A, B and C, and / or A, B, C or a combination thereof.

[0032] Referring now to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 1 a diagram of a system 10, according to an embodiment, which comprises one or more vehicles 12, e.g., a car, motorcycle, scooter, golf cart, light utility vehicle, etc. The vehicle 12 comprises battery 14 for powering at least one function of vehicle 12. In some embodiments, battery 14 may include one or more energy storage modules / cells. Although an LFP battery is described herein, the teachings described herein are equally applicable to other battery types such as other lithium ion batteries, lead acid batteries, etc. Battery 14 may include one or more batteries such as a first battery 14a, second battery 14b, third battery 14c, fourth battery 14d, etc., e.g., electrically connected (e.g., in parallel, series, etc.) as part of a battery pack. Although battery 14 is shown in conjunction with a vehicle 12, battery 14 is not limited as such and may be used in conjunction with any other component (e.g.., such as to power any other system component).

[0033] Battery 14 may include battery management system (BMS) 16 that is configured to perform one or more battery management functions described herein. In some embodiments, the BMS 16 may measure / determine certain battery parameters, e.g., temperature, resistance (e.g., battery resistance), voltage (e.g., cell voltage), current, state of charge (SoC), a time parameter, a frequency parameter, etc., and transmi t / receive data (and / or signals such as control signals) to / from another system / device. BMS 16 may also determine failures of battery components and perform actions such notify other components of system 10 (e.g., a server or computing device, not shown). A BMS 16 is configured to include a BMS management unit 18 (or battery management unit) that may be configured to perform one or more functions as described herein.

[0034] It is contemplated that one or more entities of system 10 are in communication with each other via one or more of wireless communication, power communication, wired communication, fluid communication, etc. For example, vehicle 12 and battery 14 (and / or any other device or server) may communicate with each other directly or indirectly using wireless communication, power communication, wired communication, etc. Further, while it may be assumed in one or more embodiments that there is no data or signal communication between battery 14 and vehicle 12, the embodiments described herein are equally applicable to vehicles 12 where there are at least some data / signal communications between battery 14 and vehicle 12. Further, although battery 14 is shown as part of vehicle 12 may be a standalone battery, removably couplable to any component of system 10 such as vehicle 12, etc.

[0035] FIG. 2 shows an example battery 14 constructed in accordance with the principles of the present disclosure. Battery 14 includes a housing 24 into which one or more battery components may be positioned. The components may be electrically interconnected (not shown in the FIGS), such as via an electrically conductive bus bar system which electrically interconnects the components in an electrically serial, electrically parallel or combination of electrically serial and parallel manner, depending on the intended voltage and current requirements.

[0036] A battery management system (BMS) 16 may be included. BMS 16 may include or be coupled to a monitoring connector 27 that allows for a removable external connection any other component of system 10 (e.g., to the vehicle’s data bus, to some other communication device, etc.) and / or internal connection, e.g., any components of battery 14 and / or BMS 16. Connector 27 may be comprised in BMS 16 and / or any other component of system 10. In some embodiments, connector 27 may be configured to removably couple and / or connect (electrically, physically) to another connector. Battery 14 also includes terminals, such as a positive terminal 28a and a negative terminal 28b (collectively referred to as terminals 28) to provide the contact points for electrical connection of the battery 14 (e.g., to power devices and / or the vehicle 12 and / or BMS 16). Battery 14 may also include cover 34 which may be arranged to couple to cover 30. Cover 30 may include one or more cover walls that may (e.g., along with cover 34) define cover space 32. Cover 30 may be arranged to receive BMS 16 in cover space 32 during assembly, e.g., such that BMS 16 are coupled to cover 30 and / or any other components of battery 14.

[0037] In addition, terminals 28 may be arranged to protrude through housing 24, such as protruding through cover 30 and / or cover 34. Terminals 28 may be electrically connected to the bus bars inside housing 24 and / or directly connected to cells 26 (bus bars and direct connection not shown).

[0038] Further, battery 14 may be arranged to provide many power capacities and physical sizes, and to operate under various parameters and parameter ranges. It is also noted that implementations of battery 14 some can be scaled to provide various capacities. For example, in some embodiments, the power capacity of battery 14 can range from 25 Ah to 75 Ah. It is noted, however, that this range is merely an example, and that it is contemplated that embodiments of battery 14 can be arranged to provide less than a 25 Ah capacity or more than a 75Ah capacity. Power capacity scaling can be accomplished, for example, by using higher or lower power capacity cells 26 in the housing 24, and / or by using fewer or more cells 26 in the housing 24. In some embodiments, battery 14 may be incorporated as part of a vehicle where battery power is needed. Other electrical parameters of the battery 14 can be adjusted / accommodated by using cells 26 that may cumulatively have the desired operational characteristics, e.g., current, voltage, charge, charging capacity / rate, discharge rate, etc. Thermal properties can be managed based on cell 26 characteristics, the use of heat sinks and / or thermal energy discharge plates, etc., within or external to the housing 24. Further, BMS 16 may be connected to at least one of the cells such as to determine / measure at least one parameter of battery 14 and / or cells 26.

[0039] Battery 14 may also include a plurality of leads 36, where each lead 36 is electrically connected to a cell 26 and / or BMS 16. BMS 16 may be configured to determine one or more parameters of each cell 26 via leads 36 such as SoC, voltage, cell temperature, cell pressure, etc.

[0040] Battery 14 may also have battery internal space 38, which may be defined by housing 24, cover 30, cover 34, etc. In some embodiments, battery internal space 38 may be determined to house a predetermined quantity of battery components such as cells 26, BMS 16, etc. Battery internal space 38 may be also determined to minimize unused space and to maximize the quantity or type of components it contains. Battery internal space 38 may also be arranged to contain additional battery components and to meet or exceed a predetermined internal used volume / space threshold. BMS 16 may also be couplable to or include sensor 40a which may be in physical contact with a battery cell 26 and / or sensor 40b which may be in physical contact with a battery cell 26. Sensors 40a, 40b (collectively referred to as sensor 40) arranged to measure parameters such as ambient temperature and cell temperature, respectively. Although sensors 40a, 40b are shown, the embodiments are not limited as such and battery 14 may include one sensor 40 or more than two sensors 40 (e.g., one per battery cell 26).

[0041] Further, battery cells 26 may include an anode 42 and a cathode 44. Anode 42 may include a negative electrode arranged to release electrons that create an electrochemical reaction and produce electricity. Cathode 44 may include a positive electrode arranged to receive electrons that create the electrochemical reaction and produce electricity. Although an anode 42 and a cathode 44 are shown for ease of understanding, the embodiments are not limited as such, and more than one battery cell 26 may include anode 42 and a cathode 44. Further, battery cells 26 may be LFP cells and provide supercapacitor functions, e.g., by including active carbon in the cathode 44, thereby allowing the battery cells 26 to have higher charge / discharge rate / power when the temperature is lower / higher than temperatures of typical temperature ranges. In some embodiments, cells 26 (and / or anode 42 and / or cathode 44) are arranged to provide supercapacitor functions (e.g., without battery 14 having a supercapacitor). In some other embodiments, battery 14 optionally includes a supercapacitor 46 arranged to provide supercapacitor functions. In some embodiments, supercapacitor 46 is comprised in cells 26 or any other portion of battery 14, while being electrically coupled to battery components such as BMS 16 and / or battery cells 26 and / or connector 27 and / or terminals 28, etc. A supercapacitor may refer to an energy storage device that is arranged to store and release energy, based on one or more conditions. A supercapacitor may have a capacitance that is higher than that of a capacitor.

[0042] It is understood that references to charging and / or discharging battery 14 refers to charging and / or discharging battery cells 26 within battery 14.

[0043] Example implementations, in accordance with an embodiment, of BMS 16 discussed in the preceding paragraphs will now be described with reference to FIG. 3. BMS 16 may have hardware 100 that may include a communication interface 102 that is configured to communicate with one or more entities in system 10 via wired and / or wireless communication. The communication may be protocol based communications.

[0044] The hardware 100 includes processing circuitry 106. The processing circuitry 106 may include a processor 108 and memory 110. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 106 may comprise integrated circuitry for processing and / or control, e.g., one or more processors and / or processor cores and / or FPGAs (Field Programmable Gate Array) and / or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 108 may be configured to access (e.g., write to and / or read from) memory 110, which may include any kind of volatile and / or nonvolatile memory, e.g., cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory). Hardware 100 may also have one or more circuit elements 104 such as resistors, capacitors, inductors, diodes, transistors, ground connections, source elements, sink elements, sensors, flexible printed circuit (FPC), etc. Circuit elements 104 may be arranged in any configuration or connection such as series, parallel, combinations thereof, etc.

[0045] Thus, the BMS 16 may further comprise software 112, which is stored in, for example, memory 110, or stored in external memory (e.g., database, etc.) accessible by the BMS 16. The software 112 may be executable by the processing circuitry 106.

[0046] The processing circuitry 106 may be configured to control any of the methods and / or processes described herein and / or to cause such methods, and / or processes to be performed, e.g., by BMS 16. The processor 108 corresponds to one or more processors 108 for performing BMS 16 functions described herein. The BMS 16 includes memory 110 that is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 112 may include instructions that, when executed by the processor 108 and / or processing circuitry 106, causes the processor 108 and / or processing circuitry 106 to perform the processes described herein with respect to BMS 16. For example, the processing circuitry 106 of the BMS 16 may include BMS management unit 18 that is configured to perform any step and / or task and / or process and / or method and / or feature described in the present disclosure, e.g., determining one or more parameters, steps, and / or processes associated with battery 14 such as enabling and disabling battery operation and / or selecting a battery operating mode. While BMS management unit 18 is illustrated as being part of BMS 16, BMS management unit 18 and associated functions described herein may be implemented in a device separate from BMS 16 such as in battery 14 or another device.

[0047] FIG. 4 is a flowchart of an example process of operating a battery 14 having one or more battery cells 26 in accordance with the principles of the present disclosure. One or more blocks described herein may be performed by one or more elements of battery 14 such as by one or more of BMS 16, processor 108, and / or sensor 40. Battery 14, such as via one or more of BMS 16, processor 108, and / or sensor 40 is configured to measure (Block S100) a temperature of one or both of a space exterior to a battery and the one or more battery cells 26, determine (Block SI 02) a temperature value based on the measured temperature, determine (Block SI 04) whether the temperature value is within an extended temperature range and select (Block S106) a battery operating mode based on a predetermined charge / discharge rate (C-rate) and whether the temperature value is within the extended temperature range.

[0048] In accordance with some embodiments, the BMS 16 is further configured to one or both of cause the battery 14 to enable or disable battery 14 operation based on the selected battery 14 operating mode and cause the battery 14 to operate in a predetermined operating mode to discharge and warm the battery 14 in preparation for a discharge event predetermined to be at or exceed the C-rate.

[0049] In accordance with some embodiments, the extended temperature range comprises a first subrange, a second subrange having a temperature range greater than the first subrange, and a third subrange having a temperature range greater than the second temperature range, wherein the second subrange is a typical temperature range of the battery 14 based on one or more conditions / factors associated with an environment where the battery 14 is going to be used.

[0050] In accordance with some embodiments, the selected operating mode includes operating the battery 14 by discharging the battery 14 at or above the C-rate when the temperature value is within the first temperature subrange or the third temperature subrange.

[0051] In accordance with some embodiments, the one or more battery cells 26 are lithium iron phosphate, LFP, battery cells 26 and are arranged to provide supercapacitor functions. In accordance with some embodiments, the LFP battery cells 26 comprise an anode and a cathode, and wherein at least one of the anode and cathode comprise active carbon, and wherein the supercapacitor functions are provided by one of both of the anode and cathode having the active carbon.

[0052] In accordance with some embodiments, the BMS 16 is further configured to limit operation of the battery 14 to a predetermined amount of time when the battery 14 is operating in one or more of the first subrange, the second subrange and the third subrange. In accordance with some embodiments, the BMS is further configured to limit operation of the battery 14 to a predetermined amount of time when the battery 14 is operating in the third subrange. In accordance with some embodiments, the BMS 16 is further configured to allow the battery 14 to discharge to a predetermined charge level or state of charge, SOC, to increase the internal temperature of the battery 14 in preparation for a discharge event that occurs within the first or third temperature subranges. In accordance with some embodiments, the BMS 16 is further configured prepare the battery 14 for future discharge events by causing warming of the battery 14 to a typical operating temperature range, the typical temperature range of the battery 14 based on one or more conditions / factors associated with an environment where the battery 14 is going to be used.

[0053] Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for battery system such as a lithium-ion baltery system.

[0054] Some embodiments provide a battery 14 that is operable within an extended temperature range, at a predetermined C-rate, while meeting and / or exceeding safety requirements (to avoid events associated with different stages corresponding to different temperatures). FIG. 5 shows an example of a thermal runaway process. Multiple stages are shown including stage I, state II, stage III, and stage IV. Stage I may include metal ions dissolution, and stage II may include SEI film decomposition and reaction time between lithium and electrolyte. Stage III may include separator melting, micro inner short circuit, safety venting, separator breakup, any of which may extend to stage IV. Stage IV may include large-scale inner short circuit, cathode material decomposition, electrolyte decomposition, reaction of graphite anode with binder, combustion of electrolyte. Other graph curves show a relationship between voltage / temperature and time, flow and temperature, etc.

[0055] When a battery cell is continuously operated between 85°C and 90°C, the solid electrolyte interphase (SEI) film may start to decompose and impact the cell’s cycle life and / or lead to thermal runaway events. In addition, the electrolyte (organic, liquid) may react with the lithium of the battery cell and start to decompose too. Thus, a typical operating (and / or storage) temperature range of battery cells may be defined as 70°C - 80°C, which may vary by the application and life expectancy of the battery and its components. Further, the thermal runaway process shown is associated with cell operating temperatures for a predetermined battery or cell chemistry. For different chemistries, the cell operating temperatures and / or temperature criteria may be different.

[0056] Further, a battery may be float-charged. Float charging may refer to continuously charging a battery at a constant voltage to maintain a full charge. The time for a battery to float charge may depend on the type of battery and temperature, and float charging may have a state of health effect. FIG. 6 is a graph showing an example of relationships between state of health (SOH) of a battery and floating charge (FC) time / D. Two curves are shown, one corresponds to the use of 300kgf-Clamp, and the other corresponds to no clamp being used. The SOH of both curves separates as FC time / D increases, the corresponding to the use of 300kgf-Clamp having SOH that is greater than the SOH of the no-claim curve for FC time / D greater than 0.

[0057] The process used to determine the operating temperature range of the cells may be defined, e.g., by a battery cell supplier / manufacturer / designer. For example, a battery cell supplier / manufacturer may define the operating temperatures to align with safety and committed cycle life (for example 2000 cycles 1C / 1C 100%DOD at room temperature. The cell temperature may be measured using a sensor (e.g., sensor 40), and may be placed on then the hottest point on the cell surface. BMS 16 may be configured to add temperature compensation / adjustment based on cell tests and simulation, to obtain a cell temperature histogram. In typical batteries, temperatures that are higher than the typical temperature range may exceed the safety limit, e.g., SEI film decomposition, and temperatures that are lower than the minimum temperature of the typical temperature range may cause lithium plating, i.e., the lithium will plate on the electrode and puncture the separator if accumulated to certain levels, thereby causing internal short circuits. A 75°C floating charge test may be used to simulate when a starter battery 14 (e.g., installed in the engine bay and surrounded by hot air in summer). The test may show how the capacity degradation (80% of original) and internal resistance increase the ratio (150% of original). From a test perspective, the degradation from capacity reduction may be observed, e.g., increased internal resistance (IR) and cell swelling. Cell level teardown and inspections may be performed if there is lithium plating (e.g., Lithium is shining with the black electrode material as background) on the electrode and separator (which may rupture). Further, a voltage ‘shoulder’ in the discharge SOC-OCV curve may be observed if significant lithium plating occurs.

[0058] In some embodiments, battery 14 is operable within an extended temperature range, at a predetermined C-rate, where battery 14 still meets and / or exceeds safety requirements. In one or more embodiments, battery cells 26 may have a cell operating temperature range and can store energy for a predetermined cell storage time. Supercapacitors 46 may have a supercapacitor operating temperature range that may be broader than the cell operating temperature range. Further, supercapacitors 46 may store energy for a predetermined supercapacitor storage time. The predetermined cell storage time may be greater than the predetermined supercapacitor storage time. However, any other combinations of cell operating temperature range, predetermined cell storage time, supercapacitor operating temperature range, and predetermined supercapacitor storage time are possible.

[0059] In some embodiments, battery 14 may include battery cells 26 and supercapacitors 46 inside the battery housing 24, spaces 32, 38, etc., where the battery cells 26 are electrically coupled to the supercapacitors 46 and arranged to charge the supercapacitors 46, e.g., on- demand when the vehicle 12 is going to be started.

[0060] In some other embodiments, battery 14 does not include supercapacitors 46 but includes battery cells 26 that have supercapacitor functionalities or capacitor-like performance in low operating temperatures, in addition to high operating temperatures, where the low temperatures are temperatures that are lower than a typical temperature range, and the high operating temperatures are temperatures that are higher than the typical temperature range. The supercapacitor functionalities or supercapacitor-like performance may be due, at least in part, to anode / cathode characteristics. That is, in these embodiments, battery 14 can be arranged to provide power (e.g., at a predetermined C-rate) at temperatures that are lower / higher than the typical temperature range without battery 14 having a supercapacitor 46.

[0061] In some embodiments, the battery cells 26 are (LFP) battery cells. In some other embodiments, the battery cells 26 are arranged to provide supercapacitor functions without the use of supercapacitors 46, e.g., the supercapacitor functions are provided at least by an LFP element (such as anode 42 and / or cathode 44) that has active carbon. For example, battery cells 26 may provide a combination of supercapacitor and LFP functions, by adding a predetermined portion of active carbon to LFP cathode 44 (e.g., such that a portion of lithium ions attach to the electrode surface of the cathode), thereby allowing the battery cell 26 to act as a supercapacitor. That is, the battery cell 26 can have higher charge / discharge power when the temperature is outside the typical temperature range, e.g., extremely low / high temperature. The performance of each battery cell 26 may be independent from the other battery cells 26, where, for example, one battery cell 26 may be performing supercapacitor functions, while other battery cells 26 perform only LFP functions, and the state of charge - open circuit voltage (SOC-OCV) curve is comparable (e.g., the same, within a predetermined deviation, etc.) to other LFP cells. That is, in some embodiments, battery cells 26 may perform as other LFP cells and / or exhibit characteristics (e.g., OCV, SOC) of other LPF cells and may be able to provide discharge / charge rates that meet or exceed a predetermined threshold when the temperature is within an extended temperature range. In some embodiments, battery 14 is a lithium ion battery or an LFP battery which may be arranged to operate within an extended temperature range. The extended temperature range may be a range with temperature values greater or lower than temperatures within the typical temperature range. In a nonlimiting example, the typical temperature range may be 32F to 113F, but other ranges are possible. In some embodiments, the typical temperature range may be dynamic, e.g., varies based on one or more conditions or factors. In some other embodiments, the typical temperature range may be static or fixed. In some embodiments, the typical temperature range may be configurable (e.g., by a user) based on the characteristics or specification of the battery 14. In some embodiments, BMS 16 may obtain or be configured with the typical temperature range and / or any other range or subrange. In some other embodiments, BMS 16 may determine the typical temperature range and / or any other range or subrange based on one or more conditions / factors associated with the environment where the battery 14 is going to be used, the battery 14, a particular use of the battery 14, etc.

[0062] In some embodiments, a temperature range may include the typical temperature range as a subrange and / or one or more other subranges and is referred to as an extended temperature range. In a nonlimiting example, the extended temperature range may include a first subrange, a second subrange, and a third subrange, where the second subrange is the typical temperature range. The first subrange and the third subrange provide the extended temperature range. The first subrange may include temperature values that are lower than temperature values of a typical temperature range, and the third subrange may include temperature values that are greater than temperature values of the typical temperature range. In some embodiments, the first subrange and the third subrange may be referred to as extended subranges, e.g., extending away from the typical temperature range in a temperature scale / axis. In some embodiments, the subranges may be contiguous or non-contiguous with other subranges or ranges. In some embodiments, the extended temperature range is -40F to 167F, e.g., where the first subrange is -40F to 32F (or less than 32F), the second subrange (or typical temperature range) is 32F (or greater than 32F) to 113F (or less than 113F), and the third subrange is 113F (or greater than 113F) to 167F. However, the embodiments are not limited as such, and any other extended temperature range is possible, e.g., depending on ionbased cell chemistry configurations, including lithium and sodium chemistries, and variant sub-chemistries such as validated by battery endurance and cell testing.

[0063] In some embodiments, for the battery to be operated within the third subrange (e.g., hot temperatures), the boundary of the electrolyte and solid electrolyte interphase (SEI) temperature may be attacked, while not exceeding a predetermined temperature (e.g., 185F). Further, BMS 16 may be configured to limit the operation of the battery 14 to a predetermined amount time when the battery 14 is operating in a temperature subrange (e.g., third subrange). The predetermined time may be based on floating charge testing at lower temperatures.

[0064] Although the extended temperature range is described as including three subranges, the embodiments are not limited as such, and the extended temperature range may include less than or more than three subranges, and / or include or not include the typical temperature subrange (or a portion thereof).

[0065] In some embodiments, a battery cell 26 may be arranged to perform mostly as supercapacitor with a predetermined portion (e.g., small portion) of LFP addition in the cathode 44, e.g., to increase energy density of the supercapacitor from 5-10Wh / g to 20- 30wh / g, (where LFP may be within 160-180wh / g at cell level).

[0066] In some other embodiments, BMS 16 may be configured to select and / or activate / deactivate a battery operating mode (e.g., battery enabled, battery disabled, discharge mode, charge mode, etc.) based on at least on temperature of the battery and / or temperature of a battery component and / or ambient temperature and / or a charge / discharge rate (i.e., C- rate). Temperature may be obtained by the BMS 16 via sensor 40. In some embodiments, the BMS 16 may enable the operation of battery 14 when the temperature is within the extended temperature range, more specifically, within the first subrange and / or the second subrange, and allow the battery to provide voltage / energy at a charge / discharge rate that is equal to or exceeds a predetermined charge / discharge rate threshold.

[0067] In some embodiments, the battery operating mode may include charging or discharging the battery at a predetermined C-rate. The C-rate may refer to the measurement of current in which a battery is charged and / or discharged. The embodiments may be beneficial at least because battery 14 may provide high current delivery (high C-rate for engine starting) when the temperature is within subranges that are outside the typical temperature range, e.g., at much lower temperatures than a typical LFP battery (which is typically ~20 C-rate at OF). Further, battery 14 and / or battery cells 26 may have a predetermined format, form or size that meets the requirements of other typical batteries that cannot provide the C-rate of battery 14 and / or cannot operate at the extended range that battery 14 can operate. For example, the high C rate / cold temperature performance enables cold weather cranking performance in an 116 size battery that rivals that of an 117 (larger) lead acid battery, and may allow engine start in less than 1 second. In some embodiments, BMS 16 may enable discharge (or charge) of battery 14 to manage the temperature of battery 14. For example, battery 14 may be controlled by BMS 16 to allow battery 14 to discharge to a predetermined charge level or SOC to increase the internal temperature of battery 14 in preparation for a discharge event that occurs within the first or third temperature subrange. That is, BMS 16 may prepare battery 14 for future discharge events that may occur when the temperature is outside the typical temperature range. BMS 16 may also prepare battery 14 for future discharge events by causing warming of the battery to the typical operating temperature range, i.e., not the extended temperature range, when the pre -use temperature is outside the typical temperature range.

[0068] The following is a nonlimiting list of example embodiments.

[0069] According to one aspect, a battery 14 is described. The battery 14 includes one or more battery cells 26, a sensor 40 configured to measure a temperature of one or both of a space exterior to the battery 14 and the one or more battery cells 26, and a battery management system (BMS) 16 electrically coupled to the sensor 40. The BMS 16 is configured to determine a temperature value based on the measured temperature, determine whether the temperature value is within an extended temperature range, and select a battery operating mode based on a predetermined charge / discharge rate (C-rate) and whether the temperature value is within the extended temperature range.

[0070] In some embodiments, the BMS 16 is further configured to one or both of: (A) cause the battery 14 to enable or disable battery operation based on the selected battery operating mode; and (B) cause the battery 14 to operate in a predetermined operating mode to discharge and warm the battery 14 in preparation for a discharge event predetermined to be at or exceed the C-rate.

[0071] In some other embodiments, the extended temperature range may include a first subrange, a second subrange, and a third subrange.

[0072] In some embodiments, the selected operating mode includes operating the battery 14 by discharging the battery 14 at or above the C-rate when the temperature value is within the first temperature subrange or the third temperature subrange.

[0073] In some other embodiments, the one or more battery cells 26 are lithium iron phosphate (LFP) battery cells and are arranged to provide supercapacitor functions.

[0074] It will be appreciated by persons skilled in the art that the present embodiments are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

Claims:

1. A battery compri sing : one or more battery cells; a sensor configured to measure a temperature of one or both of a space exterior to the battery and the one or more battery cells; a battery management system, BMS, electrically coupled to the sensor and configured to: determine a temperature value based on the measured temperature; determine whether the temperature value is within an extended temperature range; and select a battery operating mode based on a predetermined charge / discharge rate, C-rate, and whether the temperature value is within the extended temperature range.

2. The battery of Claim 1, wherein the BMS is further configured to one or both of: cause the battery to enable or disable battery operation based on the selected battery operating mode; and cause the battery to operate in a predetermined operating mode to discharge and warm the battery in preparation for a discharge event predetermined to be at or exceed the C-rate.

3. The battery of any one of Claims 1 and 2, wherein the extended temperature range comprises a first subrange, a second subrange having a temperature range greater than the first subrange, and a third subrange having a temperature range greater than the second temperature range, wherein the second subrange is a typical temperature range of the battery based on one or more conditions / factors associated with an environment where the battery is going to be used.

4. The battery of Claim 3, wherein the selected operating mode includes operating the battery by discharging the battery at or above the C-rate when the temperature value is within the first temperature subrange or the third temperature subrange.

5. The battery of any one of Claims 1-4, wherein the one or more battery cells are lithium iron phosphate, LFP, battery cells and are arranged to provide supercapacitor functions.

6. The battery of Claim 5, wherein the LFP battery cells comprise an anode and a cathode, and wherein at least one of the anode and cathode comprise active carbon, and wherein the supercapacitor functions are provided by one of both of the anode and cathode having the active carbon.

7. The battery of any one of Claims 3-6, wherein the BMS is further configured to limit operation of the battery to a predetermined amount of time when the battery is operating in one or more of the first subrange, the second subrange and the third subrange.

8. The battery of Claim 7, wherein the BMS is further configured to limit operation of the battery to a predetermined amount of time when the battery is operating in the third subrange.

9. The battery of any one of Claims 3-8, wherein the BMS is further configured to allow the battery to discharge to a predetermined charge level or state of charge, SOC, to increase the internal temperature of the battery in preparation for a discharge event that occurs within the first or third temperature subranges.

10. The battery of any one of Claims 1-9, wherein the BMS is further configured prepare the battery for future discharge events by causing warming of the battery to a typical operating temperature range, the typical temperature range of the battery based on one or more conditions / factors associated with an environment where the battery is going to be used.

11. A method of operating a battery having one or more battery cells, the method comprising: measuring a temperature of one or both of a space exterior to a battery and the one or more battery cells; determining a temperature value based on the measured temperature; determining whether the temperature value is within an extended temperature range; andselecting a battery operating mode based on a predetermined charge / discharge rate, C- rate, and whether the temperature value is within the extended temperature range.

12. The method of Claim 11, further comprising: causing the battery to enable or disable battery operation based on the selected battery operating mode; and causing the battery to operate in a predetermined operating mode to discharge and warm the battery in preparation for a discharge event predetermined to be at or exceed the C- rate.

13. The method of any one of Claims 11 and 12, wherein the extended temperature range comprises a first subrange, a second subrange having a temperature range greater than the first subrange, and a third subrange having a temperature range greater than the second temperature range, wherein the second subrange is a typical temperature range of the battery based on one or more conditions / factors associated with an environment where the battery is going to be used.

14. The method of Claim 13, wherein the selected operating mode includes operating the battery by discharging the battery at or above the C-rate when the temperature value is within the first temperature subrange or the third temperature subrange.

15. The method of any one of Claims 11-14, wherein the one or more battery cells are lithium iron phosphate, LFP, battery cells and are arranged to provide supercapacitor functions.

16. The method of Claim 15, wherein the LFP battery cells comprise an anode and a cathode, and wherein at least one of the anode and cathode comprise active carbon, and wherein the supercapacitor functions are provided by one of both of the anode and cathode having the active carbon.

17. The method of any one of Claims 13-16, further comprising limiting operation of the battery to a predetermined amount of time when the battery is operating in one or more of the first subrange, the second subrange and the third subrange.

18. The method of Claim 17, further comprising limiting operation of the battery to a predetermined amount of time when the battery is operating in the third subrange.

19. The method of any one of Claims 13-18, further comprising allowing the battery to discharge to a predetermined charge level or state of charge, SOC, to increase the internal temperature of the battery in preparation for a discharge event that occurs within the first or third temperature subranges.

20. The method of any one of Claims 11-19, further comprising preparing the battery for future discharge events by causing warming of the battery to a typical operating temperature range, the typical temperature range of the battery based on one or more conditions / factors associated with an environment where the battery is going to be used.

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