A battery thermal management method, system, and storage medium

Abstract

This invention relates to a battery thermal management method, system, and storage medium, belonging to the field of battery technology. The method includes pre-mixing phase change microspheres with dynamically cross-linked resin to form a composite slurry, coating it onto the surface of a battery cell, and curing it to form a composite resin coating. When the battery surface temperature rises, the solid-liquid phase change material within the coating melts into a liquid phase material through thermal conduction, absorbing heat to bring the system to a steady-state temperature. If this steady-state temperature reaches or exceeds the dissociation temperature of the dynamically cross-linked resin, the cross-linked network softens to form a viscoelastic softened matrix, while the liquid phase material vaporizes to generate a vaporization medium. The vaporization medium applies internal pressure to the viscoelastic softened matrix, causing it to foam and expand, and extend directionally within the gaps between battery cells, ultimately forming a thermal barrier that physically bridges the shells of adjacent cells. This solves the technical problem that, with a significantly increased battery heat generation rate, traditional technologies relying solely on phase change materials for heat absorption are insufficient to maintain a stable battery surface temperature within a safe range.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery thermal management method, system, and storage medium. Background Technology

[0002] In recent years, battery thermal management technology has received widespread attention in fields such as electric vehicles and energy storage systems. Existing technologies often employ passive thermal management by combining phase change materials (PCMs) with a polymer matrix. For example, solid-liquid phase change materials such as paraffin wax and fatty acids are encapsulated in microcapsules or porous carriers, mixed with traditional thermosetting resins such as epoxy resin and polyurethane, and then coated onto the battery surface. The phase change materials absorb a large amount of latent heat during the melting process, thus slowing down the rate of temperature rise in the battery. This method has a certain temperature control effect under low-rate or short-term high-power conditions and is suitable for applications where thermal response speed requirements are not high.

[0003] However, under continuous high-rate charging and discharging or long-term operation conditions, the rate of heat generation in the battery increases significantly, and it is difficult to maintain the battery surface temperature within a safe range by relying solely on the heat absorption of phase change materials. Summary of the Invention

[0004] The purpose of this invention is to at least partially solve one of the technical problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides a battery thermal management method, comprising:

[0006] Phase change microspheres are mixed with dynamic crosslinking resin in advance to form a composite slurry, and the composite slurry is coated on the surface of the battery cell. After curing, a composite resin coating is formed. The phase change microspheres include a porous framework and a solid-liquid phase change material filled in the porous framework. When the surface temperature of the battery cell rises, the solid-liquid phase change material in the composite resin coating is subjected to heat conduction according to the surface temperature, so that the solid-liquid phase change material melts into a liquid phase material. The battery cell is cooled by absorbing heat using the liquid phase material to obtain a steady-state temperature. The steady-state temperature is the constant temperature value maintained by the surface temperature of the battery cell when it reaches a dynamic thermal equilibrium due to internal heat generation and external heat dissipation during continuous charging and discharging or high-rate operation. The constant temperature value is within the phase change temperature range of the solid-liquid phase change material and is lower than the critical temperature of battery thermal runaway. When the steady-state temperature reaches or exceeds the dissociation temperature of the dynamic crosslinking resin, the crosslinking network of the dynamic crosslinking resin softens to form a viscoelastic softened matrix, while the liquid phase material vaporizes inside the composite resin coating to form a vaporization medium. The viscoelastic softened matrix is ​​foamed and expanded based on the vaporization medium to form a thermal barrier between battery cells.

[0007] Furthermore, the phase change microspheres are pre-mixed with a dynamically cross-linked resin to prepare a composite slurry, comprising: The phase change microspheres are stirred and coated with a coupling agent to obtain modified microsphere powder, and the modified microsphere powder is shaken with an organic solvent to obtain a microsphere dispersion. The microsphere dispersion and the dynamic crosslinking resin are subjected to high-speed shearing to obtain a homogeneous mixture. A dynamic crosslinking agent is then added to the homogeneous mixture for vacuum degassing to obtain the composite slurry.

[0008] Furthermore, the composite slurry is coated onto the surface of the battery cell, and after curing, a composite resin coating is formed, including: The composite slurry is subjected to high-frequency oscillation atomization to obtain micron-sized atomized droplets, and the surface of the battery cell is directionally sprayed and deposited based on the micron-sized atomized droplets to obtain an attached liquid film layer. The attached liquid film layer is heated in a stepped manner to form a solvent evaporation coating, and in-situ thermally initiated crosslinking is performed based on the solvent evaporation coating to form a semi-cured gel layer; The semi-cured gel layer is subjected to constant temperature and pressure treatment to form a dense network structure, and then cooled and shaped based on the dense network structure to form the composite resin coating after curing.

[0009] Furthermore, the composite slurry is coated onto the surface of the battery cell, and after curing, a composite resin coating is formed, including: The composite slurry is applied to the surface of the battery cell by ultrasonic atomization spraying to form a uniform liquid film. Based on the surface contour of the battery cell, the uniform liquid film is subjected to infrared thermal radiation to initiate a cross-linking reaction, forming a primary cross-linked gel layer. The primary cross-linked gel layer is then subjected to interfacial coordination bonding treatment to form an anchored network structure. The anchoring mesh structure is subjected to a stepped temperature program to remove the solvent, resulting in a non-porous solid layer. The non-porous solid layer is then annealed to release stress and set the shape. After curing, the composite resin coating is formed.

[0010] Furthermore, based on the surface temperature, heat conduction is performed on the solid-liquid phase change material within the composite resin coating, causing the solid-liquid phase change material to melt into a liquid phase material, including: Spatial partial derivative calculation is performed on the surface temperature of the battery cell to extract the extreme points of heat flux density, and the physical boundary corresponding to the extreme points of heat flux density is defined as a local hot spot region. Calculate the spatial temperature distribution of the local hot spot region and solve for the first-order partial derivatives of the spatial temperature distribution along the coordinate axis to obtain the temperature gradient vector; Based on the temperature gradient vector of the local hot spot region, the phonon transport trajectory inside the composite resin coating is vector-mapped to form a directional heat conduction link between the local hot spot region and the phase change microsphere. Along the directional heat transfer path, the transient heat flow of the local hot spot region is introduced into the porous framework of the phase change microspheres; Based on the porosity and thermal conductivity of the porous framework, lattice vibration frequency matching calculations are performed on the transient heat flow to screen out the low-frequency phonon bands that resonate with the porous framework. A low-resistance thermal conductivity region is determined within the porous skeleton based on the low-frequency phonon band. Within the low-resistivity thermal conduction region, the enthalpy integral of the solid-liquid phase change material filled in the porous framework is calculated. When the cumulative enthalpy value exceeds the latent heat threshold of the solid-liquid phase change material, the lattice deconstruction of the solid-liquid phase change material is triggered, causing the solid-liquid phase change material to undergo a phase transition and melt into a liquid phase material.

[0011] Furthermore, when the steady-state temperature reaches or exceeds the dissociation temperature of the dynamically crosslinked resin, the crosslinking network of the dynamically crosslinked resin softens, forming a viscoelastic softened matrix. Simultaneously, the liquid phase material vaporizes within the composite resin coating to form a vaporization medium, including: When the steady-state temperature reaches or exceeds the dissociation temperature of the dynamic crosslinking resin, the reversible covalent bonds of the dynamic crosslinking resin in the composite resin coating undergo a reverse reaction and disintegrate under thermal activation. Based on the overheating deviation between the steady-state temperature and the dissociation temperature, the reversible covalent bonds are broken in a nonlinear incremental manner, so that the effective crosslinking density of the crosslinking network forms a gradient decay distribution along the thickness direction of the composite resin coating. When the effective crosslinking density drops below the percolation critical threshold, the storage modulus of the dynamic crosslinking resin falls to the viscosity-flow transition range, and the crosslinking network transforms into a viscoelastic softening matrix, wherein the porous skeleton inside the viscoelastic softening matrix remains in a rigid support state. During the formation of the viscoelastic softened matrix, heat is continuously conducted to the liquid phase material retained in the porous framework, causing the temperature of the liquid phase material to exceed its saturation boiling point and form a superheated liquid film. Heterogeneous nucleation is excited between the superheated liquid film and the pore wall surface of the porous skeleton, generating vapor bubble nuclei at the pore wall surface. Under the superheated driving force provided by the superheated liquid film, the vapor bubble nuclei grow radially and aggregate to form discrete gas phase domains filling the pores of the porous skeleton. Based on the endogenous vapor pressure generated by the discrete gas phase domain, when the endogenous vapor pressure overcomes the capillary constraint force at the pore opening of the porous skeleton, the vapor in the discrete gas phase domain escapes through the pore opening of the porous skeleton into the viscoelastic softened matrix surrounding the porous skeleton. In the region where the endogenous vapor pressure exceeds the local yield stress of the viscoelastic softening matrix, vapor bubble nuclei expand and interconnect along the low-modulus interconnection path in the viscoelastic softening matrix, forming the vaporization medium dispersed within the composite resin coating.

[0012] Furthermore, the step of foaming and expanding the viscoelastic softened matrix based on the vaporization medium to form a thermal barrier between battery cells includes: An isotropic gas pressure is applied to the viscoelastic softening matrix according to the phase change expansion volume of the gasification medium, causing the viscoelastic softening matrix to undergo tensile rheology, resulting in a closed-cell bubble array. Based on the porous framework, the interfacial stress of the closed-cell bubble array is dispersed to form a bubble wall support network, and the closed-cell bubble array is shaped in three-dimensional space according to the bubble wall support network to form an expansion insulation layer. The expansion insulation layer is directionally extended and extruded along the gap between the battery cells, so that the expansion insulation layer physically bridges the outer shell boundary of the adjacent battery cells, forming the heat insulation barrier.

[0013] The present invention also provides a battery thermal management system, comprising: A mixing module is used to pre-mix phase change microspheres with dynamic cross-linking resin to prepare a composite slurry, and then coat the composite slurry onto the surface of the battery cell. After curing, a composite resin coating is formed. The phase change microspheres include a porous framework and a solid-liquid phase change material filled in the porous framework. A heat conduction module is used to conduct heat to the solid-liquid phase change material in the composite resin coating when the surface temperature of the battery cell rises, so that the solid-liquid phase change material melts into a liquid phase material. The cooling module is used to absorb heat and cool the battery cell based on the liquid phase material to obtain a steady-state temperature. The steady-state temperature is a constant temperature value maintained by the surface temperature of the battery cell when it reaches a dynamic thermal equilibrium due to internal heat generation and external heat dissipation during continuous charging and discharging or high-rate operation. The constant temperature value is within the phase change temperature range of the solid-liquid phase change material and is lower than the critical temperature of battery thermal runaway. The softening and vaporization module is used to soften the crosslinking network of the dynamic crosslinking resin when the steady-state temperature reaches or exceeds the dissociation temperature of the dynamic crosslinking resin, forming a viscoelastic softened matrix, while the liquid phase material vaporizes inside the composite resin coating to form a vaporization medium. An expansion module is used to foam and expand the viscoelastic softened matrix based on the vaporization medium to form a thermal barrier between battery cells.

[0014] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of any of the methods described above.

[0015] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any of the methods described above.

[0016] This invention provides a battery thermal management method, comprising: pre-mixing phase change microspheres with dynamically cross-linked resin to form a composite slurry, coating it onto the surface of a battery cell, and curing it to form a composite resin coating. When the battery surface temperature rises, the solid-liquid phase change material within the coating melts into a liquid phase material through thermal conduction, absorbing heat to bring the system to a steady-state temperature. If this steady-state temperature reaches or exceeds the dissociation temperature of the dynamically cross-linked resin, the cross-linked network softens to form a viscoelastic softened matrix, while the liquid phase material vaporizes to generate a vaporization medium. The vaporization medium applies internal pressure to the viscoelastic softened matrix, causing it to foam and expand, extending directionally within the gaps between battery cells. This ultimately forms a thermal barrier that physically bridges the shells of adjacent cells, solving the technical problem that traditional technologies, relying solely on phase change materials to absorb heat, struggle to maintain a stable battery surface temperature within a safe range when the battery heat generation rate increases significantly. This solution integrates heat absorption buffering and active expansion insulation within a single coating by combining phase change microspheres with dynamically cross-linked resin: in the initial temperature rise stage, the solid-liquid phase change material melts and absorbs heat, slowing the temperature increase; when the temperature rise exceeds the safety threshold and triggers resin dissociation, the in-situ generated vaporization medium drives the viscoelastic softened matrix to foam and expand, forming a thermal barrier bridging adjacent battery cells. This not only inhibits heat transfer to neighboring cells but also effectively blocks the propagation path of thermal runaway. Compared to traditional technologies that rely solely on phase change heat absorption, this solution maintains the battery surface temperature within a controllable range even under high heat generation conditions and significantly improves thermal safety at the module level. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the steps of a battery thermal management method in one embodiment of the present invention; Figure 2This is a structural block diagram of a battery thermal management system according to an embodiment of the present invention; Figure 3 This is a schematic block diagram of the structure of a computer device according to an embodiment of the present invention.

[0019] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0021] The following describes in detail, with reference to the accompanying drawings, a big data-driven digital diagnosis and treatment management system for urinary disorders according to an embodiment of the present invention.

[0022] Figure 1 This invention provides a battery thermal management method, comprising: Step S1: The phase change microspheres are mixed with dynamic crosslinking resin in advance to form a composite slurry, and the composite slurry is coated on the surface of the battery cell. After curing, a composite resin coating is formed. The phase change microspheres include a porous skeleton and a solid-liquid phase change material filled in the porous skeleton.

[0023] Specifically, in practice, phase change microspheres and dynamically crosslinked resin are first added to a stirring device in a certain proportion and mechanically mixed at room temperature or slightly above room temperature to uniformly disperse them and form a composite slurry. Then, the composite slurry is applied to the outer surface of the battery cell using a scraping, spraying, or roller coating method, with the coating thickness typically controlled within the range of 50–300 μm. Afterward, the cell is placed in an oven or ultraviolet light environment, where the crosslinking reaction is completed according to the curing mechanism of the selected dynamically crosslinked resin. Finally, a dense and well-adhesive composite resin coating is formed on the surface of the battery cell, in which the phase change microspheres retain their original structure, and the internal porous framework is pre-loaded with solid-liquid phase change materials such as paraffin or fatty acids. In this embodiment, the above scheme achieves stable embedding of the phase change microspheres in the resin matrix, avoiding leakage of the phase change material, and providing a structural basis for subsequent thermal response behavior.

[0024] Step S2: When the surface temperature of the battery cell rises, the solid-liquid phase change material in the composite resin coating is subjected to heat conduction according to the surface temperature, so that the solid-liquid phase change material melts into a liquid phase material.

[0025] Specifically, as the surface temperature of a battery cell gradually rises during charging and discharging, heat is conducted from the outside to the inside through the continuous phase of the composite resin coating. Once the local temperature reaches the melting point range of the solid-liquid phase change material (e.g., 45–60°C, depending on the selected paraffin or fatty acid material), the solid-liquid phase change material filling the phase change microspheres begins to absorb heat and undergo a phase transition, gradually melting from a solid to a liquid phase. This process relies on good thermal contact between the composite resin coating and the battery surface, as well as the uniform distribution of the phase change microspheres in the resin matrix, to ensure unobstructed heat conduction pathways. In practical applications, such as in high-rate fast charging scenarios for electric vehicles, the battery surface temperature rises rapidly. In this case, a large number of phase change microspheres within the coating respond synchronously, effectively buffering sudden temperature changes. In this embodiment, the above scheme achieves a passive, following thermal response to changes in the surface temperature of the battery cell, dynamically matching the phase change heat absorption process with the heat generation process, and avoiding localized overheating.

[0026] Step S3: The battery cell is cooled by heat absorption based on the liquid phase material to obtain a steady-state temperature; wherein, the steady-state temperature is the constant temperature value maintained by the surface temperature of the battery cell when it reaches a dynamic thermal equilibrium due to internal heat generation and external heat dissipation during continuous charging and discharging or high-rate operation, and the constant temperature value is within the phase change temperature range of the solid-liquid phase change material and is lower than the critical temperature of battery thermal runaway.

[0027] Specifically, as the battery cells continuously generate heat during high-rate charging and discharging, their surface temperature rises continuously. The solid-liquid phase change material within the composite resin coating, after melting into a liquid phase, absorbs the heat released by the battery cells, achieving a cooling effect. When the heat generated inside the battery per unit time reaches equilibrium with the heat absorbed by the coating through phase change and dissipated to the environment, the surface temperature no longer rises significantly, thus forming a steady-state temperature. This steady-state temperature typically falls within the phase change temperature range of the selected solid-liquid phase change material, such as 50–58°C, and is significantly lower than the battery's thermal runaway critical temperature (generally higher than 130°C), thereby preventing the triggering of thermal propagation. Taking electric vehicles in continuous fast charging conditions as an example, the battery pack is under high current for extended periods. This solution can effectively stabilize the surface temperature of the individual cells within a safe window. In this embodiment, the above solution maintains temperature stability of the battery cells under dynamic thermal load, suppressing performance degradation and safety hazards caused by excessively rapid temperature rise.

[0028] In step S4, when the steady-state temperature reaches or exceeds the dissociation temperature of the dynamic crosslinking resin, the crosslinking network of the dynamic crosslinking resin softens to form a viscoelastic softened matrix, while the liquid phase material vaporizes inside the composite resin coating to form a vaporization medium.

[0029] Specifically, when a battery cell operates continuously under extreme conditions, its surface steady-state temperature may further increase. Once this temperature reaches or exceeds the dissociation temperature of the dynamically cross-linked resin (e.g., 80–110°C, depending on the Diels-Alder or imine-type dynamic covalent network used), the original cross-linked structure of the resin begins to undergo reversible fracture, macroscopically manifested as softening of the coating matrix and its viscoelastic state. Simultaneously, the molten liquid phase material rapidly vaporizes inside the composite resin coating due to the ambient temperature being higher than its boiling point (e.g., some low-boiling-point fatty acid derivatives begin to vaporize above 90°C), generating a large amount of vaporization medium. In cases where an electric vehicle experiences cooling system failure or localized heat accumulation, this process can be triggered within seconds to tens of seconds. In this embodiment, the above solution, through a temperature threshold response mechanism, simultaneously achieves matrix softening and the generation of internal foaming precursors, providing the necessary conditions for the subsequent construction of the thermal insulation barrier.

[0030] Step S5: Based on the vaporization medium, the viscoelastic softened matrix is ​​foamed and expanded to form a thermal barrier between battery cells.

[0031] Specifically, as the vaporization medium continuously generates within the viscoelastic softened matrix, its pressure gradually accumulates and overcomes the local viscoelastic resistance of the resin matrix, causing the coating to expand in volume. Since the dynamically cross-linked resin loses its rigid network structure above its dissociation temperature and instead exhibits a stretchable viscoelastic state, bubbles can nucleate, grow, and stably expand within it, ultimately forming a porous foam structure. This foam layer adheres tightly to the surface of the battery cell and expands and connects between adjacent cells, forming a physically isolated thermal barrier. For example, if a cell in the battery module experiences a sudden temperature rise above 120°C due to an internal short circuit, the coating can complete foaming within 10–30 seconds, increasing its thickness to 3–8 times that of the original coating. In this embodiment, the above scheme, through an in-situ foaming mechanism, spontaneously constructs a low thermal conductivity isolation layer in the early stages of thermal runaway, effectively blocking the lateral transfer of heat to adjacent battery cells.

[0032] In a specific embodiment, phase change microspheres are pre-mixed with a dynamically crosslinked resin to prepare a composite slurry, comprising: The phase change microspheres are stirred and coated with a coupling agent to obtain modified microsphere powder, and the modified microsphere powder is shaken with an organic solvent to obtain a microsphere dispersion. The microsphere dispersion and the dynamic crosslinking resin are subjected to high-speed shearing to obtain a homogeneous mixture. A dynamic crosslinking agent is then added to the homogeneous mixture for vacuum degassing to obtain the composite slurry.

[0033] Specifically, the phase change microspheres are first subjected to surface modification treatment. The phase change microspheres and coupling agent are placed together in a stirring device and thoroughly stirred at an appropriate temperature to ensure the coupling agent is uniformly coated on the surface of the microspheres, forming modified microsphere powder. This operation aims to improve the interfacial compatibility between the microspheres and the subsequent resin system, preventing agglomeration or sedimentation during mixing.

[0034] Subsequently, the obtained modified microsphere powder was added to an organic solvent and dispersed thoroughly by shaking to obtain a stable microsphere dispersion. The shaking process must ensure that the microspheres are uniformly suspended in the solvent to avoid excessively high local concentrations or particle aggregation, thus providing a good foundation for the subsequent mixing with the resin.

[0035] Next, the microsphere dispersion is slowly introduced into the dynamically crosslinked resin and vigorously mixed using a high-speed shearing device. The high-speed shearing breaks up any potential microsphere clusters and promotes a uniform microscale distribution of the microspheres within the continuous resin phase, ultimately forming a homogeneous mixture. This step has a decisive impact on the uniformity of the slurry and the performance of subsequent coatings.

[0036] Finally, a dynamic crosslinking agent is added to the homogeneous mixture, followed by vacuum degassing. Vacuum degassing effectively removes air or volatile bubbles introduced during mixing, preventing the formation of pores or defects after coating. This treatment yields a composite slurry suitable for coating processes, characterized by stable components, no bubbles, and moderate flowability.

[0037] In this embodiment, the above scheme ensures the uniform dispersion and good interfacial bonding of phase change microspheres in the dynamically cross-linked resin matrix by sequentially performing operations such as surface coating, solvent dispersion, high-speed shearing and vacuum degassing, providing a reliable material basis for the subsequent formation of a composite coating with both phase change heat absorption and thermal response foaming functions.

[0038] In a specific embodiment, the composite slurry is coated onto the surface of the battery cell, and after curing, a composite resin coating is formed, including: The composite slurry is subjected to high-frequency oscillation atomization to obtain micron-sized atomized droplets, and the surface of the battery cell is directionally sprayed and deposited based on the micron-sized atomized droplets to obtain an attached liquid film layer. The attached liquid film layer is heated in a stepped manner to form a solvent evaporation coating, and in-situ thermally initiated crosslinking is performed based on the solvent evaporation coating to form a semi-cured gel layer; The semi-cured gel layer is subjected to constant temperature and pressure treatment to form a dense network structure, and then cooled and shaped based on the dense network structure to form the composite resin coating after curing.

[0039] Specifically, applying the aforementioned composite slurry to the surface of the battery cell to ultimately form a composite resin coating requires completing three key operational stages in sequence: atomization spraying, stepped temperature curing, and isothermal pressure densification. First, the composite slurry is introduced into a high-frequency oscillating atomization device. Utilizing the high-frequency vibration generated by piezoelectric ceramics or ultrasonic transducers, the slurry is broken into micron-sized atomized droplets at the nozzle. These droplets are then guided by compressed gas or an electrostatic field and sprayed along a specific direction onto the outer surface of the battery cell, achieving uniform coverage and forming a continuous, adhered liquid film. This spraying method effectively avoids the uneven thickness or edge buildup problems caused by traditional scraping or dipping processes, and is particularly suitable for complex pouch or prismatic battery cells.

[0040] After obtaining the attached liquid film, it is placed in a temperature-controlled oven for step-by-step heating treatment. Initially, a lower temperature is used to promote slow evaporation of the organic solvent, preventing pinholes or cracks caused by rapid solvent escape, thus obtaining a solvent-evaporated coating with a complete structure. Subsequently, the temperature is gradually increased to the thermal initiation threshold of the dynamically crosslinked resin system, activating the dynamic crosslinking agent and causing in-situ thermally initiated crosslinking reactions between resin molecular chains, forming a semi-cured gel layer with certain elasticity and cohesive strength. This process is not completed in one step, but rather through segmented temperature control to ensure complete solvent removal while avoiding premature crosslinking that could lead to film defects.

[0041] After the semi-cured gel layer forms, it is transferred to a hot-pressing platform, where a constant pressure is applied at a set temperature and maintained for a period of time. This promotes further densification of the gel network, eliminates internal micropores, and enhances the ordered stacking of molecular chains, thereby constructing a dense network structure. Subsequently, it is slowly cooled to room temperature under maintained pressure to stabilize and lock the network structure, ultimately completing the curing process and forming a composite resin coating firmly attached to the surface of the battery cell. The entire process can be integrated and implemented in the pretreatment station before the assembly of the power battery module.

[0042] In this embodiment, the above-mentioned scheme achieves uniform film formation and controllable curing of composite slurry on the surface of battery cells through a multi-step synergistic process of high-frequency oscillation atomization, directional spraying, step-temperature crosslinking, and constant-temperature pressure densification. The resulting composite resin coating has good adhesion, density, and thermal response, providing a structural prerequisite for foaming insulation behavior when thermal runaway is triggered.

[0043] In a specific embodiment, the composite slurry is coated onto the surface of the battery cell, and after curing, a composite resin coating is formed, including: The composite slurry is applied to the surface of the battery cell by ultrasonic atomization spraying to form a uniform liquid film. Based on the surface contour of the battery cell, the uniform liquid film is subjected to infrared thermal radiation to initiate a cross-linking reaction, forming a primary cross-linked gel layer. The primary cross-linked gel layer is then subjected to interfacial coordination bonding treatment to form an anchored network structure. The anchoring mesh structure is subjected to a stepped temperature program to remove the solvent, resulting in a non-porous solid layer. The non-porous solid layer is then annealed to release stress and set the shape. After curing, the composite resin coating is formed.

[0044] Specifically, to coat the composite slurry onto the surface of the battery cell and ultimately form a composite resin coating, the following operations must be completed sequentially: ultrasonic atomization spraying, infrared thermal radiation crosslinking, interfacial coordination anchoring, stepped temperature desolvation, and annealing and shaping. First, the aforementioned composite slurry is introduced into an ultrasonic atomization nozzle, where high-frequency ultrasonic vibration breaks the slurry into fine droplets. These droplets are then uniformly sprayed onto the outer surface of the battery cell using a carrier gas, thereby forming a continuous and uniform liquid film with controllable thickness. This method is particularly suitable for soft-pack or square cells with curved or angular structures, avoiding edge accumulation or incomplete coverage caused by traditional scraping coating.

[0045] Subsequently, based on the actual geometric contours of the battery cell surface, the position and power density of the infrared thermal radiation source are adjusted to trigger the cross-linking reaction of the thermosensitive groups in the dynamic cross-linking resin under localized heating conditions, thereby forming a primary cross-linked gel layer. This process is not overall heating, but rather regional energy input based on surface morphology, ensuring that even complex structural regions can achieve sufficient cross-linking. On this basis, a metal ion-containing compound (such as Zn²⁺) is applied to the primary cross-linked gel layer. + or Fe³ + The coating is treated with steam or dilute solution to allow it to coordinate with the coordinating functional groups (such as carboxyl and pyridyl groups) in the resin network, thereby constructing an anchoring network structure between the coating and the cell surface, which significantly improves adhesion and interface stability.

[0046] Next, the sample with the anchored mesh structure is placed in a programmable temperature-controlled oven, and the temperature is gradually increased according to a preset stepped heating curve. This allows the residual organic solvent to slowly escape in stages at different temperature intervals, avoiding micropores or cracks caused by rapid evaporation, ultimately obtaining a dense and non-porous solid layer. Afterward, this non-porous solid layer is annealed in an environment slightly below its glass transition temperature for several hours to relax internal thermal stress and molecular chain orientation, achieving structural fixation. The entire process can be integrated and implemented in the coating station before module encapsulation.

[0047] In this embodiment, the above-mentioned scheme achieves high adhesion, strong interfacial bonding and low defect rate curing of composite resin coating on the surface of battery cell through multi-level process coupling of ultrasonic atomization film formation, contour matching infrared crosslinking, interface coordination anchoring, step desolvation and annealing, providing a structurally complete and thermodynamically stable substrate for subsequent thermal response foaming behavior.

[0048] In a specific embodiment, based on the contour of the surface of the battery cell, the uniform liquid film is subjected to an infrared thermal radiation-induced crosslinking reaction to form a primary crosslinked gel layer, including: Polarization interferometric ranging is performed on the surface contour of the battery cell to obtain a surface topography point cloud, and curvature normal analysis is performed on the surface topography point cloud to obtain a spatial contour matrix. Based on the spatial contour matrix, the heat flux of the uniform liquid film is inverted to obtain the targeted radiation spectrum, and the targeted radiation spectrum is modulated by a pixel-level optical valve to obtain a dynamic infrared light field. The uniform liquid film is thermally excited by the dynamic infrared light field in multiple bands to obtain a local cross-linked network, and the chain segment polymerization extension is carried out based on the local cross-linked network to obtain the primary cross-linked gel layer.

[0049] Specifically, in the implementation process, firstly, polarization interferometry ranging is performed on the surface contour of the battery cell. This operation involves introducing orthogonally polarized beams and recording their phase difference after reflection from the curved surface of the battery casing, thereby obtaining a high-density surface topography point cloud. Subsequently, curvature normal analysis is performed on this surface topography point cloud, that is, a local differential geometric neighborhood is constructed with each sampling point as the center, the principal curvature direction and its corresponding normal vector are calculated, and finally the geometric information of all points is integrated into a three-dimensional spatial contour matrix. Next, based on this spatial contour matrix, heat flux inversion calculation is performed on the uniform liquid film: since the liquid film thickness varies in different curvature regions, the heat conduction path length changes accordingly. Therefore, a thermal resistance model needs to be established based on the local curvature radius and normal tilt angle, and the required infrared radiation energy density for each region is deduced by combining Fourier's law of thermal conduction, thereby generating a targeted radiation energy spectrum.

[0050] Based on this, a programmable liquid crystal light valve array is used to perform pixel-level modulation of the targeted radiation spectrum. That is, the transmittance of the corresponding pixel is dynamically adjusted according to the energy value of each spatial position in the spectrum, thereby forming a dynamic infrared light field that strictly matches the geometric features of the battery surface. Subsequently, multi-band thermal excitation is applied to the uniform liquid film through this dynamic infrared light field—for example, a mid-infrared band with a wavelength of 3.4 μm is used in high-curvature protrusion areas to enhance surface absorption, and a 2.9 μm band is superimposed in low-curvature flat areas to promote deep penetration—to selectively activate the photosensitive crosslinking agent inside the liquid film at different depths, forming a non-uniform but structurally continuous local crosslinking network. These local crosslinking networks further undergo polymerization and extension through segment diffusion and free radical coupling reactions, ultimately constructing a primary crosslinked gel layer with controllable thickness gradient and adaptive crosslinking density on the surface of the battery cell in situ.

[0051] In this embodiment, the above scheme achieves precise spatial guidance of the infrared crosslinking reaction through a series of tightly coupled operations: polarization interferometric ranging, curvature normal analysis, heat flux inversion, pixel-level light valve modulation, and multi-band thermal excitation. This not only avoids the over-crosslinking or under-crosslinking defects caused by traditional overall irradiation, but also ensures the adhesion and thermal response consistency of the gel layer on complex curved surfaces.

[0052] In a specific embodiment, based on the surface temperature, heat conduction is performed on the solid-liquid phase change material within the composite resin coating, causing the solid-liquid phase change material to melt into a liquid phase material, including: Spatial partial derivative calculation is performed on the surface temperature of the battery cell to extract the extreme points of heat flux density, and the physical boundary corresponding to the extreme points of heat flux density is defined as a local hot spot region. Calculate the spatial temperature distribution of the local hot spot region and solve for the first-order partial derivatives of the spatial temperature distribution along the coordinate axis to obtain the temperature gradient vector; Based on the temperature gradient vector of the local hot spot region, the phonon transport trajectory inside the composite resin coating is vector-mapped to form a directional heat conduction link between the local hot spot region and the phase change microsphere. Along the directional heat transfer path, the transient heat flow of the local hot spot region is introduced into the porous framework of the phase change microspheres; Based on the porosity and thermal conductivity of the porous framework, lattice vibration frequency matching calculations are performed on the transient heat flow to screen out the low-frequency phonon bands that resonate with the porous framework. A low-resistance thermal conductivity region is determined within the porous skeleton based on the low-frequency phonon band. Within the low-resistivity thermal conduction region, the enthalpy integral of the solid-liquid phase change material filled in the porous framework is calculated. When the cumulative enthalpy value exceeds the latent heat threshold of the solid-liquid phase change material, the lattice deconstruction of the solid-liquid phase change material is triggered, causing the solid-liquid phase change material to undergo a phase transition and melt into a liquid phase material.

[0053] Specifically, during the operation of a single battery cell, its surface temperature distribution is not uniform. Therefore, directional thermal activation of the solid-liquid phase change material within the composite resin coating needs to be implemented based on the measured or simulated temperature field. First, real-time temperature data of the battery cell surface is collected, and spatial partial derivative calculations are performed on this temperature field. By calculating the heat flux vector divergence at each point, the locations of local maxima of heat flux density are identified. These locations are defined as extreme points of heat flux density, and their corresponding physical boundaries are further delineated as local hotspot regions, serving as key targets for subsequent thermal management interventions.

[0054] Subsequently, a three-dimensional temperature spatial distribution model was constructed for the designated local hotspot region, and the first-order partial derivatives of this distribution were solved along the x, y, and z directions of the Cartesian coordinate system to obtain the temperature gradient vector characterizing the direction and intensity of heat transfer. This vector not only indicates the natural flow trend of heat from the high-temperature region to the low-temperature region but also provides guidance for the phonon transport path in the composite resin coating. Based on this, the temperature gradient vector was coupled with the internal microstructure of the coating, and vector mapping was performed on the phonon transport trajectory to align the phonon propagation direction with the principal axis of heat flow, thereby establishing a directional heat conduction link between the local hotspot region and the embedded phase change microspheres.

[0055] Along this directional heat conduction path, transient heat flow is efficiently introduced into the porous framework of the phase change microspheres. This porous framework is typically composed of a cross-linked polymer network, possessing controllable porosity and intrinsic thermal conductivity. At this point, frequency domain analysis of the lattice vibration modes excited by the incident heat flow is performed, taking into account the structural parameters of the porous framework. Specifically, the transient heat flow is decomposed into phonon components of different frequencies, and matched with the phonon dispersion relation of the porous framework to screen out the low-frequency phonon bands that can resonate with the framework. Because these low-frequency phonons are compatible with the framework's lattice vibration modes, they can propagate within it with low scattering loss, thereby forming a low-resistivity thermal conductivity region within the porous framework.

[0056] Within the low-resistivity thermal conductivity region, the solid-liquid phase change material (PCM) fills the channels of a porous framework. As low-frequency phonons continuously input energy, the enthalpy integral of the heat input process in this region needs to be calculated, i.e., the cumulative summation of the heat absorbed per unit mass of PCM over time. When this cumulative enthalpy reaches or exceeds the latent heat threshold of the PCM, the molecular lattice structure within the material begins to destabilize and decompose, macroscopically manifesting as a phase transition from solid to liquid. This entire process can occur in scenarios where high-rate charging and discharging of power batteries causes localized temperature rises, without the need for an external heating source.

[0057] In this embodiment, the above scheme achieves precise and on-demand activation of phase change materials in composite resin coatings through a multi-scale thermal control mechanism that identifies hot spots through spatial deflection, guides phonons through temperature gradient, constructs low-resistivity channels through low-frequency resonance, and triggers phase change through enthalpy integration. This ensures that thermal energy is efficiently absorbed only in the local areas where heat absorption is truly needed, avoiding material waste and response lag caused by global ineffective phase change.

[0058] In a specific embodiment, when the steady-state temperature reaches or exceeds the dissociation temperature of the dynamically cross-linked resin, the cross-linking network of the dynamically cross-linked resin softens, forming a viscoelastic softened matrix. Simultaneously, the liquid phase material vaporizes within the composite resin coating to form a vaporization medium, including: When the steady-state temperature reaches or exceeds the dissociation temperature of the dynamic crosslinking resin, the reversible covalent bonds of the dynamic crosslinking resin in the composite resin coating undergo a reverse reaction and disintegrate under thermal activation. Based on the overheating deviation between the steady-state temperature and the dissociation temperature, the reversible covalent bonds are broken in a nonlinear incremental manner, so that the effective crosslinking density of the crosslinking network forms a gradient decay distribution along the thickness direction of the composite resin coating. When the effective crosslinking density drops below the percolation critical threshold, the storage modulus of the dynamic crosslinking resin falls to the viscosity-flow transition range, and the crosslinking network transforms into a viscoelastic softening matrix, wherein the porous skeleton inside the viscoelastic softening matrix remains in a rigid support state. During the formation of the viscoelastic softened matrix, heat is continuously conducted to the liquid phase material retained in the porous framework, causing the temperature of the liquid phase material to exceed its saturation boiling point and form a superheated liquid film. Heterogeneous nucleation is excited between the superheated liquid film and the pore wall surface of the porous skeleton, generating vapor bubble nuclei at the pore wall surface. Under the superheated driving force provided by the superheated liquid film, the vapor bubble nuclei grow radially and aggregate to form discrete gas phase domains filling the pores of the porous skeleton. Based on the endogenous vapor pressure generated by the discrete gas phase domain, when the endogenous vapor pressure overcomes the capillary constraint force at the pore opening of the porous skeleton, the vapor in the discrete gas phase domain escapes through the pore opening of the porous skeleton into the viscoelastic softened matrix surrounding the porous skeleton. In the region where the endogenous vapor pressure exceeds the local yield stress of the viscoelastic softening matrix, vapor bubble nuclei expand and interconnect along the low-modulus interconnection path in the viscoelastic softening matrix, forming the vaporization medium dispersed within the composite resin coating.

[0059] Specifically, when the steady-state temperature of the battery cell surface reaches or exceeds the dissociation temperature of the dynamically cross-linked resin, a series of thermally induced structural evolutions occur within the composite resin coating. At this time, the reversible covalent bonds contained in the dynamically cross-linked resin (such as Diels-Alder adducts, disulfide bonds, or borate ester bonds) initiate a reverse reaction under thermal activation, gradually disintegrating. This disintegration process does not occur uniformly, but is regulated according to the overheating deviation between the steady-state temperature and the dissociation temperature: the greater the overheating deviation, the more non-linearly increasing the number of reversible covalent bonds broken per unit time becomes, resulting in a gradient decay distribution of the effective cross-linking density of the cross-linked network from the coating surface to the inner layer along the thickness direction.

[0060] As the effective crosslinking density continues to decrease, once its value falls below the percolation critical threshold (typically corresponding to the critical point where the three-dimensional network loses its continuity), the storage modulus of the dynamically crosslinked resin rapidly drops into the viscosity-flow transition range. Macroscopically, this manifests as the softening of the crosslinked network and its transformation into a viscoelastic softened matrix. Notably, during this process, the porous framework embedded in the matrix, due to its high thermal stability, maintains a rigid support state without significant deformation or collapse, thus providing a structural framework for subsequent gas phase generation.

[0061] As the viscoelastic softened matrix forms, heat continues to conduct into the porous framework, causing the temperature of the retained liquid phase material to rise continuously. When the temperature of the liquid phase material exceeds its saturation boiling point, a metastable superheated liquid film is formed. At this point, heterogeneous nucleation excitation occurs between the pore wall surface of the porous framework (which typically contains polar groups such as hydroxyl and carboxyl groups) and the superheated liquid film, promoting the preferential formation of vapor bubble nuclei at pore wall defects or chemically active sites. These vapor bubble nuclei grow rapidly radially under the driving force of superheating and aggregate with neighboring nuclei, ultimately forming discrete gas-phase domains filling the pores of the porous framework.

[0062] As vapor is continuously generated, the pressure inside the discrete gas phase domain continues to accumulate. When this endogenous vapor pressure is sufficient to overcome the capillary constraint force at the pore openings of the porous framework, determined by both surface tension and pore size, the vapor escapes from the pore openings and enters the viscoelastic softened matrix surrounding the porous framework. If the endogenous vapor pressure in a local area further exceeds the yield stress of the viscoelastic softened matrix at that location, the vapor nuclei will expand along the connecting paths with lower modulus in the matrix, forming continuous or semi-continuous gas phase channels through mutual interconnection, and ultimately dispersing within the composite resin coating, constituting the vaporization medium.

[0063] In this embodiment, the above scheme achieves in-situ generation of a high-porosity vaporization medium in the early stage of battery thermal runaway through a multi-physics coupling mechanism of thermally controlled crosslinking dissociation, gradient network softening, heterogeneous nucleation, capillary breakthrough, and yield-driven gas phase penetration. This not only preserves the structural integrity of the porous framework but also utilizes the low modulus characteristics of the viscoelastic softening matrix to promote gas phase expansion, laying the microstructural foundation for the subsequent formation of the thermal insulation expansion layer.

[0064] In a specific embodiment, the step of foaming and expanding the viscoelastic softened matrix based on the vaporization medium to form a thermal barrier between battery cells includes: An isotropic gas pressure is applied to the viscoelastic softening matrix according to the phase change expansion volume of the gasification medium, causing the viscoelastic softening matrix to undergo tensile rheology, resulting in a closed-cell bubble array. Based on the porous framework, the interfacial stress of the closed-cell bubble array is dispersed to form a bubble wall support network, and the closed-cell bubble array is shaped in three-dimensional space according to the bubble wall support network to form an expansion insulation layer. The expansion insulation layer is directionally extended and extruded along the gap between the battery cells, so that the expansion insulation layer physically bridges the outer shell boundary of the adjacent battery cells, forming the heat insulation barrier.

[0065] Specifically, in the implementation process, after the vaporization medium is generated inside the composite resin coating, its phase change expansion volume applies isotropic internal gas pressure to the surrounding viscoelastic softening matrix. This gas pressure acts on the not-yet-fully-flowed polymer network, causing the viscoelastic softening matrix to undergo tensile rheological behavior, that is, to extend uniformly in all directions under the pressure of the gas phase, thereby forming a closed-cell array composed of closed bubbles. This process relies on the characteristic that the viscoelastic softening matrix has both a certain degree of fluidity and elastic recovery ability within a specific temperature range, making it difficult for the bubbles to rupture or merge during expansion, thus maintaining structural integrity.

[0066] Subsequently, the porous framework embedded in the matrix plays a crucial supporting role for the bubble walls of the closed-cell bubble array. Due to the rigidity and continuous distribution of the porous framework, it effectively disperses localized stress concentrations caused by gas pressure at the bubble wall interface, preventing localized tearing or collapse of the bubble walls and thus forming a stable bubble wall support network. This support network not only enhances the mechanical stability of individual bubbles but also constrains the deformation freedom of the entire closed-cell bubble array through spatial interconnection. Based on this, the closed-cell bubble array is three-dimensionally shaped according to the spatial configuration of the support network, solidifying it under the combined action of thermal and stress fields into an expanding insulating layer with fixed pore size and porosity.

[0067] Finally, utilizing the plasticity of the expanded insulation layer at high temperatures, it is directionally stretched and extruded along the gap between adjacent battery cells. This operation can be achieved through a preset limiting structure of the module packaging fixture, allowing the expanded insulation layer to flow into the gap region under controlled pressure and fully fill the voids, ultimately physically bridging the shell boundaries of adjacent battery cells to form a continuous, dense insulation barrier with low thermal conductivity. The entire process requires no additional foaming agent or external gas source, relying entirely on the in-situ vaporization medium generated within the coating.

[0068] In this embodiment, the above-mentioned scheme achieves adaptive generation and precise positioning of the thermal barrier under the condition of battery thermal runaway triggering through a synergistic mechanism of gasification medium-driven tensile rheology, porous skeleton-induced interface stress dispersion, three-dimensional shaping, and directional extrusion bridging. This effectively blocks the thermal propagation path between adjacent cells while maintaining structural stability and interface adhesion.

[0069] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention. It should be noted that the information interaction, execution process, etc. between the above devices / units are based on the same concept as the method embodiments of this application. Their specific functions and technical effects can be found in the embodiment section of the control device, and will not be repeated here.

[0070] Please see Figure 2 , Figure 2 This is a schematic diagram of the framework of an embodiment of the battery thermal management system of this application. Figure 2 As shown, the battery thermal management device includes a mixing module 1, which is used to mix phase change microspheres with dynamic crosslinking resin in advance to form a composite slurry, and then coat the composite slurry on the surface of the battery cell. After curing, a composite resin coating is formed. The phase change microspheres include a porous skeleton and a solid-liquid phase change material filled in the porous skeleton. The heat conduction module 2 is used to conduct heat to the solid-liquid phase change material in the composite resin coating according to the surface temperature when the surface temperature of the battery cell rises, so that the solid-liquid phase change material melts into a liquid phase material. Cooling module 3 is used to absorb heat and cool the battery cell based on the liquid phase material to obtain a steady-state temperature; wherein, the steady-state temperature is a constant temperature value maintained by the surface temperature of the battery cell when it reaches a dynamic thermal equilibrium due to internal heat generation and external heat dissipation during continuous charging and discharging or high-rate operation, and the constant temperature value is within the phase change temperature range of the solid-liquid phase change material and is lower than the critical temperature of battery thermal runaway. The softening and vaporization module 4 is used to soften the cross-linking network of the dynamic cross-linking resin when the steady-state temperature reaches or exceeds the dissociation temperature of the dynamic cross-linking resin, forming a viscoelastic softened matrix, while the liquid phase material vaporizes inside the composite resin coating to form a vaporization medium. The expansion module 5 is used to foam and expand the viscoelastic softened matrix based on the gasification medium to form a thermal barrier between battery cells.

[0071] The above module is used to perform the steps of the battery thermal management method described above.

[0072] Reference Figure 3 This invention also provides a computer device whose internal structure can be as follows: Figure 3 As shown, the computer device includes a processor, memory, display screen, input device, network interface, and database connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores the data corresponding to this embodiment. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements the above-described method.

[0073] Those skilled in the art will understand that Figure 3 The structures shown are merely block diagrams of some structures related to the present invention and do not constitute a limitation on the computer devices on which the present invention is applied.

[0074] An embodiment of the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method. It is understood that the computer-readable storage medium in this embodiment can be a volatile readable storage medium or a non-volatile readable storage medium.

[0075] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the present invention and embodiments can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual-rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM, etc.

[0076] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0077] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A battery thermal management method, characterized in that, include: Phase change microspheres are mixed with dynamic crosslinking resin in advance to form a composite slurry, and the composite slurry is coated on the surface of the battery cell. After curing, a composite resin coating is formed. The phase change microspheres include a porous framework and a solid-liquid phase change material filled in the porous framework. When the surface temperature of the battery cell rises, the solid-liquid phase change material in the composite resin coating is subjected to heat conduction according to the surface temperature, so that the solid-liquid phase change material melts into a liquid phase material. The battery cell is cooled by absorbing heat using the liquid phase material to obtain a steady-state temperature. The steady-state temperature is the constant temperature value maintained by the surface temperature of the battery cell when it reaches a dynamic thermal equilibrium due to internal heat generation and external heat dissipation during continuous charging and discharging or high-rate operation. The constant temperature value is within the phase change temperature range of the solid-liquid phase change material and is lower than the critical temperature of battery thermal runaway. When the steady-state temperature reaches or exceeds the dissociation temperature of the dynamic crosslinking resin, the crosslinking network of the dynamic crosslinking resin softens to form a viscoelastic softened matrix, while the liquid phase material vaporizes inside the composite resin coating to form a vaporization medium. The viscoelastic softened matrix is ​​foamed and expanded based on the vaporization medium to form a thermal barrier between battery cells.

2. The battery thermal management method according to claim 1, characterized in that, A composite slurry is prepared by pre-mixing phase change microspheres with a dynamically cross-linked resin, comprising: The phase change microspheres are stirred and coated with a coupling agent to obtain modified microsphere powder, and the modified microsphere powder is shaken with an organic solvent to obtain a microsphere dispersion. The microsphere dispersion and the dynamic crosslinking resin are subjected to high-speed shearing to obtain a homogeneous mixture. A dynamic crosslinking agent is then added to the homogeneous mixture for vacuum degassing to obtain the composite slurry.

3. The battery thermal management method according to claim 1, characterized in that, The composite slurry is applied to the surface of the battery cell, and after curing, it forms a composite resin coating, including: The composite slurry is subjected to high-frequency oscillation atomization to obtain micron-sized atomized droplets, and the surface of the battery cell is directionally sprayed and deposited based on the micron-sized atomized droplets to obtain an attached liquid film layer. The attached liquid film layer is heated in a stepped manner to form a solvent evaporation coating, and in-situ thermally initiated crosslinking is performed based on the solvent evaporation coating to form a semi-cured gel layer; The semi-cured gel layer is subjected to constant temperature and pressure treatment to form a dense network structure, and then cooled and shaped based on the dense network structure to form the composite resin coating after curing.

4. The battery thermal management method according to claim 1, characterized in that, The composite slurry is applied to the surface of the battery cell, and after curing, it forms a composite resin coating, including: The composite slurry is applied to the surface of the battery cell by ultrasonic atomization spraying to form a uniform liquid film. Based on the surface contour of the battery cell, the uniform liquid film is subjected to infrared thermal radiation to initiate a cross-linking reaction, forming a primary cross-linked gel layer. The primary cross-linked gel layer is then subjected to interfacial coordination bonding treatment to form an anchored network structure. The anchoring mesh structure is subjected to a stepped temperature program to remove the solvent, resulting in a non-porous solid layer. The non-porous solid layer is then annealed to release stress and set the shape. After curing, the composite resin coating is formed.

5. The battery thermal management method according to claim 1, characterized in that, Based on the surface temperature, heat conduction is performed on the solid-liquid phase change material within the composite resin coating to melt the solid-liquid phase change material into a liquid phase material, including: Spatial partial derivative calculation is performed on the surface temperature of the battery cell to extract the extreme points of heat flux density, and the physical boundary corresponding to the extreme points of heat flux density is defined as a local hot spot region. Calculate the spatial temperature distribution of the local hot spot region and solve for the first-order partial derivatives of the spatial temperature distribution along the coordinate axis to obtain the temperature gradient vector; Based on the temperature gradient vector of the local hot spot region, the phonon transport trajectory inside the composite resin coating is vector-mapped to form a directional heat conduction link between the local hot spot region and the phase change microsphere. Along the directional heat transfer path, the transient heat flow of the local hot spot region is introduced into the porous framework of the phase change microspheres; Based on the porosity and thermal conductivity of the porous framework, lattice vibration frequency matching calculations are performed on the transient heat flow to screen out the low-frequency phonon bands that resonate with the porous framework. A low-resistance thermal conductivity region is determined within the porous skeleton based on the low-frequency phonon band. Within the low-resistivity thermal conduction region, the enthalpy integral of the solid-liquid phase change material filled in the porous framework is calculated. When the cumulative enthalpy value exceeds the latent heat threshold of the solid-liquid phase change material, the lattice deconstruction of the solid-liquid phase change material is triggered, causing the solid-liquid phase change material to undergo a phase transition and melt into a liquid phase material.

6. The battery thermal management method according to any one of claims 1-5, characterized in that, When the steady-state temperature reaches or exceeds the dissociation temperature of the dynamically cross-linked resin, the cross-linking network of the dynamically cross-linked resin softens, forming a viscoelastic softened matrix. Simultaneously, the liquid phase material vaporizes within the composite resin coating to form a vaporization medium, including: When the steady-state temperature reaches or exceeds the dissociation temperature of the dynamic crosslinking resin, the reversible covalent bonds of the dynamic crosslinking resin in the composite resin coating undergo a reverse reaction and disintegrate under thermal activation. Based on the overheating deviation between the steady-state temperature and the dissociation temperature, the reversible covalent bonds are broken in a nonlinear incremental manner, so that the effective crosslinking density of the crosslinking network forms a gradient decay distribution along the thickness direction of the composite resin coating. When the effective crosslinking density drops below the percolation critical threshold, the storage modulus of the dynamic crosslinking resin falls to the viscosity-flow transition range, and the crosslinking network transforms into a viscoelastic softening matrix, wherein the porous skeleton inside the viscoelastic softening matrix remains in a rigid support state. During the formation of the viscoelastic softened matrix, heat is continuously conducted to the liquid phase material retained in the porous framework, causing the temperature of the liquid phase material to exceed its saturation boiling point and form a superheated liquid film. Heterogeneous nucleation is excited between the superheated liquid film and the pore wall surface of the porous skeleton, generating vapor bubble nuclei at the pore wall surface. Under the superheated driving force provided by the superheated liquid film, the vapor bubble nuclei grow radially and aggregate to form discrete gas phase domains filling the pores of the porous skeleton. Based on the endogenous vapor pressure generated in the discrete gas phase domain, when the endogenous vapor pressure overcomes the capillary constraint force at the pore opening of the porous skeleton, the vapor in the discrete gas phase domain escapes through the pore opening of the porous skeleton into the viscoelastic softened matrix surrounding the porous skeleton. In the region where the endogenous vapor pressure exceeds the local yield stress of the viscoelastic softening matrix, vapor bubble nuclei expand and interconnect along the low-modulus interconnection path in the viscoelastic softening matrix, forming the vaporization medium dispersed within the composite resin coating.

7. The battery thermal management method according to claim 1, characterized in that, The process of foaming and expanding the viscoelastic softened matrix based on the vaporization medium to form a thermal barrier between battery cells includes: An isotropic gas pressure is applied to the viscoelastic softening matrix according to the phase change expansion volume of the gasification medium, causing the viscoelastic softening matrix to undergo tensile rheology, resulting in a closed-cell bubble array. Based on the porous framework, the interfacial stress of the closed-cell bubble array is dispersed to form a bubble wall support network, and the closed-cell bubble array is shaped in three-dimensional space according to the bubble wall support network to form an expansion insulation layer. The expansion insulation layer is directionally extended and extruded along the gap between the battery cells, so that the expansion insulation layer physically bridges the outer shell boundary of the adjacent battery cells, forming the heat insulation barrier.

8. A battery thermal management system, characterized in that, include: A mixing module is used to pre-mix phase change microspheres with dynamic cross-linking resin to form a composite slurry, and then coat the composite slurry onto the surface of the battery cell. After curing, a composite resin coating is formed. The phase change microspheres include a porous framework and a solid-liquid phase change material filled in the porous framework. A heat conduction module is used to conduct heat to the solid-liquid phase change material in the composite resin coating when the surface temperature of the battery cell rises, so that the solid-liquid phase change material melts into a liquid phase material. The cooling module is used to absorb heat and cool the battery cell based on the liquid phase material to obtain a steady-state temperature. The steady-state temperature is a constant temperature value maintained by the surface temperature of the battery cell when it reaches a dynamic thermal equilibrium due to internal heat generation and external heat dissipation during continuous charging and discharging or high-rate operation. The constant temperature value is within the phase change temperature range of the solid-liquid phase change material and is lower than the critical temperature of battery thermal runaway. The softening and vaporization module is used to soften the crosslinking network of the dynamic crosslinking resin when the steady-state temperature reaches or exceeds the dissociation temperature of the dynamic crosslinking resin, forming a viscoelastic softened matrix, while the liquid phase material vaporizes inside the composite resin coating to form a vaporization medium. An expansion module is used to foam and expand the viscoelastic softened matrix based on the vaporization medium to form a thermal barrier between battery cells.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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