Power battery, and health evaluation method and health evaluation apparatus therefor

Abstract

The present application relates to a power battery, and a health evaluation method and and a health evaluation apparatus therefor. The power battery comprises a battery cell, an expansion force sensor and an electrode plate sensor, the battery cell comprising electrode plates. The expansion force sensor is electrically connected to the battery cell, and is configured to collect expansion force at different thickness positions of the battery cell and evaluate the state of health of the power battery on the basis of the expansion force; the electrode plate sensor is electrically connected to the battery cell, and is configured to collect the thickness of the electrode plates at different thickness positions of the battery cell, and evaluate the state of health of the power battery on the basis of the thicknesses of the electrode plates.

Description

Power battery and health assessment method and health assessment device thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 31, 2023, with application number 202311125555.4. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, for example, to a power battery and its health assessment method and health assessment device. Background Art

[0003] With the rapid development of the new energy vehicle market, power batteries have also experienced explosive growth. Currently, standards and specifications related to power battery systems have been established, and the country has also formulated corresponding subsidy policies. Rapidly promoting the development of power batteries has become a general trend, and power batteries have been widely used in the power, energy storage, and commercial vehicle sectors. During use, power battery cells may experience problems such as overcharging, over-discharging, short circuiting, extrusion, and overheating, leading to cell failure and safety accidents. Therefore, real-time monitoring of cell health status and early prediction of cell outage alarms are of great significance. Currently, the industry lacks real-time intelligent monitoring solutions for battery cell health status, which poses a significant safety risk during battery cell use. Technical issues

[0004] This application provides a power battery and its health assessment method and device, which can monitor the expansion force of the battery cell and the change in the thickness of the electrode sheet, thereby monitoring the safety status of the battery cell and reducing the safety risk of the battery cell. Technical Solutions

[0005] In a first aspect, an embodiment of the present application provides a power battery, comprising a battery cell, an expansion force sensor, and a pole piece sensor, wherein:

[0006] The battery cell includes a pole piece;

[0007] The expansion force sensor is electrically connected to the battery cell and is configured to collect expansion forces at different thickness positions of the battery cell and evaluate the health status of the power battery based on the expansion forces;

[0008] The pole piece sensor is electrically connected to the battery cell and is configured to collect the thickness of the pole piece at different thickness positions of the battery cell and evaluate the health status of the power battery based on the thickness of the pole piece.

[0009] In a second aspect, an embodiment of the present application further provides a health assessment method for a power battery, wherein the power battery includes the power battery described above, and the health assessment method includes:

[0010] collecting the expansion force of the power battery at different thickness positions of the battery cell by an expansion force sensor, and evaluating the health status of the power battery according to the expansion force;

[0011] The thickness of the electrode sheets at different thickness positions of the battery cell is collected by a electrode sheet sensor, and the health status of the power battery is evaluated based on the thickness of the electrode sheets;

[0012] The processor further evaluates the health status of the power battery according to the evaluation results of the expansion force sensor and the evaluation results of the pole piece sensor.

[0013] In a third aspect, an embodiment of the present application further provides a health assessment device for a power battery, wherein the power battery includes the power battery described above, and the health assessment device includes a processor, and the processor is configured to further evaluate the health status of the power battery based on the evaluation results of the expansion force sensor and the evaluation results of the pole piece sensor. Beneficial effects

[0014] Beneficial effects of the present application: The above introduces a power battery and its health assessment method and health assessment device. The power battery includes: the power battery includes a battery cell, an expansion force sensor and a pole piece sensor, wherein: the battery cell includes a pole piece; the expansion force sensor is electrically connected to the battery cell, and is configured to collect the expansion force at different thickness positions of the battery cell, and evaluate the health status of the power battery based on the expansion force; the pole piece sensor is electrically connected to the battery cell, and is configured to collect the thickness of the pole piece at different thickness positions of the battery cell, and evaluate the health status of the power battery based on the thickness of the pole piece. Therefore, the health status of the battery can be evaluated by respectively collecting the expansion force at different thickness positions of the battery cell and the thickness of the pole piece of the battery cell through multiple sensors, so that the safety status of the battery cell can be monitored in real time and comprehensively, reducing the safety risk of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG1 is a schematic diagram of the main structure of a power battery provided in an embodiment of the present application;

[0016] FIG2 is a schematic diagram of a side structure of the power battery shown in FIG1 ;

[0017] FIG3 is a schematic diagram of the fixing structure of the pole piece sensor of the power battery shown in FIG2 ;

[0018] FIG4 is another side structural schematic diagram of the power battery shown in FIG1 ;

[0019] FIG5 is a schematic flow chart of a method for health assessment of a power battery provided in an embodiment of the present application;

[0020] FIG6 is a schematic block diagram of a power battery health assessment device provided in an embodiment of the present application.

[0021] The reference numerals in the embodiments of the present application are described as follows:

[0022] Power battery 100, core package 11, expansion force sensor 12, pole piece sensor 13, battery cell 111, pole ear 112, shell 14, first collection harness 121, first sampling harness 1213, first winding harness 1211, first transmission harness 1212, top surface 141, first side surface 142, second side surface 143, one-eighth thickness position 112, three-eighth thickness position 113, five-eighth thickness position 114, seven-eighth thickness Degree position 115, center line position 116, winding wires 1211A, 1211B and 1211C, high-temperature adhesive tape 150, second collection harness 131, second winding harness 1311, second sampling harness 1312, second transmission harness 1313, winding wires 1311A, 1311B and 1311C, high-temperature adhesive tape 140, liquid injection hole 144, positive electrode 145, negative electrode 146, circular hole 147, processor 21. Modes for Carrying Out the Invention

[0023] Please refer to Figures 1-4. Figure 1 is a schematic diagram of the front structure of a power battery provided in an embodiment of the present application. Figure 2 is a schematic diagram of the structure of a side view of the power battery shown in Figure 1. Figure 3 is a schematic diagram of the fixed structure of the pole piece sensor of the power battery shown in Figure 2. Figure 4 is a schematic diagram of the structure of another side view of the power battery shown in Figure 1. The power battery 100 of the embodiment of the present application includes a core pack 11, an expansion force sensor 12, and a pole piece sensor 13, wherein:

[0024] The core pack 11 includes battery cells 111 and tabs 112 extending from the battery cells 111. Depending on the number of core packs 11, the power battery 100 can be a single-cell pack battery, a dual-cell pack battery, or a multi-cell pack battery. The manufacturing process for the core pack 11 includes winding and lamination. Unless otherwise specified, the following description uses a core pack 11 including a single battery cell 111 as an example.

[0025] The battery cell 111 includes electrode sheets (not shown). The thickness of the electrode sheets changes during use, with the thickness of the negative electrode sheet changing more significantly. Batteries, especially lithium batteries, are prone to swelling after long-term storage and cycling. Due to the influence of the graphite negative electrode, the negative electrode graphite forms compounds such as LiCx during lithium insertion, causing lattice changes between molecules and generating microscopic internal stress, which leads to swelling of the negative electrode graphite end. The binder and electrolyte also affect the change in electrode sheet thickness. During charging, lithium ions are inserted from the positive electrode into the negative electrode, causing the negative electrode graphite lattice to expand, the negative electrode particles and the binder to deform, and the internal stress at the negative electrode is released, resulting in an increased expansion rate of the battery's negative electrode. Changes in the thickness of the positive and negative electrode sheets directly affect the performance and health of the battery cell. Therefore, it is necessary to monitor changes in electrode sheet thickness to guide the battery cell thickness planning for optimal performance.

[0026] The expansion force sensor 12 is electrically connected to the battery cell 111 and is configured to collect expansion forces at different thickness positions of the battery cell 111 and evaluate the health status of the power battery based on the expansion forces.

[0027] The pole piece sensor 13 is electrically connected to the battery cell 111 and is configured to collect the thickness of the pole pieces at different thickness positions of the battery cell 111 and evaluate the health status of the power battery according to the thickness of the pole pieces.

[0028] Therefore, this embodiment can use multiple sensors to collect the expansion force at different thickness positions of the battery cell and the thickness of the battery cell electrode to evaluate the health status of the battery, thereby being able to monitor the safety status of the battery cell in real time and in all directions, reducing the safety risk of the battery cell.

[0029] Optionally, the power battery 100 includes a housing 14, and the battery cell 111 is disposed within the housing 14. The housing 14 may be a wound square aluminum shell, a cylinder, a laminated square aluminum shell, or the like. When the battery cell 111 expands due to heating or other factors, excessive pressure within the battery cell 111 occurs. This embodiment collects the pressure caused by the expansion within the battery cell to measure the expansion force of the battery cell 111. Specifically, the expansion force of the electrode thickness within the battery cell 111 may be collected as the expansion force of the battery cell 111.

[0030] Optionally, the expansion force sensor 12 includes multiple groups of first acquisition harnesses 121 and a first processor (not shown) electrically connected to the first acquisition harnesses 121, the multiple groups of first acquisition harnesses 121 are respectively arranged on different side surfaces of the shell 14, the first processor is arranged on the top surface of the shell 14, and the multiple groups of first acquisition harnesses 121 respectively collect the expansion force of the battery cell 111 at different thickness positions and transmit the collected expansion force to the first processor.

[0031] Optionally, each group of the first acquisition harness 121 includes a first sampling harness 1213, a first winding harness 1211 and a first transmission harness 1212, one end of the first sampling harness 1213 is arranged inside the battery cell 111, and the other end is connected to the first winding harness 1211, the first winding harness 1211 is arranged on the side of the shell 14, and the first transmission harness 1212 is electrically connected to the first winding harness 1211 and the first processor, respectively, and is configured to transmit the expansion force.

[0032] The first sampling harnesses 1213 of the plurality of first collection harnesses 121 are respectively arranged at positions of different thicknesses of the battery cell 111 , and the first winding harness 1211 connected to the first sampling harnesses 1213 is arranged on the nearest side of the housing 14 .

[0033] In a specific embodiment, as shown in FIG1 , the housing 14 is a rectangular parallelepiped, with a first processor mounted on its top surface 141. Its four side surfaces include two parallel, larger first side surfaces 142 and two parallel, smaller second side surfaces 143. As shown in FIG4 , when there are two battery cells 111, i.e., when two battery cells 111 form a dual-cell pack battery, multiple sets of first sampling harnesses 1213 of the first acquisition harnesses 121 are respectively positioned at one-eighth thickness position 112, three-eighth thickness position 113, five-eighth thickness position 114, and seven-eighth thickness position 115 of the dual-cell pack. It should be understood that these thickness locations refer to the thickness from one cell 111 to the other after two cells 111 are stacked. As shown in Figure 4, one-eighth thickness location 112 and seven-eighth thickness location 115 are symmetrical relative to the centerline location 116 of the two-cell package. Similarly, three-eighth thickness location 113 and five-eighth thickness location 114 are symmetrical relative to the centerline location 116 of the two-cell package. By collecting the expansion force at different thickness locations, the expansion force within the cell 111 can be comprehensively monitored, thereby obtaining more accurate expansion force data and achieving precise monitoring.

[0034] Furthermore, because the two first side surfaces 142 with larger areas are located in the direction from one battery cell 111 to the other, the one-eighth thickness position 112 and the seven-eighth thickness position 115 of the battery cell 111 are closer to the first side surfaces 142, that is, the one-eighth thickness position 112 is closer to one of the first side surfaces 142, and the seven-eighth thickness position 115 is closer to the other first side surface 142. As a result, the first sampling wire harnesses 1213 at the one-eighth thickness position 112 and the seven-eighth thickness position 115 are electrically connected to the first winding wire harnesses 1211 on the corresponding first side surfaces 142 according to the principle of proximity. That is, the first sampling wire harnesses 1213 at the one-eighth thickness position 112 and the seven-eighth thickness position 115 are electrically connected to the first winding wire harnesses 1211 on the first side surface 142. Similarly, the three-eighths thickness position 113 and the five-eighths thickness position 114 of the battery cell 111 are closer to the second side surface 143, that is, the three-eighths thickness position 113 is close to one of the second side surfaces 143, and the five-eighths thickness position 114 is close to the other second side surface 143. Therefore, the first sampling wire harnesses 1213 at the three-eighths thickness position 113 and the five-eighths thickness position 114 are electrically connected to the first winding wire harnesses 1211 disposed on the corresponding second side surface 143 according to the principle of proximity. That is, the first sampling wire harnesses 1213 at the three-eighths thickness position 113 and the five-eighths thickness position 114 are electrically connected to the first winding wire harnesses 1211 on the second side surface 143.

[0035] Optionally, the first winding harness 1211 includes multiple turns of winding wire, and multiple data acquisition points 123, i.e., expansion force acquisition points, are evenly and symmetrically distributed on the middle winding wire. The first transmission line 1212 is electrically connected to the data acquisition points 123 of the winding wire to transmit the expansion force.

[0036] In a specific embodiment, the first winding wire harness 1211 may include three circles of rectangular winding wires, namely winding wires 1211A, 1211B and 1211C, with winding wire 1211B being arranged in the middle. The centers of the rectangles of winding wires 1211A, 1211B and 1211C coincide, and the center positions of winding wires 1211A, 1211B and 1211C coincide with the center positions of the side surfaces on which they are arranged. Among them, the length and width of the rectangle of the largest rectangular winding wire, that is, winding wire 1211A, are respectively about half of the length and width of its bearing surface. For example, the intersection of the diagonals of the winding wires on the first side surface 142 coincides with the diagonal of the first side surface 142. The expansion force collection points are arranged on the second circle of winding wire 1211B, and are respectively arranged at the midpoints of the four sides of the square second circle of winding wire 1211B, and are symmetrically distributed. Furthermore, the first transmission line bundle 1212 on the first side surface 142 is led out from a position of the first side surface 142 close to the top surface 141 .

[0037] For example, the intersection of the diagonal lines of the winding wires on the second side surface 143 coincides with the diagonal line of the second side surface 143. The expansion force collection points are set on the second winding wire and are symmetrically distributed. Furthermore, the first transmission line bundle 1212 on the second side surface 143 is led out from the second side surface 143 near the top surface 141.

[0038] Optionally, the first winding harness 1211 can be fixed with green high-temperature adhesive tape 150, specifically fixed in the middle of the four sides of the rectangular first winding harness 1211. The size of the high-temperature adhesive tape is about 5mm*130mm.

[0039] Optionally, the electrode sensor 13 includes a second acquisition harness 131 and a second processor (not shown) electrically connected to the second acquisition harness 131, the second processor being arranged on the top surface 141 of the shell, the second acquisition harness 131 respectively collecting the thickness of the electrode at different thickness positions of the battery cell 111, and transmitting the collected thickness of the electrode to the second processor.

[0040] Optionally, the second acquisition harness 131 includes a second winding harness 1311, multiple groups of second sampling harnesses 1312 and a second transmission harness 1313, one end of the multiple groups of second sampling harnesses 1312 are respectively arranged at positions of different thicknesses of the battery cell 111, and the other end is connected to the second winding harness 1311, the second winding harness 1311 is arranged on the side of the battery cell 111 and is located outside the thinning area of ​​the electrode piece, and the second transmission harness 1313 is electrically connected to the second winding harness 1311 and the second processor, respectively, and is configured to transmit the thickness of the electrode piece.

[0041] In a specific embodiment, as shown in FIG2 , when there are two battery cells 111, that is, when the two battery cells 111 form a dual-cell battery pack, the second winding harness 1311 is positioned between the two battery cells 111, and the second transmission harness 1313 is led upward from the middle of the two battery cells and further led out in the middle of the two electrode tabs 112. The second sampling harness 1312 includes four groups, one end of each of the four groups of second sampling harnesses 1312 is respectively positioned at one-eighth thickness position 112, three-eighth thickness position 113, five-eighth thickness position 114, and seven-eighth thickness position 115 of the dual-cell pack. By collecting the thickness of the electrode sheets at different thickness positions, the electrode sheets of the battery cells 111 can be monitored in all directions, thereby obtaining more accurate electrode sheet thickness data and achieving precise monitoring. Furthermore, the other ends of the four groups of second sampling harnesses 1312 are all electrically connected to the second winding harness 1311 located between the two battery cells 111 to achieve data output.

[0042] Optionally, the second winding harness 1311 includes multiple turns of winding wire, and multiple data collection points 133 are evenly and symmetrically distributed on the middle winding wire, that is, the collection points of the thickness of the electrode. The second transmission harness 1313 is electrically connected to the data collection points 133 of the winding wire to transmit the thickness of the electrode.

[0043] In a specific embodiment, the second winding wire harness 1311 may include three circles of rectangular winding wires, namely winding wires 1311A, 1311B and 1311C, with winding wire 1311B being arranged in the middle. The centers of the rectangles of winding wires 1311A, 1311B and 1311C coincide with each other, and the center positions of winding wires 1311A, 1311B and 1311C coincide with the center positions of the side surfaces on which they are arranged. Among them, the length and width of the rectangle of the largest rectangular winding wire, that is, winding wire 1311A, are respectively about one-half of the length and width of its bearing surface. The pole piece thickness collection points are arranged on the second circle of winding wire 1311B, and are distributed in sequence on each side of the rectangle, and are symmetrically distributed.

[0044] 3 , the second winding harness 1311 can be fixed with green high-temperature adhesive tape 140, specifically fixed in the middle of the four sides of the rectangular second winding harness 1311. The size of the high-temperature adhesive tape is approximately 5mm*130mm.

[0045] Optionally, an injection hole 144, a positive electrode column 145 and a negative electrode column 146 are provided on the top surface 141 of the shell 14, and a circular hole 147 is provided between the injection hole 144 and the positive electrode column 145. The first transmission harness 1212 and the second transmission harness 1312 are derived from the circular hole 147 and connected to the first processor and the second processor to analyze the data and predict the abnormal thickness of the battery cell in advance.

[0046] In this embodiment, the expansion force sensor 12 and the electrode sensor 13 can be fiber optic sensors. The first acquisition harness 121 and the second acquisition harness 131 can be fiber optic harnesses of the fiber optic sensor, and the first processor and the second processor can be chips of the fiber optic sensor. Furthermore, the fiber optic harness can be passed through a silicone sealant sleeve and then led out of the circular hole 147. The fiber optic harness can also be packaged using a sealing ring or other form. Furthermore, the sensor chip can be connected to the server wirelessly or wired. After the server terminal receives the corresponding data (cell expansion force and electrode thickness), it can perform big data analysis to monitor whether problems such as overheating and battery expansion occur within the cell 111. The server terminal can be a module terminal, an on-board server terminal, a server terminal for an energy storage integrated box, or a cloud terminal.

[0047] Therefore, the health status of the battery can be evaluated by collecting the expansion force of the battery cell and the thickness of the battery cell electrode through multiple sensors, so as to monitor the safety status of the battery cell in real time and reduce the safety risk of the battery cell.

[0048] This embodiment of the present application also provides a power battery health assessment method based on the power battery 100 described above. Please refer to Figure 5, which shows a power battery health assessment method provided by this embodiment of the present application. The power battery includes the power battery 100 described above. As shown in Figure 5, the health assessment method of this embodiment includes the following steps:

[0049] Step S1: collecting the expansion force of the power battery at different thickness positions of the battery cell by an expansion force sensor, and evaluating the health status of the power battery according to the expansion force.

[0050] This step can determine whether the expansion force is greater than the expansion force threshold. If so, the health of the power battery is evaluated as abnormal.

[0051] The expansion force sensor can be used to collect the expansion force at different thickness positions in the battery cell of the power battery, and then the health abnormality of the power battery can be evaluated based on the expansion force at different positions.

[0052] In a specific embodiment, when two cells form a dual-cell pack, the expansion force sensor can collect expansion force data at one-eighth, three-eighth, five-eighth, and seven-eighth locations within the dual-cell pack. By collecting expansion force data at different thickness locations, the expansion force within the cell can be comprehensively monitored, resulting in more accurate expansion force data and precise monitoring. The specific data collection process is described above and will not be repeated here.

[0053] Step S2: collecting the thickness of the pole pieces at different thickness positions of the battery cell through a pole piece sensor, and evaluating the health status of the power battery based on the pole piece thickness.

[0054] In this step, it is determined whether the electrode thickness exceeds the electrode thickness threshold. If so, the battery health is assessed as abnormal. Furthermore, changes in electrode thickness can guide R&D personnel to redesign the thickness chip to better meet the battery cell's operating requirements.

[0055] In one embodiment, the pole piece sensor may be used to collect the thickness of pole pieces at different thickness positions in the battery cell of the power battery.

[0056] In a specific embodiment, when the battery cell includes two cells, that is, when the two cells form a dual-cell pack battery, the electrode sheet sensor can collect the thickness of the electrode sheet at one-eighth, three-eighth, five-eighth, and seven-eighth of the thickness of the dual-cell pack. By collecting the thickness of the electrode sheet at different thickness positions, the thickness of the electrode sheet inside the battery cell can be fully monitored, thereby obtaining more accurate electrode sheet thickness data and achieving precise monitoring. The specific collection process is as described above and will not be repeated here.

[0057] Step S3: further evaluating the health status of the power battery according to the evaluation results of the expansion force sensor and the evaluation results of the pole piece sensor by the processor.

[0058] The processor can further evaluate the health status of the power battery based on the evaluation results of each of the above sensors. The above sensors simply evaluate the abnormality of the corresponding parameters, which leads to the abnormal health status of the power battery, but no comprehensive evaluation is performed. This step can comprehensively judge the health status of the battery by summarizing the evaluation results of each sensor. Specifically, the evaluation results of the expansion force sensor and the pole piece sensor can be set to corresponding health levels, that is, the health status of the power battery can be divided into levels, and each parameter corresponds to a health level. For example, the expansion force corresponds to the first health level of the power battery, and the thickness change of the pole piece corresponds to the second health level. Different health levels correspond to different levels of urgency for processing.

[0059] The processor analyzes the evaluation results of each sensor to obtain the corresponding health level of the power battery. If there are multiple health levels, the highest health level is used for processing. Specifically, if both the expansion force sensor and the pole piece sensor assess that the power battery is in an abnormal health state, the processor processes it according to the highest level, that is, the level 1 health level corresponding to the expansion force, and prompts the operator that special emergency treatment is required. For another example, if only the pole piece sensor assesses that the power battery is in an abnormal health state, the operator is prompted to perform general treatment. It should be understood that the comprehensive evaluation method of the processor is not limited to the technical solution introduced above.

[0060] Please refer to Figure 6, which is a schematic block diagram of a power battery health assessment device 200 provided in an embodiment of the present application. The power battery includes the power battery 100 described above. As shown in Figure 6, the health assessment device 200 of this embodiment includes a processor 21. The processor 21 is configured to further assess the health status of the power battery based on the evaluation results of the expansion force sensor 12 and the evaluation results of the pole piece sensor 13.

[0061] The processor 21 can further evaluate the health status of the power battery based on the evaluation results of each of the above sensors. The above sensors simply evaluate the abnormality of the corresponding parameters, which leads to the abnormal health status of the power battery, but do not perform a comprehensive evaluation. This step can comprehensively judge the health status of the battery by summarizing the evaluation results of each sensor. Specifically, the evaluation results of the expansion force sensor and the electrode sensor can be set to corresponding health levels, that is, the health status of the power battery can be divided into levels, and each parameter corresponds to a health level. For example, the expansion force corresponds to the first health level of the power battery, and the thickness change of the electrode corresponds to the second health level. Different health levels correspond to different levels of urgency for processing.

[0062] The processor 21 analyzes the evaluation results of each sensor to determine the corresponding power battery health level. If multiple health levels exist, the highest health level is used for processing. Specifically, if both the expansion force sensor and the pole piece sensor assess that the power battery is in an abnormal health state, the processor processes the battery according to the highest level, namely the level 1 health level corresponding to the expansion force, and notifies the operator that special emergency measures are required. For another example, if only the pole piece sensor assesses that the power battery is in an abnormal health state, the operator is prompted to perform general treatment. It should be understood that the processor's comprehensive evaluation method is not limited to the technical solution described above.

[0063] In summary, the present application provides a power battery and a health assessment method thereof. The power battery includes: the power battery includes a battery cell, an expansion force sensor and a pole piece sensor, wherein: the battery cell includes a pole piece; the expansion force sensor is electrically connected to the battery cell, and is configured to collect the expansion force of the battery cell at different thickness positions, and evaluate the health status of the power battery based on the expansion force; the pole piece sensor is electrically connected to the battery cell, and is configured to collect the thickness of the pole piece at different thickness positions of the battery cell, and evaluate the health status of the power battery based on the thickness of the pole piece. Therefore, the health status of the battery can be assessed by collecting the expansion force of the battery cell and the thickness of the pole piece of the battery cell respectively through multiple sensors, so that the safety status of the battery cell can be monitored in real time and the safety risk of the battery cell can be reduced.

[0064] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A power battery, comprising a battery cell, an expansion force sensor and a pole piece sensor, wherein: The battery cell comprises a pole piece; The expansion force sensor is electrically connected to the battery cell and is configured to collect expansion forces at different thickness positions of the battery cell and evaluate the health status of the power battery according to the expansion force; The pole piece sensor is electrically connected to the battery cell, and is configured to collect the thickness of the pole piece at different thickness positions of the battery cell, and evaluate the health status of the power battery according to the thickness of the pole piece.

2. The power battery according to claim 1, wherein: The power battery includes a shell configured to accommodate the battery cell. The expansion force sensor includes multiple groups of first acquisition wire harnesses and a first processor electrically connected to the first acquisition wire harnesses. The multiple groups of first acquisition wire harnesses are respectively arranged on different side surfaces of the shell. The first processor is arranged on the top surface of the shell. The multiple groups of first acquisition wire harnesses respectively collect the expansion force of the battery cell at different thickness positions and transmit the collected expansion force to the first processor.

3. The power battery according to claim 2, wherein: Each group of the first acquisition harnesses includes a first sampling harness, a first winding harness and a first transmission harness. One end of the first sampling harness is arranged inside the battery cell, and the other end is electrically connected to the first winding harness. The first winding harness is arranged on the side of the shell. The first transmission harness is electrically connected to the first winding harness and the first processor, respectively, and is configured to transmit the expansion force.

4. The power battery according to claim 3, wherein: One ends of the first sampling wire harnesses of the plurality of groups of the first acquisition wire harnesses are respectively arranged at positions of different thicknesses of the battery core, and the first winding wire harness connected to the first sampling wire harnesses is arranged on the side surface of the nearest shell.

5. The power battery according to claim 3 or 4, wherein: The pole piece sensor includes a second acquisition harness and a second processor electrically connected to the second acquisition harness, the second processor being disposed on the top surface of the shell, the second acquisition harness respectively acquiring the thickness of the pole pieces at different thickness positions of the battery cell, and transmitting the acquired thickness of the pole pieces to the second processor.

6. The power battery according to claim 5, wherein: The second acquisition harness includes a second winding harness, multiple groups of second sampling harnesses and a second transmission harness, one end of the multiple groups of second sampling harnesses are respectively arranged at positions of different thicknesses of the battery cell, and the other end is electrically connected to the second winding harness, the second winding harness is arranged on the side of the battery cell and is located outside the thinning area of ​​the pole piece, and the second transmission harness is electrically connected to the second winding harness and the second processor, respectively, and is configured to transmit the thickness of the pole piece.

7. The power battery according to claim 6, wherein: The first winding harness and the second winding harness both include a winding wire with multiple turns, and a plurality of data acquisition points are evenly and symmetrically distributed on the middle winding wire. The first transmission harness and the second transmission harness are respectively electrically connected to the corresponding data acquisition points of the winding wire to respectively transmit the expansion force and the thickness of the pole piece.

8. The power battery according to claim 6, wherein: The first winding wire harness and the second winding wire harness each include a winding wire wound in multiple turns, and the center position of the winding wire coincides with the center position of the side surface on which the winding wire is arranged.

9. A health assessment method for a power battery, the power battery comprising the power battery according to any one of claims 1 to 8, the health assessment method comprising: The expansion force at different thickness positions of the power battery cell is collected by an expansion force sensor, and the health status of the power battery is evaluated according to the expansion force; The thickness of the pole pieces at different thickness positions of the battery cell is collected by a pole piece sensor, and the health status of the power battery is evaluated according to the thickness of the pole pieces; The processor further evaluates the health status of the power battery according to the evaluation results of the expansion force sensor and the evaluation results of the pole piece sensor.

10. The health assessment method according to claim 9, wherein: The step of further evaluating the health status of the power battery according to the evaluation result of the expansion force sensor and the evaluation result of the pole piece sensor by the processor further includes: Setting the evaluation results of the expansion force sensor and the pole piece sensor to corresponding health levels; The processor analyzes the health level of the corresponding power battery according to the health level corresponding to the expansion force sensor and the health level corresponding to the pole piece sensor to obtain the health level of the corresponding power battery.

11. A health assessment device for a power battery, the power battery comprising the power battery according to any one of claims 1 to 8, the health assessment device comprising a processor, the processor being configured to further assess the health status of the power battery based on an assessment result of the expansion force sensor and an assessment result of the pole piece sensor.

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