A negative lithium precipitation early warning system and method based on battery pressure distribution characteristics

Abstract

A negative lithium precipitation early warning system and method based on battery pressure distribution characteristics, which incorporates spatial position information of pressure response to achieve accurate extraction of battery local anomalies, and aggregates distributed pressure measurement points into lithium precipitation high sensitive areas according to response intensity and spatial continuity. This area-level judgment method can greatly reduce the influence of single-point noise and online calculation amount. The pressure increment and differential characteristics of the lithium precipitation high sensitive area usually change earlier than the global average signal, so this method can provide more sufficient intervention time for the charging process. In addition, the method excludes the influence of temperature-pressure response when obtaining the pressure-charging capacity trajectory, reducing the interference on local abnormal pressure increment, sensitive area identification and differential warning criterion. At the same time, in some embodiments, the global pressure sensing can be converted to focus only on the local high sensitive area, thereby effectively reducing the number of sensors and acquisition channels, data processing burden and cost.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery fault diagnosis technology, specifically relating to an early warning system and method for negative electrode lithium plating based on battery pressure distribution characteristics. Background Technology

[0002] As lithium-ion batteries age and undergo numerous charge-discharge cycles, the lithium intercalation kinetics on the negative electrode surface gradually become unable to match the external charging rate. Lithium ion reduction on the negative electrode surface leads to lithium deposition, inducing capacity decay, dendrite growth, and interfacial side reactions, and even triggering internal short circuits and thermal runaway. Because lithium deposition causes additional deformations within the battery that differ from the normal lithium intercalation process, resulting in a spatially differentiated pressure distribution, many existing technologies, such as Chinese patents CN118777904A, CN120334773A, CN121216677A, and CN122362138A, have proposed methods and solutions for diagnosing lithium deposition using battery expansion force. However, when collecting the total expansion force signal, most existing technologies aggregate the responses of different regions within a large area of ​​the cell into a single overall curve. But the weak pressure anomalies concentrated in localized areas during the initial stages of lithium deposition are easily weakened by normal pressure increases or load transfers in other regions, resulting in a deviation between the signal and the true value. In addition, existing distributed sensing-based solutions not only face a large amount of processing work such as single-point features, cyclic trends, or global data reconstruction, but also still lack the ability to perform real-time lithium plating diagnosis and early warning for any charging process. Summary of the Invention

[0003] In view of this, and to address the technical problems existing in this field, the present invention provides an early warning method for lithium plating on the negative electrode based on battery pressure distribution characteristics, specifically including the following steps: S1. Distributed pressure measuring points are set between the outer surface of one or more individual cells inside the battery pack and the constraint components. During battery charging, pressure, temperature, current and voltage data of each measuring point are collected synchronously. The charging capacity is calculated and spatial coordinates are established according to the arrangement of the measuring points to obtain the pressure-charging capacity trajectory of each measuring point as the pressure changes with the charging capacity. The influence of pressure changes caused by different temperatures and states of charge is eliminated for this trajectory to obtain the pressure-charging capacity trajectory after thermo-mechanical coupling correction. S2. Select charging data where lithium plating did not occur, for spatial coordinates ( i , j At any measurement point of the charging start pressure, the pressure increment is calculated based on the charging start pressure, and the normal pressure increment benchmark corresponding to different charging capacities is obtained by aligning the charging capacity with the pressure-charging capacity trajectory. S3. Compare the pressure increment at each measuring point under the working condition to be analyzed with the normal pressure increment benchmark under the same filling capacity to obtain the local abnormal pressure increment. S4. Based on the magnitude of the local abnormal pressure increment at each measuring point after thermo-mechanical coupling correction, the measuring points are sorted and graded according to their response intensity; and based on the grading, combined with the adjacency relationship and spatial continuity between measuring points, adjacent measuring points with the same or similar response levels are aggregated into spatial regions; and the regions in which continuous aggregation forms and the local abnormal pressure increment is large are identified as highly sensitive regions for lithium plating. S5. Spatial averaging or weighted fusion of the pressure at each measuring point in the highly sensitive lithium plating region after thermo-mechanical coupling correction is performed to obtain the representative pressure signal of the region; for the pressure at each measuring point in each region under non-lithiation or quasi-equilibrium conditions after thermo-mechanical coupling correction, smoothing and differentiation are performed to obtain the first and second derivative characteristics of the pressure with respect to the charging capacity in the normal lithium intercalation state region, and the corresponding normal lithium intercalation derivative characteristic thresholds are calibrated. S6. Charge the target battery online and obtain the measurement point data of the lithium plating high-sensitivity area in its predetermined spatial location through the same method as S4 and S5. Calculate the first and second derivative characteristics of the pressure in the area with the charging capacity and compare them with the normal lithium intercalation derivative characteristic threshold to realize lithium plating judgment and early warning. S7. Based on the lithium plating determination and warning information, output the warning status and area location of the corresponding battery cell, and generate charging control commands.

[0004] Furthermore, in S1, a flexible thin-film pressure sensor array, a piezoresistive array, a capacitive array, a piezoelectric array, or other sensing devices with different measurement point densities capable of acquiring pressure at multiple points are specifically adopted for the distributed pressure measurement points.

[0005] Furthermore, the process of thermo-mechanical coupling correction for the pressure-charge capacity trajectory at each measuring point is as follows: Beforehand, under different representative states of charge, the monitored battery is subjected to controlled temperature changes by applying short-duration charge-discharge pulses, etc., while maintaining a constant charge capacity. The temperature and pressure changes at each measuring point or spatial region are recorded, establishing a temperature-pressure response relationship. Based on the real-time temperature and this response relationship, the corresponding pressure is subtracted from the original pressure-charge capacity trajectory to obtain the corrected pressure-charge capacity trajectory. This temperature-pressure response relationship can be established separately for a single measuring point, a spatial region composed of multiple adjacent measuring points, or a pressure sensing channel, to adapt to differences in initial contact states and mechanical transmission at different locations on the battery surface. When the temperature distribution on the surface of the monitored battery is uneven, multiple temperature measuring points can be set on the surface, and the local temperature corresponding to each measuring point can be obtained based on the measurement results and spatial location of each measuring point.

[0006] Furthermore, the representative pressure of the S5 medium-sensitive lithium plating region is specifically calculated by spatial averaging or weighted fusion of the thermo-mechanical coupling corrected pressure at each measuring point within the region.

[0007] Furthermore, the normal lithium intercalation threshold mentioned in S5 is specifically determined based on the differential characteristic extrema of multiple normal lithium intercalation samples, the degree of data dispersion, and measurement noise.

[0008] Furthermore, in S6, the first-order differential feature and the second-order differential feature are used as independent early warning paths, or one or a combination of the two can be selected to form an early warning path for lithium plating determination based on data stability.

[0009] Furthermore, the lithium plating determination and warning process in S6 is as follows: when the regional differential characteristics reach the preset determination conditions along the lithium plating anomaly direction and remain within a certain number of consecutive sampling points or a set charging capacity range, the position that first meets the determination conditions is determined as the lithium plating warning point, and the corresponding warning time, charging capacity, temperature, corresponding single cell and the location of the highly sensitive area are recorded.

[0010] Furthermore, S7 specifically sends control commands to the charging side or the power generation side based on lithium plating determination and early warning information, and performs controls including reducing the current charging current, adjusting charging stage parameters, extending the resting time, and stopping charging, in order to suppress the continued development of lithium plating.

[0011] Accordingly, the present invention also provides an early warning system for lithium plating on the negative electrode based on battery pressure distribution characteristics, for executing the above method. This system comprises a battery management system, a mechanical constraint structure, a distributed pressure acquisition module, a temperature acquisition module, and a voltage and current acquisition module. The mechanical constraint structure is used to form a stable force boundary with the individual battery cell or battery pack; the distributed pressure acquisition module is set between the monitored battery surface and adjacent cells, spacers, buffers, heat insulation components, end plates or other constraint components to acquire the pressure at multiple corresponding measurement points; the temperature acquisition module is used to acquire the battery temperature; the voltage and current acquisition module is used to acquire voltage and current information during the charging process; the battery management system is used to control the battery charging and discharging process and acquire data provided by each acquisition module to determine lithium plating and provide early warning.

[0012] The early warning system and method for negative electrode lithium plating based on battery pressure distribution characteristics provided by the present invention have at least the following advantages compared with the prior art: 1. The method incorporates spatial location information of pressure response, enabling the accurate extraction of local anomalies that are easily weakened by total force or global average signal, thereby improving the ability to perceive early mechanical changes in lithium plating of the negative electrode.

[0013] 2. By aggregating distributed pressure measurement points into highly sensitive lithium plating regions based on response intensity and spatial continuity, and using regional pressure signals for determination, the impact of single-point noise and the amount of online computation can be significantly reduced.

[0014] 3. By effectively utilizing the phenomenon that the pressure increment and differential characteristics of the lithium plating highly sensitive region usually change earlier than the average signal across the entire region, more sufficient intervention time can be provided for the charging process.

[0015] 4. When acquiring the pressure-charging capacity trajectory at the measurement point, the influence of temperature-pressure response is eliminated, reducing the interference of ambient temperature fluctuations and charging temperature rise on local abnormal pressure increments, sensitive area identification, and differential early warning criteria.

[0016] 5. After completing the full-area calibration, the data processing is changed from distributed pressure sensing across the entire surface to focusing only on local areas with high sensitivity, which can significantly reduce the number of sensors, acquisition channels, data processing burden and cost.

[0017] 6. This invention is applicable to various types of batteries and can output accurate and localizable lithium plating warning results for both individual cells and battery packs. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the offline stage process of the method provided by the present invention; Figure 2 This is a schematic diagram of the online stage process of the method provided by the present invention; Figure 3 This is a diagram illustrating the process of shifting from distributed global perception to local perception in highly sensitive areas during the implementation of this invention. Figure 4 This is a schematic diagram illustrating a preferred deployment method of the system provided by the present invention. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] This invention provides an early warning method for lithium plating on the negative electrode based on battery pressure distribution characteristics, such as... Figure 1 , 2 As shown, the specific steps include: S1. Distributed pressure measurement points are set between the outer surface of the individual battery cells and the constraint components inside the battery pack. During battery charging, pressure, temperature, current, and voltage data of each measurement point are collected synchronously. The charging capacity is calculated, and spatial coordinates are established according to the arrangement of the measurement points to obtain the pressure-charging capacity trajectory of each measurement point as the pressure changes with the charging capacity. The original pressure data is processed by channel calibration, invalid region clipping, outlier removal, and smoothing to obtain the charging capacity synchronously. The pressure sequence of each measurement point is converted into a trajectory of pressure change with the charging capacity. For pressure sensing units with zero point or sensitivity drift, an optional total force sensor set in the main force path can be used for reference calibration. Alternatively, the sensor's own zero point correction, sensitivity compensation, periodic calibration, relative change calculation, or other methods can be used to correct the measurement point deviation. The setting of the total force sensor does not affect the subsequent establishment of normal pressure increment benchmark, calculation of local abnormal pressure increment, and lithium plating warning. The influence of pressure changes caused by different temperatures and states of charge is eliminated for this trajectory to obtain the pressure-charging capacity trajectory after thermo-mechanical coupling correction. S2. Select charging data where lithium plating did not occur, for spatial coordinates ( i , j At any measuring point, the pressure increment Δ is calculated based on the initial charging pressure. P ( i , j , Q ), and according to the filling capacity Q Aligning with the pressure-filled capacity trajectory, the normal pressure increment reference Δ corresponding to different filling capacities is obtained. P ref ( i , j , Q ); S3. Compare the pressure increment at each measuring point under the operating condition to be analyzed with the normal pressure increment benchmark under the same filling capacity, and obtain the local abnormal pressure increment as follows:

[0021] Where, Δ P a ( i , j , Q ) indicates the measuring point ( i , j ) In charge capacity Q The local pressure response is newly added compared to the normal lithium intercalation condition. After capacity alignment, benchmark subtraction can reduce the influence of changes in the normal lithium intercalation stage, initial contact state, and differences in shell morphology on the results.

[0022] S4. Based on the magnitude of the local abnormal pressure increment at each measuring point after thermo-mechanical coupling correction, the measuring points are sorted and graded according to their response intensity; and based on the grading, combined with the adjacency relationship and spatial continuity between measuring points, adjacent measuring points with the same or similar response levels are aggregated into spatial regions; and the regions in which continuous aggregation forms and the local abnormal pressure increment is large are identified as highly sensitive regions for lithium plating. S5. Spatially average or weightedly fuse the pressures at each measuring point in the highly sensitive lithium-plating region after thermo-mechanical coupling correction to obtain the representative pressure signal for that region; For the pressures at each measuring point in each region under non-lithium-plating or quasi-equilibrium conditions after thermo-mechanical coupling correction... P r ( Q Then, smoothing and differentiation are performed to obtain the first and second derivative characteristics of the pressure versus charge capacity in the normal lithium intercalation region. and And calibrate the corresponding normal lithium intercalation differential characteristic threshold. T n ; S6. Charge the target battery online, and obtain the thermo-mechanically coupled corrected measurement point data of the lithium plating highly sensitive region in its predetermined spatial location using the same methods as S4 and S5. Calculate the first and second derivative characteristics of the region's pressure with respect to the charging capacity and compare them with the normal lithium intercalation derivative characteristic threshold. If this occurs, lithium plating is determined to have taken place; S7. Based on the lithium plating determination and warning information, output the warning status and area location of the corresponding battery cell, and generate charging control commands.

[0023] In some preferred embodiments, S1 specifically employs a flexible thin-film pressure sensor array, a piezoresistive array, a capacitive array, a piezoelectric array, or other sensing devices with different measurement point densities capable of acquiring pressure at multiple points for the distributed pressure measurement points.

[0024] In some preferred embodiments, the process of thermo-mechanical coupling correction for the pressure-charge capacity trajectory at each measuring point is as follows: Beforehand, under different representative states of charge, the monitored battery is subjected to controlled temperature changes by applying short-duration charge-discharge pulses, etc., while maintaining a constant charge capacity. The temperature and pressure changes at each measuring point or spatial region are recorded, and a temperature-pressure response relationship is established accordingly. Based on the real-time temperature and this response relationship, the corresponding pressure is subtracted from the original pressure-charge capacity trajectory to obtain the corrected pressure-charge capacity trajectory. This temperature-pressure response relationship can be established separately for a single measuring point, a spatial region composed of multiple adjacent measuring points, or a pressure sensing channel, to adapt to differences in initial contact states and mechanical transmission at different locations on the battery surface. When the temperature distribution on the surface of the monitored battery is uneven, multiple temperature measuring points can be set on the surface, and the local temperature corresponding to each measuring point can be obtained based on the measurement results and spatial location of each measuring point.

[0025] In some preferred embodiments, the representative pressure of the moderately lithium-plating highly sensitive region S5 is specifically calculated by spatially averaging the thermo-mechanically coupled corrected pressure at each measuring point within the region as follows:

[0026] in, P k ( Q ) is the first in the region k Each measuring point at the charging capacity Q Pressure at that point P r ( Q The pressure is representative of the region. When there are differences in contact area, measurement stability, or signal-to-noise ratio at different measuring points, a weighted fusion method can also be used to obtain the regional pressure.

[0027] In some preferred embodiments, the normal lithium intercalation threshold in S5 is specifically determined based on the differential characteristic extrema of multiple normal lithium intercalation samples, the degree of data dispersion, and measurement noise.

[0028] In some preferred embodiments, in S6, the first-order differential feature and the second-order differential feature are specifically used as independent early warning paths, or one or a combination of the two is selected to form an early warning path for lithium plating determination based on data stability.

[0029] In some preferred embodiments, the lithium plating determination and warning process in S6 is as follows: when the regional differential characteristics reach the preset determination condition along the lithium plating anomaly direction and remain within a certain number of consecutive sampling points or a set charging capacity range, the position that first meets the determination condition is determined as the lithium plating warning point, and the corresponding warning time, charging capacity, temperature, corresponding single cell and the location of the highly sensitive area are recorded.

[0030] In some preferred embodiments, S7 specifically sends control commands to the charging side or the power generation side based on lithium plating determination and early warning information, and performs controls including reducing the current charging current, adjusting charging stage parameters, extending the resting time, and stopping charging, so as to suppress the continued development of lithium plating.

[0031] Accordingly, the present invention also provides an early warning system for lithium plating on the negative electrode based on battery pressure distribution characteristics, for executing the above-described method. The system is as follows: Figure 4 As shown, it consists of a battery management system, a mechanical constraint structure, a distributed pressure acquisition module, a temperature acquisition module, and a voltage and current acquisition module; The mechanical constraint structure is used to form a stable force boundary with the individual battery cell or battery pack; the distributed pressure acquisition module is set between the monitored battery surface and adjacent cells, spacers, buffers, heat insulation components, end plates or other constraint components to acquire the pressure at multiple corresponding measurement points; the temperature acquisition module is used to acquire the battery temperature; the voltage and current acquisition module is used to acquire voltage and current information during the charging process; the battery management system is used to control the battery charging and discharging process and acquire data provided by each acquisition module to determine lithium plating and provide early warning.

[0032] In a specific embodiment of the present invention, a constrained prismatic lithium-ion battery pack is used as the monitoring object. The battery pack consists of multiple prismatic lithium-ion battery cells arranged sequentially, and thickness constraints are applied through end plates, connectors, and fastening structures. Each individual cell selects a large surface facing the same arrangement direction as the monitored surface. A distributed pressure sensing unit is installed between this monitored surface and buffer components, heat insulation components, separators, or end plates, thereby obtaining the pressure distribution on the surface of each individual cell. After system deployment, the charging side or power generation side provides charging energy to the battery pack and receives charging control commands sent by the battery management system. Under laboratory testing conditions, the charging side or power generation side can be a charge / discharge testing device or charger; in vehicle applications, it can be a vehicle charging pile; in energy storage applications, it can be an energy storage converter, a grid-side power interface, or a power input side connected to photovoltaic, wind power, and other power generation units. Each distributed pressure sensing unit has an independent acquisition channel. The battery management system stores the correspondence between the individual cell number, sensor channel, and spatial coordinates of the measurement point. Therefore, subsequent identification and early warning are based on individual battery cells as the basic monitoring object, and the early warning results can point to specific individual battery cells and their surface areas, rather than just outputting the overall abnormal state of the battery pack.

[0033] The distributed pressure acquisition module specifically employs a flexible thin-film pressure sensor. The sensor array includes 27 rows and 39 columns of measuring points, totaling 1053 measuring points. Each measuring point measures 2 mm × 2 mm and has a range of 500 kPa. Since the sensor's sensing range is larger than the monitored surface of the square battery, edge areas not in effective contact with the battery are removed during data processing, and rows 9 to 22 and columns 3 to 37 are selected as the effective sensing area. The above array specifications and trimming range are specific to this embodiment and can be adjusted according to the size of the individual battery cells and the sensor structure. To overcome potential zero-point or sensitivity drift in the thin-film pressure sensor during long-term pressure application, a total force sensor is also included as a calibration component. The total force sensor measures the change in the total expansion force of the battery pack, which is then used to perform reference calibration on each distributed pressure sensing unit. Suitable pressure sensors, such as load cells, can be used as the total force sensor.

[0034] In this example, the experiment was conducted at 0 °C with charging conditions of 0.3C, 0.5C, 0.7C and 0.9C, and compared with the pressure signal obtained by averaging the measurement points across the entire region. The results showed that the differential characteristics of the highly sensitive lithium plating region showed abnormal changes earlier, indicating that the local region can retain the early lithium plating mechanical response weakened by the global averaging process.

[0035] After identifying highly sensitive lithium plating regions for battery packs with the same battery model, casing size, internal structure, arrangement direction, and constraints, the same experience can be used to re-execute lithium plating judgment and warning processes, converting the distributed measurement point data across the entire area to focus only on highly sensitive regions. Figure 3 As shown, this can significantly reduce the number of sensors, acquisition channels, data processing burden, and costs. In some cases, only a small number of local strain sensors can be used, and their outputs can be converted into equivalent pressure after loading calibration and temperature compensation. Subsequently, the pressure increment, regional pressure, and their capacity differential characteristics can still be used as the basis for early warning.

[0036] It is important to note that after switching from global distributed pressure sensing to local sensors, the temperature-pressure response relationship, normal pressure increment reference, and normal lithium intercalation threshold need to be recalibrated according to the new sensor contact area, packaging stiffness, and installation status. The results obtained in the global distributed pressure sensing stage are mainly used to determine the sensor deployment location and are not directly transferred to the local sensors from the original array.

[0037] This invention is widely applicable to various usage scenarios, including consumer electronics batteries, power batteries, and energy storage batteries. The monitored battery can be a prismatic hard-shell battery, a pouch battery, a cylindrical battery, or a lithium-ion battery with other casing forms. For batteries with a flat surface, distributed pressure sensing units can be positioned between the cell surface and the constraint components; for batteries with curved casings, measurement points can be arranged along the curved surface of the casing or its contact surface with the constraint structure, and the measurement point positions can be mapped to two-dimensional unfolded coordinates. When applied to battery packs, pressure sensing units can be placed between one or more target individual cells and adjacent cells, buffer components, heat insulation components, end plates, or other constraint components. The battery management system stores the correspondence between the measurement channels, spatial coordinates, and the monitored individual cells.

[0038] It should be understood that the sequence number of each step in the embodiments of the present invention does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for early warning of lithium plating in negative electrodes based on battery pressure distribution characteristics, characterized in that: Specifically, the following steps are included: S1. Distributed pressure measuring points are set between the outer surface of one or more individual cells inside the battery pack and the constraint components. During battery charging, pressure, temperature, current and voltage data of each measuring point are collected synchronously. The charging capacity is calculated and spatial coordinates are established according to the arrangement of the measuring points to obtain the pressure-charging capacity trajectory of each measuring point as the pressure changes with the charging capacity. The influence of pressure changes caused by different temperatures and states of charge is eliminated for this trajectory to obtain the pressure-charging capacity trajectory after thermo-mechanical coupling correction. S2. Select charging data where lithium plating did not occur, for spatial coordinates ( i , j At any measurement point of the charging start pressure, the pressure increment is calculated based on the charging start pressure, and the normal pressure increment benchmark corresponding to different charging capacities is obtained by aligning the charging capacity with the pressure-charging capacity trajectory. S3. Compare the pressure increment at each measuring point under the working condition to be analyzed with the normal pressure increment benchmark under the same filling capacity to obtain the local abnormal pressure increment. S4. Based on the magnitude of the local abnormal pressure increment at each measuring point after thermo-mechanical coupling correction, sort and classify the response intensity of the measuring points. Based on the aforementioned classification, and considering the adjacency relationship and spatial continuity between measurement points, adjacent measurement points with the same or similar response levels are aggregated into spatial regions; and regions in which continuous aggregation patterns are formed and local abnormal pressure increments are identified as highly sensitive regions for lithium plating. S5. Spatial averaging or weighted fusion of the pressure at each measuring point in the highly sensitive lithium plating region after thermo-mechanical coupling correction is performed to obtain the representative pressure signal of the region; for the pressure at each measuring point in each region under non-lithiation or quasi-equilibrium conditions after thermo-mechanical coupling correction, smoothing and differentiation are performed to obtain the first and second derivative characteristics of the pressure with respect to the charging capacity in the normal lithium intercalation state region, and the corresponding normal lithium intercalation derivative characteristic thresholds are calibrated. S6. Charge the target battery online and obtain the measurement point data of the lithium plating high-sensitivity area in its predetermined spatial location through the same method as S4 and S5. Calculate the first and second derivative characteristics of the pressure in the area with the charging capacity and compare them with the normal lithium intercalation derivative characteristic threshold to realize lithium plating judgment and early warning. S7. Based on the lithium plating determination and warning information, output the warning status and area location of the corresponding battery cell, and generate charging control commands.

2. The method as described in claim 1, characterized in that: S1 specifically employs a flexible thin-film pressure sensor array, a piezoresistive array, a capacitive array, or a piezoelectric array for the aforementioned distributed pressure measurement points.

3. The method as described in claim 1, characterized in that: The process of thermo-mechanical coupling correction for the pressure-charge capacity trajectory at each measuring point is as follows: In advance, under different representative states of charge, the monitored battery is subjected to short-time charge-discharge pulses to induce controlled temperature changes while keeping the charge capacity constant. The temperature and pressure changes at each measuring point or spatial region are recorded, and the temperature-pressure response relationship is established accordingly. Based on the real-time temperature and the response relationship, the original pressure-capacity trajectory is modified by subtracting the corresponding pressure from the original pressure-capacity trajectory.

4. The method as described in claim 1, characterized in that: The representative pressure of the S5 medium-sensitive lithium plating region is calculated by spatial averaging or weighted fusion of the thermo-mechanical coupling corrected pressure at each measuring point in the region.

5. The method as described in claim 1, characterized in that: The normal lithium intercalation threshold described in S5 is specifically determined based on the differential characteristic extrema of multiple normal lithium intercalation samples, the degree of data dispersion, and measurement noise.

6. The method as described in claim 1, characterized in that: Specifically, S6 uses first-order differential features and second-order differential features as independent early warning paths, or selects one or a combination of the two based on data stability to form an early warning path for lithium plating determination.

7. The method as described in claim 1, characterized in that: The lithium plating detection and warning process in S6 is as follows: when the regional differential characteristics reach the preset detection conditions along the abnormal lithium plating direction and remain within a certain number of consecutive sampling points or a set charging capacity range, the position that first meets the detection conditions is determined as the lithium plating warning point, and the corresponding warning time, charging capacity, temperature, corresponding single cell and the location of the highly sensitive area are recorded.

8. The method as described in claim 1, characterized in that: Specifically, S7 sends control commands to the charging or generating side based on lithium plating determination and early warning information, and performs controls such as reducing the current charging current, adjusting charging stage parameters, extending the resting time, and stopping charging to suppress the continued development of lithium plating.

9. An early warning system for lithium plating on a negative electrode based on battery pressure distribution characteristics, used to perform the method as described in any one of claims 1-8, comprising a battery management system, a mechanical constraint structure, a distributed pressure acquisition module, a temperature acquisition module, and a voltage and current acquisition module; in, Mechanical constraint structures are used to form stable force boundaries with individual battery cells or battery packs; distributed pressure acquisition modules are set at multiple different locations on the battery surface and inside to acquire the pressure at the corresponding measurement points; temperature acquisition modules are used to acquire battery temperature; voltage and current acquisition modules are used to acquire voltage and current information during the charging process. The battery management system is used to control the battery charging and discharging process and to acquire data from various acquisition modules to determine and warn of lithium plating.

Images