Battery module and pressure test method of battery module

Abstract

The invention relates to the technical field of new energy batteries, in particular to a battery module and a pressure testing method of the battery module, the battery module comprises a pressure sensor, an integrated busbar and a battery cell module, the battery cell module comprises a plurality of stacked battery cells and an end plate arranged at the outermost battery cell, the pressure sensor is clamped between two adjacent battery cells, the pressure sensor is electrically connected with the integrated busbar, and the integrated busbar covers one side, provided with a pole, of each battery cell. According to the battery module disclosed by the invention, the pressure sensor is arranged between two adjacent battery cells, so that the requirement of detecting the battery pressure of the battery module can be met, the expansion force between the battery cells can be better detected by pressure detection data, the pressure sensor is integrated on the integrated busbar, and the data is transmitted to a BMS (Battery Management System), so that an early warning effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy batteries, and in particular to a battery module and a pressure testing method for the battery module. Background Art

[0002] At present, the safety of battery modules is still the most important consideration. In order to ensure the safety of battery modules, monitoring the status of battery modules is one of the effective methods. Among them, the monitoring of battery modules mainly uses battery sensors to collect the voltage and temperature signals of the battery, and then connects the battery signals to the battery management system (BMS). The BMS analyzes and judges the battery signals to achieve real-time monitoring of the battery module operation. This part of the work mainly belongs to the work of CCS (Cell contact system). The current monitoring does not cover pressure sensors. Generally, battery manufacturers only test the pressure of batteries in the laboratory, and only battery modules with higher requirements have battery pressure detection.

[0003] Chinese patent CN116794537 A discloses a pressure sensor and a battery module. The pressure sensor is mainly used to monitor changes in pressure values, but the patent does not provide a specific implementation method of the pressure sensor. Summary of the invention

[0004] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide a battery module, which can meet the demand for battery pressure detection of the battery module by arranging a pressure sensor between two adjacent battery cells. The pressure detection data can better check the expansion force between the battery cells, and the pressure sensor is integrated into the integrated busbar to transmit the data to the BMS to achieve the purpose of early warning.

[0005] The purpose of the present invention is to provide a battery module pressure testing method, which can meet the needs of detecting the battery pressure of the battery module and integrate the pressure sensor into the integrated busbar, thereby solving the problem of inaccurate pressure detection of a single battery cell. Then, through the integrated busbar connection, the health status of the battery cell can be warned.

[0006] The objective of the present invention is achieved through the following technical scheme: a battery module, comprising a pressure sensor, an integrated busbar and a cell module, wherein the cell module comprises a plurality of stacked cells and an end plate arranged at the outermost cell, the pressure sensor is clamped between two adjacent cells, the pressure sensor is electrically connected to the integrated busbar, and the integrated busbar cover is arranged on a side of the cell having a pole.

[0007] In the present invention, by arranging a pressure sensor and an integrated busbar on the battery cell module, and clamping the pressure sensor between two adjacent battery cells, the demand for detecting battery pressure of the battery module can be met, and the pressure sensor is integrated into the integrated busbar, which can be placed on the CCS of the wiring harness or integrated into the CCS of the FPC; the problem of inaccurate pressure detection of a single battery cell is solved, and then through the integrated busbar connection, an early warning of the health status of the battery cell is achieved.

[0008] Preferably, the integrated busbar is a wiring harness plate integrated busbar, a hot-pressed film integrated busbar, an FFC integrated busbar or a PC film integrated busbar.

[0009] Preferably, the FFC integrated busbar comprises a blister box, an FFC component and a plurality of conductive aluminum bars, the upper end surface of the blister box is provided with a bonding area and a plurality of inlay areas, the FFC component is stacked on the bonding area, the inlay areas are evenly distributed on both sides of the bonding area, the conductive aluminum bars are respectively embedded in the inlay areas, the conductive aluminum bars are electrically connected to the FFC component, at least a plurality of solder pads are provided on both sides of the FFC component, and the solder pads are connected to the pressure sensor through flying wires.

[0010] The FFC integrated busbar of the present invention adopts a structure of a blister box, an FFC component and a conductive aluminum busbar, which has the advantages of simple structure, lightness, thinness, and stable connection. At the same time, by optimizing the coating design of the surface of the copper wire in the FFC component, the reliability of the welding between the copper wire and the aluminum busbar can be improved. In addition, the FFC busbar uses copper foil or other metal foils during the manufacturing process, which can well prevent signal interference and electromagnetic wave radiation, thereby ensuring the quality and stability of data transmission.

[0011] Preferably, the pressure sensor is an array-type thin film pressure sensor or a single-point thin film pressure sensor.

[0012] Preferably, the point-type thin film pressure sensor comprises an upper conductive layer, a first sensing layer, a spacer layer, a second sensing layer and a lower conductive layer stacked in sequence, and the upper conductive layer and the lower conductive layer are both connected to the pad via flying leads.

[0013] The point-type thin film pressure sensor in the present invention is a highly sensitive resistive pressure sensor. When pressure acts on the sensing layer area, the resistance of the sensor changes accordingly. The greater the pressure, the smaller the resistance value; at the same time, it will cause a change in the output voltage. The greater the pressure, the greater the output voltage, which can well reflect the pressure exerted by the expansion between the battery cells.

[0014] Preferably, the first sensing layer and the second sensing layer are both nano-sensitive layers, and the nano-sensitive layers are coated with nano-sensitive coatings.

[0015] Preferably, the nano-sensitive coating comprises the following raw materials in parts by weight: 20-40 parts of platinum-based tetrakispentafluorophenylporphyrin, 40-60 parts of trifluorotoluene, 5-10 parts of adhesive, 1-3 parts of titanium dioxide, 4-8 parts of PVDF, 1-5 parts of ZnO nanoparticles, and 1-3 parts of hollow mesoporous silica nanospheres.

[0016] The nano-sensitive coating in the present invention is made of the above-mentioned raw materials, and the sensor manufactured using the nano-sensitive coating has the characteristics of high sensitivity, good mechanical properties, arbitrary bending and low energy consumption. The nano zinc oxide particles used in the nano-sensitive coating package are a high-end, high-function fine inorganic product with piezoelectricity, non-migration, and the ability to absorb and scatter ultraviolet rays. They can be used as piezoelectric materials, varistors, etc.; PVDF can obtain a variety of different crystalline phases according to different processing conditions, among which the α phase has excellent mechanical properties, and the β phase has strong piezoelectric, dielectric, and thermoelectric properties; in addition, PVDF is easy to form a β phase with piezoelectric properties under the action of electric field force, and ZnO nanoparticles have excellent piezoelectricity combined, which promotes PVDF / ZnO micro-nanoparticles. Rice fibers have stronger pressure sensitivity and generate a voltage that changes with the pressure under the action of pressure. Therefore, in the absence of an external voltage source, the pressure sensor can be directly connected to an ammeter. When the pressure on the sensitive material changes, the value displayed on the ammeter changes accordingly, that is, the pressure change on the surface of the sensitive material can be tested without an external power supply. In addition, the hollow mesoporous silica nanospheres used can utilize the pressure alternation effect to change the configuration of the supramolecule, so that the platinum-based tetrakis-pentafluorophenylporphyrin can be released to the outside of the microspheres through the supramolecule, thereby realizing the pressure-sensitive release function.

[0017] Preferably, the adhesive is composed of epoxy resin, phenolic resin and heptafluorobutyl methacrylate in a mass ratio of 0.8-1.2:0.6-1.0:0.4-0.8.

[0018] The adhesive of the present invention has good bonding, film-forming and oxygen dissolving abilities, and is used as a polymer adhesive in nano-sensitive coatings to encapsulate platinum-based tetrafluorophenylporphyrin, titanium dioxide and hollow mesoporous silica nanospheres, and exhibits film-forming properties after the coating is dried and cured.

[0019] Preferably, the nano-sensitive coating is prepared by the following method:

[0020] A1. According to parts by weight, platinum-based tetrakispentafluorophenylporphyrin, adhesive, trifluorotoluene and titanium dioxide are mixed and added into a reaction device, which is sealed and heated to 20-40° C. and stirred for 30-60 min to obtain a mixed system for standby use;

[0021] A2. According to parts by weight, PVDF, ZnO nanoparticles and hollow mesoporous silica nanospheres are mixed evenly and added to the mixed system obtained in step A1. The raw materials are mixed evenly by shaking, oscillating or rotating to obtain a nano-sensitive coating.

[0022] The nano-sensitive coating of the present invention is prepared by the above method, and the nano-sensitive coating prepared by the above method has the advantages of high sensitivity and good mechanical properties. In the preparation process, the platinum-based tetrapentafluorinated phenylporphyrin must be mixed in after the adhesive is completely dissolved, so that the polymer adhesive can wrap the platinum-based tetrapentafluorinated phenylporphyrin well. After the platinum-based tetrapentafluorinated phenylporphyrin is completely dissolved, titanium dioxide is added and shaken until the titanium dioxide is evenly dispersed, so that the pressure-sensitive probe molecules in the solution system are evenly adsorbed. Therefore, in the newly prepared coating, the preparation must be strictly carried out in accordance with the order in which the above components are added.

[0023] The present invention also provides a battery module pressure testing method, comprising the following steps:

[0024] S1. Establish a battery module as described above, apply a preload force to the battery module, and control the preload force to be 0.18-0.22MPa;

[0025] S2, placing the array-type thin-film pressure sensor on the largest surface between two adjacent battery cells, and measuring the maximum expansion value of the square battery cell;

[0026] S3. Perform cyclic discharge and charge of the battery module, find the place where the expansion force of the battery is the largest through data comparison, and then calculate how many single-point film pressure sensors are suitable to be placed in a group of batteries, and then replace the single-point film pressure sensors at the place where the expansion force is the largest;

[0027] S4. Finally, a maximum value is set on the BMS. If the value measured by the single-point film pressure sensor exceeds this maximum value, an alarm will be generated, thereby completing the inspection of the health status of the battery cell.

[0028] When the battery module is subjected to a battery pressure test in the present invention, a pre-tightening force is applied to the battery module, and an array-type thin film pressure sensor is placed on the largest surface of the battery module. The battery module is cyclically discharged and charged, and the location where the expansion force of the battery is the largest is found through data comparison (the array-type thin film pressure sensor can measure the area of ​​the battery expansion force in the area where the entire battery surface is located and the magnitude of the force. The measured data is N, which needs to be converted into pressure. The pressure value is obtained through P=F / S (P=pressure, F=expansion force, S=area), and the array-type thin film pressure sensor can measure the area generated by the expansion (because the accuracy of the expansion force is improved, the size of the specific area is easy to adjust the accuracy). After these, we can select the range and accuracy of the single-point thin film pressure sensor; measure the maximum expansion of the battery cell by charging and discharging the battery cell module, compare the data, and then calculate how many single-point thin film pressure sensors are suitable to be placed in a group of battery cells (through P=F / S, we can get the force of the area where each single-point thin film pressure sensor is located, so we can calculate how many battery cells are suitable to be placed; finally, set a maximum value on the BMS (this is obtained by calculating the maximum expansion value of the entire module, the maximum value on the BMS = the maximum expansion value measured by the single-point thin film pressure sensor of the battery cell module), and then generate an alarm if it exceeds this maximum value, which is of great significance for checking the health status of the battery cell.

[0029] The beneficial effects of the present invention are as follows: the battery module of the present invention can meet the demand for battery pressure detection of the battery module by arranging a pressure sensor between two adjacent battery cells. The pressure detection data can better check the expansion force between the battery cells, and the pressure sensor is integrated into the integrated busbar to transmit the data to the BMS to achieve the effect of early warning.

[0030] A battery module pressure testing method of the present invention can meet the demand for detecting the battery pressure of the battery module, and integrates the pressure sensor into the integrated busbar, solving the problem of inaccurate pressure detection of a single battery cell, and then uses the integrated busbar connection to warn the health status of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is an exploded schematic diagram of a battery module using a single-point thin-film pressure sensor;

[0032] Figure 2 It is a disassembled schematic diagram of a battery module using an array-type thin-film pressure sensor;

[0033] Figure 3 It is a schematic diagram of the structure of the integrated busbar of the present invention;

[0034] Figure 4 is an exploded schematic diagram of the integrated busbar of the present invention;

[0035] Figure 5 It is a structural schematic diagram of a single-point thin film pressure sensor of the present invention;

[0036] Figure 6 is an exploded schematic diagram of a single-point thin film pressure sensor of the present invention;

[0037] Figure 7 is a schematic structural diagram of an array-type thin film pressure sensor of the present invention;

[0038] Figure 8 It is a curve chart of the test pressure VS resistance change for single-point thin film pressure sensor;

[0039] Fig. 9 It is a curve chart of the test pressure VS output voltage change for single-point thin film pressure sensor;

[0040] Fig.10 It is a graph that characterizes the output voltage of different measuring resistances RM for a single-point thin-film pressure sensor.

[0041] The figure numbers are: 1-pressure sensor, 11-upper conductive layer, 12-first sensing layer, 13-interlayer, 14-second sensing layer, 15-lower conductive layer, 2-integrated busbar, 21-blister box, 211-fitting area, 212-inlay area, 22-FFC component, 23-conductive aluminum busbar, 24-soldering pad, 25-flying lead, 3-battery cell module, 31-battery cell and 32-end plate. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of those skilled in the art, the following embodiments and attached Figure 1-10 The present invention is further described, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0043] Example 1

[0044] See Figure 1-10 A battery module includes a pressure sensor 1, an integrated busbar 2 and a battery cell module 3, wherein the battery cell module 3 includes a plurality of stacked battery cells 31 and an end plate 32 arranged at the outermost battery cells 31, the pressure sensor 1 is sandwiched between two adjacent battery cells 31, the pressure sensor 1 is electrically connected to the integrated busbar 2, and the integrated busbar 2 covers a side of the battery cell 31 having a pole.

[0045] The integrated busbar 2 is an FFC integrated busbar 2.

[0046] The FFC integrated busbar 2 includes a blister box 21, an FFC component 22 and a plurality of conductive aluminum bars 23. The upper end surface of the blister box 21 is provided with a bonding area 211 and a plurality of inlay areas 212. The FFC component 22 is stacked on the bonding area 211. The inlay areas 212 are evenly distributed on both sides of the bonding area 211. The conductive aluminum bars 23 are respectively embedded in the inlay areas 212. The conductive aluminum bars 23 are electrically connected to the FFC component 22. At least a plurality of solder pads 24 are provided on both sides of the FFC component 22. The solder pads 24 are connected to the pressure sensor 1 through flying wires 25.

[0047] The pressure sensor 1 is an array-type thin film pressure sensor 1 or a single-point thin film pressure sensor 1 .

[0048] The point-type thin film pressure sensor 1 comprises an upper conductive layer 11 , a first sensing layer 12 , a spacer 13 , a second sensing layer 14 and a lower conductive layer 15 which are stacked in sequence. The upper conductive layer 11 and the lower conductive layer 15 are both connected to the pad 24 via a flying lead 25 .

[0049] The first sensing layer 12 and the second sensing layer 14 are both nano-sensitive layers, and the nano-sensitive layers are coated with nano-sensitive coatings.

[0050] The nano-sensitive coating comprises the following raw materials in parts by weight: 20 parts of platinum-based tetrakispentafluorophenylporphyrin, 40 parts of trifluorotoluene, 5 parts of adhesive, 1 part of titanium dioxide, 4 parts of PVDF, 1 part of ZnO nanoparticles, and 1 part of hollow mesoporous silica nanospheres.

[0051] The adhesive is composed of epoxy resin, phenolic resin and heptafluorobutyl methacrylate in a mass ratio of 0.8:0.6:0.4.

[0052] The nano-sensitive coating is prepared by the following method:

[0053] A1. According to parts by weight, platinum-based tetrakispentafluorophenylporphyrin, adhesive, trifluorotoluene and titanium dioxide are mixed and added into a reaction device, which is sealed and heated to 20° C. and stirred for 30 min to obtain a mixed system for standby use;

[0054] A2. According to parts by weight, PVDF, ZnO nanoparticles and hollow mesoporous silica nanospheres are mixed evenly and added to the mixed system obtained in step A1. The raw materials are mixed evenly by shaking, oscillating or rotating to obtain a nano-sensitive coating.

[0055] A battery module pressure testing method comprises the following steps:

[0056] S1. Establish a battery module as described above, apply a preload force to the battery cell module 3, and control the preload force to be 0.18 MPa;

[0057] S2, placing the array-type thin film pressure sensor 1 on the largest surface between two adjacent battery cells 31, and measuring the maximum expansion value of the square battery cell 31;

[0058] S3, cyclically discharge and charge the battery module 3, and by comparing the data, find the place where the expansion force of the battery 31 is the largest, and then calculate how many single-point film pressure sensors 1 are suitable to be placed in a group of battery cells 31, and then replace the single-point film pressure sensor 1 at the place where the expansion force is the largest;

[0059] S4. Finally, a maximum value is set on the BMS. If the value measured by the single-point film pressure sensor 1 exceeds the maximum value, an alarm will be generated, thereby completing the inspection of the health status of the battery cell 31.

[0060] Example 2

[0061] A battery module includes a pressure sensor 1, an integrated busbar 2 and a battery cell module 3, wherein the battery cell module 3 includes a plurality of stacked battery cells 31 and an end plate 32 arranged at the outermost battery cells 31, the pressure sensor 1 is sandwiched between two adjacent battery cells 31, the pressure sensor 1 is electrically connected to the integrated busbar 2, and the integrated busbar 2 covers a side of the battery cell 31 having a pole.

[0062] The integrated busbar 2 is an FFC integrated busbar 2.

[0063] The FFC integrated busbar 2 includes a blister box 21, an FFC component 22 and a plurality of conductive aluminum bars 23. The upper end surface of the blister box 21 is provided with a bonding area 211 and a plurality of inlay areas 212. The FFC component 22 is stacked on the bonding area 211. The inlay areas 212 are evenly distributed on both sides of the bonding area 211. The conductive aluminum bars 23 are respectively embedded in the inlay areas 212. The conductive aluminum bars 23 are electrically connected to the FFC component 22. At least a plurality of solder pads 24 are provided on both sides of the FFC component 22. The solder pads 24 are connected to the pressure sensor 1 through flying wires 25.

[0064] The pressure sensor 1 is an array-type thin film pressure sensor 1 or a single-point thin film pressure sensor 1 .

[0065] The point-type thin film pressure sensor 1 comprises an upper conductive layer 11 , a first sensing layer 12 , a spacer 13 , a second sensing layer 14 and a lower conductive layer 15 which are stacked in sequence. The upper conductive layer 11 and the lower conductive layer 15 are both connected to the pad 24 via a flying lead 25 .

[0066] The first sensing layer 12 and the second sensing layer 14 are both nano-sensitive layers, and the nano-sensitive layers are coated with nano-sensitive coatings.

[0067] The nano-sensitive coating comprises the following raw materials in parts by weight: 30 parts of platinum-based tetrakispentafluorophenylporphyrin, 50 parts of trifluorotoluene, 8 parts of adhesive, 2 parts of titanium dioxide, 6 parts of PVDF, 3 parts of ZnO nanoparticles, and 2 parts of hollow mesoporous silica nanospheres.

[0068] The adhesive is composed of epoxy resin, phenolic resin and heptafluorobutyl methacrylate in a mass ratio of 1.0:0.8:0.6.

[0069] The nano-sensitive coating is prepared by the following method:

[0070] A1. According to parts by weight, platinum-based tetrakispentafluorophenylporphyrin, adhesive, trifluorotoluene and titanium dioxide are mixed and added into a reaction device, which is sealed and heated to 30° C. and stirred for 45 minutes to obtain a mixed system for standby use;

[0071] A2. According to parts by weight, PVDF, ZnO nanoparticles and hollow mesoporous silica nanospheres are mixed evenly and added to the mixed system obtained in step A1. The raw materials are mixed evenly by shaking, oscillating or rotating to obtain a nano-sensitive coating.

[0072] A battery module pressure testing method comprises the following steps:

[0073] S1. Establish a battery module as described above, apply a preload force to the battery cell module 3, and control the preload force to be 0.2 MPa;

[0074] S2, placing the array-type thin film pressure sensor 1 on the largest surface between two adjacent battery cells 31, and measuring the maximum expansion value of the square battery cell 31;

[0075] S3, cyclically discharge and charge the battery module 3, and by comparing the data, find the place where the expansion force of the battery 31 is the largest, and then calculate how many single-point film pressure sensors 1 are suitable to be placed in a group of battery cells 31, and then replace the single-point film pressure sensor 1 at the place where the expansion force is the largest;

[0076] S4. Finally, a maximum value is set on the BMS. If the value measured by the single-point film pressure sensor 1 exceeds the maximum value, an alarm will be generated, thereby completing the inspection of the health status of the battery cell 31.

[0077] Example 3

[0078] A battery module includes a pressure sensor 1, an integrated busbar 2 and a battery cell module 3, wherein the battery cell module 3 includes a plurality of stacked battery cells 31 and an end plate 32 arranged at the outermost battery cells 31, the pressure sensor 1 is sandwiched between two adjacent battery cells 31, the pressure sensor 1 is electrically connected to the integrated busbar 2, and the integrated busbar 2 covers a side of the battery cell 31 having a pole.

[0079] The integrated busbar 2 is an FFC integrated busbar 2.

[0080] The FFC integrated busbar 2 includes a blister box 21, an FFC component 22 and a plurality of conductive aluminum bars 23. The upper end surface of the blister box 21 is provided with a bonding area 211 and a plurality of inlay areas 212. The FFC component 22 is stacked on the bonding area 211. The inlay areas 212 are evenly distributed on both sides of the bonding area 211. The conductive aluminum bars 23 are respectively embedded in the inlay areas 212. The conductive aluminum bars 23 are electrically connected to the FFC component 22. At least a plurality of solder pads 24 are provided on both sides of the FFC component 22. The solder pads 24 are connected to the pressure sensor 1 through flying wires 25.

[0081] The pressure sensor 1 is an array-type thin film pressure sensor 1 or a single-point thin film pressure sensor 1 .

[0082] The point-type thin film pressure sensor 1 comprises an upper conductive layer 11 , a first sensing layer 12 , a spacer 13 , a second sensing layer 14 and a lower conductive layer 15 which are stacked in sequence. The upper conductive layer 11 and the lower conductive layer 15 are both connected to the pad 24 via a flying lead 25 .

[0083] The first sensing layer 12 and the second sensing layer 14 are both nano-sensitive layers, and the nano-sensitive layers are coated with nano-sensitive coatings.

[0084] The nano-sensitive coating comprises the following raw materials in parts by weight: 40 parts of platinum-based tetrakispentafluorophenylporphyrin, 60 parts of trifluorotoluene, 10 parts of adhesive, 3 parts of titanium dioxide, 8 parts of PVDF, 5 parts of ZnO nanoparticles, and 3 parts of hollow mesoporous silica nanospheres.

[0085] The adhesive is composed of epoxy resin, phenolic resin and heptafluorobutyl methacrylate in a mass ratio of 1.2:1.0:0.8.

[0086] The nano-sensitive coating is prepared by the following method:

[0087] A1. According to parts by weight, platinum-based tetrakispentafluorophenylporphyrin, adhesive, trifluorotoluene and titanium dioxide are mixed and added into a reaction device, which is sealed and heated to 40° C. and stirred for 60 min to obtain a mixed system for standby use;

[0088] A2. According to parts by weight, PVDF, ZnO nanoparticles and hollow mesoporous silica nanospheres are mixed evenly and added to the mixed system obtained in step A1. The raw materials are mixed evenly by shaking, oscillating or rotating to obtain a nano-sensitive coating.

[0089] A battery module pressure testing method comprises the following steps:

[0090] S1. Establish a battery module as described above, apply a preload force to the battery cell module 3, and control the preload force to be 0.22 MPa;

[0091] S2, placing the array-type thin film pressure sensor 1 on the largest surface between two adjacent battery cells 31, and measuring the maximum expansion value of the square battery cell 31;

[0092] S3, cyclically discharge and charge the battery module 3, and by comparing the data, find the place where the expansion force of the battery 31 is the largest, and then calculate how many single-point film pressure sensors 1 are suitable to be placed in a group of battery cells 31, and then replace the single-point film pressure sensor 1 at the place where the expansion force is the largest;

[0093] S4. Finally, a maximum value is set on the BMS. If the value measured by the single-point film pressure sensor 1 exceeds the maximum value, an alarm will be generated, thereby completing the inspection of the health status of the battery cell 31.

[0094] Example 4

[0095] A battery module includes a pressure sensor 1, an integrated busbar 2 and a battery cell module 3, wherein the battery cell module 3 includes a plurality of stacked battery cells 31 and an end plate 32 arranged at the outermost battery cells 31, the pressure sensor 1 is sandwiched between two adjacent battery cells 31, the pressure sensor 1 is electrically connected to the integrated busbar 2, and the integrated busbar 2 covers a side of the battery cell 31 having a pole.

[0096] The integrated busbar 2 is an FFC integrated busbar 2.

[0097] The FFC integrated busbar 2 includes a blister box 21, an FFC component 22 and a plurality of conductive aluminum bars 23. The upper end surface of the blister box 21 is provided with a bonding area 211 and a plurality of inlay areas 212. The FFC component 22 is stacked on the bonding area 211. The inlay areas 212 are evenly distributed on both sides of the bonding area 211. The conductive aluminum bars 23 are respectively embedded in the inlay areas 212. The conductive aluminum bars 23 are electrically connected to the FFC component 22. At least a plurality of solder pads 24 are provided on both sides of the FFC component 22. The solder pads 24 are connected to the pressure sensor 1 through flying wires 25.

[0098] The pressure sensor 1 is an array-type thin film pressure sensor 1 or a single-point thin film pressure sensor 1 .

[0099] The point-type thin film pressure sensor 1 comprises an upper conductive layer 11 , a first sensing layer 12 , a spacer 13 , a second sensing layer 14 and a lower conductive layer 15 which are stacked in sequence. The upper conductive layer 11 and the lower conductive layer 15 are both connected to the pad 24 via a flying lead 25 .

[0100] The first sensing layer 12 and the second sensing layer 14 are both nano-sensitive layers, and the nano-sensitive layers are coated with nano-sensitive coatings.

[0101] The nano-sensitive coating comprises the following raw materials in parts by weight: 30 parts of platinum-based tetrakispentafluorophenylporphyrin, 50 parts of trifluorotoluene, 8 parts of adhesive, 2 parts of titanium dioxide, 6 parts of PVDF, 3 parts of ZnO nanoparticles, and 2 parts of hollow mesoporous silica nanospheres.

[0102] The adhesive is composed of epoxy resin, phenolic resin and heptafluorobutyl methacrylate in a mass ratio of 1.2:1.0:0.8.

[0103] The nano-sensitive coating is prepared by the following method:

[0104] A1. According to parts by weight, platinum-based tetrakispentafluorophenylporphyrin, adhesive, trifluorotoluene and titanium dioxide are mixed and added into a reaction device, which is sealed and heated to 40° C. and stirred for 60 min to obtain a mixed system for standby use;

[0105] A2. According to parts by weight, PVDF, ZnO nanoparticles and hollow mesoporous silica nanospheres are mixed evenly and added to the mixed system obtained in step A1. The raw materials are mixed evenly by shaking, oscillating or rotating to obtain a nano-sensitive coating.

[0106] A battery module pressure testing method comprises the following steps:

[0107] S1. Establish a battery module as described above, apply a preload force to the battery cell module 3, and control the preload force to be 0.22 MPa;

[0108] S2, placing the array-type thin film pressure sensor 1 on the largest surface between two adjacent battery cells 31, and measuring the maximum expansion value of the square battery cell 31;

[0109] S3, cyclically discharge and charge the battery module 3, and by comparing the data, find the place where the expansion force of the battery 31 is the largest, and then calculate how many single-point film pressure sensors 1 are suitable to be placed in a group of battery cells 31, and then replace the single-point film pressure sensor 1 at the place where the expansion force is the largest;

[0110] S4. Finally, a maximum value is set on the BMS. If the value measured by the single-point film pressure sensor 1 exceeds the maximum value, an alarm will be generated, thereby completing the inspection of the health status of the battery cell 31.

[0111] Comparative Example 1

[0112] The difference between this comparative example and the above-mentioned Example 2 is that no adhesive is used in the raw materials of the nano-sensitive coating of this comparative example. The rest of the contents of this comparative example are the same as those of Example 2, and will not be repeated here.

[0113] Comparative Example 2

[0114] The difference between this comparative example and the above-mentioned Example 2 is that no ZnO nanoparticles and hollow mesoporous silica nanospheres are added to the raw materials of the nano-sensitive coating of this comparative example. The rest of the contents of this comparative example are the same as those of Example 2 and will not be repeated here.

[0115] The performance of the nano-sensitive coatings prepared in Example 2 and Comparative Examples 1-2 was tested after film formation, and the results are shown in Table 1:

[0116] Neutral salt spray resistance test method: Determined in accordance with GB / T 1771-2007 test method;

[0117] Impact resistance (positive impact) test method: measured in accordance with the GB / T 1732-2020 test method;

[0118] Adhesion: measured according to GB / T9286 test method, technical index ≤ level 1 (01mm cross-cut method);

[0119] Surface drying time: measured according to the test method of GB / T1728-1979, technical index ≤4h.

[0120] Table 1

[0121]

[0122] It can be seen from Example 2 that the air-permeable nano-sensitive coating prepared in the present invention has the advantages of good weather resistance, impact resistance, neutral salt spray resistance, as well as good adhesion and surface drying performance.

[0123] From the comparison between Example 2 and Comparative Examples 1-2, it can be seen that under the same conditions, the addition of accelerator, acrylic monomer, diethoxyacetophenone and coupling agent to the formula makes the prepared nano-sensitive coating have good weather resistance, impact resistance, neutral salt spray resistance, as well as good adhesion and surface drying performance, and has broad market prospects and application value.

[0124] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention may also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A battery module, characterized in that: It includes a pressure sensor, an integrated busbar and a battery cell module. The battery cell module includes a plurality of stacked battery cells and an end plate arranged at the outermost battery cell. The pressure sensor is clamped between two adjacent battery cells. The pressure sensor is electrically connected to the integrated busbar. The integrated busbar cover is arranged on a side of the battery cell having a pole.

2. A battery module according to claim 1, characterized in that: The integrated busbar is a wiring harness plate integrated busbar, a hot pressed film integrated busbar, an FFC integrated busbar or a PC film integrated busbar.

3. A battery module according to claim 2, characterized in that: The FFC integrated busbar includes a blister box, an FFC component and a plurality of conductive aluminum bars. The upper end surface of the blister box is provided with a bonding area and a plurality of inlay areas. The FFC component is stacked on the bonding area. The inlay areas are evenly distributed on both sides of the bonding area. The conductive aluminum bars are respectively embedded in the inlay areas. The conductive aluminum bars are electrically connected to the FFC component. At least a plurality of pads are provided on both sides of the FFC component. The pads are connected to the pressure sensor through flying wires.

4. A battery module according to claim 1, characterized in that: The pressure sensor is an array-type thin film pressure sensor or a single-point thin film pressure sensor.

5. A battery module according to claim 4, characterized in that: The point-type thin film pressure sensor comprises an upper conductive layer, a first sensing layer, a spacer layer, a second sensing layer and a lower conductive layer stacked in sequence, and the upper conductive layer and the lower conductive layer are both connected to the pad via flying wires.

6. A battery module according to claim 5, characterized in that: The first sensing layer and the second sensing layer are both nano-sensitive layers, and the nano-sensitive layers are coated with nano-sensitive coatings.

7. A battery module according to claim 6, characterized in that: The nano-sensitive coating comprises the following raw materials in parts by weight: 20-40 parts of platinum-based tetrakispentafluorophenylporphyrin, 40-60 parts of trifluorotoluene, 5-10 parts of adhesive, 1-3 parts of titanium dioxide, 4-8 parts of PVDF, 1-5 parts of ZnO nanoparticles, and 1-3 parts of hollow mesoporous silica nanospheres.

8. A battery module and a battery module pressure testing method according to claim 7, characterized in that: The adhesive is composed of epoxy resin, phenolic resin and heptafluorobutyl methacrylate in a mass ratio of 0.8-1.2:0.6-1.0:0.4-0.

8.

9. A battery module and a battery module pressure testing method according to claim 7, characterized in that: The nano-sensitive coating is prepared by the following method: A1. According to parts by weight, platinum-based tetrakispentafluorophenylporphyrin, adhesive, trifluorotoluene and titanium dioxide are mixed and added into a reaction device, which is sealed and heated to 20-40° C. and stirred for 30-60 min to obtain a mixed system for standby use; A2. According to parts by weight, PVDF, ZnO nanoparticles and hollow mesoporous silica nanospheres are mixed evenly and added to the mixed system obtained in step A1. The raw materials are mixed evenly by shaking, oscillating or rotating to obtain a nano-sensitive coating.

10. A battery module pressure testing method, characterized in that: The steps include: S1. Establish a battery module as described in any one of claims 1 to 9, apply a pre-tightening force to the battery cell module, and control the pre-tightening force to be 0.18-0.22 MPa; S2, placing the array-type thin-film pressure sensor on the largest surface between two adjacent battery cells, and measuring the maximum expansion value of the square battery cell; S3. Perform cyclic discharge and charge of the battery module, find the place where the expansion force of the battery is the largest through data comparison, and then calculate how many single-point film pressure sensors are suitable to be placed in a group of batteries, and then replace the single-point film pressure sensors at the place where the expansion force is the largest; S4. Finally, a maximum value is set on the BMS. If the value measured by the single-point film pressure sensor exceeds this maximum value, an alarm will be generated, thereby completing the inspection of the health status of the battery cell.

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