A safety threshold optimization method and system for a lithium titanate battery explosion-proof valve

Abstract

The application relates to the technical field of lithium ion battery safety design, in particular to a safety threshold optimization method and system for a lithium titanate battery explosion-proof valve. The application changes the design basis of the explosion-proof valve from a static mechanical strength empirical value to a dynamic safety model based on the real chemical reaction state (SOC, pressure and gas concentration) in the battery, so that the risk of gas ignition during pressure relief can be accurately predicted and actively cut off in the design stage, and when the internal pressure of the battery is increased due to limit overcharging, the explosion-proof valve can timely and safely relieve pressure before the combustible gas concentration reaches a dangerous level, thereby fundamentally avoiding the secondary fire or explosion caused by pressure relief itself and realizing the essential improvement of the battery safety strategy from passive response to active prevention.

Description

Technical Field

[0001] This application relates to the field of lithium-ion battery safety design technology, specifically to a method and system for optimizing the safety threshold of an explosion-proof valve for lithium titanate batteries. Background Technology

[0002] Lithium-ion batteries, due to their high energy density and long cycle life, have been widely used in electric vehicles, energy storage systems, and consumer electronics. However, under extreme conditions such as mechanical abuse, thermal abuse, or electrical abuse, batteries can still experience thermal runaway, leading to safety accidents. Lithium titanate batteries, in particular, while exhibiting high stability under mechanical and thermal abuse, can still experience severe combustion or even explosions under extreme overcharge conditions, becoming a bottleneck restricting their further application in scenarios with high safety requirements.

[0003] Currently, lithium titanate batteries typically employ a passive safety design with an explosion-proof valve. Their burst pressure threshold is often set within a fixed empirical range (e.g., 0.4 MPa–1.2 MPa) based on the mechanical strength of the battery casing and internal pressure growth models. This design approach is essentially a static, mechanically protection-oriented passive pressure relief strategy. Its threshold setting relies on extensive engineering experience and does not correlate with the battery's internal electrochemical reaction state, combustible gas generation dynamics, or concentration changes during overcharging.

[0004] Therefore, existing explosion-proof valves cannot respond in real time to changes in the internal chemical state of the battery during extreme overcharging, which can easily lead to two risks: first, premature explosion, affecting the reliability of normal battery use; second, delayed explosion, where the concentration of internal flammable gases has already exceeded the minimum flammability limit, and the gas is ignited during the depressurization process, causing secondary fire or explosion. Current technology lacks a precise design method that can dynamically correlate the internal chemical state with the depressurization trigger threshold, making it difficult to fundamentally prevent safety accidents after depressurization. Summary of the Invention

[0005] The purpose of this application is to provide a method and system for optimizing the safety threshold of a lithium titanate battery explosion-proof valve, so as to solve the problem of the empirical and static nature of the existing explosion-proof valve burst pressure threshold setting method.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: According to one aspect of the embodiments of this application, a method for optimizing the safety threshold of a lithium titanate battery explosion-proof valve is provided, comprising: determining a lower limit of the flammability concentration of the mixed flammable gas based on the composition and proportion of the flammable gas inside the target model lithium titanate battery under overcharge conditions; determining the theoretical maximum safe burst pressure to ensure the gas is non-flammable based on an internal state correlation model and the lower limit of the flammable concentration; wherein, the internal state correlation model is used to characterize the correspondence between the battery's overcharge state, internal pressure, and flammable gas concentration; obtaining the maximum internal pressure of the target model lithium titanate battery during normal operation throughout its entire life cycle; and determining an explosion pressure optimization threshold for the explosion-proof valve based on the theoretical maximum safe burst pressure and the maximum internal pressure, wherein the explosion pressure optimization threshold is less than or equal to the theoretical maximum safe burst pressure.

[0007] Based on the above technical means, the explosion pressure threshold design of the explosion-proof valve is directly linked to the dynamically changing chemical state (gas concentration, pressure, SOC) inside the battery. This allows for the accurate calculation of the theoretical safe pressure red line that ensures the gas is non-flammable during pressure relief, and forces the optimized threshold to be limited below this red line. This eliminates the risk of the pressure relief port becoming an ignition source from the design source, achieving a fundamental leap from "passive mechanical pressure relief" to "active chemical prevention" for the explosion-proof valve.

[0008] Furthermore, based on the composition and proportion of the combustible gas inside the target model lithium titanate battery under overcharge conditions, the lower limit of the combustible concentration of the mixed combustible gas is determined, including: calculating the lower limit of the combustible concentration of the mixed combustible gas using the Le Chatelier formula, wherein the calculation process is expressed by the following formula (1): LFL -g mix =1 / Σ(V -X / LFL -X (1), In the formula, V -X LFL is the volume fraction of combustible gas component X in the combustible gas mixture. -X The lower limit of flammability (LFL) is the concentration of a combustible gas in a single-component pure substance. -g mix This is the lower limit of the flammability concentration of the mixed flammable gas.

[0009] Based on the above technical means, the combustion and explosion characteristics of complex multi-component combustible gases are transformed into accurate and calculable engineering parameters, avoiding misjudgment of LFL of a single gas, providing a scientific and reliable basic input for subsequent pressure red line calculation, and significantly improving the accuracy and universality of the entire optimization method.

[0010] Furthermore, based on the internal state correlation model and combined with the lower limit of the flammability concentration of the mixed combustible gas, the theoretical maximum safe explosion pressure to ensure the gas is non-flammable is determined, including: determining the overcharge state of the target model lithium titanate battery when it reaches the lower limit of the flammability concentration according to the mapping relationship between the overcharge state of the target model lithium titanate battery and the lower limit of the flammability concentration; wherein, the mapping relationship between the overcharge state of the target model lithium titanate battery and the lower limit of the flammability concentration of the combustible gas is expressed by the following formula (2): LFL -g mix =g(SOC, C -rate (2), In the formula, LFL -g mix is the lower limit of the flammability concentration of the mixed flammable gas, SOC is the overcharge state of the battery when the flammability concentration reaches the lower limit of the flammability concentration, and C-rate is the overcharge rate. Using the lower limit of the combustible concentration of the mixed combustible gas as the target concentration value, and substituting it into the functional relationship represented by the internal state correlation model, the corresponding internal pressure of the battery is obtained by solving the following formula (3): C -gas =f(SOC, P -CIP C -rate (3), In the formula, C -gas P represents the internal flammable gas concentration, SOC represents the overcharge state of the battery when it reaches the lower limit of flammable gas concentration, and P represents the internal flammable gas concentration. -CIP Let C be the internal pressure of the battery to be solved. -rate This refers to the overcharge rate. The internal pressure P of the battery obtained by the solution -CIP It was determined to be the theoretical maximum safe blast pressure.

[0011] Based on the above technical means, the abstract "safe pressure relief" target is transformed into a clear mathematical problem, realizing a seamless mapping from "gas concentration safety threshold" to "pressure design threshold". This provides the explosion-proof valve design with traceable and verifiable quantitative basis, which is the core calculation engine of the "proactive prevention" logic of this invention.

[0012] Furthermore, based on the theoretical maximum safe burst pressure and the maximum internal pressure, the burst pressure optimization threshold of the explosion-proof valve is determined, including: within the interval with the maximum internal pressure as the lower limit and the theoretical maximum safe burst pressure as the upper limit, a sub-interval that meets the engineering safety and reliability requirements is determined according to the safety factor k1 and the reliability factor k2, and the explosion pressure optimization threshold of the explosion-proof valve is selected from the sub-interval; The subinterval satisfies the following condition: P -nor_max k2≤P -optimal ≤P -max k1, Among them, P -nor_max For maximum internal pressure, P -max P is the theoretical maximum safe burst pressure. -optimal To optimize the threshold for burst pressure, the reliability coefficient k2 ranges from 1.3 to 1.5, and the safety coefficient k1 ranges from 0.8 to 0.95.

[0013] Based on the above technical means, a safety factor k1 and a reliability factor k2 are introduced within the safety window, and an optimal range of values ​​is given (k1=0.8~0.95, k2=1.3~1.5). This solves the problem of matching theoretical calculation values ​​with engineering manufacturing tolerances, material creep, and batch fluctuations, so that the optimization threshold has both theoretical safety and production reliability and economy, which greatly improves the industrialization degree of the technical solution and product consistency.

[0014] Furthermore, the internal combustible gas comprises one or more of hydrogen, carbon monoxide, methane, and ethane.

[0015] Based on the above technical means, the main gas generation characteristics of lithium titanate batteries under extreme overcharge conditions were clarified, providing clear target materials for gas sampling, LFL calculation, and model training. This enhanced the operability and relevance of the solution to specific products, and facilitated the rapid implementation and verification of the technical solution.

[0016] According to another aspect of the embodiments of this application, a dynamic design system for the burst pressure of a lithium titanate battery explosion-proof valve is also provided, comprising: a gas analysis module for obtaining the composition and proportion of combustible gas inside a target model lithium titanate battery under overcharge conditions; a combustible lower limit calculation module for determining the lower limit of combustible concentration of the mixed combustible gas based on the composition and proportion; a safe pressure calculation module for determining the theoretical maximum safe burst pressure to ensure the gas is non-flammable based on an internal state correlation model and the lower limit of combustible concentration; wherein, the internal state correlation model is used to characterize the correspondence between the battery's overcharge state, internal pressure, and combustible gas concentration; a normal pressure acquisition module for obtaining the maximum internal pressure of the target model lithium titanate battery during normal operation throughout its entire life cycle; and a threshold decision module for determining the explosion pressure optimization threshold of the explosion-proof valve based on the theoretical maximum safe burst pressure and the maximum internal pressure, wherein the explosion pressure optimization threshold is less than or equal to the theoretical maximum safe burst pressure.

[0017] According to another aspect of the embodiments of this application, a lithium titanate battery is also provided, comprising: a casing; An explosion-proof valve is installed on the housing. The explosion-proof valve has an explosion pressure optimization threshold determined by the safety threshold optimization method for lithium titanate battery explosion-proof valves according to any one of claims 1 to 5, and is configured to open and release pressure when the internal pressure of the battery reaches the preset explosion pressure optimization threshold; wherein the preset explosion pressure optimization threshold is less than or equal to the internal pressure corresponding to the internal flammable gas concentration of the lithium titanate battery reaching the lower limit of flammable concentration under extreme overcharge conditions.

[0018] Furthermore, there is an inherent correspondence between the internal pressure and the internal combustible gas concentration of a lithium titanate battery. This inherent correspondence matches the internal state correlation model, which characterizes the correspondence between the battery's overcharge state, internal pressure, and combustible gas concentration.

[0019] According to another aspect of the embodiments of this application, an electronic device is also provided, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; wherein the memory is used to store a computer program; and the processor is used to execute the safety threshold optimization method for the lithium titanate battery explosion-proof valve in any of the above embodiments by running the computer program stored in the memory.

[0020] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, wherein the storage medium stores a computer program, wherein the computer program is configured to execute the safety threshold optimization method for the lithium titanate battery explosion-proof valve in any of the above embodiments when running.

[0021] The beneficial effects of this application are: This application transforms the design basis of the explosion-proof valve from static mechanical strength empirical values ​​to a dynamic safety model based on the actual chemical reaction state (SOC, pressure, gas concentration) inside the battery. This enables the accurate prediction and proactive cutoff of the risk of gas ignition during pressure relief during the design phase. It ensures that when the internal pressure of the battery rises due to extreme overcharging, the explosion-proof valve can relieve pressure in a timely and safe manner before the concentration of flammable gas reaches a dangerous level. This fundamentally avoids secondary fires or explosions caused by pressure relief itself, achieving a substantial improvement in battery safety strategy from passive response to proactive prevention. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0023] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the hardware environment for an optional safety threshold optimization method for a lithium titanate battery explosion-proof valve provided in an embodiment of this application; Figure 2 This is a flowchart illustrating an optional safety threshold optimization method for a lithium titanate battery explosion-proof valve provided in an embodiment of this application. Figure 3 The overcharge SOC and mixed gas concentration C-gas, lower flammability limit LFL-gmix, and internal battery pressure P- provided in the embodiments of this application are as follows: CIP A diagram illustrating the trend and functional relationship; Figure 4 This is a schematic diagram showing the relationship between overcharge SOC and battery voltage and temperature provided in the embodiments of this application; Figure 5 This is a schematic diagram of the battery explosion-proof valve bursting and producing a flame jet when the battery is overcharged to 233% of its SOC, as provided in the embodiments of this application. Figure 6 This is a schematic diagram showing the explosion threshold optimization provided in the embodiments of this application, where the battery explosion valve explodes when the battery is overcharged to 163.7% of its SOC, without flame jet or combustion. Figure 7 This is a structural block diagram of an optional dynamic design system for the burst pressure of a lithium titanate battery explosion-proof valve provided in an embodiment of this application; Figure 8 This is a structural block diagram of an optional electronic device provided in an embodiment of this application. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] According to one aspect of the embodiments of this application, a method for optimizing the safety threshold of a lithium titanate battery explosion-proof valve is provided. Optionally, in this embodiment, the above-described method for optimizing the safety threshold of a lithium titanate battery explosion-proof valve can be applied to a hardware environment consisting of a terminal and a server. The server is connected to the terminal via a network and can be used to provide services to the terminal or clients installed on the terminal. A database can be set up on the server or independently of the server to provide data storage services to the server.

[0028] The aforementioned network may include, but is not limited to, at least one of the following: wired network, wireless network. The aforementioned wired network may include, but is not limited to, at least one of the following: wide area network, metropolitan area network, local area network. The aforementioned wireless network may include, but is not limited to, at least one of the following: Wi-Fi (Wireless Fidelity), Bluetooth. The terminal may not be limited to PC, mobile phone, tablet computer, etc.

[0029] The safety threshold optimization method for the lithium titanate battery explosion-proof valve in this application embodiment can be executed by a server, a terminal, or both. Specifically, the terminal executing the safety threshold optimization method for the lithium titanate battery explosion-proof valve in this application embodiment can also be executed by a client installed on it.

[0030] Taking the safety threshold optimization method for the lithium titanate battery explosion-proof valve in this embodiment, executed by the server, as an example, please refer to [link to relevant documentation]. Figure 1 , Figure 1 This is a schematic diagram of the hardware environment for an optional safety threshold optimization method for a lithium titanate battery explosion-proof valve provided in an embodiment of this application, as shown below. Figure 1As shown, the hardware environment for the safety threshold optimization method of the lithium titanate battery explosion-proof valve includes: a terminal 102 and a server 104 connected to the terminal 102 via a network. The server 104 is used to deploy an internal state association model and, based on the battery parameters sent by the terminal 102 (including the composition and proportion of combustible gases inside the target model lithium titanate battery under overcharge conditions, the maximum internal pressure of the battery during normal operation throughout its entire life cycle, etc.), executes the safety threshold optimization method of the lithium titanate battery explosion-proof valve according to this application embodiment to calculate the explosion pressure optimization threshold of the explosion-proof valve. The terminal 102 is used to receive battery parameters input by the user and send the parameters to the server 104, and to receive and display the explosion pressure optimization threshold returned by the server 104, wherein the explosion pressure optimization threshold is calculated by the server 104 based on the internal state association model, the lower limit of combustible concentration, and the maximum internal pressure. Furthermore, the server 104 can also store intermediate data involved in the calculation process (such as the lower limit of combustible concentration of mixed combustible gases, the theoretical maximum safe explosion pressure, etc.) in a database for subsequent querying or verification.

[0031] This method can be applied to scenarios such as battery safety design and performance optimization. For example, lithium titanate battery manufacturers can precisely set the burst pressure of the explosion-proof valve during the battery R&D stage to ensure the safety of the battery under extreme overcharge conditions. Battery safety testing institutions can use this method to optimize the explosion-proof valve parameters of the battery under test before conducting overcharge tests according to national standards (such as GB / T 36276, GB 38032, etc.) to improve the test pass rate. It can also provide data support for formulating reasonable safety pressure relief strategies during the design of battery management systems. This application uses the battery R&D process of a lithium titanate battery manufacturer as an example to illustrate the above-mentioned method for optimizing the safety threshold of the lithium titanate battery explosion-proof valve.

[0032] In existing technologies, the burst pressure threshold of lithium titanate battery explosion-proof valves is typically set to a fixed empirical range (e.g., 0.4–1.2 MPa) based on the mechanical strength limit of the battery casing and an internal pressure growth model. This static, empirical setting method fails to dynamically correlate with the internal electrochemical processes and combustible gas generation characteristics of the battery under extreme overcharge conditions. Therefore, under extreme overcharge conditions, when the explosion-proof valve opens, the internal combustible gas concentration may have already exceeded its lower flammability limit (LFL), causing the high-pressure combustible gas to be ejected and ignited, leading to a secondary fire or explosion. Existing technologies lack a method to accurately determine the safe burst pressure based on the real-time chemical state inside the battery, making it difficult to prevent the risk of combustion after pressure relief from the design stage.

[0033] To address the aforementioned issues, this embodiment provides a method for optimizing the safety threshold of a lithium titanate battery explosion-proof valve running on the aforementioned server. Please refer to [link to relevant documentation]. Figure 2 , Figure 2This is a flowchart illustrating an optional safety threshold optimization method for a lithium titanate battery explosion-proof valve provided in an embodiment of this application. Figure 2 As shown, the safety threshold optimization method for the lithium titanate battery explosion-proof valve in this application embodiment specifically includes the following steps: Step S201: Determine the lower limit of the flammability concentration of the mixed flammable gas based on the composition and proportion of the flammable gas inside the target model lithium titanate battery under overcharge conditions. Step S202: Based on the internal state correlation model and combined with the lower limit of combustible concentration, determine the theoretical maximum safe explosion pressure to ensure that the gas is non-flammable; wherein, the internal state correlation model is used to characterize the overcharge state of the battery, the correspondence between internal pressure and combustible gas concentration; Step S203: Obtain the maximum internal pressure of the target model lithium titanate battery during normal operation throughout its entire life cycle; based on the theoretical maximum safe burst pressure and the maximum internal pressure, determine the burst pressure optimization threshold of the explosion-proof valve, wherein the burst pressure optimization threshold is less than or equal to the theoretical maximum safe burst pressure.

[0034] By directly linking the explosion pressure threshold design of the explosion-proof valve to the dynamically changing chemical state (gas concentration, pressure, SOC) inside the battery through the above steps S201 to S203, the theoretical safe pressure red line that ensures the gas is non-flammable during pressure relief can be accurately calculated, and the optimized threshold is forcibly limited to below this red line. This eliminates the risk of the pressure relief port becoming an ignition source from the design source, realizing a fundamental leap from "passive mechanical pressure relief" to "active chemical prevention" for the explosion-proof valve, and solving the problem of the empirical and static nature of the existing explosion-proof valve explosion pressure threshold setting method.

[0035] The following is combined Figure 2 The method for optimizing the safety threshold of the lithium titanate battery explosion-proof valve in the embodiments of this application is explained.

[0036] In the technical solution of step S201, the lower limit of the flammability concentration of the mixed flammable gas is determined based on the composition and proportion of the flammable gas inside the target model lithium titanate battery under overcharge conditions.

[0037] As an optional embodiment, the internal combustible gas refers to the gas mixture generated by electrolyte decomposition and electrode material side reactions under extreme overcharge conditions of the lithium titanate battery. This gas mixture mainly contains combustible components such as hydrogen (H2), carbon monoxide (CO), methane (CH4), and ethane (C2H6), and its specific composition and volume fraction change dynamically with the degree of overcharge (SOC).

[0038] The lower flammability limit (LFL) refers to the minimum concentration at which a mixture of flammable gas or vapor and air can ignite or explode upon contact with an ignition source; below this concentration, it cannot be ignited. For mixed flammable gases, the LFL cannot be directly obtained from a table; it needs to be calculated based on the concentration of each component and the LFL value of each individual component.

[0039] As an optional implementation method, this embodiment uses Le Chatelier's rule to determine the lower limit of flammability concentration of the mixed flammable gas, and the calculation formula is as follows: LFL-g mix=1 / Σ(V -X / LFL -X (1), In the formula, V -X LFL is the volume fraction of combustible gas component X in the combustible gas mixture. -X The lower limit of flammability concentration (volume fraction, %) of a combustible gas X a single-component pure substance, LFL -g mix This represents the lower limit of flammability concentration (volume fraction, %) of the mixed flammable gas.

[0040] For example, at a certain overcharge node, GC-MS analysis shows that the volume fractions of H2, CO, CH4, and C2H6 are 40%, 30%, 20%, and 10%, respectively. Looking up the table, the LFL values ​​for each component are 4.0%, 12.5%, 5.0%, and 3.0%, respectively. The LFL of the mixed gas is then calculated as follows: LFL-g mix = 1 / (0.4 / 4.0 + 0.3 / 12.5 + 0.2 / 5.0 + 0.1 / 3.0) ≈ 5.08%.

[0041] As the overcharge state of charge (SOC) continues to rise, the proportion of low-lflare-value gases such as H2 increases, and the LFL value of the mixed gas shows a downward trend. This means that the gas mixture is becoming increasingly easier to ignite, and the safety risks increase accordingly.

[0042] Based on the above technical means, this embodiment achieves precise quantification of the combustion and explosion characteristics of the complex mixed gas inside the lithium titanate battery, transforming the abstract "combustion risk" into specific and calculable engineering parameters (LFL value), providing a scientific and reliable basis for subsequent determination of the safe pressure relief red line, and avoiding the errors caused by approximate calculations using the LFL value of a single gas.

[0043] In the technical solution of step S202, based on the internal state correlation model and combined with the lower limit of combustible concentration, the theoretical maximum safe explosion pressure to ensure that the gas is non-flammable is determined; wherein, the internal state correlation model is used to characterize the overcharge state of the battery, the correspondence between internal pressure and combustible gas concentration.

[0044] During the overcharging process of lithium titanate batteries, there is a specific mapping relationship between the overcharge state and the lower limit of flammability concentration of combustible gases. This relationship can be expressed as: LFL -g mix =g(SOC, C -rate (2), In the formula, LFL -g mix The lower limit of flammability concentration of the mixed flammable gas (volume fraction, %), SOC is the state of overcharge when the battery reaches the lower limit of flammability concentration (expressed as a percentage, 100% is the state of full charge), and C-rate is the overcharge rate (reflecting the impact of different levels of abuse on the gas production rate). This mapping relationship reflects the dynamic law that as the SOC increases, the proportion of low LFL components (such as H2) in the gas mixture increases, leading to a continuous decrease in the overall lower limit of flammability concentration of the gas mixture.

[0045] The internal state correlation model is obtained by conducting extreme overcharge tests on the target lithium titanate battery at multiple different overcharge rates (e.g., 0.5C, 1.0C, 2.0C), simultaneously collecting data on the battery's state of charge (SOC), internal pressure (P), and internal combustible gas concentration (C), and fitting these data with a high-dimensional function relationship using multiple regression analysis or machine learning algorithms (e.g., random forest, neural network). The basic form of this model can be expressed as: C -gas =f(SOC, P -CIP C -rate (3), In the formula, C -gas P represents the internal combustible gas concentration (volume fraction, %), SOC represents the state of overcharge when the battery reaches the lower limit of combustible gas concentration (expressed as a percentage, 100% is the fully charged state). -CIP Let C be the internal pressure of the battery to be solved (unit: MPa). -rate This refers to the overcharge rate (reflecting the impact of different levels of abuse on the gas production rate). Based on the above model, the theoretical maximum safe burst pressure P is determined. -max The specific steps are as follows: First, based on the mapping relationship shown in formula (2), determine whether the battery reaches the lower limit of flammability concentration (LFL). -g mix The overcharge state at SOC0 is obtained by solving the equation: LFL -g mix =g(SOC, C -rate ); Next, the LFL calculated in step S201 -g mix As the target concentration value, it is substituted into the internal state correlation model shown in formula (3), and the SOC0 obtained in the previous step and the given overcharge rate C are also substituted. -rateSolve for the corresponding internal pressure P of the battery. -CIP : LFL -g mix = f(SOC0, P -CIP C -rate ); Finally, the obtained P -CIP The theoretical maximum safe burst pressure P was determined. -max The significance of this pressure value lies in the fact that when the internal pressure of the battery reaches P... -max At that time, the concentration of combustible gas inside is exactly equal to its lower flammability limit (LFL). -g mix In other words, when the pressure is less than or equal to P -max Under certain conditions, the explosion-proof valve is opened to release pressure, and the emitted combustible gas has a concentration lower than LFL. -g mix It cannot be ignited.

[0046] Taking a 40Ah square aluminum-cased lithium titanate battery as an example, according to Figure 3 The experimental data shown indicate that when SOC = 175.983%, C -gas = LFL -g mix = 8.231%, substituting into the internal state correlation model, we can deduce the corresponding internal pressure P. -CIP = 0.489MPa, which is the theoretical maximum safe burst pressure P in this embodiment. -max . Figure 3 Intersection point (C) -gas With LFL -g mix The intersection of the curves visually illustrates the physical significance of this critical point—below this pressure, the gas concentration drops below the lower flammability limit and cannot be ignited.

[0047] Based on the aforementioned technical means, this embodiment transforms the abstract safety pressure relief target into a clear mathematical problem, achieving a seamless mapping from the gas concentration safety threshold to the pressure design threshold. This method provides a traceable and verifiable quantitative basis for the design of the explosion-proof valve's burst pressure, fundamentally solving the technical problem that traditional empirical methods cannot be dynamically correlated with the internal chemical state of the battery.

[0048] As an optional embodiment, the internal state correlation model is obtained through systematic experimental modeling of the target type of lithium titanate battery. Its construction process is not completed through a single-variable simulation experiment, but rather a multi-step, multi-variable correlation system engineering project, specifically including the following steps: (1) Experimental sampling Select lithium titanate battery samples of the target model to ensure randomness and representativeness in sampling. Prioritize battery samples with high rate performance and low charging heat generation to eliminate interference from additional heat source variables on the test results.

[0049] (2) Test parameter matrix design To simulate different overcharge abuse scenarios, a test matrix covering multiple overcharge rates (e.g., 0.5C, 1.0C, 2.0C) was designed. The state of overcharge (SOC) started at 100% and increased incrementally in increments of 10% or 20% until battery failure, thus covering the entire process from normal to extreme overcharge.

[0050] (3) Monitoring and collection of key experimental parameters During testing, the following parameters were monitored and recorded in real time: voltage, current, and temperature in typical battery areas; internal battery pressure: internal pressure changes were collected in real time by installing a high-precision pressure sensor through an opening in the battery cover; composition and concentration of internal combustible gases: gas samples were collected using non-destructive sampling methods, and qualitative and quantitative analyses were performed using gas chromatography-mass spectrometry (GC-MS). Sampling can be performed using one of the following two methods or a combination thereof: Option A (Sampling at Preset SOC Nodes): When the battery reaches preset SOC critical nodes (such as 100%, 120%, 140%, 160%, etc.), gas sampling and analysis are automatically triggered. Option B (Sampling at preset pressure nodes): When the internal pressure of the battery reaches a preset pressure node (such as 0.1MPa, 0.2MPa, 0.3MPa, etc.), gas sampling and analysis are automatically triggered.

[0051] (4) Model building and function fitting Data from all test samples were aggregated to form a high-dimensional dataset including overcharge rate, battery temperature, initial SOC (100%), real-time SOC, real-time internal pressure, and combustible gas composition and concentration. Data modeling techniques such as multiple regression analysis and machine learning algorithms (e.g., random forest, neural networks) were employed to fit the data at an overcharge current rate C. -rate Below, the total concentration of combustible gas C -gas As for SOC and battery internal pressure P -CIP The functional relationship between them can be expressed in basic form as follows: C -gas =f(SOC, P -CIP C -rate ) Alternatively, the internal pressure P of the battery can be... -CIP Expressed as SOC and combustible gas concentration C -gas Functions: P -CIP =g(SOC, C -gas C -rate ) This model, the internal state correlation model described in this application, quantitatively characterizes the dynamic correspondence between the overcharge state, internal pressure, and combustible gas concentration during battery overcharging, providing a core calculation basis for subsequently determining the theoretical maximum safe burst pressure. This dynamic correspondence is as follows: Figure 3 As shown.

[0052] like Figure 3 and Figure 4 As shown, Figure 3 and Figure 4 The following figures illustrate the changing trends of key parameters with overcharge SOC in the 1C rate limit overcharge test of the 40Ah square aluminum-cased lithium titanate battery involved in this embodiment.

[0053] like Figure 3 As shown, as the overcharge SOC increases from 100% to 240%, the total concentration of combustible gases C inside the battery increases. -gas (The solid curve in the figure) rose continuously from 3.50% to 9.00%, while the lower limit of flammability concentration (LFL) of the mixed combustible gas... -g mix (The dashed curve in the figure) gradually decreases from 13.00% to 7.40%. At approximately 210% SOC, C -gas Curve and LFL -g mix When the curves intersect, C -gas = LFL -g mix ≈ 8.20%, corresponding to internal pressure P -CIP (The dotted line curve in the figure) is approximately 0.49 MPa. The intersection point is the theoretical maximum safe burst pressure P described in this application. -max The critical point—when SOC is below this intersection point, C -gas <LFL -g mix The gas is non-flammable; when the SOC is higher than this intersection point, C -gas LFL -g mix The gas is flammable.

[0054] Figure 3 The text also provides C. -gas LFL -g mix P -CIP The fitting function relationship and goodness of fit (R² both greater than 0.99) as SOC changes indicate that the experimental data have good regularity and the established internal state correlation model has high reliability.

[0055] like Figure 4As shown, during the same overcharge process, the battery voltage gradually increased from an initial 3.00V (SOC 100%) to a peak of 4.50V (SOC approximately 170%), and then decreased to 3.00V (SOC 240%). The battery temperature, however, slowly and continuously increased from 40℃ to 68℃, demonstrating the relatively low temperature rise of lithium titanate batteries during overcharge (compared to ternary lithium batteries or lithium iron phosphate batteries). This temperature data can be used to verify that no thermal runaway occurred during the test, ensuring that the collected gas concentration and pressure data primarily originated from electrochemical side reaction gas production, rather than thermal decomposition gas production.

[0056] In the technical solution of step S203, the maximum internal pressure of the target model lithium titanate battery during normal operation throughout its entire life cycle is obtained; based on the theoretical maximum safe burst pressure and the maximum internal pressure, the burst pressure optimization threshold of the explosion-proof valve is determined, wherein the burst pressure optimization threshold is less than or equal to the theoretical maximum safe burst pressure.

[0057] As an optional embodiment, the maximum internal pressure during normal operation throughout the entire life cycle (denoted as P) -nor_max The internal pressure (EPP) refers to the maximum internal pressure of a battery under normal charge / discharge conditions (including ambient temperature cycling, high temperature storage, and rate charging / discharging) and at the end of its life (EOL) stage, caused by factors such as normal gas production and temperature changes. This parameter can be obtained through the following methods: Experimental testing method: Full lifecycle simulation testing is performed on the target battery model, including room temperature cycle life testing (e.g., 100% DOD cycling to 80% capacity decay), high-temperature storage testing, and charge / discharge tests at different rates. During the testing process, the internal pressure changes of the battery are monitored in real time, and the maximum pressure value under all test conditions is taken as P. -nor_max .

[0058] Simulation prediction method: Based on the gas generation mechanism model and thermo-mechanical coupling model of the battery, the maximum internal pressure that the battery may reach during its entire life cycle is predicted through simulation calculation, and the results are calibrated in combination with experimental data.

[0059] In the above embodiments, the maximum internal pressure P of the 40Ah square aluminum-cased lithium titanate battery during normal operation throughout its entire life cycle is... -nor_max It is 0.25 MPa. Figure 2 The peak value of the voltage curve shown (SOC≈170%) and Figure 1 C -gas With LFL -g mix The intersection of the curves (SOC≈176%) is basically consistent, indicating that when the battery voltage reaches its peak and begins to decline, the internal gas concentration is about to reach the lower limit of flammability. If the explosion-proof valve can be opened in time at this point, the subsequent risk of combustion can be avoided.

[0060] The final optimized burst pressure threshold range determined in this embodiment is 0.35–0.4165 MPa, which is significantly lower than... Figure 3 P shown -max (0.489MPa), which is higher than the normal operating pressure of the battery (0.25MPa), achieving a unified design of safety and reliability.

[0061] In obtaining P -nor_max P calculated in step S202 -max Subsequently, the two together constitute a pressure design range, where P -nor_max The lower limit (to ensure that the battery does not explode accidentally during normal use), P -max This is the upper limit (ensuring the gas is non-flammable during pressure relief). Theoretically, the optimal burst pressure threshold P for an explosion-proof valve is... -optimal Only P needs to be satisfied -nor_max <P -optimal ≤ P -max This can simultaneously meet the requirements of safety and reliability.

[0062] However, in practical engineering applications, the influence of factors such as manufacturing tolerances, material creep, and environmental fluctuations must also be considered. Therefore, as a preferred embodiment, this method further introduces a safety factor k1 and a reliability factor k2 to perform engineering modifications on the theoretical design interval, forming a more stringent sub-interval: P -nor_max k2≤P -optimal ≤P -max k1, Where: k1 and k2 are safety factors, ranging from 0.8 to 0.95, used in P -max On this basis, the threshold is further reduced to leave a safety margin for gas concentration measurement errors, model fitting deviations, etc. k2 is the reliability coefficient, ranging from 1.3 to 1.5, used in P -nor_max Based on this, the lower threshold is increased to ensure that the explosion-proof valve will not be accidentally triggered even under extreme conditions such as battery aging and environmental changes.

[0063] When we take k1=0.85 and k2=1.4, substitute them into P -nor_max =0.25MPa, P -max =0.489MPa, the ideal range for the optimized threshold is calculated to be: 0.25 × 1.4 ≤ P -optimal ≤ 0.489 × 0.85, i.e., 0.35 MPa ≤ P -optimal ≤ 0.4165MPa Finally, a specific value (e.g., 0.38 MPa) was selected from this sub-range as the optimized burst pressure threshold for the explosion-proof valve of this battery model. After the explosion-proof valve made with this threshold was assembled with the battery, in the extreme overcharge verification test, when the battery was overcharged to 163.7% SOC, the explosion-proof valve opened, and only a mist of electrolyte was sprayed out, with no visible flame jet generated, successfully achieving safe pressure relief.

[0064] Based on the aforementioned technical means, this embodiment, by introducing a safety factor and a reliability factor, constructs an optimized design range that balances theoretical safety and engineering reliability, building upon the theoretical safety window. This range ensures that the explosion-proof valve opens promptly before the gas concentration reaches ignition (safety) and guarantees that it will not malfunction under normal operating conditions throughout its entire life cycle (reliability), achieving a unified design of safety and reliability and significantly enhancing the industrial application value of the technical solution.

[0065] Taking a large square aluminum-cased lithium titanate battery with a design capacity of 128Ah as an example, the original design explosion-proof valve burst threshold of this battery was 1.0±0.02MPa. Using a 0.5C current rate for extreme overcharge testing, the battery was continuously overcharged to 183% SOC when the explosion-proof valve burst and released pressure. Immediately, a violent jet of flame erupted from the pressure relief opening, resulting in a severe thermal runaway accident involving fire and explosion. The phenomenon is similar to... Figure 5 similar.

[0066] This scheme is used to optimize the design of this battery: First, an internal state correlation model of this battery model is established through experiments, and the theoretical maximum safe burst pressure P is calculated. -max Then, obtain the maximum internal pressure P of the battery during its normal operation throughout its entire lifespan. -nor_max Finally, a safety factor k1=0.85 and a reliability factor k2=1.4 were introduced to determine the optimized burst pressure threshold range as 0.726~0.867MPa.

[0067] The explosion-proof valve was remade using an optimized threshold and the battery was assembled. Samples were taken and the 0.5C extreme overcharge experiment was repeated. Results showed that when the battery was continuously overcharged to 163.7% SOC, the explosion-proof valve opened to release pressure, and only a mist of electrolyte was ejected. High-speed photography and gas sampling analysis confirmed that the ejected gas was not ignited, and no flame jet was generated. Figure 6 As shown in the image. Testing revealed that the concentration of combustible gases in the outside air after depressurization was far below the flammability limit, indicating successful safe depressurization.

[0068] contrast Figure 5 and Figure 6The experimental results show that the explosion pressure threshold of the lithium titanate battery optimized using the technical solution of this application is precisely set within the critical range before the internal flammable gas concentration reaches the lower flammability limit, ensuring the safety of the pressure relief process. In contrast, the unoptimized battery, due to its excessively high threshold setting, only opens the pressure relief mechanism when the gas already poses a risk of combustion and explosion, leading to serious safety accidents. This comparative result fully demonstrates the significant effect of the technical solution of this application in improving the safety of lithium titanate batteries under extreme overcharge conditions.

[0069] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0070] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM (Read-Only Memory) / RAM (Random Access Memory), magnetic disk, optical disk), and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of this application.

[0071] According to another aspect of the embodiments of this application, a lithium titanate battery is also provided, comprising: a casing; An explosion-proof valve is installed on the housing. The explosion-proof valve has an explosion pressure optimization threshold determined by the safety threshold optimization method for lithium titanate battery explosion-proof valves according to any one of claims 1 to 5, and is configured to open and release pressure when the internal pressure of the battery reaches the preset explosion pressure optimization threshold; wherein the preset explosion pressure optimization threshold is less than or equal to the internal pressure corresponding to the internal flammable gas concentration of the lithium titanate battery reaching the lower limit of flammable concentration under extreme overcharge conditions.

[0072] Furthermore, there is an inherent correspondence between the internal pressure and the internal combustible gas concentration of a lithium titanate battery. This inherent correspondence matches the internal state correlation model, which characterizes the correspondence between the battery's overcharge state, internal pressure, and combustible gas concentration.

[0073] SOC - Battery Internal Pressure P under Extreme Overcharge Conditions -CIP -Concentration of combustible gas mixture C -gas The corresponding function relationship is as follows Figure 3 As shown.

[0074] After extreme overcharge testing, the sample battery's explosion-proof valve ruptured when it reached 233.1% SOC. Frame-by-frame examination with a high-speed camera revealed a violent flame jet 50ms after internal gas ejection (recording frequency 20Hz), followed by intense combustion of the battery. Figure 5 As shown in the figure. This phenomenon indicates that the explosion-proof valve with a traditional fixed burst pressure threshold (0.6±0.02MPa) only opens to release pressure when the concentration of combustible gas inside the battery has significantly exceeded its lower flammability limit (LFL), causing the high-pressure combustible gas to be ejected and ignited, leading to a secondary combustion accident.

[0075] According to another aspect of the embodiments of this application, a dynamic design system for the burst pressure of a lithium titanate battery explosion-proof valve is also provided for implementing the above-described method for optimizing the safety threshold of the lithium titanate battery explosion-proof valve. Please refer to... Figure 7 , Figure 7 This is a structural block diagram of an optional dynamic design system for the burst pressure of a lithium titanate battery explosion-proof valve, provided in an embodiment of this application. Figure 7 As shown, the system 700 may include: Gas analysis module 701 is used to obtain the composition and proportion of combustible gases inside the target type lithium titanate battery under overcharge conditions; The lower flammability limit calculation module 702 is used to determine the lower flammability concentration limit of the mixed flammable gas based on its composition and proportion. The safety pressure calculation module 703 is used to determine the theoretical maximum safe explosion pressure that ensures the gas is non-flammable based on the internal state correlation model and the lower limit of flammable concentration; wherein, the internal state correlation model is used to characterize the overcharge state of the battery, the correspondence between internal pressure and flammable gas concentration. Normal pressure acquisition module 704 is used to acquire the maximum internal pressure of the target model lithium titanate battery during normal operation throughout its entire life cycle. The threshold decision module 705 is used to determine the explosion pressure optimization threshold of the explosion-proof valve based on the theoretical maximum safe explosion pressure and the maximum internal pressure, wherein the explosion pressure optimization threshold is less than or equal to the theoretical maximum safe explosion pressure.

[0076] It should be noted that the gas analysis module 701 in this embodiment can be used to perform the above step S201, the combustible lower limit calculation module 702 in this embodiment can be used to perform the above step S202, the safe pressure calculation module 703 in this embodiment can be used to perform the above step S203, the normal pressure acquisition module 704 in this embodiment can be used to perform the above step S204, and the threshold decision module 705 in this embodiment can be used to perform the above step S205.

[0077] Regarding the dynamic design system for the explosion pressure of the lithium titanate battery explosion-proof valve in this embodiment, the specific manner in which its gas analysis module 701, combustible lower limit calculation module 702, safe pressure calculation module 703, normal pressure acquisition module 704, and threshold decision module 705 execute the above-mentioned safety threshold optimization method for the lithium titanate battery explosion-proof valve has been described in detail in the embodiments related to the safety threshold optimization method for the lithium titanate battery explosion-proof valve, and will not be elaborated here.

[0078] It is understood that the technical solution provided in this embodiment, in the dynamic design system for the explosion pressure of the lithium titanate battery explosion-proof valve, transforms the design basis of the explosion-proof valve from static mechanical strength empirical values ​​to a dynamic safety model based on the actual chemical reaction state (SOC, pressure, gas concentration) inside the battery. This allows for accurate prediction and proactive cutoff of the risk of gas ignition during pressure relief during the design phase. It ensures that when the internal pressure of the battery rises due to extreme overcharging, the explosion-proof valve can relieve pressure in a timely and safe manner before the concentration of combustible gas reaches a dangerous level. This fundamentally avoids secondary fires or explosions caused by pressure relief itself, achieving a fundamental improvement in battery safety strategy from passive response to proactive prevention.

[0079] In addition to the modules described above, the system in this embodiment may also include modules that execute any method in any of the embodiments of the safety threshold optimization method for any lithium titanate battery explosion-proof valve.

[0080] It should be noted that the examples and application scenarios implemented by the above modules and corresponding steps are the same, but are not limited to the content disclosed in the above embodiments. It should be noted that the above modules, as part of the device, can operate in ways such as... Figure 1 The method shown can be implemented in either software or hardware within a hardware environment, where the hardware environment includes a network environment.

[0081] According to another aspect of the embodiments of this application, an electronic device for implementing the above-described method for optimizing the safety threshold of the lithium titanate battery explosion-proof valve is also provided. The electronic device may be a server, a terminal, or a combination thereof.

[0082] According to another embodiment of this application, an electronic device is also provided; please refer to [link to relevant documentation]. Figure 8 , Figure 8 This is a structural block diagram of an optional electronic device provided in an embodiment of this application, such as... Figure 8 As shown, the electronic device may include: a processor 1501, a communication interface 1502, a memory 1503, and a communication bus 1504, wherein the processor 1501, the communication interface 1502, and the memory 1503 communicate with each other through the communication bus 1504.

[0083] Memory 1503 is used to store computer programs; When processor 1501 executes the program stored in memory 1503, it performs the following steps: Step S201: Determine the lower limit of the flammability concentration of the mixed flammable gas based on the composition and proportion of the flammable gas inside the target model lithium titanate battery under overcharge conditions. Step S202: Based on the internal state correlation model and combined with the lower limit of combustible concentration, determine the theoretical maximum safe explosion pressure to ensure that the gas is non-flammable; wherein, the internal state correlation model is used to characterize the overcharge state of the battery, the correspondence between internal pressure and combustible gas concentration; Step S203: Obtain the maximum internal pressure of the target model lithium titanate battery during normal operation throughout its entire life cycle; based on the theoretical maximum safe burst pressure and the maximum internal pressure, determine the burst pressure optimization threshold of the explosion-proof valve, wherein the burst pressure optimization threshold is less than or equal to the theoretical maximum safe burst pressure.

[0084] It is understood that the technical solution provided in this embodiment, in which the processor of the electronic device, transforms the design basis of the explosion-proof valve from static mechanical strength empirical values ​​to a dynamic safety model based on the actual chemical reaction state (SOC, pressure, gas concentration) inside the battery, can accurately predict and actively cut off the risk of gas ignition during pressure relief during the design stage. This ensures that when the internal pressure of the battery increases due to extreme overcharging, the explosion-proof valve can relieve pressure in a timely and safe manner before the concentration of combustible gas reaches a dangerous level, fundamentally avoiding secondary fires or explosions caused by pressure relief itself, and realizing an essential improvement in battery safety strategy from passive response to active prevention.

[0085] Optionally, in this embodiment, the communication bus can be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. This communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is used to represent it in the figure, but this does not mean that there is only one bus or one type of bus. The communication interface is used for communication between the aforementioned electronic device and other devices.

[0086] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0087] The processor mentioned above can be a general-purpose processor, including but not limited to: CPU (Central Processing Unit), NP (Network Processor), etc.; it can also be DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0088] This application also provides a computer-readable storage medium, which includes a stored program, wherein the program executes the method steps of the above method embodiments when it runs.

[0089] Optionally, in this embodiment, the storage medium may include, but is not limited to, various media capable of storing program code, such as USB flash drives, ROMs, RAMs, portable hard drives, magnetic disks, or optical disks.

[0090] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0091] If the integrated units in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in the aforementioned computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause one or more computer devices (which may be personal computers, servers, or network devices, etc.) to execute all or part of the steps of the methods of the various embodiments of this application.

[0092] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0093] In the several embodiments provided in this application, it should be understood that the disclosed client can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or the indirect coupling or communication connection of units or modules may be electrical or other forms.

[0094] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the solution provided in this embodiment, depending on actual needs.

[0095] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0096] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for optimizing the safety threshold of an explosion-proof valve for lithium titanate batteries, characterized in that, include: The lower limit of the flammability concentration of the mixed flammable gas is determined based on the composition and proportion of the internal flammable gas of the target model lithium titanate battery under overcharge conditions. Based on the internal state correlation model and combined with the lower limit of flammable concentration, the theoretical maximum safe explosion pressure to ensure that the gas is non-flammable is determined; wherein, the internal state correlation model is used to characterize the correspondence between the battery's overcharge state, internal pressure and flammable gas concentration. Obtain the maximum internal pressure of the target model lithium titanate battery during normal operation throughout its entire life cycle; based on the theoretical maximum safe burst pressure and the maximum internal pressure, determine the burst pressure optimization threshold of the explosion-proof valve, wherein the burst pressure optimization threshold is less than or equal to the theoretical maximum safe burst pressure.

2. The method for optimizing the safety threshold of the lithium titanate battery explosion-proof valve according to claim 1, characterized in that, Based on the composition and proportion of combustible gases inside the target model of lithium titanate battery under overcharge conditions, determine the lower limit of the combustible concentration of the mixed combustible gases, including: The lower limit of flammability concentration of the mixed combustible gas is calculated using the Le Chatelier formula, wherein the calculation process is expressed by the following formula (1): LFL -g mix =1 / Σ(V -X / LFL -X )(1), In the formula, V -X LFL is the volume fraction of combustible gas component X in the combustible gas mixture. -X The lower limit of flammability (LFL) is the concentration of a combustible gas in a single-component pure substance. -g mix This is the lower limit of the flammability concentration of the mixed flammable gas.

3. The method for optimizing the safety threshold of the lithium titanate battery explosion-proof valve according to claim 1, characterized in that, Based on the internal state correlation model and combined with the lower limit of the flammability concentration of the mixed flammable gas, the theoretical maximum safe explosion pressure to ensure the gas is non-flammable is determined, including: Based on the mapping relationship between the overcharge state of the target model lithium titanate battery and the lower limit of flammable gas concentration, the overcharge state of the target model lithium titanate battery when it reaches the lower limit of flammable gas concentration is determined; wherein, the mapping relationship between the overcharge state of the target model lithium titanate battery and the lower limit of flammable gas concentration is expressed by the following formula (2): LFL -g mix =g(SOC, C -rate )(2), In the formula, LFL -g mix The lower limit of the flammability concentration of the mixed flammable gas, SOC is the overcharge state of the battery when the flammability concentration reaches the lower limit of the flammability concentration, and C-rate is the overcharge rate. Using the lower limit of the combustible concentration of the mixed combustible gas as the target concentration value, and substituting it into the functional relationship represented by the internal state correlation model, the corresponding internal pressure of the battery is obtained by solving the following formula (3): C -gas =f(SOC, P -CIP , C -rate )(3), In the formula, C -gas The internal combustible gas concentration is P, and SOC is the overcharge state of the battery when the combustible gas concentration reaches the lower limit. -CIP Let C be the internal pressure of the battery to be solved. -rate This refers to the overcharge rate. The internal pressure P of the battery obtained by the solution -CIP The theoretical maximum safe burst pressure was determined to be [the pressure].

4. The method for optimizing the safety threshold of the lithium titanate battery explosion-proof valve according to claim 1, characterized in that, Based on the theoretical maximum safe burst pressure and the maximum internal pressure, the optimal burst pressure threshold for the explosion-proof valve is determined, including: Within the range of the maximum internal pressure as the lower limit and the theoretical maximum safe burst pressure as the upper limit, a sub-range that meets the engineering safety and reliability requirements is determined based on the safety factor k1 and the reliability factor k2, and the explosion-proof valve burst pressure optimization threshold is selected from the sub-range. The subinterval satisfies the following condition: P -nor_max k2≤P -optimal ≤P -max k1, Among them, P -nor_max P is the maximum internal pressure. -max P is the theoretical maximum safe burst pressure. -optimal The reliability coefficient k2 ranges from 1.3 to 1.5, and the safety coefficient k1 ranges from 0.8 to 0.95, which is the threshold value for the burst pressure optimization.

5. The method for optimizing the safety threshold of the lithium titanate battery explosion-proof valve according to claim 1, characterized in that, The internal combustible gas comprises one or more of hydrogen, carbon monoxide, methane, and ethane.

6. A dynamic design system for the burst pressure of an explosion-proof valve for lithium titanate batteries, characterized in that, include: The gas analysis module is used to obtain the composition and proportion of combustible gases inside the target model of lithium titanate battery under overcharge conditions; The lower flammability limit calculation module is used to determine the lower flammability concentration limit of the mixed flammable gas based on the components and proportions. The safety pressure calculation module is used to determine the theoretical maximum safe explosion pressure to ensure the gas is non-flammable based on the internal state correlation model and the lower limit of flammable concentration; wherein, the internal state correlation model is used to characterize the overcharge state of the battery, the correspondence between internal pressure and flammable gas concentration; The normal pressure acquisition module is used to acquire the maximum internal pressure of the target model lithium titanate battery during normal operation throughout its entire life cycle; The threshold decision module is used to determine the explosion pressure optimization threshold of the explosion-proof valve based on the theoretical maximum safe explosion pressure and the maximum internal pressure, wherein the explosion pressure optimization threshold is less than or equal to the theoretical maximum safe explosion pressure.

7. A lithium titanate battery, characterized in that, include: case; An explosion-proof valve is provided on the housing, the explosion-proof valve having a burst pressure optimization threshold determined by the safety threshold optimization method for lithium titanate battery explosion-proof valves according to any one of claims 1 to 5, and is configured to open and release pressure when the internal pressure of the battery reaches the preset burst pressure optimization threshold. Wherein, the preset explosion pressure optimization threshold is less than or equal to the internal pressure corresponding to the lower limit of combustible gas concentration inside the lithium titanate battery under extreme overcharge state.

8. The lithium titanate battery according to claim 7, characterized in that, There is an inherent correspondence between the internal pressure and the internal combustible gas concentration of the lithium titanate battery. This inherent correspondence matches the internal state correlation model, which characterizes the correspondence between the battery's overcharge state, internal pressure, and combustible gas concentration.

9. An electronic device comprising a processor, a communication interface, a memory, and a communication bus, wherein, The processor, the communication interface, and the memory communicate with each other via the communication bus, characterized in that... The memory is used to store computer programs; The processor is configured to execute the safety threshold optimization method for the lithium titanate battery explosion-proof valve according to any one of claims 1 to 5 by running the computer program stored in the memory.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, wherein the computer program is configured to execute the safety threshold optimization method for the lithium titanate battery explosion-proof valve as described in any one of claims 1 to 5 when it runs.

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