Electrolyte solid interface film detection method and device

Abstract

The invention provides an electrolyte solid interface film detection method and device, electronic equipment, a storage medium and a vehicle. The method comprises the following steps: if the cycle charging period number of a battery cell under a first charging strategy reaches a preset period number, acquiring cycle internal voltage data and cycle voltage data of the battery cell in a cycle period; differential processing is carried out on the cyclic internal pressure data and the cyclic voltage data, cyclic differential ratios corresponding to the cyclic internal pressure data and the cyclic voltage data are determined, and a cyclic curve corresponding to the cyclic differential ratios is constructed; and comparing the circulation curve with a pre-constructed formation curve, and if the circulation curve and the formation curve have the same film forming site, determining that the electrolyte solid interface film in the battery cell is reconstructed. Whether the electrolyte solid interface thin film of the battery cell is reconstructed or not is detected according to the acquired internal voltage data and voltage data of the battery cell in real time, so that whether the performance of the battery is degraded or not is quickly determined.

Description

Technical Field

[0001] This disclosure relates to the field of battery cell technology, and in particular to a method, apparatus, electronic device, storage medium, and vehicle for detecting electrolyte solid interface thin films. Background Technology

[0002] During the charging and discharging process of a lithium-ion battery, the reducing substances and oxides produced by the decomposition of solutes in the electrolyte react on the electrode surface to form a thin film, known as the solid electrolyte interface (SEI) film. This film possesses certain conductivity and stability, preventing further decomposition of the solutes in the electrolyte and thus protecting the electrode materials inside the battery.

[0003] However, during the cycling process of lithium-ion batteries, the negative electrode material may undergo volume changes due to the insertion and extraction of lithium ions, leading to severe expansion or microcracks in the negative electrode, damaging or altering the original SEI film structure. In this case, SEI film reconstruction or repair is necessary. However, SEI film reconstruction or repair is accompanied by the generation of a large amount of gas and the loss of active lithium, resulting in a decline in battery performance. Battery performance includes key indicators such as capacity, energy density, cycle life, and safety. Because current technology cannot effectively predict or detect changes in the SEI, the cell may suddenly malfunction or experience performance degradation during use, posing risks to practical applications. Therefore, how to detect or predict the reconstruction of the SEI film is currently of paramount importance. Summary of the Invention

[0004] This disclosure provides a method, apparatus, electronic device, storage medium, and vehicle for detecting electrolyte solid interface thin films.

[0005] According to a first aspect of this disclosure, a method for detecting electrolyte solid-state interface films is provided. The method includes: if the number of cycle charging cycles of a battery cell under a first charging strategy reaches a preset number of cycles, then acquiring cycle internal pressure data and cycle voltage data of the battery cell within the cycle, wherein the first charging strategy is an initial charging strategy preset for the battery cell; performing differential processing on the cycle internal pressure data and cycle voltage data to determine the cycle differential ratio corresponding to the cycle internal pressure data and cycle voltage data, and constructing a cycle curve corresponding to the cycle differential ratio; comparing the cycle curve with a pre-constructed formation curve, and if the cycle curve and formation curve have the same film formation sites, then determining the reconstruction of the electrolyte solid-state interface film in the battery cell, wherein the formation curve is a curve constructed by using the formation voltage data and formation internal pressure data of the battery cell during the formation process.

[0006] In some embodiments of this disclosure, the cycling curve is compared with a pre-constructed formation curve. If the cycling curve contains the same film-forming sites as the formation curve, the electrolyte solid interface film reconstruction in the cell is determined. Then, the method includes: adjusting the cell rate in the first charging strategy, and using the adjusted cell rate as the cell rate of the second charging strategy to obtain the adjusted second charging strategy.

[0007] In some embodiments of this disclosure, the cycling curve is compared with a pre-constructed formation curve. If the cycling curve contains a film-forming site identical to the formation curve, the reconstruction of the electrolyte solid interface film in the cell is determined. Prior to this, the method includes: determining formation voltage data and formation internal pressure data during the formation process of the cell; performing differential processing on the formation internal pressure data and formation voltage data to determine the formation differential ratio corresponding to the formation internal pressure data and formation voltage data, and constructing a formation curve corresponding to the formation differential ratio; analyzing the formation curve to determine the formation gas generation peak in the formation curve and the formation differential value and formation voltage value of the formation gas generation peak; using the formation gas generation peak as a film-forming site, and the formation voltage value and formation differential value as the film-forming voltage value and film-forming differential value of the film-forming site.

[0008] In some embodiments of this disclosure, the cycling curve is compared with a pre-constructed formation curve. If the cycling curve contains a film-forming site identical to the formation curve, the reconstruction of the electrolyte solid interface film in the cell is determined. This includes: determining the cycling gas generation peak in the cycling curve, and the cycling differential value and cycling voltage value corresponding to the cycling gas generation peak; comparing the cycling curve with the formation curve, if the cycling differential value and cycling voltage value in the cycling curve are the same as the film-forming voltage value and film-forming differential value of the film-forming site in the formation curve, then the existence of a film-forming site identical to the formation curve in the cycling curve is determined.

[0009] In some embodiments of this disclosure, the method further includes: comparing the cycling curve with a pre-constructed formation curve; if the cycling curve does not contain the same film-forming sites as the formation curve, then it is determined that the electrolyte solid interface film in the cell has not been reconstructed.

[0010] In some embodiments of this disclosure, if the battery cell reaches a preset cycle under the first charging strategy, the cyclic internal pressure data and cyclic voltage data of the battery cell are acquired, including: acquiring the cyclic internal pressure value generated by the battery cell within the cyclic cycle under the first charging strategy as determined by the battery cell internal pressure detection device, wherein the cyclic internal pressure value is obtained by the battery cell internal pressure detection device by converting the gas pressure value generated by the battery cell within the cyclic charging cycle under the first charging strategy; and acquiring the cyclic voltage data generated by the battery cell within the cyclic charging cycle under the first charging strategy collected by the voltage detection device.

[0011] According to a second aspect of this disclosure, an electrolyte solid interface thin film detection device is provided, the device comprising:

[0012] The acquisition unit is used to acquire the cyclic internal pressure data and cyclic voltage data of the battery cell within the cyclic period if the number of cyclic charging cycles of the battery cell under the first charging strategy reaches the preset number of cycles. The first charging strategy is the initial charging strategy preset for the battery cell.

[0013] The construction unit is used to perform differential processing on the cyclic internal pressure data and cyclic voltage data, determine the cyclic differential ratio corresponding to the cyclic internal pressure data and cyclic voltage data, and construct the cyclic curve corresponding to the cyclic differential ratio.

[0014] The determination unit is used to compare the cycling curve with the pre-constructed formation curve. If the cycling curve and the formation curve have the same film formation sites, the electrolyte solid interface film reconstruction in the cell is determined. The formation curve is a curve constructed by using the differential ratio of the cell's formation voltage data and formation internal pressure data during the cell formation process.

[0015] According to a third aspect of this disclosure, an electronic device is provided, comprising:

[0016] At least one processor; and

[0017] A memory communicatively connected to the at least one processor; wherein,

[0018] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method described in the first aspect above.

[0019] According to a fourth aspect of this disclosure, a non-transitory computer-readable storage medium is provided storing computer instructions, wherein the computer instructions are configured to cause the computer to perform the method described in the first aspect above.

[0020] According to a fifth aspect of this disclosure, a vehicle is provided, including an area determining device as described in the second aspect above or an electronic device as described in the third aspect above.

[0021] The electrolyte solid-state interface film detection method, apparatus, electronic device, storage medium, and vehicle disclosed herein acquire cyclic internal pressure data and cyclic voltage data of the battery cell within a cyclic period if the number of cyclic charging cycles of the battery cell under a first charging strategy reaches a preset number of cycles. The first charging strategy is an initial charging strategy pre-set for the battery cell. The cyclic internal pressure data and cyclic voltage data are differentiated to determine the corresponding cyclic differential ratio and construct a cyclic curve corresponding to the cyclic differential ratio. The cyclic curve is compared with a pre-constructed formation curve. If the cyclic curve and the formation curve have the same film formation sites, it is determined that the electrolyte solid-state interface film in the battery cell has reconstructed. The formation curve is a curve constructed using the differential ratio of the formation voltage data and formation internal pressure data of the battery cell during the formation process. This enables real-time detection of whether electrolyte solid-state interface film reconstruction has occurred in the battery cell based on the acquired internal pressure data and voltage data, thereby quickly determining whether battery performance has deteriorated.

[0022] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0023] The accompanying drawings are provided to better understand this solution and do not constitute a limitation of this disclosure. Wherein:

[0024] Figure 1 This is a schematic flowchart of a method for detecting electrolyte solid interface thin films provided in an embodiment of this disclosure;

[0025] Figure 2 This is a schematic flowchart of another method for detecting electrolyte solid interface thin films provided in an embodiment of this disclosure;

[0026] Figure 3 A schematic diagram of a first charging strategy and a second charging strategy provided in an embodiment of this disclosure;

[0027] Figure 4 This is a schematic flowchart of another method for detecting electrolyte solid interface thin films provided in an embodiment of this disclosure;

[0028] Figure 5 This is a schematic flowchart of another method for detecting electrolyte solid interface thin films provided in an embodiment of this disclosure;

[0029] Figure 6 This is a schematic diagram illustrating the comparison between a cyclic curve and a transformation curve provided in an embodiment of this disclosure.

[0030] Figure 7This is a schematic flowchart of another method for detecting electrolyte solid interface thin films provided in an embodiment of this disclosure;

[0031] Figure 8 This is a schematic diagram of a battery cell internal pressure detection device provided in an embodiment of the present disclosure;

[0032] Figure 9 This is a schematic diagram of a specific method for detecting electrolyte solid interface thin films provided in an embodiment of this disclosure;

[0033] Figure 10 This is a schematic diagram of the structure of an electrolyte solid interface thin film detection device provided in an embodiment of this disclosure;

[0034] Figure 11 A schematic block diagram of an example electronic device 1100 provided for embodiments of this disclosure. Detailed Implementation

[0035] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0036] To address the problems in related technologies, this disclosure utilizes a cell internal pressure detection device and a voltage detection device installed inside the vehicle to obtain the cell's cyclic internal pressure data and cyclic external pressure data. Based on the cell's cyclic voltage data and the cell's cyclic internal pressure data of gas production, a cyclic curve is plotted. The presence of electrolyte solid interface film formation sites identical to those in the formation curve is confirmed in the current cyclic curve using a pre-plotted formation curve. This allows for the determination of whether electrolyte solid interface film reconstruction has occurred in the cyclic curve, thereby providing timely warnings of cell performance risks and adjusting the charging strategy accordingly.

[0037] The following description, with reference to the accompanying drawings, outlines an electrolyte solid-state interface film detection method, apparatus, electronic device, storage medium, and vehicle according to embodiments of the present disclosure.

[0038] Figure 1 This is a schematic flowchart of a method for detecting electrolyte solid interface thin films provided in an embodiment of this disclosure. Figure 1 As shown, the method includes:

[0039] Step 101: If the number of charging cycles of the battery cell under the first charging strategy reaches the preset number of cycles, then obtain the internal pressure data and the cycle voltage data of the battery cell within the cycle.

[0040] In this disclosure, the first charging strategy is the initial charging strategy pre-set for the battery cell.

[0041] In some embodiments, a battery cell refers to the most basic component of a battery, typically an electrochemical device encapsulated in a metal casing. The first charging strategy refers to a pre-set initial charging strategy for the battery cell, which can be set by operators based on actual conditions and experience. For example, at a SOC of 50%, the corresponding cell rate is 3.5; at a SOC of 70%, the corresponding cell rate is 3. Specific values ​​are not limited in this embodiment. The first charging strategy includes the mapping relationship between the battery cell's SOC and the cell rate.

[0042] Cell rate refers to the rate at which a battery cell discharges per unit time. SOC (State of Charge) refers to the state of charge of a battery cell, representing the ratio of remaining charge to its rated capacity.

[0043] In this disclosure, the battery cell can be charged according to the first charging strategy in a cyclic charging cycle. If the current number of cyclic charging cycles reaches the preset number of cycles, the battery cell internal pressure acquisition device and voltage acquisition device inside the vehicle can be used to acquire the internal pressure value and voltage value of the battery cell, thereby obtaining the cyclic internal pressure data and cyclic voltage data of the battery cell in the current cyclic cycle.

[0044] The preset cycle number refers to the number of cycles of battery cell charging that is set in advance. Specifically, it can be set by the staff based on the actual situation and practical experience. It is not limited in this embodiment of the disclosure. In this disclosure, the preset cycle can be 100cyc or 200cyc as an example.

[0045] Step 102: Perform differential processing on the cyclic internal pressure data and cyclic voltage data to determine the cyclic differential ratio corresponding to the cyclic internal pressure data and cyclic voltage data, and construct the cyclic curve corresponding to the cyclic differential ratio.

[0046] In some embodiments, when the cyclic internal pressure data and cyclic voltage data within the current charging cycle are obtained, the cyclic internal pressure data and cyclic voltage data at each moment can be differentiated to obtain the cyclic internal pressure differential value corresponding to each cyclic internal pressure data and the cyclic voltage differential value corresponding to each cyclic voltage data; the cyclic differential ratio of the cyclic internal pressure differential value and the cyclic voltage differential value at each moment is determined; the cyclic differential ratio is used as the vertical axis of the cyclic curve, and the cyclic voltage value is used as the horizontal axis of the cyclic curve, thereby constructing the cyclic curve of the current charging cycle.

[0047] Step 103: Compare the cycling curve with the pre-constructed formation curve. If the cycling curve and the formation curve have the same film formation sites, then the electrolyte solid interface film reconstruction in the cell is determined.

[0048] In this disclosure, the formation curve is a curve constructed by using the formation voltage data and the formation internal pressure data of the battery cell during the formation process as the differential ratio of the formation process.

[0049] In some embodiments, the cycle curve of the current charging cycle is compared with the formation curve of the pre-constructed cell during the formation process to determine whether the current cycle curve has the same film formation sites as the formation curve. If the same film formation sites exist, the electrolyte solid interface film reconstruction in the current cell is determined.

[0050] The formation curve refers to the curve constructed by using the differential ratio of the formation voltage data and the formation internal pressure data of the battery cell during the formation process. The formation process refers to the process after the battery is manufactured, through a certain charging and discharging method to activate the positive and negative electrode materials inside the battery, thereby improving the battery's charging and discharging performance as well as its comprehensive performance such as self-discharge and storage.

[0051] Furthermore, when comparing the cycling curve with the pre-constructed formation curve, if the cycling curve does not contain the same film-forming sites as the formation curve, it is determined that the electrolyte solid interface film in the cell has not been reconstructed.

[0052] It is understandable that the electrolyte solid interface film that can form during the first charge and discharge of a lithium-ion battery is stable under normal circumstances, as the electrolyte does not decompose and no film-forming sites are generated in the cycle curve. Similarly, when the electrolyte solid interface film deteriorates and the electrolyte decomposes, film-forming sites will be generated in the cycle curve, indicating that the cell has experienced performance degradation during long-term cycle charging, the electrolyte solid interface film has undergone extensive reconstruction, and the cell generates a large amount of gas.

[0053] In summary, the technical solution provided in this disclosure, if the number of cycle charging cycles of the battery cell under the first charging strategy reaches a preset number of cycles, acquires the cycle internal pressure data and cycle voltage data of the battery cell within the cycle. The first charging strategy is the initial charging strategy preset for the battery cell. Differential processing is performed on the cycle internal pressure data and cycle voltage data to determine the cycle differential ratio corresponding to the cycle internal pressure data and cycle voltage data, and a cycle curve corresponding to the cycle differential ratio is constructed. The cycle curve is compared with a pre-constructed formation curve. If the cycle curve and formation curve have the same film formation sites, electrolyte solid interface film reconstruction in the battery cell is determined. The formation curve is a curve constructed during the formation process of the battery cell using the formation voltage data and formation internal pressure data of the battery cell. This enables real-time detection of whether electrolyte solid interface film reconstruction has occurred in the battery cell based on the acquired internal pressure data and voltage data, thereby quickly determining whether battery performance has deteriorated.

[0054] As one possible implementation, such as Figure 2 The flowchart of another method for detecting electrolyte solid-state interface films is shown. Based on the above embodiment, the cycling curve is compared with the pre-constructed formation curve. If the cycling curve contains the same film formation sites as the formation curve, the reconstruction of the electrolyte solid-state interface film in the cell is determined. The subsequent specific process includes the following steps:

[0055] Step 201: Adjust the cell rate in the first charging strategy, and use the adjusted cell rate as the cell rate in the second charging strategy to obtain the adjusted second charging strategy.

[0056] In some embodiments, since the electrolyte solid-state interface film detection method of this disclosure can be applied to the vehicle BMS control system, after determining the reconstruction of the electrolyte solid-state interface film in the battery cell, the vehicle BMS control system of this disclosure can directly adjust the cell rate corresponding to the SOC of some cells in the first charging strategy, thereby adjusting the first charging strategy to the second charging strategy. The second charging strategy includes the mapping relationship between the adjusted SOC of the battery cell and the cell rate.

[0057] While adjusting the battery cell rate, the vehicle's BMS control system can generate a warning signal corresponding to the current battery cell and send this warning signal to other control modules on the vehicle. The warning signal indicates that there is a problem with the current battery cell's status.

[0058] In one alternative embodiment of this disclosure, such as Figure 3 The schematic diagrams of the first and second charging strategies shown are for reference only. Figure 3The normal charging strategy is the first charging strategy in this disclosure, and the adjusted strategy is the second charging strategy in this disclosure. This disclosure adjusts the cell rate when the cell's SOC is 80%, 90%, and 100%, thereby obtaining the adjusted second charging strategy.

[0059] The specific value of the adjusted cell ratio can be determined based on the actual situation and is not limited in this embodiment.

[0060] It should be noted that after obtaining the second charging strategy, this disclosure will monitor the battery cell under the second charging strategy according to the cycle charging period. If the electrolyte solid interface film reconstruction in the battery cell is detected again, an early warning signal will be sent again and the second charging strategy will be adjusted. The specific process is the same as the above steps and will not be repeated in this disclosure.

[0061] In summary, this disclosure reduces the charging current and alleviates and improves the capacity decay phenomenon of the battery cell by adjusting the charging strategy in a timely manner after determining the reconstruction of the electrolyte solid interface film in the battery cell.

[0062] As one possible implementation, such as Figure 4 The flowchart of another method for detecting electrolyte solid-state interface films is shown. Based on the above embodiment, the cycling curve is compared with the pre-constructed formation curve. If the cycling curve contains the same film formation sites as the formation curve, the reconstruction of the electrolyte solid-state interface film in the cell is determined. The specific process before this also includes the following steps:

[0063] Step 301: Determine the formation voltage data and formation internal pressure data during the cell formation process.

[0064] In some embodiments, before comparison, it is necessary to construct the formation curve of the cell during the formation process. Specifically, the same cell internal pressure acquisition device and voltage acquisition device as in step 101 can be used to acquire the formation voltage value and formation internal pressure value of the cell during the formation process, thereby obtaining formation voltage data and formation internal pressure data.

[0065] Step 302: Perform differential processing on the formation internal pressure data and formation voltage data to determine the formation differential ratio corresponding to the formation internal pressure data and formation voltage data, and construct the formation curve corresponding to the formation differential ratio.

[0066] In some embodiments, when the formation internal pressure data and formation voltage data in the current formation process are obtained, the formation internal pressure data and formation voltage data at each moment can be differentiated to obtain the formation internal pressure differential value corresponding to each formation internal pressure data and the formation voltage differential value corresponding to each formation voltage data; the formation differential ratio of the formation internal pressure differential value and the formation voltage differential value at each moment is determined; the formation differential ratio is used as the vertical axis of the formation curve and the formation voltage value is used as the horizontal axis of the formation curve to construct the formation curve of the current cell in the formation process.

[0067] Step 303: Analyze the formation curve to determine the formation gas production peak, the formation differential value, and the formation voltage value of the formation gas production peak.

[0068] In some embodiments, after obtaining the formation curve, the formation gas production peak in the current formation curve, as well as the formation differential value and formation voltage value, can be determined. The formation gas production peak is the peak of the curve formed in the current formation curve; the formation differential value is the ratio of the formation internal pressure differential value and the formation voltage differential value mentioned in step 302, i.e., the ordinate of the formation curve; the formation voltage value is the voltage value in the formation voltage data determined in step 301 above.

[0069] Step 304: The gas generation peak of the formation is used as the film formation site. The formation voltage value and the formation differential value are the film formation voltage value and the film formation differential value of the film formation site.

[0070] In summary, the technical solution provided in this disclosure, by pre-forming the curve and determining the film formation sites, as well as the film formation voltage and differential value of the film formation sites, allows for comparison of the cycling curves, thereby determining whether electrolyte solid interface film reconstruction has occurred in the current cell and quickly determining whether battery performance has deteriorated.

[0071] As one possible implementation, such as Figure 5 The flowchart of another method for detecting electrolyte solid-state interface films is shown. Based on the above embodiments, the cycling curve is compared with the pre-constructed formation curve. If the cycling curve contains the same film formation sites as the formation curve, the specific process of electrolyte solid-state interface film reconstruction in the cell is determined. The method also includes the following steps:

[0072] Step 401: Determine the cyclic gas production peak in the cyclic curve, as well as the corresponding cyclic differential value and cyclic voltage value.

[0073] In some embodiments, this disclosure can analyze the circulation curve to determine the circulation gas production peak formed by the circulation curve, as well as the corresponding circulation differential value and circulation voltage value. The circulation gas production peak is the peak of the curve formed in the current circulation curve; the circulation differential value is the ratio of the circulation internal pressure differential value and the circulation voltage differential value mentioned in step 102, i.e., the ordinate of the circulation curve; the circulation voltage value is the voltage value in the circulation voltage data determined in step 101 above.

[0074] Step 402: Compare the cyclic curve with the formation curve. If the cyclic differential value and cyclic voltage value in the cyclic curve are the same as the film formation voltage value and film formation differential value of the film formation site in the formation curve, then it is determined that there is a film formation site in the cyclic curve that is the same as the formation curve.

[0075] In some embodiments, the obtained cyclic curve can be compared and analyzed with the formation curve. If the cyclic differential value and cyclic voltage value of the cyclic gas production peak of the cyclic curve are the same as the film formation voltage value and film formation differential value of the film formation site in the formation curve, it is determined that the cyclic curve has the same film formation site as the formation curve.

[0076] In one alternative embodiment of this disclosure, such as Figure 6 The diagram shows a comparison between the cyclic curve and the formation curve. The dashed line represents the cyclic curve, and the solid line represents the formation curve. The vertical axis represents the differential value, and the horizontal axis represents the voltage value. 2.65V, 3.4V, and 3.6V are all film formation sites.

[0077] In summary, the technical solution provided in this disclosure compares the cycling curve and the formation curve to confirm whether there are film-forming sites of the same electrolyte solid interface film as in the formation curve in the current cycling curve. This allows for the determination of whether electrolyte solid interface film reconstruction occurs in the cycling curve, thereby providing timely warnings of cell performance risks and adjusting the charging strategy accordingly.

[0078] As one possible implementation, such as Figure 7 The flowchart of another electrolyte solid interface thin film detection method is shown. Based on the above embodiment, if the battery cell reaches a preset cycle charging cycle under the first charging strategy, the specific process of obtaining the battery cell's cycle internal pressure data and cycle voltage data further includes the following steps:

[0079] Step 501: Obtain the cyclic internal pressure value generated by the battery cell during the cycle under the first charging strategy, as determined by the battery cell internal pressure detection device. The cyclic internal pressure value is obtained by converting the gas pressure value generated by the battery cell during the cyclic charging cycle under the first charging strategy by the battery cell internal pressure detection device.

[0080] In some embodiments, such as Figure 8The schematic diagram of the battery cell internal pressure detection device shown includes: a gas generating nail 1, a silicone oil pipe 2, an adapter pipe 3, a pressure gauge 4, an internal pressure detector 5, and a battery cell 6; one end of the gas generating nail 1 is welded to the liquid injection port of the battery cell 6; the other end of the gas generating nail 1 is connected to one end of the silicone oil pipe 2, the other end of the silicone oil pipe 2 is connected to one end of the adapter pipe 3, the other end of the adapter pipe 3 is connected to one end of the pressure gauge 4; and the other end of the pressure gauge 4 is connected to the internal pressure detector 5.

[0081] The gas-generating nail is connected to the silicone oil tube by a 100° bend at the upper middle part. The silicone oil tube is made of Teflon and filled with silicone oil. All connection ports in this disclosure are coated with epoxy sealant.

[0082] The cell internal pressure detection device can determine the cyclic internal pressure data using the above structure. Specifically, the gas generated during the cell's cyclic charging process compresses the silicone oil, causing a pressure gauge to detect the pressure change within the silicone oil tube. A data transmission line connects the gas pressure value from the pressure gauge to the internal pressure detector. The collected gas pressure values ​​can be transmitted and recorded via software, enabling real-time online monitoring.

[0083] Step 502: Obtain the cyclic voltage data generated by the battery cell during the cyclic charging cycle under the first charging strategy, collected by the voltage detection device.

[0084] In some embodiments, the voltage detection device is any detection device capable of detecting the voltage of the current battery cell, and is not limited in this disclosure.

[0085] In summary, the technical solution provided in this disclosure can acquire the internal pressure and voltage data of the battery cell in real time through the vehicle's built-in voltage detection device and the battery cell internal pressure detection device, so as to make a subsequent judgment on whether the electrolyte solid interface film of the battery cell has been reconstructed.

[0086] As one possible implementation, based on the above embodiments, such as Figure 9 As shown, this disclosure provides a schematic diagram of a specific method for detecting electrolyte solid interface thin films.

[0087] In some embodiments, this disclosure can be applied to a vehicle system. The vehicle system can integrate a cell internal pressure acquisition device, a voltage acquisition device, and an analysis module. During battery use, the cell internal pressure acquisition device and the voltage acquisition device can collect the cell internal pressure data and voltage data in real time under the first charging strategy according to the cycle charging cycle. When the number of cycle charging cycles reaches a preset number of cycles, the analysis module is used to draw a cycle curve (dG / dV-V curve), where dG is the differential value corresponding to the cell internal pressure data, dV is the differential value corresponding to the cell voltage data, and V is the cell voltage data.

[0088] Before comparing the formation curve and the cycling curve, this disclosure requires first constructing a formation curve (dG / dV-V curve) during the cell formation process, and confirming the film formation site X of the electrolyte solid interface film based on the formation curve.

[0089] By comparing the cycle curve during battery use with the formation curve during cell formation, if a film formation site X appears in the cycle curve, an early warning for the cell status is required, and the currently used first charging strategy is adjusted, i.e., the charging rate is reduced, and a second charging strategy is obtained.

[0090] If no film-forming site X appears in the cyclic curve, the original first charging strategy can be used to continue the cyclic detection.

[0091] Corresponding to the above-described method for detecting electrolyte-solid interface films, this invention also proposes an electrolyte-solid interface film detection device. Since the device embodiments of this invention correspond to the above-described method embodiments, details not disclosed in the device embodiments can be referred to the above-described method embodiments, and will not be repeated here.

[0092] Figure 10 This is a schematic diagram of the structure of an electrolyte solid interface thin film detection device provided in an embodiment of this disclosure, as shown below. Figure 10 As shown, the device includes:

[0093] The acquisition unit 1010 is used to acquire the cyclic internal pressure data and cyclic voltage data of the battery cell in the cyclic period if the number of cyclic charging cycles of the battery cell under the first charging strategy reaches the preset number of cycles. The first charging strategy is the initial charging strategy preset for the battery cell.

[0094] The construction unit 1020 is used to perform differential processing on the cyclic internal pressure data and cyclic voltage data, determine the cyclic differential ratio corresponding to the cyclic internal pressure data and cyclic voltage data, and construct the cyclic curve corresponding to the cyclic differential ratio.

[0095] The determination unit 1030 is used to compare the cycling curve with the pre-constructed formation curve. If the cycling curve and the formation curve have the same film formation sites, the electrolyte solid interface film reconstruction in the cell is determined. The formation curve is a curve constructed by using the differential ratio of the cell's formation voltage data and formation internal pressure data during the cell formation process.

[0096] In some embodiments of this disclosure, the apparatus 1000 further includes: an adjustment unit, configured to compare the cycling curve with a pre-constructed formation curve, and if the cycling curve contains the same film formation site as the formation curve, determine the electrolyte solid interface film reconstruction in the cell, and then adjust the cell rate in the first charging strategy, and use the adjusted cell rate as the cell rate of the second charging strategy to obtain the adjusted second charging strategy.

[0097] In some embodiments of this disclosure, the apparatus 1000 further includes: a pre-construction unit, configured to, before comparing the cycling curve with the pre-constructed formation curve and determining the electrolyte solid interface film reconstruction in the cell if the cycling curve contains a film-forming site identical to the formation curve, determine the formation voltage data and formation internal pressure data during the formation process of the cell; perform differential processing on the formation internal pressure data and formation voltage data to determine the formation differential ratio corresponding to the formation internal pressure data and formation voltage data, and construct the formation curve corresponding to the formation differential ratio; analyze the formation curve to determine the formation gas generation peak in the formation curve and the formation differential value and formation voltage value of the formation gas generation peak; the formation gas generation peak is used as a film-forming site, and the formation voltage value and formation differential value are the film-forming voltage value and film-forming differential value of the film-forming site.

[0098] In some embodiments of this disclosure, the determining unit 1030 is used to: determine the cyclic gas production peak in the cyclic curve, and the cyclic differential value and cyclic voltage value corresponding to the cyclic gas production peak; compare the cyclic curve with the formation curve, and if the cyclic differential value and cyclic voltage value in the cyclic curve are the same as the film formation voltage value and film formation differential value of the film formation site in the formation curve, then determine that there is a film formation site in the cyclic curve that is the same as the formation curve.

[0099] In some embodiments of this disclosure, the determining unit 1030 is further configured to: compare the cycling curve with the pre-constructed formation curve; if there is no film-forming site in the cycling curve that is the same as the formation curve, then determine that the electrolyte solid interface film in the cell has not been reconstructed.

[0100] In some embodiments of this disclosure, the acquisition unit 1010 is used to: acquire the cyclic internal pressure value generated by the battery cell during the cyclic period under the first charging strategy, as determined by the battery cell internal pressure detection device, wherein the cyclic internal pressure value is obtained by the battery cell internal pressure detection device by converting the gas pressure value generated by the battery cell during the cyclic charging period under the first charging strategy; and acquire the cyclic voltage data generated by the battery cell during the cyclic charging period under the first charging strategy collected by the voltage detection device.

[0101] It should be noted that the foregoing explanation of the method embodiments also applies to the apparatus of this embodiment, and the principle is the same, so it is not limited in this embodiment.

[0102] According to embodiments of this disclosure, this disclosure also provides an electronic device, a readable storage medium, and a vehicle.

[0103] Figure 11A schematic block diagram of an example electronic device 1100 that can be used to implement embodiments of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0104] like Figure 11 As shown, device 1100 includes a computing unit 1101, which can perform various appropriate actions and processes based on a computer program stored in ROM (Read-Only Memory) 1102 or loaded from storage unit 1108 into RAM (Random Access Memory) 1103. RAM 1103 may also store various programs and data required for the operation of device 1100. The computing unit 1101, ROM 1102, and RAM 1103 are interconnected via bus 1104. I / O (Input / Output) interface 1105 is also connected to bus 1104.

[0105] Multiple components in device 1100 are connected to I / O interface 1105, including: input unit 1106, such as keyboard, mouse, etc.; output unit 1107, such as various types of monitors, speakers, etc.; storage unit 1108, such as disk, optical disk, etc.; and communication unit 1109, such as network card, modem, wireless transceiver, etc. Communication unit 1109 allows device 1100 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0106] The computing unit 1101 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 1101 include, but are not limited to, CPUs (Central Processing Units), GPUs (Graphics Processing Units), various special-purpose AI (Artificial Intelligence) computing chips, various computing units running machine learning model algorithms, DSPs (Digital Signal Processors), and any suitable processor, controller, microcontroller, etc. The computing unit 1101 performs the various methods and processes described above, such as the electrolyte solid-state interface thin film detection method. For example, in some embodiments, the electrolyte solid-state interface thin film detection method can be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as storage unit 1108. In some embodiments, part or all of the computer program can be loaded and / or installed on device 1100 via ROM 1102 and / or communication unit 1109. When the computer program is loaded into RAM 1103 and executed by the computing unit 1101, one or more steps of the methods described above can be performed. Alternatively, in other embodiments, the computing unit 1101 may be configured to perform the aforementioned electrolyte solid interface film detection method by any other suitable means (e.g., by means of firmware).

[0107] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, FPGAs (Field Programmable Gate Arrays), ASICs (Application-Specific Integrated Circuits), ASSPs (Application-Specific Standard Products), SOCs (System-on-Chips), CPLDs (Complex Programmable Logic Devices), computer hardware, firmware, software, and / or combinations thereof. These various implementations may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0108] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0109] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, RAM, ROM, EPROM (Electrically Programmable Read-Only Memory) or flash memory, optical fiber, CD-ROM (Compact Disc Read-Only Memory), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0110] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (Cathode-Ray Tube) or LCD (Liquid Crystal Display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0111] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication (e.g., communication networks) of any form or medium. Examples of communication networks include LANs (Local Area Networks), WANs (Wide Area Networks), the Internet, and blockchain networks.

[0112] Computer systems can include clients and servers. Clients and servers are generally geographically separated and typically interact via communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. A server can be a cloud server, also known as a cloud computing server or cloud host, a hosting product within the cloud computing service ecosystem, addressing the shortcomings of traditional physical hosts and VPS (Virtual Private Server, or simply "VPS") services, such as high management difficulty and weak business scalability. Servers can also be servers for distributed systems or servers incorporating blockchain technology.

[0113] It's important to note that artificial intelligence (AI) is the study of enabling computers to simulate certain human thought processes and intelligent behaviors (such as learning, reasoning, thinking, and planning). It encompasses both hardware and software technologies. AI hardware technologies generally include sensors, dedicated AI chips, cloud computing, distributed storage, and big data processing. AI software technologies primarily include computer vision, speech recognition, natural language processing, machine learning / deep learning, big data processing, and knowledge graph technologies.

[0114] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0115] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for detecting electrolyte-solid interface thin films, characterized in that, The method includes: If the number of cyclic charging cycles of the battery cell under the first charging strategy reaches the preset number of cycles, then the cyclic internal pressure data and cyclic voltage data of the battery cell within the cyclic cycle are obtained. The first charging strategy is the initial charging strategy preset for the battery cell. The cyclic internal pressure data and the cyclic voltage data are differentiated to determine the cyclic differential ratio corresponding to the cyclic internal pressure data and the cyclic voltage data, and the cyclic curve corresponding to the cyclic differential ratio is constructed. The cycle curve is compared with the pre-constructed formation curve. If the cycle curve and the formation curve have the same film formation sites, the electrolyte solid interface film reconstruction in the cell is determined. The formation curve is a curve constructed by the formation differential ratio of the cell's formation voltage data and formation internal pressure data during the formation process.

2. The method according to claim 1, characterized in that, The method involves comparing the cycling curve with a pre-constructed formation curve. If the cycling curve contains film-forming sites identical to those on the formation curve, then the electrolyte solid-state interface film reconstruction in the cell is determined. The method then includes: The cell ratio in the first charging strategy is adjusted, and the adjusted cell ratio is used as the cell ratio in the second charging strategy to obtain the adjusted second charging strategy.

3. The method according to claim 1, characterized in that, The step of comparing the cycling curve with the pre-constructed formation curve, and determining the electrolyte solid-state interface film reconstruction in the cell if the cycling curve contains the same film-forming sites as the formation curve, includes the following steps: Determine the formation voltage data and formation internal pressure data during the formation process of the battery cell; The formation internal pressure data and formation voltage data are differentiated to determine the formation differential ratio corresponding to the formation internal pressure data and the formation voltage data, and the formation curve corresponding to the formation differential ratio is constructed. Analyze the formation curve to determine the formation gas production peak in the formation curve, as well as the formation differential value and formation voltage value of the formation gas production peak; The formation gas peak serves as the film formation site, and the formation voltage value and formation differential value are the film formation voltage value and film formation differential value of the film formation site.

4. The method according to claim 1, characterized in that, The step of comparing the cycling curve with the pre-constructed formation curve, and determining the electrolyte solid-state interface film reconstruction in the cell if the cycling curve contains the same film formation sites as the formation curve, includes: Determine the cyclic gas production peak in the cyclic curve, as well as the cyclic differential value and cyclic voltage value corresponding to the cyclic gas production peak; By comparing the cyclic curve with the formation curve, if the cyclic differential value and cyclic voltage value in the cyclic curve are the same as the film formation voltage value and film formation differential value of the film formation site in the formation curve, then it is determined that there is a film formation site in the cyclic curve that is the same as the formation curve.

5. The method according to claim 4, characterized in that, The method further includes: The cycling curve is compared with the pre-constructed formation curve. If there is no film-forming site in the cycling curve that is the same as the formation curve, it is determined that the electrolyte solid interface film in the cell has not been reconstructed.

6. The method according to claim 1, characterized in that, If the battery cell reaches a preset cycle in the first charging strategy, then the cyclic internal pressure data and cyclic voltage data of the battery cell are acquired, including: The internal pressure value of the battery cell generated during the cycle under the first charging strategy is obtained by the internal pressure detection device. The internal pressure value is obtained by the internal pressure detection device by converting the gas pressure value generated by the battery cell during the cycle under the first charging strategy. The voltage detection device collects the cyclic voltage data generated by the battery cell during the cyclic charging cycle under the first charging strategy.

7. An electrolyte solid interface thin film detection device, characterized in that, The device includes: The acquisition unit is used to acquire the cyclic internal pressure data and cyclic voltage data of the battery cell within the cyclic period if the number of cyclic charging cycles of the battery cell under the first charging strategy reaches a preset number of cycles. The first charging strategy is the initial charging strategy preset for the battery cell. A construction unit is used to perform differential processing on the cyclic internal pressure data and the cyclic voltage data, determine the cyclic differential ratio corresponding to the cyclic internal pressure data and the cyclic voltage data, and construct the cyclic curve corresponding to the cyclic differential ratio. A determination unit is used to compare the cycle curve with the pre-constructed formation curve. If the cycle curve and the formation curve have the same film formation sites, the electrolyte solid interface film reconstruction in the cell is determined. The formation curve is a curve constructed by the formation differential ratio of the cell's formation voltage data and formation internal pressure data during the formation process.

8. An electronic device, characterized in that, include: At least one processor; as well as A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to perform the method according to any one of claims 1 to 6.

10. A vehicle, characterized in that, This includes the electrolyte solid interface film detection device as described in claim 7 or the electronic device as described in claim 8.

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