Lithium battery wireless charging device and charging method

Abstract

The invention relates to the technical field of wireless charging, in particular to a lithium battery wireless charging device and method, and the method comprises the steps: obtaining the communication duration of a lithium battery and a charging receiving end in a lithium battery wireless charging mode, and adjusting a sensitivity threshold value of temperature monitoring; respectively acquiring a first surface temperature and a second surface temperature in a wireless charging mode; according to the first surface temperature and the second surface temperature, the surface structure adaptation stability is judged, and the initial charging rate of the lithium battery to the charging receiving end is adjusted; the attenuation rate of the first surface temperature in the charging process is monitored, a real-time charging oscillogram is drawn, the overlap ratio of the attenuation interval of the first surface temperature in the charging oscillogram and the time interval of heat dissipation characteristic change of the lithium battery is analyzed, and the initial charging rate is readjusted; and continuously performing wireless charging on the charging receiving end according to the readjusted initial charging rate so as to complete the wireless charging process of the lithium battery. The wireless charging efficiency of the lithium battery is improved.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and in particular to a lithium battery wireless charging device and charging method. Background Technology

[0002] In practical applications, existing wireless charging systems still face numerous challenges in terms of stability, efficiency, and safety. The charging process is susceptible to complex interference from various internal and external factors. The thermal compatibility of the contact interface is a core factor affecting charging efficiency and safety. To achieve efficient energy transfer, the lithium battery and the receiver coil must maintain precise alignment and tight contact. Although magnetic structures provide initial alignment, in actual use, microscopic deformation caused by manufacturing tolerances, wear, or external stress can create tiny gaps between the two contact surfaces, introducing contact thermal resistance. While wireless charging systems have inherent heat dissipation models in their design, random changes in ambient wind speed and direction can drastically alter the design. The existing technology struggles to distinguish between temperature rises caused by increased equipment load and temperature drops caused by ambient air cooling, given the surface convection heat dissipation conditions. Furthermore, the air cooling effect may couple with the aforementioned contact interface issues. Additionally, electrostatic discharge (ESD), a common source of transient electromagnetic interference, can affect communication links between devices. Existing solutions typically employ fixed communication protocols and retry mechanisms, but they cannot effectively distinguish between ESD interference and other types of communication faults. When an ESD pulse causes a transient decrease in communication quality, the system may simply perform a communication reset or slowdown, which to some extent increases overall power consumption and thermal load. Therefore, there is an urgent need for a wireless charging device and charging method that can sense and distinguish different interference sources and perform adaptive and coordinated control.

[0003] Chinese Patent Publication No. CN111917195A discloses a wireless charging system for lithium batteries and its efficiency optimization method. The main circuit of the system includes a high-frequency inverter circuit, a wireless power transmission system lithium battery, a wireless power transmission system receiver, a rectifier circuit, and an impedance matching circuit. The efficiency of the inverter circuit is optimized based on novel switching transistor materials and soft-switching technology. A multi-objective optimization algorithm is proposed based on compensation network topology analysis for efficiency optimization. Load-optimized efficiency tracking is proposed based on impedance matching technology. However, the wireless charging system and its efficiency optimization method for lithium batteries suffer from several problems. In dry environments, electrostatic discharge acts as an interference source, causing repeated handshakes or failed handshakes between the lithium battery and the receiver, reducing charging efficiency. Furthermore, in practical use, the presence of a small gap between the lithium battery charging contact surface and the charging receiver's charging contact surface, coupled with uneven deformation due to temperature differences in the contact area, leads to increased absolute temperature differences in the contact area under external wind cooling conditions, further interfering with magnetic coupling. Summary of the Invention

[0004] To address this, the present invention provides a wireless charging device and method for lithium batteries, which overcomes the problems in the prior art where electrostatic discharge in a dry environment acts as an interference source, causing repeated handshakes or handshake failures between the lithium battery and the receiver, thus reducing charging efficiency. Furthermore, in actual use, the presence of a small gap between the lithium battery charging contact surface and the charging receiver charging contact surface, coupled with uneven deformation caused by temperature differences in the contact area, leads to a larger absolute temperature difference in the contact area under external wind-cooling conditions, further interfering with magnetic coupling.

[0005] On one hand, the present invention provides a method for wireless charging of lithium batteries, comprising:

[0006] Obtain the connection duration between the lithium battery and the charging receiver in the wireless charging mode of the lithium battery;

[0007] Adjust the sensitivity threshold of temperature monitoring according to the connection duration;

[0008] The first surface temperature of the lithium battery charging contact surface and the second surface temperature of the charging contact surface of the charging receiver are obtained at the start of charging in wireless charging mode.

[0009] The surface structure adaptation stability is determined based on the first surface temperature and the second surface temperature.

[0010] Based on the fact that the surface structure adaptation stability does not meet the requirements, the initial charging rate of the lithium battery to the charging receiver is adjusted.

[0011] Monitor the rate of temperature decay of the first surface during charging at the initial charging rate;

[0012] Based on the temperature decay rate, a real-time charging waveform diagram is plotted, and the overlap between the decay range of the first surface temperature in the charging waveform diagram and the time range of the change in the heat dissipation characteristics of the lithium battery is analyzed.

[0013] The initial charging rate is readjusted based on the degree of overlap.

[0014] The charging receiver continues to wirelessly charge according to the readjusted initial charging rate to complete the wireless charging process of the lithium battery.

[0015] The initial charging rate is the average charging speed of the lithium battery during the initial charging period in wireless charging mode.

[0016] Further, adjusting the sensitivity threshold for temperature monitoring based on the connection duration includes,

[0017] Compare the connection duration with the preset connection duration;

[0018] If the connection duration is greater than the preset connection duration, then the sensitivity threshold of the temperature monitoring is reduced.

[0019] Furthermore, adjusting the initial charging rate of the lithium battery to the charging receiver based on the surface structure adaptation stability not meeting the requirements includes:

[0020] The absolute value of the difference between the first surface temperature and the second surface temperature is compared with a preset difference value;

[0021] If the absolute value of the difference is greater than the preset difference, it is determined that the surface structure adaptation stability does not meet the requirements, and the initial charging rate of the lithium battery to the charging receiver is reduced.

[0022] Furthermore, the initial charging rate is negatively correlated with the absolute value of the difference.

[0023] Further, the step of plotting a real-time charging waveform based on the temperature decay rate and analyzing the overlap between the decay interval of the first surface temperature in the charging waveform and the time interval of the change in the heat dissipation characteristics of the lithium battery includes:

[0024] The decay rate of the first surface temperature is calculated based on the temperature drop of the first surface within a unit monitoring cycle.

[0025] Real-time charging waveforms of the charging process are plotted based on the time series corresponding to each calculated decay rate and the time series corresponding to the change in the heat dissipation characteristics of the lithium battery.

[0026] The overlap ratio between the length of the time interval in the real-time charging waveform where the decay rate meets the preset decay rate condition and the length of the time interval corresponding to the change in the heat dissipation characteristics of the lithium battery, and the length of the time interval corresponding to the change in the heat dissipation characteristics of the lithium battery, is determined as the overlap degree.

[0027] The preset attenuation rate condition is that the attenuation rate is greater than the preset attenuation rate.

[0028] Further, the decay rate is the ratio of the temperature decrease to the period length of the unit monitoring cycle, wherein,

[0029] The temperature drop is the difference between the temperature value of the lithium battery charging contact surface at the beginning and the end of the unit monitoring cycle.

[0030] Furthermore, the heat dissipation characteristics of the lithium battery are changed such that the structural deformation of the lithium battery within the unit monitoring cycle is greater than or equal to a preset deformation, wherein,

[0031] The structural deformation is the difference between the surface curvature value of the lithium battery at the beginning and the end of a unit monitoring cycle.

[0032] Further, the step of readjusting the initial charging rate based on the overlap degree includes:

[0033] The degree of overlap is compared with a preset degree of overlap;

[0034] If the overlap is greater than the preset overlap, it is determined that the interference of the ambient wind speed on the lithium battery charging contact surface does not meet the requirements, and the initial charging rate is increased.

[0035] Furthermore, the initial charging rate is positively correlated with the degree of overlap.

[0036] On the other hand, the present invention provides a charging device for a lithium battery wireless charging method, comprising:

[0037] Lithium batteries;

[0038] The detection module, which is connected to the lithium battery, includes a first surface temperature of the lithium battery charging contact surface and a second surface temperature of the charging contact surface of the charging receiver at the start of charging in wireless charging mode, and a temperature sensor array for monitoring the decay rate of the first surface temperature during charging, and a surface deformation sensor for obtaining the structural deformation of the lithium battery.

[0039] A data processing module, which is connected to the detection module, is used to draw a real-time charging waveform based on the temperature decay rate and analyze the overlap between the decay range of the first surface temperature in the charging waveform and the time range of the change in the heat dissipation characteristics of the lithium battery.

[0040] The control module is connected to the detection module and the data processing module respectively. It adjusts the sensitivity threshold of temperature monitoring according to the connection time between the lithium battery and the charging receiver, and determines the initial charging rate of the lithium battery according to the first surface temperature, the second surface temperature and the overlap.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows: Based on the connection time between the lithium battery and the charging receiver in the wireless charging mode of lithium batteries, when the connection time is longer than the preset connection time, it indicates that the connection time between the lithium battery and the charging receiver may be longer due to electrostatic discharge. By reducing the sensitivity threshold of temperature monitoring, the control module can capture the small temperature spikes caused by electrostatic secondary effects. The electrostatic secondary effect refers to the increased local temperature change caused by electric sparks or small arcs generated in the conductor gap, i.e., the area between the lithium battery and the charging receiver, during electrostatic discharge, as well as the eddy current heating induced by electromagnetic pulses in the lithium battery. Therefore, by reducing the sensitivity threshold of temperature monitoring to adapt to the monitoring requirements of transient electrostatic discharge risk in electrostatic environment, and based on the reduced sensitivity threshold of temperature monitoring, it is recommended to send a timing adjustment command to the communication control module inside the lithium battery to stagger the connection segment with the time period of electrostatic generation, further improving the charging efficiency of wireless charging, avoiding energy waste caused by communication retransmission and power negotiation failure, and ensuring that the handshake time in the electromagnetic environment is in a state of reliable data transmission.

[0042] Furthermore, this invention determines the surface structure adaptation stability based on the first and second surface temperatures. When the absolute value of the difference between the first surface temperature of the lithium battery's contact surface area and the second surface temperature of the receiver's contact surface area during the charging initialization phase is greater than a preset difference, it indicates poor thermal contact at the physical contact interface between the lithium battery and the receiver. The absolute value of the difference reflects the magnitude of the thermal resistance between the two contact surfaces, which is directly related to the tightness of the physical contact. Therefore, when the absolute difference is greater than the preset difference, the contact area of ​​the surface exhibits uneven thermal deformation due to the temperature difference, thereby increasing the effective distance between the coils. Further interference with magnetic coupling is achieved by reducing the initial charging rate at this point. This aims to actively reduce the power of the heat source to prevent the heat generation from continuously exceeding the thermal conductivity of the charging contact interface, thereby preventing the lithium battery temperature from rising further. This effectively blocks the uneven thermal deformation of the surface contact area caused by the increased temperature difference. When the absolute value of the difference is detected to decrease and fall within the preset difference value, it is determined that the surface structure adaptation stability meets the requirements, and the charging rate is restored to the optimal charging rate calculated by the system. This further improves the effective energy transmission efficiency and reduces the energy eddy current loss caused by the uneven thermal deformation of the surface contact area, which leads to the magnetic coupling misalignment of the charging contact surface.

[0043] Furthermore, this invention analyzes the overlap between the temperature decay interval and the time interval of the lithium battery heat dissipation characteristic change in the waveform diagram. When the structural deformation of the lithium battery within a unit monitoring cycle is greater than or equal to the preset deformation, it indicates that the deformation of the lithium battery charging contact surface does not meet the charging conditions of the initial charging rate. When there is uneven thermal deformation in the contact area of ​​the surface, the time interval of the change in the lithium battery heat dissipation characteristic caused by uneven thermal deformation is relatively fixed, while the time interval of rapid temperature decay caused by ambient airflow, i.e., the temperature decay rate of the lithium battery charging contact surface, is random and fluctuating. When the time interval of the change in the lithium battery heat dissipation characteristic, i.e., the time interval of the structural deformation of the lithium battery surface being greater than or equal to the preset deformation, is highly synchronized with the time interval of the decay rate of the lithium battery charging contact surface being greater than the preset decay rate, it constitutes a strong correlation between the low compatibility of the contact area between the lithium battery and the charging receiver and the environmental wind cooling interference. Therefore, when the decay rate based on the lithium battery charging contact surface... When the overlap calculated between the time interval where the rate of decay is greater than the preset decay rate and the time interval where the structural deformation of the lithium battery surface is greater than or equal to the preset deformation is greater than the preset overlap, the heat dissipation environment of the lithium battery is dominated by the ambient airflow. The ambient airflow not only directly cools the surface of the charging receiver, but may also preferentially carry away the heat from the surface of the lower-temperature charging receiver due to the external ambient airflow. The higher-temperature lithium battery, due to continuous internal heat generation and the inability of the heat to be effectively conducted away through the contact interface between the lithium battery and the charging receiver, results in a slower temperature drop of the lithium battery, increasing the absolute temperature difference between the two surfaces and further interfering with the magnetic coupling charging process. At this time, by increasing the initial charging rate, the heat carried away from the contact interface due to the air cooling effect is offset, and heat energy is actively provided to the charging lithium battery to compensate for the heat lost by the airflow. This helps the interface between the charging and charging contact surfaces maintain or restore a thermal equilibrium state conducive to stable magnetic coupling, further restoring high-efficiency energy transfer. Attached Figure Description

[0044] Figure 1 This is an overall flowchart of the lithium battery wireless charging method according to an embodiment of the present invention;

[0045] Figure 2 This is a flowchart illustrating the real-time charging waveform diagram of the lithium battery wireless charging method according to an embodiment of the present invention.

[0046] Figure 3 This is a real-time charging waveform diagram showing the decay range of the first surface temperature and the time interval of the change in the heat dissipation characteristics of the lithium battery in the wireless charging method of the present invention.

[0047] Figure 4 This is an overall structural block diagram of the charging device for the lithium battery wireless charging method according to an embodiment of the present invention. Detailed Implementation

[0048] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0049] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0050] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0051] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] Please see Figure 1 The diagram shown is an overall flowchart of a lithium battery wireless charging method according to an embodiment of the present invention. The lithium battery wireless charging method according to an embodiment of the present invention includes:

[0053] Step S1: Obtain the connection duration between the lithium battery and the charging receiver in the lithium battery wireless charging mode.

[0054] Step S2: Adjust the sensitivity threshold of temperature monitoring according to the connection duration;

[0055] Step S3: Obtain the first surface temperature of the lithium battery charging contact surface and the second surface temperature of the charging contact surface of the charging receiver at the start of charging in wireless charging mode.

[0056] Step S4: Determine the surface structure adaptation stability based on the first surface temperature and the second surface temperature;

[0057] Step S5: Based on the fact that the surface structure adaptation stability does not meet the requirements, adjust the initial charging rate of the lithium battery to the charging receiver.

[0058] Step S6: Monitor the rate of temperature decay of the first surface during charging at the initial charging rate;

[0059] Step S7: Draw a real-time charging waveform diagram based on the temperature decay rate, and analyze the overlap between the decay interval of the first surface temperature in the charging waveform diagram and the time interval of the change in the heat dissipation characteristics of the lithium battery.

[0060] Step S8: Readjust the initial charging rate based on the overlap.

[0061] Step S9: Continue wirelessly charging the charging receiver according to the readjusted initial charging rate to complete the wireless charging process of the lithium battery.

[0062] The initial charging rate is the average charging speed of the lithium battery during the initial charging period in wireless charging mode.

[0063] In implementation, this invention is based on the connection duration between the lithium battery and the charging receiver in the wireless charging mode. When the connection duration exceeds the preset connection duration, it indicates that the connection duration between the lithium battery and the charging receiver may be prolonged due to electrostatic discharge. By reducing the sensitivity threshold of temperature monitoring, the control module can capture the small temperature spikes caused by electrostatic secondary effects. The electrostatic secondary effect refers to the increased local temperature change caused by electric sparks or small arcs generated in the conductor gap, i.e., the area between the lithium battery and the charging receiver, during electrostatic discharge, as well as the eddy current heating induced by electromagnetic pulses in the lithium battery. Therefore, by reducing the sensitivity threshold of temperature monitoring, it is adapted to the monitoring requirements of transient electrostatic discharge risk in electrostatic environments. Based on the reduced sensitivity threshold of temperature monitoring, it is recommended to send a timing adjustment command to the communication control module inside the lithium battery to stagger the connection time period with the electrostatic discharge time period, further improving the charging efficiency of wireless charging, avoiding energy waste caused by communication retransmission and power negotiation failure, and ensuring that the handshake time in the electromagnetic environment is in a state of reliable data transmission.

[0064] Specifically, adjusting the sensitivity threshold for temperature monitoring based on the connection duration includes:

[0065] Compare the connection duration with the preset connection duration;

[0066] If the connection duration is greater than the preset connection duration, then the sensitivity threshold of the temperature monitoring is reduced.

[0067] Optionally, the preset connection duration can be selected within the range of [200ms, 800ms].

[0068] Preferably, the preferred embodiment of the preset connection duration is 500ms.

[0069] Specifically, adjusting the initial charging rate of the lithium battery to the charging receiver based on the surface structure adaptation stability not meeting the requirements includes:

[0070] The absolute value of the difference between the first surface temperature and the second surface temperature is compared with a preset difference value;

[0071] If the absolute value of the difference is greater than the preset difference, it is determined that the surface structure adaptation stability does not meet the requirements, and the initial charging rate of the lithium battery to the charging receiver is reduced.

[0072] Optionally, the preset difference can be selected within the range of [3℃, 8℃].

[0073] Preferably, the preferred embodiment of the preset difference is 5°C.

[0074] Specifically, the initial charging rate is negatively correlated with the absolute value of the difference.

[0075] In implementation, when the absolute value of the current difference is within 1°C of the preset difference, the initial charging rate is adjusted to 95% of the current initial charging rate. When the absolute value of the current difference exceeds 1°C of the preset difference, the initial charging rate is reduced by 0.05% for every 0.5°C exceeding 1°C. In a specific embodiment, the absolute value of the current difference is 7°C, the current initial charging rate is 10W, and the reduced initial charging rate is 10W × 95% × (1 - 0.1%) = 9.5W × 0.999 ≈ 9.49W. When the calculated pre-handshake time has more than three decimal places, it is rounded to two decimal places, i.e., 9.49W.

[0076] In implementation, this invention determines the surface structure adaptation stability based on the first and second surface temperatures. When the absolute value of the difference between the first surface temperature of the lithium battery's contact surface area and the second surface temperature of the receiver's contact surface area during the charging initialization phase is greater than a preset difference, it indicates poor thermal contact at the physical contact interface between the lithium battery and the receiver. The absolute value of the difference reflects the magnitude of the thermal resistance between the two contact surfaces, which is directly related to the tightness of the physical contact. Therefore, when the absolute difference is greater than the preset difference, the contact area of ​​the surface exhibits uneven thermal deformation due to the temperature difference, thereby increasing the effective distance between the coils. Further interference with magnetic coupling is achieved by reducing the initial charging rate at this point. This aims to actively reduce the power of the heat source to prevent the heat generation from continuously exceeding the thermal conductivity of the charging contact interface, thereby preventing the lithium battery temperature from rising further. This effectively blocks the uneven thermal deformation of the surface contact area caused by the increased temperature difference. When the absolute value of the difference is detected to decrease and fall within the preset difference value, it is determined that the surface structure adaptation stability meets the requirements, and the charging rate is restored to the optimal charging rate calculated by the system. This further improves the effective energy transmission efficiency and reduces the energy eddy current loss caused by the uneven thermal deformation of the surface contact area, which leads to the magnetic coupling misalignment of the charging contact surface.

[0077] Please see Figure 2 The diagram shown is a flowchart of the real-time charging waveform diagram plotting method for lithium battery wireless charging according to an embodiment of the present invention. The step of plotting the real-time charging waveform diagram based on the temperature decay rate and analyzing the overlap between the decay interval of the first surface temperature in the charging waveform diagram and the time interval of the change in the heat dissipation characteristics of the lithium battery includes:

[0078] Step S71: Calculate the decay rate of the first surface temperature based on the temperature drop of the first surface temperature within a unit monitoring cycle.

[0079] Step S72: Based on the calculated time series corresponding to each decay rate and the heat dissipation characteristics of the lithium battery, draw the real-time charging waveform of the charging process.

[0080] Step S73: The overlap length between the length of the time interval in the real-time charging waveform where the decay rate meets the preset decay rate condition and the length of the time interval corresponding to the change in the heat dissipation characteristics of the lithium battery is equal to the length of the time interval corresponding to the change in the heat dissipation characteristics of the lithium battery is determined as the overlap degree.

[0081] The preset attenuation rate condition is that the attenuation rate is greater than the preset attenuation rate.

[0082] Optionally, the preset decay rate can be selected within the range of [0.1℃ / s, 0.5℃ / s].

[0083] Preferably, the preset decay rate is 0.2℃ / s in the preferred embodiment.

[0084] Please see Figure 3 As shown, it is a real-time charging waveform diagram of the decay range of the first surface temperature and the time interval of the change of the heat dissipation characteristics of the lithium battery in the wireless charging method of the present invention. The horizontal axis of the real-time charging waveform diagram is time; the negative axis value of the vertical axis of the real-time charging waveform diagram is the temperature decay rate.

[0085] Specifically, the decay rate is the ratio of the temperature drop to the length of the unit monitoring cycle, wherein,

[0086] The temperature drop is the difference between the temperature value of the lithium battery charging contact surface at the beginning and the end of the unit monitoring cycle.

[0087] Specifically, the change in the heat dissipation characteristics of the lithium battery is such that the structural deformation of the lithium battery within the unit monitoring cycle is greater than or equal to a preset deformation, wherein,

[0088] The structural deformation is the difference between the surface curvature value of the lithium battery at the beginning and the end of a unit monitoring cycle.

[0089] Please continue reading. Figure 3 As shown, the positive axis value of the vertical axis of the real-time charging waveform graph represents the structural deformation of the lithium battery.

[0090] Optionally, the preset range of deformable values ​​is [0.02 / ]. 0.15 / ].

[0091] Preferably, the preferred embodiment of the preset deformation is 0.08 / .

[0092] Please continue reading. Figure 3 As shown, in a specific embodiment of the present invention, the time interval during which the decay rate meets the preset decay rate condition is the duration covered by the temperature decay rate continuously being lower than -0.1℃ / s within the range of [8s, 18s], and the time interval corresponding to the change in the heat dissipation characteristics of the lithium battery is the range where the structural deformation is greater than or equal to 0.08 / s within the range of [8s, 22s]. The overlap was calculated to be 80% based on the length of time covered.

[0093] Specifically, the step of readjusting the initial charging rate based on the overlap includes:

[0094] The degree of overlap is compared with a preset degree of overlap;

[0095] If the overlap is greater than the preset overlap, it is determined that the interference of the ambient wind speed on the lithium battery charging contact surface does not meet the requirements, and the initial charging rate is increased.

[0096] Optionally, the preset overlap range is [50%, 80%].

[0097] Preferably, the preferred embodiment with a preset overlap ratio is 60%.

[0098] Specifically, the initial charging rate is positively correlated with the degree of overlap.

[0099] In implementation, when the overlap is greater than the preset overlap by less than 15%, the initial charging rate is adjusted to 1.1 times the current initial charging rate. When the overlap exceeds the preset overlap by more than 15%, the initial charging rate is increased by 0.05% for every 1% exceeding 15%. In a specific embodiment, the current overlap is 78%, the current initial charging rate is 10W, and the increased initial charging rate is 10W × 1.1 × (1 + 0.15%) = 11.0165W. When the calculated initial charging rate has more than three decimal places, it is rounded to two decimal places, i.e., 11.02W.

[0100] In implementation, this invention analyzes the overlap between the temperature decay interval and the time interval of lithium battery heat dissipation characteristic change in the waveform diagram. When the structural deformation of the lithium battery within a unit monitoring cycle is greater than or equal to the preset deformation, it indicates that the deformation of the lithium battery charging contact surface does not meet the charging conditions of the initial charging rate. When there is uneven thermal deformation in the contact area of ​​the surface, the time interval of the change in lithium battery heat dissipation characteristics caused by uneven thermal deformation is relatively fixed, while the time interval of rapid temperature decay caused by ambient airflow, i.e., the temperature decay rate of the lithium battery charging contact surface, is random and fluctuating. When the time interval of the change in lithium battery heat dissipation characteristics, i.e., the time interval of the structural deformation of the lithium battery surface being greater than or equal to the preset deformation, is highly synchronized with the time interval of the decay rate of the lithium battery charging contact surface being greater than the preset decay rate, it constitutes a strong correlation between the low compatibility of the contact area between the lithium battery and the charging receiver and the environmental wind cooling interference. Therefore, when the decay rate based on the lithium battery charging contact surface... When the overlap calculated between the time interval where the rate of decay is greater than the preset decay rate and the time interval where the structural deformation of the lithium battery surface is greater than or equal to the preset deformation is greater than the preset overlap, the heat dissipation environment of the lithium battery is dominated by the ambient airflow. The ambient airflow not only directly cools the surface of the charging receiver, but may also preferentially carry away the heat from the surface of the lower-temperature charging receiver due to the external ambient airflow. The higher-temperature lithium battery, due to continuous internal heat generation and the inability of the heat to be effectively conducted away through the contact interface between the lithium battery and the charging receiver, results in a slower temperature drop of the lithium battery, increasing the absolute temperature difference between the two surfaces and further interfering with the magnetic coupling charging process. At this time, by increasing the initial charging rate, the heat carried away from the contact interface due to the air cooling effect is offset, and heat energy is actively provided to the charging lithium battery to compensate for the heat lost by the airflow. This helps the interface between the charging and charging contact surfaces maintain or restore a thermal equilibrium state conducive to stable magnetic coupling, further restoring high-efficiency energy transfer.

[0101] Please refer to Figure 4 The diagram shown is an overall module diagram of the charging device for the wireless charging method of lithium batteries according to an embodiment of the present invention. The charging device for the wireless charging method of lithium batteries according to an embodiment of the present invention includes,

[0102] Lithium batteries;

[0103] The detection module, which is connected to the lithium battery, includes a first surface temperature of the lithium battery charging contact surface and a second surface temperature of the charging contact surface of the charging receiver at the start of charging in wireless charging mode, and a temperature sensor array for monitoring the decay rate of the first surface temperature during charging, and a surface deformation sensor for obtaining the structural deformation of the lithium battery.

[0104] A data processing module, which is connected to the detection module, is used to draw a real-time charging waveform based on the temperature decay rate and analyze the overlap between the decay range of the first surface temperature in the charging waveform and the time range of the change in the heat dissipation characteristics of the lithium battery.

[0105] The control module is connected to the detection module and the data processing module respectively. It adjusts the sensitivity threshold of temperature monitoring according to the connection time between the lithium battery and the charging receiver, and determines the initial charging rate of the lithium battery according to the first surface temperature, the second surface temperature and the overlap.

[0106] Specifically, an embedded digital signal processor is used to plot a real-time charging waveform based on the temperature decay rate, and a programmable logic device is used to analyze the overlap between the decay range of the first surface temperature in the charging waveform and the time range of the change in the heat dissipation characteristics of the lithium battery.

[0107] Specifically, the sensitivity threshold for temperature monitoring is adjusted through the threshold register of the microcontroller.

[0108] Specifically, the initial charging rate of the lithium battery is adjusted by a pulse width modulation controller and a power MOSFET drive circuit.

[0109] As will be understood by those skilled in the art, the operating principles and processes of embedded digital signal processors, programmable logic devices, threshold registers, pulse width modulation controllers, and power MOSFET drive circuits are conventional techniques well-known to those skilled in the art. Therefore, the operating principles and processes of embedded digital signal processors, programmable logic devices, threshold registers, pulse width modulation controllers, and power MOSFET drive circuits will not be elaborated here.

[0110] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for wireless charging a lithium battery, characterized in that, include: Obtain the connection duration between the lithium battery and the charging receiver in the wireless charging mode of the lithium battery; Adjust the sensitivity threshold of temperature monitoring according to the connection duration; The first surface temperature of the lithium battery charging contact surface and the second surface temperature of the charging contact surface of the charging receiver are obtained at the start of charging in wireless charging mode. The surface structure adaptation stability is determined based on the first surface temperature and the second surface temperature. Based on the fact that the surface structure adaptation stability does not meet the requirements, the initial charging rate of the lithium battery to the charging receiver is adjusted. Monitor the rate of temperature decay of the first surface during charging at the initial charging rate; Based on the temperature decay rate, a real-time charging waveform diagram is plotted, and the overlap between the decay range of the first surface temperature in the charging waveform diagram and the time range of the change in the heat dissipation characteristics of the lithium battery is analyzed. The initial charging rate is readjusted based on the degree of overlap. The charging receiver continues to wirelessly charge according to the readjusted initial charging rate to complete the wireless charging process of the lithium battery. The initial charging rate is the average charging speed of the lithium battery during the initial charging period in wireless charging mode.

2. The lithium battery wireless charging method according to claim 1, characterized in that, The step of adjusting the sensitivity threshold for temperature monitoring based on the connectivity duration includes: Compare the connection duration with the preset connection duration; If the connection duration is greater than the preset connection duration, then the sensitivity threshold of the temperature monitoring is reduced.

3. The lithium battery wireless charging method according to claim 2, characterized in that, The adjustment of the initial charging rate of the lithium battery to the charging receiver based on the surface structure adaptation stability not meeting the requirements includes: The absolute value of the difference between the first surface temperature and the second surface temperature is compared with a preset difference value; If the absolute value of the difference is greater than the preset difference, it is determined that the surface structure adaptation stability does not meet the requirements, and the initial charging rate of the lithium battery to the charging receiver is reduced.

4. The lithium battery wireless charging method according to claim 3, characterized in that, The initial charging rate is negatively correlated with the absolute value of the difference.

5. The lithium battery wireless charging method according to claim 4, characterized in that, The step of plotting a real-time charging waveform based on the temperature decay rate and analyzing the overlap between the decay interval of the first surface temperature in the charging waveform and the time interval of the change in the heat dissipation characteristics of the lithium battery includes: The decay rate of the first surface temperature is calculated based on the temperature drop of the first surface within a unit monitoring cycle. Real-time charging waveforms of the charging process are plotted based on the time series corresponding to each calculated decay rate and the time series corresponding to the change in the heat dissipation characteristics of the lithium battery. The overlap ratio between the length of the time interval in the real-time charging waveform where the decay rate meets the preset decay rate condition and the length of the time interval corresponding to the change in the heat dissipation characteristics of the lithium battery, and the length of the time interval corresponding to the change in the heat dissipation characteristics of the lithium battery, is determined as the overlap degree. The preset attenuation rate condition is that the attenuation rate is greater than the preset attenuation rate.

6. The lithium battery wireless charging method according to claim 5, characterized in that, The attenuation rate is the ratio of the temperature decrease to the length of the unit monitoring cycle, wherein, The temperature drop is the difference between the temperature value of the lithium battery charging contact surface at the beginning and the end of the unit monitoring cycle.

7. The lithium battery wireless charging method according to claim 6, characterized in that, The change in the heat dissipation characteristics of the lithium battery is such that the structural deformation of the lithium battery within the unit monitoring cycle is greater than or equal to a preset deformation, wherein... The structural deformation is the difference between the surface curvature value of the lithium battery at the beginning and the end of a unit monitoring cycle.

8. The lithium battery wireless charging method according to claim 7, characterized in that, The step of readjusting the initial charging rate based on the overlap includes: The degree of overlap is compared with a preset degree of overlap; If the overlap is greater than the preset overlap, it is determined that the interference of the ambient wind speed on the lithium battery charging contact surface does not meet the requirements, and the initial charging rate is increased.

9. The lithium battery wireless charging method according to claim 8, characterized in that, The initial charging rate is positively correlated with the degree of overlap.

10. A charging device using the lithium battery wireless charging method according to any one of claims 1 to 9, characterized in that, include: Lithium batteries; The detection module, which is connected to the lithium battery, includes a first surface temperature of the lithium battery charging contact surface and a second surface temperature of the charging contact surface of the charging receiver at the start of charging in wireless charging mode, and a temperature sensor array for monitoring the decay rate of the first surface temperature during charging, and a surface deformation sensor for obtaining the structural deformation of the lithium battery. A data processing module, which is connected to the detection module, is used to draw a real-time charging waveform based on the temperature decay rate and analyze the overlap between the decay range of the first surface temperature in the charging waveform and the time range of the change in the heat dissipation characteristics of the lithium battery. The control module is connected to the detection module and the data processing module respectively. It adjusts the sensitivity threshold of temperature monitoring according to the connection time between the lithium battery and the charging receiver, and determines the initial charging rate of the lithium battery according to the first surface temperature, the second surface temperature and the overlap.

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