770 results about "Thermal safety" patented technology

The invention discloses a ternary internet-of-things battery management system, particularly relates to the technical field of lithium battery management, realizes lithium battery thermal safety closed-loop management through multi-sensor fusion, and comprises the following steps: deploying a digital sensor array to obtain time-space associated data; constructing a spatio-temporal feature vector including fusion of a local temperature gradient, a neighborhood temperature gradient and a stress coupling ratio; a density clustering algorithm is adopted to dynamically divide spontaneous heating, radiant heat and stress coupling clusters, and cluster boundaries are updated in real time; calculating a dual thermal coupling coefficient based on a clustering result, and eliminating the interference of temperature reading through a dual temperature compensation formula; a three-level alarm mechanism of a radiant heat proportion, a stress coupling degree and a compensation error is established, a side gateway is linked to realize parameter adaptive optimization, and the thermal runaway early warning precision and the structural failure detection rate are improved; strain monitoring resource optimization is realized through physically-driven key point screening and dynamic graph neural network prediction.

The invention relates to an intelligent energy-saving method for a large building refrigerating system based on a large language model, and belongs to the field of intelligence of large building refrigerating systems. A reinforcement learning framework is constructed, a multi-dimensional state space formed by building thermal loads, equipment operation states and thermal environment parameters is defined, and a dynamic reward mechanism is designed by taking improvement of energy efficiency, guarantee of thermal safety constraints and maintenance of thermal comfort as optimization objectives; developing a word embedding model special for the refrigeration field and a cross-modal decision conversion model, and realizing bidirectional analysis of a natural language instruction and a physical control parameter through feature coding and embedding mapping; and performing low-rank adaptive fine tuning on the pre-trained large language model based on the reinforcement learning experience set, and constructing a closed-loop verification system. Generalized migration and multi-target collaborative decision-making of equipment control strategies are achieved, the self-adaptive regulation and control capacity of a refrigeration system under dynamic loads is improved, and a universal intelligent solution for energy efficiency optimization, thermal safety and comfort is provided for a large building.

The invention relates to the field of battery materials, in particular to a battery cell and an electrochemical device comprising the battery cell, the battery cell comprises a positive pole piece, a negative pole piece, electrolyte and a diaphragm located between the positive pole piece and the negative pole piece; the diaphragm comprises a first coating and a second coating of a base membrane, the first coating is located on the surface of one side of the base membrane and faces the positive pole piece, the second coating is located on the surface of the other side of the base membrane and faces the negative pole piece, and the first coating and the second coating both comprise a first element and a second element; the difference between the mass content ratio b of the first element to the second element on the surface of the second coating and the mass content ratio a of the first element to the second element on the surface of the first coating is controlled to meet a certain range, so that the battery has long circulation and excellent thermal safety performance.

The invention relates to a soft package lithium battery internal and external temperature real-time monitoring method, which comprises the following steps of: in a soft package battery packaging process, implanting a plurality of superfine thermocouples into a key area in a battery to obtain a temperature change condition in the battery; the key area comprises an area below the current collector, a maximum thickness position and an area close to the bottom of the shell; meanwhile, a plurality of distributed temperature measuring points are arranged on the outer surface of the battery, superfine thermocouples are arranged respectively, a distributed monitoring network is formed, and the temperature change condition outside the battery is obtained; the proportion of the total volume of the implanted superfine thermocouple to the internal space of the battery is lt; 0.03% by weight; temperature data are recorded in real time through high-precision acquisition equipment, the sampling frequency is adjustable, and the temperature error does not exceed + / -0.01 DEG C. By optimizing a sensor arrangement strategy, the original performance of the battery is maintained to the maximum extent while accurate temperature monitoring is achieved, and the method is suitable for temperature field accurate management and thermal safety control in the fields of power batteries, energy storage batteries and the like.

A vehicle battery protection device for preserving the charge of the vehicle battery is electrically connectable between a vehicle battery and a vehicle electrical system. The device includes a solid-state switch commandable between an on state and an off state. A thermal safety algorithm executable by the device may include a switch derating process, a thermal analysis calibration, a vehicle profile function, and a data reconciliation function. The device employs hardware and software solutions to reduce the risk of thermal runaways and component failures in the device, while maximizing its useful operating envelope. The software solutions may include predicting future thermal loads for the device based on vehicle usage patterns specific to the vehicle within which the device is installed. Those predictions may be used to generate risk datasets which influence whether and to what extent thermal mitigation measures will be employed by the device at any point in time.

The invention discloses a thermal management control method for a power battery. The method comprises the following steps: establishing a basic model for calculating heating and cooling of the battery; basic control logic is set, and the basic model is substituted into different temperatures to select different control modes; data management and analysis including real-time state monitoring, historical data calling, cloud platform data calling and big data comparison rule searching; a model learning algorithm is introduced, historical working conditions, environmental parameters and user behavior data are fused, the system temperature trend is predicted, and temperature management is started in advance; a temperature control model is dynamically optimized through big data; the optimal energy consumption of the control temperature is used as a target function; and 5) fault early warning: obtaining characteristic laws of temperature, voltage, time and the like during a thermal event and each fault event, and realizing early warning when the vehicle has similar characteristics. According to the invention, temperature uniformity control in the whole life cycle of the power battery can be realized, the service life of the battery is prolonged, and timely early warning can be carried out on thermal safety control.

The invention discloses a lithium battery thermal parameter online monitoring method and equipment. According to the method, a one-dimensional heat transfer model of the battery is established, and a finite element model is solved by inversion of battery surface temperature change actually measured in operation, so that combined monitoring of the heat conductivity coefficient, the convective heat transfer coefficient, the average temperature and the heat production power P of the lithium battery is realized. Meanwhile, only the temperature sensor needs to be arranged on the surface of the battery, the battery does not need to be disassembled or an internal sensor does not need to be implanted, the battery integrity is kept, and the method is suitable for battery full-life-cycle monitoring. According to the method, the key thermal parameters of the lithium battery can be identified online in a non-intrusive, low-cost and high-reliability manner, support is provided for thermal management, health assessment and thermal safety early warning of the battery, and the method is suitable for various battery configurations and thermal management systems.

Provided are a coating composition, a separator, an electrochemical device, and an electronic device, the coating composition including a fiber material, filler particles, and a binder, the fiber material including at least one of a first inorganic ceramic or a first organic matter containing a miscellaneous element, the fiber material comprises at least one of a first inorganic ceramic and a second organic matter containing a hetero-element, the filler particles comprise at least one of a second inorganic ceramic and a second organic matter containing a hetero-element, at least one of the fiber material and the filler particles is an organic matter containing a hetero-element, the hetero-element comprises a nitrogen element or / and a phosphorus element, and the mass percentage of the hetero-element is 10%-60% based on the mass of the coating composition. When the coating composition is applied to the diaphragm, the diaphragm is coated with the coating composition to form a coating, so that the thermal safety and high-temperature cycle performance of the electrochemical device are improved.

The invention discloses a battery evaluation method based on safety area modeling, and belongs to the technical field of battery safety. The method comprises the following steps: acquiring running state data of a battery, wherein the running state data comprises current density, battery temperature and battery charge state; the operation state data are input into a force-heat-electricity safety boundary model, the safety radius of the operation state data in the safety space is obtained, and the force-heat-electricity safety boundary model is a three-dimensional model constructed based on the safety space; the safety space is a three-dimensional space formed based on a force safety model boundary, a thermal safety model boundary and a voltage safety model boundary; based on the safety radius, the safety of the battery is evaluated, and the method improves the safety and reliability of the battery.

The invention provides a pole charging variable flow thermal safety control method and system based on AI multi-objective optimization, and relates to the technical field of pole charging variable flow thermal safety control, and the method comprises the steps: collecting the electrical state quantity and thermodynamic state quantity of a pole charging converter in real time; constructing a digital twinborn model of the polar charging converter; constructing a DRL training environment, and training a DRL intelligent agent; setting a security guard strategy independent of the DRL intelligent agent; the optimal optimization strategy is deployed to a converter control system, and the converter and a cooling system are controlled in real time; and carrying out on-line calibration on key parameters of the digital twin model. According to the method, the digital twinborn model is constructed and the DRL is combined to carry out multi-objective optimization decision making, so that intelligent, accurate and adaptive control on the thermal safety of the electrode charging converter is realized; the digital twin is self-calibrated, so that the thermal management level, the operation efficiency, the reliability and the long-term adaptability to equipment aging and environment change of a converter system are effectively improved.

The invention relates to the technical field of energy storage battery performance detection, and discloses a performance detection device and method for an energy storage battery, and the method comprises the steps: calculating a thermal safety coefficient based on the internal temperature of the battery, the temperature gradient, the Joule heat generation rate and the environment temperature; calculating a voltage safety coefficient based on the battery end voltage, the voltage change rate and the voltage range; according to the thermal safety coefficient, the voltage safety coefficient, the battery expansion strain and the internal pressure, calculating the collaboration reflecting the multi-physical field state coordination; calculating an aging coefficient based on the accumulated current stress, the accumulated cycle index and the high stress duration of the battery; and finally, based on the collaboration, the aging coefficient and the rated current, calculating the target charging and discharging current and performing real-time adjustment. The device comprises a memory and a processor and is used for executing the method. According to the invention, multi-dimensional fusion evaluation and self-adaptive management of thermal, electrical and mechanical states and aging processes of the energy storage battery are realized, and the operation safety and service life of the battery are remarkably improved.

A modified positive electrode material and a preparation method therefor, a positive electrode sheet, and a lithium-ion battery. The modified positive electrode material comprises a positive electrode material serving as a matrix, and a composite coating layer generated in situ on the surface of the matrix. The composite coating layer comprises a spinel phase coating layer disposed on the inner side and a composite nitride coating layer disposed on the outer side, wherein the chemical formula of the composite nitride coating layer is selected from αANβOγ·(1-α)DδEε. The thermal conductivity and electrical conductivity of the modified positive electrode material are effectively improved. Moreover, when used in a lithium-ion battery, the modified positive electrode material has excellent thermal safety and electrochemical performance.

The invention relates to the technical field of liquid-cooled cabinets, and discloses a liquid-cooled cabinet based on a dual-cycle refrigeration system and a use method thereof, and the method comprises the following steps: analyzing graph structure features and evaluating node importance; constructing a calculation precision-energy consumption-temperature three-dimensional correlation model; generating a precision distribution strategy of graph structure perception based on node importance; designing a cooling capacity distribution strategy of the liquid cooling system based on the precision distribution strategy; a precision-cooling capacity combined optimization controller is realized; designing a dynamic graph structure adaptation mechanism; wherein the precision distribution strategy distributes different calculation precision to different nodes in the graph based on node importance scores, the cooling capacity distribution strategy dynamically adjusts the cooling capacity according to thermal load distribution caused by precision distribution, and the precision-cooling capacity joint optimization controller cooperatively adjusts the calculation precision and the cooling capacity distribution according to a real-time system state. Dynamically adapting to graph structure change; the method has the advantages of calculation performance improvement, energy efficiency optimization, thermal safety guarantee, dynamic adaptive capacity and expandability.

The invention provides an immersed battery thermal safety management test system and method, and the system comprises a battery device disposed in an immersion box, and an immersed cooling structure is built through assembly combination. The liquid cooling circulation module is used for driving cooling liquid to flow; the charging and discharging module is used for performing a charging and discharging test or a thermal safety performance test on the battery device; the needling module is used for needling to trigger the working condition of thermal runaway; the electric control module is in signal connection with the liquid cooling circulation module, and monitors and adjusts the flow, the water temperature and the water pressure of the cooling liquid in the liquid cooling circulation module in real time; the data acquisition module is used for acquiring temperature and voltage change characteristics of the battery device; through the system and the method, thermal performance and safety performance tests can be carried out, the test requirements of different types of batteries under various working conditions can be met, the thermal performance and safety of the battery immersed liquid cooling system can be accurately evaluated under various complex working conditions, and powerful data support is provided for thermal management design and optimization of the battery.

The invention provides a high-safety flame-retardant lithium ion battery electrolyte with a low-reactivity coordination structure, and relates to the technical field of energy storage batteries. High-stability bis (fluorosulfonyl) imide lithium salt is used as lithium salt, an ether solvent with weak solvation ability is used as an auxiliary solvent, and an additive is added. The low-reaction-activity solvent and the high-stability salt are adopted to replace high-reaction-activity components in a traditional electrolyte, the proportion of the lithium salt, the solvent and the additive is regulated and controlled to construct the high-safety flame-retardant lithium ion battery electrolyte with a low-reaction-activity coordination structure, and the thermal safety of the battery can be remarkably improved. According to the electrolyte, the self-heat-production reaction rate of an electrolyte-electrode interface and the generation of combustible gas are effectively inhibited, the thermal failure starting temperature and the triggering temperature of the battery are increased, the maximum temperature of thermal runaway is reduced, the intrinsic thermal safety of the high-energy-density lithium ion battery is greatly improved, and the electrolyte is suitable for the high-specific-energy lithium ion battery.

The invention discloses a diaphragm and an electrochemical device, and belongs to the field of electrochemical energy storage. The diaphragm is used for the electrochemical device and comprises a base membrane and a coating arranged on one side or two sides of the base membrane in the thickness direction, the coating comprises a composite phase-change material, the composite phase-change material comprises a conductive polymer layer and a tubular material, the conductive polymer layer partially or completely coats the surface of the tubular material, and the tubular material is coated with the conductive polymer layer. A phase change material is contained in the tube of the tubular material. According to the diaphragm, the high-temperature thermal safety performance of the diaphragm can be improved under the condition that the high-temperature mechanical performance of the diaphragm is not damaged.

The invention provides an energy storage battery liquid cooling dual-mode heat management and battery storage space heat recovery temperature and humidity coordinated regulation and control system and method. The system is composed of a heat pipe cooling module, a steam compression refrigeration cycle module and a module for waste heat recovery and runner regeneration. The heat pipe cooling module and the circulating pump form a natural cooling loop through the liquid cooling plate and the heat pipe heat exchanger; the vapor compression refrigeration cycle module efficiently and rapidly reduces the temperature of cooling liquid through a phase change refrigeration working medium. And the waste heat recovery module uses condensation waste heat for rotary wheel dehumidification regeneration. The system automatically switches double modes according to the temperature of cooling liquid: heat pipe energy-saving cooling is started when the temperature is lower than or equal to 35 DEG C, steam compression refrigeration is switched when the temperature is higher than 35 DEG C, and condensation waste heat of the two modes preheats regenerated air through a heat pipe heat exchanger, then the temperature is supplemented to the regeneration temperature through an electric heater, a rotating wheel is driven to dehumidify, and dry air is fed into a battery cabin. The method gives consideration to energy efficiency and thermal safety, and is suitable for thermal management and space humidity regulation and control of an energy storage battery system.

The invention provides a positive pole piece, an electrochemical device and an electronic device, the positive pole piece comprises a positive current collector, a positive active material layer and a coating, the coating is located on the surface and / or inside the positive active material layer, and the coating comprises an organic compound, the organic compound includes at least one functional group selected from a cyano group, an isonitrile group, an azinyl group, and an isocyanate group, and the thickness of the coating layer is 0.3 [mu] m to 3 [mu] m. The positive pole piece provided by the invention can improve the thermal safety, the high-temperature cycle performance, the high-temperature storage expansion rate and the mechanical safety of the electrochemical device.

The embodiment of the invention provides a method and a device for determining thermal safety margin of a reactor core, and belongs to the technical field of nuclear power. The method comprises the steps that initial information of various fuel assemblies in a reactor core is obtained, and the initial information comprises stirring and mixing grillwork geometric characteristics of the fuel assemblies and test results obtained by conducting a critical heat flux density test on the fuel assemblies; determining a target critical heat flux density relational expression corresponding to the reactor core according to the initial information of the multiple fuel assemblies; and performing thermal safety margin calculation on the reactor core according to the target critical heat flux relational expression to obtain a target thermal safety margin. According to the embodiment of the invention, the problem of low accuracy of thermal safety margin calculation of the reactor core in the prior art can be solved, the characteristic difference of different types of fuel assemblies is fully considered, and the accuracy of a thermal safety margin analysis result is improved.

The invention provides a binder, a positive pole piece and a secondary battery. The binder comprises a fluorine-free polymer, the fluorine-free polymer comprises a first structural unit and a second structural unit, and the pH value of the binder is 6-10. The binder disclosed by the invention not only has good bonding performance, but also has the effects of inhibiting collapse of a main material structure under high temperature and high voltage and reducing internal heat production of the secondary battery, so that the positive pole piece has good safety performance and cohesion, and the thermal safety performance and energy density of the secondary battery are improved.

The invention discloses a wall breaking machine overload dynamic control method based on multi-source signal fusion, and particularly relates to the field of control and regulation, and the method comprises the steps: firstly executing multi-source signal collection and feature enhancement processing, synchronously collecting electrical, motion, mechanical and thermal signals, and extracting a related feature set after preprocessing; secondly, carrying out multi-dimensional complex coupling analysis, constructing functions of load intensity, mechanical state and thermal safety to quantify single-field risks, and designing three coupling terms of load and machinery, machinery and heat and load and heat to represent a multi-field synergistic effect; generating a comprehensive risk value and a dynamic threshold value, solving the risk value and speed increase, setting the threshold value in a grading manner by combining mode characteristics, and identifying a dominant coupling item; and finally, executing four-stage progressive regulation and control, and starting early warning preparation, card breaking intervention, emergency dredging and final recovery or shutdown actions according to a risk state. According to the invention, physical driving is taken as a core, accurate quantification of risks and coupling-oriented regulation are realized, and equipment safety and effect are both considered.

The invention discloses a high-capacity IV type hydrogen storage cylinder filling deformation test device and method, and relates to the technical field of hydrogen energy storage and transportation. The testing device comprises a medium filling system and a deformation measuring rack. The medium filling system comprises a water storage tank, a first filling pipeline, a second filling pipeline, a third filling pipeline, a first discharge pipeline and a second discharge pipeline which are used for low-pressure pumping water and high-pressure pumping water of the high-capacity IV type hydrogen storage bottle in sequence and are used for simulating the internal pressure effect of a hydrogen filling working condition; the deformation measuring rack comprises a temperature control system, a deformation measuring system and a flexible supporting system, and is used for measuring radial and axial deformation of the high-capacity IV-type hydrogen storage cylinder under the filling working condition, so that the radial and axial deformation influence of the high-capacity IV-type hydrogen storage cylinder during heating is calculated under the medium-high pressure state. The device is high in measurement precision, capable of soaking the fiber layer and the inner container layer of the high-capacity IV-type hydrogen storage bottle, good in safety performance and capable of providing scientific guidance for design of large-scale storage and transportation equipment for hydrogen energy.

The invention belongs to the technical field of thermal management of immersed liquid-cooled batteries, and particularly relates to a battery module temperature equalization and flow resistance self-adaptive liquid cooling system based on temperature and flow velocity monitoring. Multi-point temperature information of a battery module is obtained through a temperature monitoring unit, and a temperature equalization index is calculated; the flow resistance change of the liquid cooling loop is judged by combining the flow speed monitoring unit with the running state of the circulating cooling pump, and the central control unit dynamically adjusts the rotating speed of the circulating cooling pump and / or controls the flow channel adjusting assembly to switch the cooling liquid flow channel based on the combination result of the temperature uniformity state and the flow resistance state. Therefore, the temperature consistency of the battery module and the self-adaptive control of the flow resistance of the liquid cooling system are realized under different operation conditions, the cooling of a key area can be enhanced when local hot spots exist, the flow path is optimized and the energy consumption is reduced when the flow resistance is increased or the load is relatively low, the thermal safety, the operation stability and the energy efficiency level of the battery system are improved, and the service life of the battery system is prolonged. The method is suitable for liquid cooling heat management scenes of high-energy-density batteries.

The invention belongs to the technical field of fire extinguishing agents, and particularly relates to a lithium battery microcapsule fire extinguishing coating and a preparation method and application thereof. By means of the microcapsule technology, the heat stability and the response speed of the fire extinguishing agent are improved. And through the core-shell structure design, effective coating and controlled release of the fire extinguishing agent are achieved. The hydroxymethyl cellulose is used as a matrix, so that the adhesive force and the mechanical strength of the coating are enhanced, a uniform fireproof layer is further formed on the surface of the lithium battery, and the thermal safety performance of the battery is improved. Therefore, the microcapsule fire extinguishing coating for the lithium battery disclosed by the invention can quickly release the microcapsule fire extinguishing agent when the battery is subjected to thermal runaway, so as to realize an inhibition effect on thermal runaway propagation.

The invention relates to the technical field of battery preparation, and particularly discloses a high-rate lithium ion battery, which improves the rate performance, cycle performance and thermal safety of the battery by controlling the relation among the infiltration time t of an electrolyte on a negative plate, the weight of a solid electrolyte interface film (SEI film) and the capacity c of a positive plate. The capacity retention ratio of the prepared battery after 500 times of charge and discharge cycles at the rate of 0.2 C / 10C is 81% or above, the capacity retention ratio of charge and discharge at the rate of 0.2 C / 15C is 85% or above, and the temperature rise rate of discharge at the rate of 15C is 0.6-0.9 DEG C / (s * Ah); and meanwhile, by controlling the infiltration time of the electrolyte on the negative plate, the high-rate discharge performance of the battery is further improved.

The invention provides a silicon-based material and a preparation method thereof, a lithium ion battery monomer, a battery device and a power utilization device, the silicon-based material comprises a porous carbon matrix and silicon nanoparticles located in pores of the porous carbon matrix, the surface of each silicon nanoparticle is provided with a silicon oxide passivation layer formed through a passivation reaction, the ratio of the ID / IG of the silicon-based material to the ID / IG of the porous carbon matrix before the passivation reaction is (0.95-1.05): 1; the mass multiple of the Si element and the C element in the silicon-based material is recorded as A, the mass multiple of the Si element and the C element before the passivation reaction is recorded as B, and the ratio of A to B is (0.95-1.05): 1. According to the invention, the thermal safety performance, the cycle performance and the rate capability of the lithium ion battery monomer can be improved.

The invention discloses a socket with safety protection. The socket comprises a multi-mode thermal sensing array, and a fusion array of a miniature infrared thermal imaging sensor array and a distributed fiber grating temperature sensor which are integrated at key points in the socket; according to the active locking mechanism based on the thermal deformation prediction model, a micro servo motor, a ball screw, a pre-tightening spring and a spring bolt form an electronic lock, a shape memory alloy wire is used for rapid and silent emergency unlocking, and the micro servo motor is used for high-precision conventional locking; the dynamic thermal safety boundary algorithm module is used for dynamically calculating the optimal temperature upper limit and the optimal power upper limit of each component in the current state according to factors such as a real-time temperature field, predicted thermal deformation, current charging power and historical charging data; the main controller is used for transmitting a large amount of real-time temperature field data. Through multi-mode sensing, predictive modeling and master-redundancy cooperative execution, thermal safety and mechanical reliability of the charging interface under extreme working conditions are guaranteed.

The invention provides a multifunctional comprehensive experimental platform and experimental method for a new working medium Brayton cycle system, and belongs to the technical field of thermal engineering experiments. The problem that an experimental device for researching unknown transient characteristics such as start / stop / power change of a new working medium Brayton cycle system, unknown transient safety characteristics under various typical accident conditions, a reliable start / stop / accident safety control strategy and composite control strategy thermal safety characteristics is lacked is solved. The device comprises a new working medium gas charging and discharging system, a Brayton cycle main loop system, a circulating cooling water system, a simulated crevasse system, a measuring instrument system and a power distribution cabinet, the simulation crevasse system comprises a first manual stop valve, a first crevasse test point, a movable crevasse eruption collecting device and the like which are located on a branch near an inlet of the temperature and pressure reducing device and connected in sequence. The device is mainly used for experimental research of the new working medium Brayton cycle system.

The invention provides a negative electrode plate, a secondary battery and an electronic device, the negative electrode plate comprises a negative electrode current collector and a negative electrode material layer located on at least one surface of the negative electrode current collector, the negative electrode material layer comprises a negative electrode active material and a first compound, the infrared spectrum of the negative electrode material layer has infrared characteristic peaks between 1050 cm <-1 > and 1300 cm <-1 >, between 1620 cm <-1 > and 1680 cm <-1 >, and between 1730 cm <-1 > and 1750 cm <-1 >. Through the arrangement, the dynamics, the high-temperature performance, the thermal safety and the cycle performance of the secondary battery can be improved.

The present application discloses a lithium ion battery separator and a lithium ion battery. The lithium ion battery separator comprises a base membrane; at least one surface of the base membrane is provided with a functional coating; the functional coating contains negative temperature coefficient (NTC) material particles and ceramic particles; based on the functional coating, the mass content of the NTC material particles is 30-80 wt%; the base membrane is a base membrane having a low rupture temperature; and the rupture temperature of the base membrane is not higher than 180°C. According to the present application, a base membrane having a low rupture temperature is used in combination with an NTC material, so that in the early stage of a thermal safety test (before failure), micro short circuit points are formed by the base membrane having a low rupture temperature, and then large-area micro self-discharge is achieved by a combined coating of the NTC material and ceramic particles; by means of the cooperation of the base membrane having a low rupture temperature and the NTC material within a certain range, a controllable self-discharge rate can be achieved, the SOC of the battery can be quickly reduced, and the thermal safety performance of the battery can be improved.