Battery multi-physics field coupling fast charging method and device

Abstract

The invention belongs to the technical field of batteries, and particularly relates to a battery multi-physics field coupling fast charging method and device. The fast charging method comprises the following steps: arranging a reference electrode on a battery, and monitoring the temperature of the battery and a negative reference potential on the reference electrode in real time; acquiring a preset pressure applied to the battery through a pressure device; and the maximum charging rate of the battery under the 0% SOC is obtained, preset pressure is applied to the battery, and the battery is charged at the maximum charging rate under the 0% SOC. According to the quick charging method provided by the invention, the influence of temperature rise and pressure exertion in the charging process of the battery on the quick charging performance can be fully considered, and the quick charging condition of the battery is perfected and optimized, so that the battery is safer during quick charging, and the occurrence of safety accidents is effectively avoided.

Description

Technical Field

[0001] The present invention belongs to the field of battery technology, and specifically relates to a battery multi-physical field coupling fast charging method and device. Background Art

[0002] With the increasing popularity of electric vehicles, demands for faster charging performance and safety are becoming increasingly stringent. Determining the lithium plating boundary through three-electrode testing can optimize charging strategies, increasing charging speed while preventing lithium plating, extending battery life, and improving the user experience and safety of electric vehicles.

[0003] During actual use, batteries are placed in a fixed space, with the cells tightly fitted together. When charging, a certain amount of pressure is generated between the cells and the battery, which can affect the battery's fast-charging performance. For example, a fully charged battery will expand to a certain extent. If the pressure on the battery is too low, the electrodes may not fit tightly together, which can easily lead to internal ion transport, making it difficult to charge at high rates.

[0004] In view of this, the existing fast charging method does not take into account the temperature rise of the battery and the pressure applied to the battery, making it difficult to obtain the optimal assembly pressure and optimal fast charging conditions for the battery. Summary of the Invention

[0005] An embodiment of the present invention provides a battery multi-physics field coupled fast charging method and device thereof, which is used to solve the technical problem in the prior art that the battery assembly pressure and battery temperature rise are not taken into consideration during battery fast charging, resulting in the battery being unable to achieve optimal fast charging performance.

[0006] In a first aspect, an embodiment of the present invention provides a battery multi-physics field coupled fast charging method, comprising:

[0007] A reference electrode is provided on the battery, and the temperature of the battery and the negative reference potential on the reference electrode are monitored in real time;

[0008] obtaining a preset pressure applied to the battery by a pressure device;

[0009] The maximum charge rate of the battery at 0% SOC is obtained, and the preset pressure is applied to the battery to charge the battery at the maximum charge rate at 0% SOC.

[0010] In an optional implementation manner, obtaining a preset pressure applied to the battery includes:

[0011] Obtaining a maximum charge rate of the battery at x% SOC, and charging the battery to x% SOC at the maximum charge rate at x% SOC;

[0012] Applying pressure to the battery at x% SOC by a pressure device, and charging the battery in the same charging manner, and obtaining the preset pressure by performing data fitting on the pressure value of the applied pressure and the SOC value;

[0013] The value range of x is 0 <x<100。

[0014] In an optional embodiment, the preset pressure ranges from 0 MPa to 0.5 MPa, preferably 0.1 MPa;

[0015] And / or, the charging mode includes any one of constant current charging, constant voltage charging or trickle charging.

[0016] In an optional implementation manner, obtaining the maximum charge rate of the battery at 0% SOC and applying the preset pressure on the battery to charge the battery includes:

[0017] Charging the battery at the maximum charge rate at the 0% SOC, and setting a preset temperature range and a preset value;

[0018] The maximum charge rate is changed according to whether the temperature of the battery is within the preset temperature range; and / or the charging current is changed according to whether the negative reference potential reaches the preset value.

[0019] In an optional implementation manner, changing the maximum charge rate according to whether the temperature of the battery is within the preset temperature range includes:

[0020] Applying the preset pressure on the battery and charging the battery in an empty state at a maximum charge rate at 0% SOC;

[0021] Within the preset temperature range, when the negative reference potential on the reference electrode reaches the preset value, the battery is stopped from being charged, and is left to stand, with the charging current gradually reduced until the battery is fully charged or reaches the preset voltage of the battery.

[0022] In an optional implementation manner, the changing the charging current according to whether the negative reference potential reaches the preset value further includes:

[0023] Applying the preset pressure on the battery and charging the battery in an empty state at a maximum charge rate at 0% SOC within a temperature range;

[0024] Before the negative reference potential reaches the preset value, the temperature of the battery is greater than the temperature range, and the maximum charge rate of the battery at the current temperature needs to be recalculated and charged until the battery is fully charged or reaches the preset voltage of the battery;

[0025] Preferably, the preset value is 0V.

[0026] In an optional embodiment, before the negative reference potential reaches the preset value, the temperature of the battery is greater than the preset temperature range, and the maximum charge rate of the battery at the current temperature needs to be recalculated for charging, further comprising:

[0027] At a first moment, obtaining a maximum charge rate at 0% SOC and a first temperature of the battery, and charging the battery at the maximum charge rate at 0% SOC;

[0028] At a second moment, obtaining a second temperature of the battery, and if a difference between the first temperature and the second temperature is greater than the temperature range, obtaining a maximum charge rate corresponding to y% SOC at the second moment;

[0029] charging the battery at a maximum charge rate corresponding to y% SOC at the second moment until the battery is fully charged or reaches a preset voltage of the battery;

[0030] The value range of y is 0 <y<100。

[0031] In an optional embodiment, the gradually reducing the charging rate includes reducing the charging rate in stages; preferably, the step size of the step reduction is 0.02C to 0.1C;

[0032] And / or, the standing time is 8s to 20s.

[0033] In an optional implementation manner, the method for obtaining the maximum charging rate includes:

[0034] Measuring the open circuit voltage of the battery at different states of charge to determine the internal resistance of the battery;

[0035] charging the battery with different charging currents, and measuring the polarization voltages corresponding to the different charging currents;

[0036] A functional relationship model is established based on the internal resistance, charging current and polarization voltage, and the maximum charging rate is obtained through data fitting.

[0037] Preferably, the functional relationship model includes a linear functional relationship model or a quadratic functional relationship model;

[0038] The data fitting includes the following test conditions according to the polarization voltage:

[0039] OCV(SOC)+I×R Ω +Vp(I)=V cutoff ;

[0040] Increasing the charging current, when the equation of the polarization voltage test condition is satisfied and the negative parameter potential is greater than or equal to 0, the charging current is the maximum charging rate;

[0041] Preferably, the functional relationship model may be Vp(I)=k(SOC)×I+b(SOC);

[0042] Where, I represents the charging current, Vp(I) represents the polarization voltage, and V cutoff represents the charge cut-off voltage, k(SOC) and b(SOC) represent the correlation coefficients.

[0043] In a second aspect, an embodiment of the present invention provides a battery multi-physics field coupled fast charging device, comprising:

[0044] A monitoring unit, configured to provide a reference electrode on the battery and monitor the temperature of the battery and the negative reference potential on the reference electrode in real time;

[0045] a force applying unit, configured to obtain a preset pressure applied to the battery through a pressure device;

[0046] A charging unit is used to obtain the maximum charging rate of the battery at 0% SOC, and apply the preset pressure on the battery to charge the battery at the maximum charging rate at 0% SOC.

[0047] The implementation of the technical solution of the present invention has at least the following beneficial effects:

[0048] An embodiment of the present invention provides a battery multi-physics field coupled fast charging method and device thereof. The method comprises providing a reference electrode on the battery and monitoring the battery temperature and the negative reference potential on the reference electrode in real time. A pressure device is used to obtain a preset pressure applied to the battery. The maximum charge rate of the battery at 0% SOC is obtained, and a preset pressure is applied to the battery to charge the battery at the maximum charge rate at 0% SOC. The fast charging method provided by the present invention fully considers the effects of the battery's temperature rise and applied pressure on fast charging performance during the charging process, improves and optimizes the battery's fast charging conditions, makes the battery safer during fast charging, and effectively avoids the occurrence of safety accidents.

[0049] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0051] Figure 1 The figure shows the process of the fast charging method of battery multi-physics field coupling provided by the embodiment of the present invention. Figure 1 ;

[0052] Figure 2 The figure shows the process of the fast charging method of battery multi-physics field coupling provided by the embodiment of the present invention. Figure 2 ;

[0053] Figure 3 The figure shows the process of the fast charging method of battery multi-physics field coupling provided by the embodiment of the present invention. Figure 3 ;

[0054] Figure 4 FIG2 is a schematic diagram of the structure of a battery multi-physics field coupled fast charging device provided by an embodiment of the present invention;

[0055] Figure 5 Shown is a test SOC curve diagram of the battery multi-physics field coupled fast charging method provided by an embodiment of the present invention.

[0056] The above drawings illustrate specific embodiments of the present invention, which will be described in more detail below. These drawings and the accompanying description are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0057] The present invention will be further described below with reference to specific examples. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0058] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range or the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0059] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0060] Unless otherwise specified, all technical features and optional technical features of the present invention can be combined with each other to form a new technical solution.

[0061] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0062] Unless otherwise specified, the terms "include" and "comprising" used in the present invention may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0063] First, the nouns appearing in the present invention are explained:

[0064] SOC: The battery's state of charge (SOC) refers to the remaining charge in the battery, typically expressed as a percentage. The most classic definition of SOC is: SOC = Qremain / Qrated × 100%.

[0065] When the assembly pressure of the battery is low or no pressure is applied to the battery, the pole pieces are not tightly fitted, lithium ion transmission is blocked, cell polarization increases, and capacity decay is aggravated, which greatly affects the battery life. When the assembly pressure of the battery is high, after the pressure increases to a certain level, it will cause the boundary to decrease. For example, when the graphite negative electrode material is fully charged, the expansion of the pole piece exceeds 20%. In this process, if the assembly pressure is too low, the ion transmission channels between the particles will be blocked, causing a large polarization phenomenon, making high-rate charging difficult. The greater the pressure, the smaller the gaps between the active materials, resulting in greater tortuosity inside the pole piece and a longer lithium ion transmission path. Macroscopically, this manifests as a large polarization internal resistance, which shortens the transmission speed of lithium ions, resulting in a decrease in the fast charge rate.

[0066] In view of this, an embodiment of the present application provides a fast charging method for batteries with multi-physical field coupling. By fully considering the applied pressure and temperature rise of the battery, the battery can obtain the optimal applied pressure, thereby optimizing the fast charging conditions of the battery, making the battery safer during fast charging and reducing the occurrence of safety accidents.

[0067] Figure 1 A fast charging method process for battery multi-physics field coupling provided by an embodiment of the present invention Figure 1 .like Figure 1As shown, the embodiment of the present application provides a fast charging method for battery multi-physical field coupling, including:

[0068] S101. Setting a reference electrode on the battery and monitoring the temperature of the battery and the negative reference potential on the reference electrode in real time.

[0069] The battery can be a plurality of batteries or a single battery. It can be a battery composed of a single cell or a battery composed of multiple cells. A reference electrode is set on the battery, and the reference electrode is used as a reference to determine the absolute change of the negative electrode potential. Taking the production of three electrodes in a soft-pack battery as an example, a copper wire is used as a reference electrode. The corroded copper wire is attached to the diaphragm with tape, and the diaphragm is placed in the middle layer of the electrode. The end of the copper wire (immersion area) is placed in the middle area of the battery cell. The tabs do not collide with each other. The copper wire is led out from the top during assembly, and the preliminary production of the three-electrode battery is completed.

[0070] By setting up the reference electrode, during the charging process, the positive and negative poles of the battery can be connected to the charging equipment, and the negative reference potential on the reference electrode can be monitored in real time, and the battery temperature can be monitored in real time.

[0071] S102: Obtain a preset pressure applied to the battery through a pressure device.

[0072] Pressure equipment also needs to be installed on the battery to apply pressure to the battery; at the same time, the applied pressure needs to be monitored and recorded in real time.

[0073] Through step S101 and the applied pressure values obtained in step S102, the preset pressure on the battery is obtained through data fitting or data simulation. That is, when the battery is fast charged, the preset pressure is applied, which can prevent the ion transmission channels between the particles in the battery from being blocked, reduce the polarization phenomenon of the battery, and enable high-rate charging.

[0074] S103 : Obtain the maximum charge rate of the battery at 0% SOC, apply a preset pressure on the battery, and charge the battery at the maximum charge rate at 0% SOC.

[0075] Through steps S101 and S102, a preset pressure is applied to the battery to obtain the maximum charge rate of the battery at 0% SOC, and charging is performed at this maximum charge rate. At the same time, the negative reference potential and battery temperature are monitored in real time. If the battery temperature rises too high during charging, charging can be suspended and the battery can be left to stand for a period of time before being charged again.

[0076] An embodiment of the present invention provides a fast-charging method for batteries that couples multiple physical fields. The method involves providing a reference electrode on the battery and monitoring the battery's temperature and the negative reference potential on the reference electrode in real time. A pressure device is used to obtain a preset pressure applied to the battery. The battery's maximum charge rate at 0% SOC is obtained, and a preset pressure is applied to the battery to charge the battery at the maximum charge rate at 0% SOC. The fast-charging method provided by the present invention fully considers the effects of the battery's temperature rise and applied pressure on fast-charging performance during charging, improves and optimizes battery fast-charging conditions, makes fast-charging safer, and effectively avoids safety accidents.

[0077] Figure 2 A fast charging method process for battery multi-physics field coupling provided by an embodiment of the present invention Figure 2 .like Figure 2 As shown, in some embodiments of the present invention, obtaining a preset pressure applied to the battery includes:

[0078] S201 . Obtain a maximum charge rate of a battery at x% SOC, and charge the battery to x% SOC at the maximum charge rate at x% SOC.

[0079] For the preset pressure, the maximum charge rate for the battery at x% SOC is calculated, where x can be any of 10, 20, 30, 40, 50, 60, 70, 80, or 90. The battery is then charged to x% SOC at the maximum charge rate at x% SOC. The internal characteristics of the battery change under different pressures, and the maximum charge current it can withstand also changes, resulting in different SOCs when charged at the same rate.

[0080] S202 , applying pressure to the battery at x% SOC through a pressure device, and charging the battery in the same charging method, and obtaining a preset pressure by performing data fitting on the pressure value of the applied pressure and the SOC value.

[0081] Apply pressure to a battery charged to x% SOC using a pressure device. Continue charging the battery using the same charging method, which can be constant current, constant voltage, or trickle charging. Record the applied pressure values and the battery SOC values during this process, and perform data fitting to determine the preset pressure.

[0082] For example, the maximum charge rate to 50% SOC is calculated, and the battery is charged to 50% SOC, and this is used as a benchmark. The battery is charged with a constant current, wherein the battery can be subjected to pressure through a clamp, and the pressure range is 0-0.5MPa. When the negative reference voltage is 0, charging is stopped, and the charging SOC value at this time is recorded. The test curve is fitted and derived to obtain the pressure value at the inflection point, which is the preset pressure. Figure 5 As shown in the figure, the maximum pressure that the battery can withstand without affecting the charging system is 0.1 MPa. At the same time, excessive pressure will have a great impact on the internal structure of the battery. 0.5 MPa can be derived from theory and experience, and the maximum pressure that the battery can withstand during this period is obtained.

[0083] Furthermore, in some embodiments of the present invention, the value range of x is 0 <x<100。

[0084] Specifically, x can be any value among 10, 20, 30, 40, 50, 60, 70, 80, or 90, or any number between any two values. Under different pressures, the internal characteristics of the battery will change, the maximum charge current it can withstand will also change, and the SOC that can be achieved at the same charging rate will also vary.

[0085] Furthermore, in some embodiments of the present invention, the preset pressure ranges from 0 MPa to 0.5 MPa, preferably 0.1 MPa.

[0086] Specifically, the preset pressure can be any one of 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, or 0.5 MPa, or any number between any two values. If the preset pressure exceeds this range, it will significantly affect the internal structure of the battery, affecting the overall performance of the battery. The preferred value of 0.5 MPa is derived from theory and experience, and the maximum pressure that the battery can withstand is obtained within this range.

[0087] Furthermore, in some embodiments of the present invention, the charging method includes any one of constant current charging, constant voltage charging or trickle charging.

[0088] Figure 3 A fast charging method process for battery multi-physics field coupling provided by an embodiment of the present invention Figure 3 .like Figure 3 As shown, in some embodiments of the present invention, obtaining the maximum charge rate of the battery at 0% SOC and applying the preset pressure on the battery to charge the battery includes:

[0089] The battery is charged at the maximum charge rate at 0% SOC and according to the preset temperature range and preset value.

[0090] Changing the maximum charge rate based on whether the battery temperature is within a preset temperature range; and / or changing the charging current based on whether the negative reference potential reaches a preset value; specifically including:

[0091] S301, setting a reference electrode on the battery, and monitoring the temperature of the battery and the negative reference potential on the reference electrode in real time; and obtaining a preset pressure applied to the battery through a pressure device.

[0092] S302 : Apply a preset pressure to the battery, and charge the battery in an empty state at a maximum charge rate at 0% SOC.

[0093] S303. When the negative reference potential on the reference electrode reaches a preset value within a preset temperature range, stop charging the battery, let it stand, and gradually reduce the charging current until the battery is fully charged or reaches a preset voltage of the battery; preferably, the preset value is 0V.

[0094] After steps S301 and S302, a preset pressure is applied to the battery to begin charging. A temperature range is set, which can be determined by those skilled in the art through testing methods or experience. The battery is charged at the maximum charge rate at 0% SOC, and the battery temperature is monitored in real time. If the battery temperature is within this temperature range and the negative reference potential is detected to be a preset value, charging is stopped. After a period of rest, the charging current is reduced to continue charging the battery.

[0095] Exemplarily, the above process can be repeated multiple times. The battery is first charged at the maximum charge rate at 0% SOC. When the temperature of the battery is within the temperature range and the negative parameter potential is monitored to be a preset value, charging is stopped, and after standing for a period of time, the charging current is reduced for charging; when the negative parameter potential reaches the preset value again, charging is stopped again, and the battery is allowed to stand, and charging is continued after the charging current is reduced.

[0096] Furthermore, before the negative reference potential reaches the preset value, if the battery temperature is greater than the preset temperature range, it is necessary to recalculate the maximum charge rate of the battery at the current temperature for charging, specifically through the following steps:

[0097] S304 : At a first moment, obtain a maximum charge rate at 0% SOC and a first temperature of the battery, and charge the battery at the maximum charge rate at 0% SOC.

[0098] S305 , obtaining a second temperature of the battery at a second moment, and if the difference between the first temperature and the second temperature is greater than a preset temperature range, obtaining a maximum charge rate corresponding to y% SOC at the second moment.

[0099] If, during charging in step S303, it is detected that the battery temperature exceeds the preset temperature range and the negative reference potential has not yet reached the preset value, it is necessary to change the maximum charge rate through step S305 and charge at the changed maximum charge rate.

[0100] S306, charging the battery at the maximum charge rate corresponding to y% SOC at the second moment until the battery is fully charged or reaches a preset voltage of the battery; wherein the value range of y is 0 <y<100。

[0101] The above steps S304 to S306 may be performed once or repeated multiple times; and steps S302 to S303 and steps S304 to S306 may be performed independently during the battery charging process, or may be performed repeatedly during the battery charging process.

[0102] Furthermore, in some embodiments of the present invention, gradually reducing the charging rate includes reducing the charging rate in stages; preferably, the step size of the stage-by-stage reduction is 0.02C to 0.1C.

[0103] The step size of the step-down current can be 0.02C, 0.03C, 0.04C, 0.05C, 0.06C, 0.07C, 0.08C, 0.09C or 0.1C. Within this range, firstly, charging efficiency can be improved: in the early stages of charging, the battery charge is low, and charging with a larger current can quickly replenish the battery charge and shorten the charging time. Secondly, it can protect the battery: excessively high charging current may cause damage to the battery, such as causing battery overheating and accelerated battery aging. Step-down current charging can automatically adjust the current size according to the battery's charging status, providing a larger current when the battery charge is low to meet the needs of fast charging, while reducing the current when the battery charge is close to full to avoid overcharging, thereby effectively protecting the battery and extending the battery life. Step-down current charging achieves a balance between speed, life and safety by dynamically adjusting the current, and is particularly suitable for fast charging scenarios of high-energy-density batteries.

[0104] Furthermore, in some embodiments of the present invention, the standing time is 8s to 20s.

[0105] The resting time is 8s to 20s. Specifically, the resting time can be 8s, 9s, 10s, 11s, 13s, 14s, 15s, 16s, 17s, 18s, 19s or 20s. Within this range, polarization is effectively reduced and electrode stress is relieved.

[0106] Furthermore, in some embodiments of the present invention, the method for obtaining the maximum charge rate includes:

[0107] Measure the open circuit voltage of the battery at different states of charge to determine the internal resistance R of the battery Ω .

[0108] The battery is charged with different charging currents I, and the polarization voltage Vp(I) corresponding to the different charging currents is measured.

[0109] According to the internal resistance R Ω , charging current I and polarization voltage, establish a functional relationship model, and obtain the maximum charging rate through data fitting.

[0110] In some embodiments of the present invention, the functional relationship model includes a linear functional relationship model or a quadratic functional relationship model;

[0111] The data fitting includes the following test conditions according to the polarization voltage:

[0112] OCV(SOC)+I×R Ω +Vp(I)=V cutoff ;

[0113] The charging current is increased. When the equation of the polarization voltage test condition is satisfied and the negative parameter potential is greater than or equal to 0, the charging current is the maximum charging rate.

[0114] In some embodiments of the present invention, the functional relationship model is Vp(I)=k(SOC)×I+b(SOC);

[0115] Where, I represents the charging current, Vp(I) represents the polarization voltage, and V cutoff represents the charge cut-off voltage, k(SOC) and b(SOC) represent the correlation coefficients.

[0116] Figure 4 Schematic diagram of a battery multi-physics field coupled fast charging device according to an embodiment of the present invention. The present invention provides a battery multi-physics field coupled fast charging device 40, comprising:

[0117] Monitoring unit 401, used to set a reference electrode on the battery and monitor the battery temperature and the negative reference potential on the reference electrode in real time;

[0118] A force applying unit 402 is used to obtain a preset pressure applied to the battery through a pressure device;

[0119] The charging unit 403 is used to obtain the maximum charge rate of the battery at 0% SOC, and apply a preset pressure on the battery to charge the battery at the maximum charge rate at 0% SOC.

[0120] The force applying unit 402 is further used to obtain the maximum charge rate of the battery at x% SOC, and charge the battery to x% SOC at the maximum charge rate at x% SOC;

[0121] The pressure device is used to apply pressure to the battery at x% SOC, and the battery is charged in the same charging mode. The preset pressure is obtained by fitting the pressure value and the SOC value.

[0122] The charging unit 403 is further configured to charge the battery at a maximum charge rate at 0% SOC and set a preset temperature range and a preset value;

[0123] The maximum charge rate is changed according to whether the temperature of the battery is within a preset temperature range; and / or the charging current is changed according to whether the negative reference potential reaches a preset value.

[0124] The charging unit 403 is further configured to apply the preset pressure to the battery and charge the battery in an empty state at the maximum charge rate at 0% SOC;

[0125] When the negative reference potential on the reference electrode reaches the preset value within the preset temperature range, the battery is stopped from charging and left to stand, with the charging current gradually reduced until the battery is fully charged or reaches the preset voltage of the battery.

[0126] The charging unit 403 is further configured to apply a preset pressure to the battery and charge the battery in an empty state at a maximum charge rate at 0% SOC within a preset temperature range;

[0127] Before the negative reference potential reaches the preset value, the temperature of the battery is greater than the temperature range, and the maximum charge rate of the battery at the current temperature needs to be recalculated and charged until the battery is fully charged or reaches the preset voltage of the battery.

[0128] The charging unit 403 is further configured to obtain, at a first moment, a maximum charging rate at 0% SOC and a first temperature of the battery, and charge the battery at the maximum charging rate at 0% SOC;

[0129] At a second moment, obtaining a second temperature of the battery; if the difference between the first temperature and the second temperature is greater than a preset temperature range, obtaining a maximum charge rate corresponding to y% SOC at the second moment;

[0130] The battery is charged at the maximum charge rate corresponding to y% SOC at the second moment until the battery is fully charged or reaches a preset voltage of the battery.

[0131] Parts of the present invention that are not described in detail are well known to those skilled in the art.

[0132] The basic principles of the present invention have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in the present invention are merely illustrative and non-limiting, and should not be construed as necessarily possessed by each embodiment of the present invention. Furthermore, the specific details disclosed above are provided for illustrative purposes and to facilitate understanding, and are not intended to be limiting. These details do not necessarily limit the present invention to being implemented using these specific details.

[0133] It should be noted that the terms "and / or" or " / " used herein are merely a description of an association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The singular forms "a," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0134] In the detailed description and claims, a list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0135] If the integrated unit / module is implemented in hardware, the hardware may be digital circuits, analog circuits, etc. The physical implementation of the hardware structure includes, but is not limited to, transistors, memristors, etc. Unless otherwise specified, the processor may be any appropriate hardware processor, such as a CPU, GPU, FPGA, DSP, and ASIC. Unless otherwise specified, the storage unit may be any appropriate magnetic storage medium or magneto-optical storage medium, such as resistive random access memory (RRAM), dynamic random access memory (DRAM), static random access memory (SRAM), enhanced dynamic random access memory (EDRAM), high-bandwidth memory (HBM), hybrid memory cube (HMC), etc.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A battery multi-physics field coupling fast charging method, characterized in that: include: A reference electrode is provided on the battery, and the temperature of the battery and the negative reference potential on the reference electrode are monitored in real time; obtaining a preset pressure applied to the battery by a pressure device; The maximum charge rate of the battery at 0% SOC is obtained, and the preset pressure is applied to the battery to charge the battery at the maximum charge rate at 0% SOC.

2. The fast charging method according to claim 1, characterized in that: The obtaining of a preset pressure applied to the battery includes: Obtaining a maximum charge rate of the battery at x% SOC, and charging the battery to x% SOC at the maximum charge rate at x% SOC; Applying pressure to the battery at x% SOC by a pressure device, and charging the battery in the same charging manner, and obtaining the preset pressure by performing data fitting on the pressure value of the applied pressure and the SOC value; The value range of x is 0 <x<100。 3. The fast charging method according to claim 2, characterized in that: The preset pressure ranges from 0 MPa to 0.5 MPa, preferably 0.1 MPa; And / or, the charging mode includes any one of constant current charging, constant voltage charging or trickle charging.

4. The fast charging method according to claim 1, characterized in that: The obtaining of the maximum charge rate of the battery at 0% SOC and applying the preset pressure on the battery to charge the battery includes: Charging the battery at the maximum charge rate at the 0% SOC, and setting a preset temperature range and a preset value; The maximum charge rate is changed according to whether the temperature of the battery is within the preset temperature range; and / or the charging current is changed according to whether the negative reference potential reaches the preset value.

5. The fast charging method according to claim 4, characterized in that: Changing the maximum charge rate according to whether the temperature of the battery is within a preset temperature range includes: Applying the preset pressure on the battery and charging the battery in an empty state at a maximum charge rate at 0% SOC; When the negative reference potential on the reference electrode reaches the preset value within the preset temperature range, charging of the battery is stopped and the battery is left to stand, with the charging current gradually reduced until the battery is fully charged or reaches the preset voltage of the battery.

6. The fast charging method according to claim 4, characterized in that: The changing of the charging current according to whether the negative reference potential reaches the preset value further includes: Applying the preset pressure on the battery and charging the battery in an empty state at a maximum charge rate at 0% SOC; Before the negative reference potential reaches the preset value, the temperature of the battery is greater than the preset temperature range, and the maximum charge rate of the battery at the current temperature needs to be recalculated and charged until the battery is fully charged or reaches the preset voltage of the battery; Preferably, the preset value is 0V.

7. The fast charging method according to claim 6, characterized in that: Before the negative parameter potential reaches the preset value, the temperature of the battery is greater than the preset temperature range, and the maximum charge rate of the battery at the current temperature needs to be recalculated for charging, further comprising: At a first moment, obtaining a maximum charge rate at 0% SOC and a first temperature of the battery, and charging the battery at the maximum charge rate at 0% SOC; At a second moment, obtaining a second temperature of the battery, and if a difference between the first temperature and the second temperature is greater than the temperature range, obtaining a maximum charge rate corresponding to y% SOC at the second moment; charging the battery at a maximum charge rate corresponding to y% SOC at the second moment until the battery is fully charged or reaches a preset voltage of the battery; The value range of y is 0 <y<100。 8. The fast charging method according to claim 5, characterized in that: The gradually reducing the charging rate includes reducing the charging rate in stages; preferably, the step size of the step reduction is 0.02C to 0.1C; And / or, the standing time is 8s to 20s.

9. The fast charging method according to claim 1, characterized in that: The method for obtaining the maximum charging rate includes: Measuring the open circuit voltage of the battery at different states of charge to determine the internal resistance of the battery; charging the battery with different charging currents, and measuring the polarization voltages corresponding to the different charging currents; Establishing a functional relationship model based on the internal resistance, charging current and polarization voltage, and obtaining the maximum charging rate through data fitting; Preferably, the functional relationship model includes a linear functional relationship model or a quadratic functional relationship model; The data fitting includes the following test conditions according to the polarization voltage: OCV(SOC)+I×R Ω +Vp(I)=V cutoff ; Increasing the charging current, when the equation of the polarization voltage test condition is satisfied and the negative parameter potential is greater than or equal to 0, the charging current is the maximum charging rate; Preferably, the functional relationship model may be Vp(I)=k(SOC)×I+b(SOC); Where, I represents the charging current, Vp(I) represents the polarization voltage, and V cutoff represents the charge cut-off voltage, k(SOC) and b(SOC) represent the correlation coefficients.

10. A battery multi-physics field coupled fast charging device, characterized in that: include: A monitoring unit, configured to provide a reference electrode on the battery and monitor the temperature of the battery and the negative reference potential on the reference electrode in real time; a force applying unit, configured to obtain a preset pressure applied to the battery through a pressure device; A charging unit is used to obtain the maximum charging rate of the battery at 0% SOC, and to apply the preset pressure on the battery to charge the battery at the maximum charging rate.

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