Battery, battery module and terminal device

Abstract

Provided are a battery, a battery module, and a terminal device. The battery comprises a casing and a cell assembly accommodated in the casing. The cell assembly comprises electrode sheets (1) and a separator (5). Each electrode sheet (1) comprises a current collector and an active substance layer located on the current collector. The separator (5) separates the active substance layers on two adjacent electrode sheets (1). At least part of each electrode sheet (1) is a blank area, and no active substance layer is provided in the blank area. The battery further comprises at least one sheet-type sensor (2). The sheet-type sensor (2) is arranged on the separator (5), and is arranged corresponding to the blank area of each electrode sheet (1). By arranging the sheet-type sensor (2) in the battery to measure physical signals, such as the temperature, pressure, air pressure, current, and voltage inside a cell, the working state of the cell can be rapidly predicted on the basis of actual working conditions inside the cell while the impact on the overall thickness of the cell is reduced, thereby achieving real-time monitoring of the cell and improving the safety performance of the battery.

Description

Battery and battery module, terminal device

[0001] The present application claims priority to the Chinese patent application No. 202410731621.0, filed on June 6, 2024, and entitled "Battery and battery module, terminal device", the content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of organic compound synthesis, in particular, to a battery and a battery module, and a terminal device. BACKGROUND

[0003] Battery energy storage technology has been widely used in various aspects of people's production and life. From various terminal portable devices to vehicle power systems, household energy storage, data center backup power systems, and large-scale energy storage power stations, batteries play an important role as an important energy storage medium. In addition to the battery charging and discharging performance, the battery-related safety accidents in recent years highlight the importance of battery safety warning and state estimation. The complex multi-physical field behavior inside the battery significantly affects the performance state of the battery (such as capacity, attack rate, energy density, etc.). How to accurately obtain the information of the multi-physical field inside the battery has become an important challenge for battery safety diagnosis and simulation modeling.

[0004] As a real-time detection means, sensing technology has been gradually applied to the collection of battery temperature, strain, air pressure and other physical field information. However, the current sensor technology based on the module level can only measure the surface information of the battery. The temperature sampling device on the traditional battery management system is a thermistor (abbreviated as NTC), which is usually placed between several cells in each module to sample the temperature of each module. Due to the gradient effect and local effect, compared with the internal temperature change of the battery, there is a lag of tens of seconds, which cannot timely and accurately reflect the temperature change of the battery. At the same time, the detection signal dimension is single, which cannot meet the demand of effective warning. Therefore, it is urgent to develop implantable multi-signal sensors to help obtain more accurate physical field signals and more comprehensively understand the working conditions of the battery, which helps to improve the safety performance of the battery.

[0005] SUMMARY

[0006] The present application provides a battery and a battery module, and a terminal device. By setting a sheet-shaped sensor in the battery, the physical signals such as the temperature, pressure, air pressure, current and voltage inside the battery cell are detected. While reducing the overall thickness of the battery cell, the working state of the battery cell can be quickly predicted according to the real working condition inside the battery cell, and the real-time monitoring of the battery cell can be realized, thereby improving the safety performance of the battery.

[0007] In a first aspect, the present application provides a battery, comprising a shell and a battery cell assembly received in the shell.

[0008] The electrode assembly comprises an electrode tab and a separator; the electrode tab comprises a current collector and an active material layer on the current collector, and the separator separates the active material layers on two adjacent electrode tabs; at least part of the electrode tab is a blank area, and the blank area is not provided with the active material layer.

[0009] The battery further comprises at least one sheet-shaped sensor, which is arranged on the separator and corresponds to the blank area of the electrode tab.

[0010] In the above technical solution, the sheet-shaped sensor is independently arranged on the separator of the electrode assembly, and the sheet-shaped sensor is arranged to correspond to the blank area of the electrode tab. In this way, the thickness space of the original active material layer can be used to install the sheet-shaped sensor, thereby reducing the influence of the sheet-shaped sensor on the overall thickness of the electrode assembly and reducing the influence of local bulging or unevenness on the safety performance of the electrode. Moreover, the current production line process can be compatible and adapted, and a large number of processes do not need to be added to realize implantation. The sheet-shaped sensor integrates multiple sensors, and after the sheet-shaped sensor and the electrode tab are wound or laminated, the sheet-shaped sensor is located in the inside of the electrode assembly, and can detect physical signals such as temperature, pressure, air pressure, current, voltage and the like in the electrode in real time. Further, since the position of the sheet-shaped sensor on the separator corresponds to the blank area of the electrode tab, the sheet-shaped sensor does not affect the transmission of lithium ions and the kinetic characteristics, and the sheet-shaped sensor is not prone to lithium precipitation and the like on the surface during the charging and discharging cycle process, and the service life and detection accuracy of the sheet-shaped sensor can be improved. Therefore, the battery provided in the present application can reduce the influence on the overall thickness of the electrode while predicting the working state of the electrode according to the real working condition in the electrode by using the sheet-shaped sensor, and can realize real-time monitoring of the electrode and improve the safety performance of the battery.

[0011] In some embodiments, the difference between the double-layer thickness of the active material layer and the thickness of the sheet-shaped sensor is ≤0.1 mm.

[0012] In the above technical solution, since the difference between the double-layer thickness of the active material layer and the thickness of the sheet-shaped sensor is less than or equal to 0.1 mm, it can be seen that the thickness of the sheet-shaped sensor is equivalent to that of the active material layer, and the sheet-shaped sensor is installed by using the thickness space of the original active material layer, which can reduce the influence on the size of the entire electrode and will not affect the flatness of the current collector of the electrode tab, reduce the local deformation or shedding of the active material layer due to the installation of the sheet-shaped sensor, and improve the safety and use stability of the electrode.

[0013] In some embodiments, the thickness of the sheet-shaped sensor is 0.02mm-0.5mm. Specifically, it can be 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.1mm, 0.15mm, 0.18mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm, etc., and of course, it can also be other values within the above range, which is not limited herein.

[0014] It can be understood that controlling the thickness of the sheet-shaped sensor within the above range can further reduce the influence of the installation of the sheet-shaped sensor on the size of the entire battery cell and the flatness of the pole piece.

[0015] In some embodiments, the sheet-shaped sensor is a flexible sheet-shaped sensor, and the surface of the sheet-shaped sensor away from the diaphragm is not in direct contact with the active material layer.

[0016] In the above technical solution, the sheet-shaped sensor is a flexible sheet-shaped sensor, which has the characteristics of soft texture and good ductility. The sheet-shaped sensor does not contact the active material layer, which can reduce the risk of lithium precipitation caused by the contact between the sheet-shaped sensor and the active material, and improve the safety of the battery cell assembly.

[0017] In some embodiments, the sheet-shaped sensor includes a substrate layer, a sensor array disposed on the substrate layer, and a protective film located on the surface of the sensor array, and the sensor array includes at least two of a strain sensor, a temperature sensor, a pressure sensor, a gas sensor, a potential sensor, and a current sensor.

[0018] In some embodiments, the substrate layer is selected from a flexible substrate, and the flexible substrate is adhesively connected to the diaphragm.

[0019] In some embodiments, the substrate layer and the diaphragm are both selected from thermoplastic materials, and the substrate layer and the diaphragm of the sheet-shaped sensor are adhesively connected after being melted by a hot pressing process. The thermoplastic material can be polyethylene, polypropylene, polytetrafluoroethylene, etc., which is not limited herein. When the substrate layer and the diaphragm are selected from the same material, the adhesion after melting is more stable.

[0020] In some embodiments, the battery cell assembly is of a winding structure, the pole piece includes a positive pole piece and a negative pole piece, the positive pole piece, the negative pole piece and the diaphragm are wound to form N turns, N is an integer greater than 2; wherein the pole piece area on both sides of the diaphragm provided with the sheet-shaped sensor is single-sided coated, and the other areas of the pole piece except the area where the sheet-shaped sensor is placed are double-sided coated.

[0021] In some embodiments, the starting winding end of the positive electrode sheet and the starting winding end of the negative electrode sheet are both single-sided coated, the sheet-shaped sensor is arranged at the starting winding end of the diaphragm, and the positive electrode sheet and the negative electrode sheet are double-sided coated except for the starting winding end.

[0022] In the above technical solution, the sheet-shaped sensor is arranged at the starting winding end of the diaphragm, and the positive electrode sheet and the negative electrode sheet stacked with the sheet-shaped sensor are single-sided coated. Understandably, the internal stress will be concentrated and released at the position of uneven thickness, causing the force imbalance of the wound structure of the battery cell assembly, and the local swelling is intensified. The thickness space formed by single-sided coating is used to install the sheet-shaped sensor, so that the thickness balance of the wound structure of the battery cell assembly is improved, the local swelling is reduced, and the safety of the battery is improved.

[0023] In other embodiments, any area of the positive electrode sheet or the negative electrode sheet can be set as a blank area, and the sheet-shaped sensor is arranged on the diaphragm and corresponds to the blank area. Arranging the sheet-shaped sensor at the starting winding end of the diaphragm is only one implementation, which is not limited in the present application.

[0024] In some embodiments, the battery cell assembly is a Z-shaped stack structure, the electrode sheet includes n positive electrode sheets and n+1 negative electrode sheets, n≥2; wherein the positive electrode sheet and the negative electrode sheet on both sides of the diaphragm provided with the sheet-shaped sensor are single-sided coated, and the remaining electrode sheets are double-sided coated.

[0025] In the above solution, the positive electrode sheet and the negative electrode sheet on both sides of the diaphragm provided with the sheet-shaped sensor are single-sided coated, and the thickness space formed by single-sided coating is used to install the sheet-shaped sensor, so that the thickness balance of the wound structure of the battery cell assembly is improved, the local swelling is reduced, and the safety of the battery is improved.

[0026] In some embodiments, the sheet-shaped sensor is embedded in the blank area of the electrode sheet along the thickness direction, and the distance between the side edge of the sheet-shaped sensor and the active material layer of the electrode sheet is 0mm-0.01mm, which can be 0mm, 0.005mm, 0.007mm, 0.009mm or 0.01mm, etc., which is not limited herein.

[0027] In some embodiments, the battery further comprises an optical fiber sensor, and the optical fiber sensor is located in the diaphragm gap of the side edge of the battery cell assembly.

[0028] In the technical solution, the sheet-shaped sensor and the optical fiber sensor are used in cooperation, which can monitor the working state inside the battery cell assembly and the working state outside the battery cell assembly, realize omnibearing monitoring of the battery cell, and will not greatly affect the size of the battery cell and the flatness of the pole piece. The sheet-shaped sensor and the optical fiber sensor will not be in direct contact with the active material, which can improve the accuracy of the data signal collected by the sensor.

[0029] In some embodiments, the diameter of the optical fiber sensor is 0.02mm-0.2mm, specifically 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.1mm, 0.15mm, 0.18mm, 0.19mm or 0.2mm, etc., and of course it can also be other values within the above range, which is not limited here. Understandably, controlling the diameter of the optical fiber sensor within the above range can further reduce the influence of the installation of the optical fiber sensor on the size and flatness of the entire battery cell.

[0030] In a second aspect, the application provides a battery module, which comprises the battery described above. The battery module provided by the application can reduce the influence on the overall thickness of the battery cell while quickly predicting the working state of the battery cell according to the real working condition in the battery cell by using the sheet-shaped sensor, realizing real-time monitoring of the battery cell and improving the safety performance of the battery.

[0031] In a third aspect, the application provides a terminal device comprising the battery module described above.

[0032] Compared with the prior art, the application has at least the following distinguishing technical features: the sheet-shaped sensor is independently arranged on the diaphragm of the battery cell assembly, and the sheet-shaped sensor is arranged in correspondence with the blank area of the pole piece, so that the thickness space of the original active material layer can be used for installing the sheet-shaped sensor, thereby reducing the influence of the sheet-shaped sensor on the overall thickness of the battery cell assembly and reducing the influence of local bulging or unevenness on the safety performance of the battery cell. It is compatible with the current production line process and can be implanted without adding a large number of processes. Since the position of the sheet-shaped sensor on the diaphragm corresponds to the blank area of the pole piece, it will not affect the transmission of lithium ions and the kinetic characteristics, and the sheet-shaped sensor surface is not prone to lithium precipitation during the charging and discharging cycle, which can improve the service life and detection accuracy of the sheet-shaped sensor. BRIEF DESCRIPTION OF DRAWINGS

[0033] FIG. 1 is a structural schematic diagram of a battery provided by the application.

[0034] FIG. 2 is a structural schematic diagram of a wound structure of a battery cell assembly provided by the first embodiment of the application.

[0035] Fig. 3 is a schematic view of a pole piece structure of an electric core assembly according to an embodiment of the present application.

[0036] Fig. 4 is a schematic view of an electric core assembly according to an embodiment of the present application.

[0037] Fig. 5 is another schematic view of an electric core assembly according to an embodiment of the present application.

[0038] Fig. 6 is a schematic view of an electric core assembly according to an embodiment of the present application.

[0039] Fig. 7 is a schematic view of an electric core assembly according to an embodiment of the present application.

[0040] Fig. 8 is a schematic view of an electric core assembly according to an embodiment of the present application.

[0041] Fig. 9 is a schematic view of an electric core assembly according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] The technical solutions provided by the present application will be further described below in combination with specific examples and comparative examples, but the present application is not limited to the following examples.

[0043] In order to better understand the technical solutions of the present application, the embodiments of the present application will be described in detail below.

[0044] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application.

[0045] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0046] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0047] In the description of the embodiments of the present application, the term "and / or" is merely to describe an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A existing alone, A and B existing simultaneously, and B existing alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0048] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0049] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship shown based on the orientation or positional relationship shown in the drawings, and are merely for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0050] Power batteries are not only applied to energy storage power systems such as hydroelectric, thermal, wind and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also increasing.

[0051] A lithium ion battery is a common power battery, as shown in FIG. 1, which is composed of a positive electrode, a negative electrode, an electrolyte and a separator. The positive and negative active materials are the main part of the lithium battery to play the function of energy storage, which determines the energy density, cycle performance and safety performance of the battery cell. The electrolyte is the carrier for the transmission of lithium ions between the positive and negative electrodes. The ion-conducting but electron-insulating separator ensures the migration of lithium ions while separating the positive and negative electrodes to prevent short circuit. Among them, the electrolyte is the medium for the transmission of lithium ions between the positive and negative electrodes, which plays an important role in the electrochemical performance and safety performance of the battery. The working principle can be divided into two processes of charging and discharging. When the lithium ion battery is charged, the lithium ions in the positive electrode material (such as lithium cobaltate, lithium manganate, etc.) will migrate to the negative electrode (such as graphite, silicon-based material, lithium titanate LTO, etc.), and at the same time, the external power supply of the lithium ion battery will provide current to transport electrons to the positive electrode, so that the positive electrode undergoes a chemical reaction, lithium ions are separated from the positive electrode and migrate to the negative electrode, at this time the battery stores electrical energy. When the lithium ion battery is discharged, the chemical reaction between the positive and negative electrodes is reversed, the lithium ions in the negative electrode migrate to the positive electrode, and at the same time, the electrons flow in the external circuit to form a current for the work of the electrical equipment, thereby realizing the conversion of electrical energy.

[0052] In addition to the battery charge and discharge performance, the battery-related safety accidents in recent years highlight the importance of battery safety warning and state estimation. The complex multi-physical field behavior inside the battery significantly affects the performance state of the battery (such as capacity, attack rate, energy density, etc.). How to accurately obtain the information of the multi-physical field inside the battery has become an important challenge for battery safety diagnosis and simulation modeling.

[0053] As a real-time detection means, sensing technology has been gradually applied to the collection of battery temperature, strain, gas pressure and other physical field information. However, the sensor technology based on the module level can only measure the surface information of the battery. The temperature sampling device on the traditional battery management system is a thermistor (abbreviated as NTC), which is usually placed between several cells in each module to sample the temperature of each module. Due to the gradient effect and local effect, compared with the tens of seconds of lag in the internal temperature change of the battery, it cannot timely and accurately reflect the temperature change of the cell. At the same time, the detection signal dimension is single, which cannot meet the demand of effective early warning. Therefore, it is urgent to develop implantable multi-signal sensors to help obtain more accurate physical field signals and more comprehensively understand the battery working conditions, which helps to improve the safety performance of the battery.

[0054] Through implantable sensing technology, the internal temperature field, strain field, gas pressure, gas and other information of the battery monomer throughout the life cycle are quickly and accurately obtained. Combined with high-precision simulation model for data integration analysis and processing, the real working conditions of each cell are reconstructed in real time and the future working state is predicted, which is an effective way to solve the problem of high safety and high stability of the cell. It is expected to realize early warning, early isolation and early disposal. In addition, with the help of real-time data monitoring, accurate simulation management and intelligent charging and discharging strategy, this technology is expected to realize the life extension and secondary service of the cell.

[0055] In some embodiments, a temperature sensing unit can be directly integrated on the current collector of the pole piece. By etching the current collector and then depositing the sensing element, a new type of current collector with integrated sensing and current collector is prepared. This new type of composite current collector has a sensing element in the inner layer, which easily affects the flatness of the current collector, causing uneven stress after loading of the active material, subsequent deformation, powder falling, etc. At the same time, the current collector with the sensor is easy to cause damage and failure of the internal sensor during the high-temperature coating and rolling process in the pole piece manufacturing process. The service life and detection stability of the sensor are reduced.

[0056] In some embodiments, a fiber sensor with a diameter of 125 μm is embedded between the double-layer separator, and a new type of separator with a coupled fiber sensor is formed after curing by a material such as polyethylene. The embedding of the fiber sensor increases the thickness of the separator, which leads to an increase in the kinetic polarization of the positive and negative electrodes in contact; meanwhile, the internal silica fiber tube has a certain impact on the transmission of lithium ions. At the same time, this special separator has matching problems in the continuous preparation of the winding / stacking process.

[0057] In some other embodiments, the fiber Bragg grating sensors of multiple detection points can also be fixed on the outside of the battery cell assembly after the winding or stacking of the battery cell assembly is completed, and the state measurement of multiple points at any positions inside the battery can be realized by the fiber Bragg grating sensors of multiple detection points. In this technical solution, the fiber sensor is placed on the outer surface of the battery cell after packaging, and it is difficult to measure the signals on the inside of the battery cell assembly.

[0058] Therefore, the current implantable sensing technology has many problems when buried: first, stability: the implantation of the sensor usually has an impact on the cycle performance and cycle life of the battery cell, such as the implantation of the sensor between the positive and negative electrode plates or the modification of the separator, which hinders the transmission of lithium ions, affects the kinetic characteristics, and increases the polarization. The new current collector prepared by modifying the sensor on the current collector is integrated with the current collector, which is easy to be damaged in the subsequent high-temperature coating and rolling process. Second, measurement accuracy: the existing implantable sensor selects the large surface between the winding core and the shell or between two winding cores as the sensor burial position, which usually cannot accurately measure the internal signals of the battery cell, and has little difference from the external sensor. Third, process adaptability: the selection of the sensor implantation position is difficult to be compatible with the current production line process, and additional multiple processes need to be added for implantation, which is complex.

[0059] On this basis, the application provides a battery, which comprises a shell and a battery cell assembly accommodated in the shell; the battery cell assembly comprises electrode plates and separators; the electrode plates comprise current collectors and active material layers on the current collectors, and the separators separate the active material layers on adjacent two electrode plates; at least part of the electrode plates is a blank area, and the blank area is not provided with the active material layer.

[0060] The battery further comprises at least one sheet-shaped sensor, which is arranged on the separator and corresponds to the blank area of the electrode plate.

[0061] In the technical solution, the sheet-shaped sensor is independently arranged on the diaphragm of the battery cell assembly, and the sheet-shaped sensor is arranged in correspondence with the blank area of the pole piece. In this way, the thickness space of the original active material layer can be used to install the sheet-shaped sensor, thereby reducing the influence of the sheet-shaped sensor on the overall thickness of the battery cell assembly and reducing the influence of local bulging or unevenness on the safety performance of the battery cell. Moreover, the current production line process can be compatible and adapted, and a large number of processes do not need to be added to realize implantation. The sheet-shaped sensor integrates multiple sensors, and after the sheet-shaped sensor and the pole piece are wound or laminated, the sheet-shaped sensor is located in the inside of the battery cell assembly, and can detect physical signals such as temperature, pressure, air pressure, current and voltage in the battery cell in real time. Further, since the position of the sheet-shaped sensor on the diaphragm is arranged in correspondence with the blank area of the pole piece, the lithium ion transmission is not affected, the kinetic characteristics are not affected, and lithium precipitation and other phenomena are less likely to occur on the surface of the sheet-shaped sensor during the charging and discharging cycle. The service life and detection accuracy of the sheet-shaped sensor can be improved. Therefore, the battery provided in the present application can reduce the influence on the overall thickness of the battery cell while quickly predicting the working state of the battery cell according to the real working condition in the battery cell by using the sheet-shaped sensor, so that real-time monitoring of the battery cell can be realized, and the safety performance of the battery can be improved.

[0062] The battery cell assembly is the core component of the battery, which can be a lithium battery, a sodium battery, a zinc battery, etc., without limitation. According to different manufacturing processes, the battery cell can be roughly divided into a wound battery cell and a laminated battery cell. Taking the wound battery cell as an example, the positive pole piece, the diaphragm and the negative pole piece can be sequentially laminated and arranged, and then wound to form a wound structure of the battery cell assembly.

[0063] As an optional technical solution of the present application, FIG. 2 is a structural schematic diagram of a wound structure of a battery cell assembly according to an embodiment of the present application. As shown in FIG. 2, the pole piece 1 includes a positive pole piece 3 and a negative pole piece 4, and the positive pole piece 3, the negative pole piece 4 and the diaphragm 5 are wound to form N turns, where N is an integer greater than 2.

[0064] In some embodiments, the positive pole piece 3 includes a positive current collector and a positive active material layer 31 arranged on the positive current collector, and the positive active material layer 31 includes a positive active material. The specific type of the positive active material can be a lithium-based positive active material or a sodium-based positive active material, and the specific type is not limited and can be selected according to the needs. For example, the positive active material is selected from at least one of lithium nickel cobalt manganese ternary material (NCM for short), lithium manganate (LiMn2O4) or lithium cobaltate (LiCoO2). The positive current collector can be an aluminum foil or a nickel foil, etc., without limitation.

[0065] It should be noted that the positive electrode sheet and the negative electrode sheet can be manufactured by any method known in the prior art. In some embodiments, the electrode sheet can be manufactured by adding a binder and a solvent to the active material and adding a thickening agent, a conductive material, a filler, etc. as needed to form a slurry, coating the slurry on the current collector, drying, and then pressing to form.

[0066] In some embodiments, the negative electrode sheet 4 includes a negative electrode current collector and a negative electrode active material layer 41 disposed on the negative electrode current collector, and the negative electrode active material layer 41 includes a negative electrode active material, which can be a carbon-based negative electrode material, a silicon-based negative electrode material, an oxide negative electrode material, a silicon-carbon composite negative electrode material, a metal negative electrode material, etc. without limitation. The negative electrode active material layer on the negative electrode current collector can be a single-sided coating or a double-sided coating. The single-sided coating is to coat the active material layer on any one side of the current collector, and the double-sided coating is to coat the active material layer on both sides of the current collector.

[0067] In some embodiments, the negative electrode current collector can be selected from a copper foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foam, a polymer substrate coated with a conductive metal, and combinations thereof. In some embodiments, the negative electrode current collector is a copper foil.

[0068] In some embodiments, the separator film is selected from a composite of one or more of a polyethylene film, a polypropylene film, a polyvinylidene fluoride film, and a glass fiber film.

[0069] FIG. 3 is a schematic diagram of the electrode sheet structure of the battery cell assembly according to an embodiment of the present application. As shown in FIG. 3, the electrode sheet regions on both sides of the separator film provided with the sheet sensor 2 are single-sided coated, and the other regions of the electrode sheet except for the regions where the sheet sensor 2 is disposed are double-sided coated. It can be understood that the internal stress will be concentrated and released at the positions with uneven thickness, resulting in an unbalanced stress on the wound structure of the battery cell assembly and an intensified swelling. In the present application, the sheet sensor with a thickness comparable to that of the active material is installed in the thickness space formed by the single-sided coating, and the sheet sensor replaces the original coating layer, so that the overall thickness of the electrode sheet at this position is almost the same as the thickness of the electrode sheet at other positions, which improves the thickness balance of the wound structure of the battery cell assembly, reduces the local swelling, and improves the safety of the battery.

[0070] In some embodiments, as shown in FIG. 2, the starting winding end of the positive electrode sheet 3 and the negative electrode sheet 4 is single-sided coated, the sheet sensor 2 is disposed at the starting winding end of the separator film 5, and the other regions of the positive electrode sheet 3 and the negative electrode sheet 4 except for the starting winding end are double-sided coated. It can be understood that any region of the positive electrode sheet or the negative electrode sheet can be set as a blank region, and the sheet sensor is disposed on the separator film and corresponds to the blank region. The sheet sensor disposed at the starting winding end of the separator film is only one implementation, and the present application is not limited thereto.

[0071] FIG. 4 is a structural schematic diagram of the electrode core assembly of the lamination structure provided in Embodiment Two of the present application. As shown in FIG. 4, the electrode sheet 1 includes n positive electrode sheets 3 and n+1 negative electrode sheets 4, and n≥2. The electrode sheets on both sides of the diaphragm 5 provided with the sheet sensor 2 are single-sided coated, and the rest of the electrode sheets are double-sided coated.

[0072] In some embodiments, the difference between the double-layer thickness of the active material layer and the thickness of the sheet sensor 2 is ≤0.1 mm. As shown in FIG. 2 or FIG. 4, the electrode sheets on both sides of the diaphragm provided with the sheet sensor are single-sided coated, i.e., the reduced thickness of the active material layer of the two electrode sheets is the thickness of the two single-sided coated active material layers. The electrode sheets on both sides of the diaphragm provided with the sheet sensor can both be negative electrode sheets, or both be positive electrode sheets, or one can be a single-sided coated positive electrode sheet and the other can be a single-sided coated negative electrode sheet. When the difference between the double-layer thickness of the active material layer and the thickness of the sheet sensor 2 is greater than 0.1 mm, the installation of the sheet sensor 2 can cause uneven stress on the electrode sheet, leading to deformation, powder falling, etc. Therefore, the present application controls the thickness difference within 0.1 mm, so that the sheet sensor 2 can occupy the thickness vacancy of the active material layer, and the uniformity of the thickness of the electrode sheet after installation is higher. Understandably, after high-temperature coating and roll forming of the electrode sheet, the sheet sensor is arranged on the diaphragm and located in the blank area of the electrode sheet, so that the sheet sensor does not affect the coating and roll forming of the electrode sheet, and does not affect the sensitivity of the sheet sensor, reducing the damage of the roll forming process to the sensing elements inside the sheet sensor. As shown in FIG. 5, the diaphragm is provided on both sides of the sheet sensor 2, the two electrode sheets adjacent to the sheet sensor 2 are single-sided coated positive electrode sheets 3, and the active material layer on the surface of the positive electrode sheet 3 is located on the side of the positive electrode current collector away from the sheet sensor 2.

[0073] Understandably, the present application installs the sheet sensor in the thickness space formed by single-sided coating, so that the thickness balance of the electrode core assembly of the winding structure or the lamination structure is improved, the local expansion is reduced, and the safety of the battery is improved.

[0074] In some embodiments, the sheet sensor on the diaphragm forms a layering structure, and the layering structure is specifically a single-sided active material layer negative electrode sheet-sheet sensor-diaphragm-single-sided active material layer positive electrode sheet. The rest of the electrode sheets are double-sided coated active material electrode sheets.

[0075] In some embodiments, the thickness of the sheet-shaped sensor is 0.02 mm to 0.5 mm, and can be 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, or 0.5 mm, and the like, and can also be other values within the above range, which is not limited herein. It can be understood that controlling the thickness of the sheet-shaped sensor within the above range can further reduce the influence of the installation of the sheet-shaped sensor on the size and flatness of the entire cell.

[0076] In order to be more suitable for the winding / lamination process of the entire cell assembly, the sheet-shaped sensor is a flexible sheet-shaped sensor, which has the characteristics of soft texture and good ductility. In the present application, the surface of the sheet-shaped sensor away from the separator is not in direct contact with the active material layer. As shown in FIG. 2 or FIG. 4, the two sides of the sheet-shaped sensor are the separator or the current collector, and the sheet-shaped sensor just occupies the redundant space of the thickness of the single-sided coated pole piece, which can not only guarantee the uniformity of the thickness of the entire cell assembly and improve the flatness after winding / lamination forming, but also reduce the risk of lithium precipitation caused by the contact between the sheet-shaped sensor and the active material, and improve the safety of the cell assembly.

[0077] In some embodiments, the sheet-shaped sensor includes a substrate layer, a sensor array arranged on the substrate layer, and a protective film on the surface of the sensor array. The material of the substrate layer and the protective film can be a flexible polymer film, such as polyimide (abbreviated as PI), polypropylene (abbreviated as PP), and the like, and can also be a high polymer film such as polydimethylsiloxane (abbreviated as PDMS), polytetrafluoroethylene (abbreviated as PTFE), and the like.

[0078] In some embodiments, the substrate layer is selected from a flexible substrate, and the flexible substrate is bonded to the separator. It can be understood that the bonding method can guarantee the stability of the connection between the sensor and the separator, and improve the stability and durability of the overall structure of the cell. The chemical method such as high polymer adhesive, heat curing process can be used for fixation, and the substrate layer can also be functionalized and complexed to enhance the adhesion effect between the separator and the substrate layer material.

[0079] In some embodiments, the base layer and the diaphragm are both selected from thermoplastic materials, and the base layer and the diaphragm of the sheet-shaped sensor are bonded and connected after being melted by a hot pressing process. The thermoplastic material can be polyethylene, polypropylene, polytetrafluoroethylene, etc., which is not limited herein. When the base layer and the diaphragm are selected from the same material, the sensor and the diaphragm are processed by hot pressing integration, and the two are bonded after being melted, which is more stable. In terms of process, a pressing device can be added in the cell winding process to position and press the sensor and the diaphragm. Understandably, compared with the new current collector scheme formed by integrating the sensor and the current collector, the overall process of the technical scheme of the present application is simpler, the adaptation effect with the cell is better, and the cost is also lower.

[0080] Specifically, the sensor array includes at least one or more of a strain sensor, a temperature sensor, a pressure sensor, a gas sensor, a potential sensor, and a current sensor. The strain sensor can be used to monitor the deformation of the pole piece at the location. The temperature sensor can be used to monitor the temperature at the location. The pressure sensor can be used to monitor the pressure at the location. The gas sensor can be used to monitor the type and amount of gas in the cell assembly. The potential sensor can be used to monitor the potential at the location. The current sensor can be used to monitor the current at the location. Exemplarily, the temperature sensor can be a flexible thermocouple temperature sensor, a thermistor sensor, etc., the gas sensor can be a semiconductor gas sensor, and the pressure sensor can be a pressure-sensitive sensor.

[0081] Understandably, the surface of the sheet-shaped sensor has a protective film, which can prevent the electrolyte from eroding the sensor. Each sensor is connected to the controller through a signal line. The controller can monitor the working state in the cell according to the data sent by each sensor and send a warning signal. In some specific embodiments, when the signal of the sensor is led out from the cell to the outside of the cell, the interface of the aluminum-plastic film of the soft package battery can be modified to enhance the connection stability of the signal line and the material at the interface. For example, the interface material can be modified with polyimide or a composite polyimide film to enhance the bonding stability of the thermoplastic polypropylene film on the surface of the signal line and the thermoplastic material at the interface. For square cell batteries, the signal line can be led out through the original gap or aperture, or connected and fixed by three-pole column welding, etc.

[0082] The controller can be arranged in the battery management system or other components of the battery management system, as long as it can receive the signal of the sensor. In some embodiments, the signal of the sensor can also be transmitted by a wireless chip transmission method.

[0083] Figure 6 is a structural schematic diagram of the winding structure of the battery cell assembly according to the third embodiment of the present application. As shown in Figure 6, in order to monitor the working state of the battery cell in all directions and ensure the safety of the battery, the battery further comprises an optical fiber sensor 6, which is located in the separator gap at the side of the battery cell assembly. In this embodiment, the embedding mode of the optical fiber sensor is single-side reciprocating intercalation. In other embodiments, the embedding mode of the optical fiber sensor can also be double-side reciprocating intercalation.

[0084] It can be understood that the optical fiber sensor 6 can also be a sensor array arranged at intervals along the extension direction of the optical fiber, which includes at least one or more of a strain sensor, a temperature sensor, a pressure sensor, a gas sensor, a potential sensor, and a current sensor. The sensor array is arranged in the separator gap at the side of the winding or laminated battery cell assembly, which does not contact the active material, ensures the monitoring accuracy of the sensor, and cooperates with the sheet sensor to realize omnidirectional monitoring of the battery cell from the inside to the outside, thereby improving the reliability of the battery cell assembly monitoring.

[0085] Figure 7 is a structural schematic diagram of the winding structure of the battery cell assembly according to the fourth embodiment of the present application. As shown in Figure 7, the electrode sheet includes a positive electrode sheet and a negative electrode sheet, and the positive electrode sheet, the negative electrode sheet, and the separator are wound to form N turns, where N is an integer greater than 2. The optical fiber sensor 6 is located in the separator gap at the side of the battery cell assembly. The embedding mode of the optical fiber sensor can be linear single intercalation. The optical fiber sensor is intercalated into the separator gap at the side of the battery cell assembly, which can reduce the side gap of the battery cell assembly while monitoring the internal state of the battery cell assembly. In this embodiment, the optical fiber sensor cooperates with the sheet sensor, wherein the sheet sensor can monitor the temperature, pressure, and other physical signals inside the battery cell assembly; the optical fiber sensor can monitor the air pressure, current, voltage, and other physical signals at the side or outside of the battery cell assembly; and the two can cooperate to realize omnidirectional monitoring, thereby further improving the reliability of the battery cell assembly monitoring without affecting the flatness of the electrode sheet.

[0086] Figure 8 is a structural schematic diagram of the laminated structure of the battery cell assembly according to the fifth embodiment of the present application. As shown in Figure 8, the electrode sheet includes n positive electrode sheets 3 and n+1 negative electrode sheets 4, where n≥2. The positive electrode sheet and the negative electrode sheet on both sides of the separator provided with the sheet sensor are single-sided coated, and the remaining electrode sheets are double-sided coated. The optical fiber sensor 6 is located in the separator gap at the side of the battery cell assembly. As shown in Figure 8, the embedding mode of the optical fiber sensor is single-side reciprocating intercalation. In other embodiments, the embedding mode of the optical fiber sensor can also be double-side reciprocating intercalation. It can be understood that the cooperation of the optical fiber sensor and the sheet sensor can monitor the working state of the battery cell assembly in all directions.

[0087] FIG. 9 is a structural schematic diagram of the cell assembly with the lamination structure according to the sixth embodiment of the present application. As shown in FIG. 9, the electrode sheet includes n positive electrode sheets 3 and n+1 negative electrode sheets 4, and n≥2. Different from the fifth embodiment, the embedded mode of the optical fiber sensor is linear interpenetration, and the optical fiber sensor can also be linearly interpenetrated on both sides of the cell assembly, which is not limited herein.

[0088] In some embodiments, the diameter of the optical fiber sensor is 0.02mm-0.2mm, and can be 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.1mm, 0.15mm, 0.18mm, 0.19mm or 0.2mm, and can also be other values within the above range, which is not limited herein. It can be understood that controlling the diameter of the optical fiber sensor within the above range can further reduce the influence of the installation of the optical fiber sensor on the size of the entire cell and the flatness of the electrode sheet.

[0089] Specifically, the optical fiber sensor can be fixed in the membrane side gap by a high polymer adhesive or the like. The optical signal collected by the optical fiber sensor can be extended to the outside of the cell 1 along the extended optical fiber 61 and connected with an optical signal processor. The optical signal processor includes a light source, a demodulator and the like. When the optical fiber sensor transmits data, the cable is led out from the inside of the cell to the outside of the cell, and the material at the interface of the battery can be modified to enhance the connection stability of the extended optical fiber and the material at the interface. For example, the material at the interface can be modified with polyimide or a composite polyimide film, so that the bonding stability of the thermoplastic PP film on the outer surface of the extended optical fiber and the thermoplastic material at the interface. For a square cell, a wire hole can be provided on the top cover of the battery, or a signal line can be led out through the original gap or aperture, or a three-pole column welding or the like can be used for connection and fixation.

[0090] In the present application, the use of the sheet-shaped sensor and the optical fiber sensor can monitor the working state inside the cell assembly and the working state outside the cell assembly, realize all-round monitoring of the cell, and will not greatly affect the size of the cell and the flatness of the electrode sheet. The sheet-shaped sensor and the optical fiber sensor do not directly contact the active material, which can improve the accuracy of the data signals collected by the sensor.

[0091] As an optional technical solution of the present application, the above-mentioned battery can be a primary battery, a secondary battery, a soft package battery, a semi-solid battery, a solid-state battery or a lithium-ion battery, which is not limited herein.

[0092] In a second aspect, the application further provides a terminal device comprising the battery of the second aspect. The battery of the application has good safety performance, and thus the application of the battery in the terminal device enables the terminal device to have good safety performance.

[0093] The terminal device in the application can be specifically a car, an energy storage system, etc., which is not limited herein.

[0094] The above is only a preferred embodiment of the application, and is not used to limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

[0095] The application is disclosed as above with a preferred embodiment, but is not used to limit the claims. Any person skilled in the art can make several possible changes and modifications without departing from the concept of the application, and thus the protection scope of the application shall be subject to the range defined by the claims of the application.

Claims

1. A battery, characterized by, The battery comprises a shell and an electrode assembly accommodated in the shell; The electrode assembly comprises a tab and a separator; the tab comprises a current collector and an active material layer on the current collector, and the separator separates the active material layers on adjacent two tabs; at least part of the tab is a blank area which is not provided with the active material layer; The battery further comprises at least one sheet-shaped sensor layer which is arranged on the separator and corresponds to the blank area of the tab.

2. The battery of claim 1, wherein, The thickness difference between the double-layer thickness of the active material layer and the thickness of the sheet-shaped sensor is less than or equal to 0.1 mm.

3. The battery of claim 1, wherein, The thickness of the sheet-shaped sensor is 0.02 mm to 0.5 mm.

4. The battery of claim 1, wherein, The surface of the sheet-shaped sensor layer away from the separator is not in direct contact with the active material layer.

5. The battery of claim 1, wherein, The sheet-shaped sensor comprises a substrate layer, a sensor array arranged on the substrate layer, and a protective film on the surface of the sensor array, and the sensor array comprises at least two of a strain sensor, a temperature sensor, a pressure sensor, a gas sensor, a potential sensor, and a current sensor.

6. The battery of claim 5, wherein, The substrate layer is selected from a flexible substrate which is adhesively connected to the separator.

7. The battery of claim 1, wherein, The electrode assembly is in a winding structure, the tab comprises a positive tab and a negative tab, and the positive tab, the negative tab, and the separator are wound to form N turns, N being an integer greater than 2; wherein the tab area on both sides of the separator provided with the sheet-shaped sensor is single-sided coated, and the other areas of the tab except the area where the sheet-shaped sensor is placed are double-sided coated.

8. The battery of claim 7, wherein, The starting winding end of the positive tab and the starting winding end of the negative tab are both single-sided coated, the sheet-shaped sensor is arranged at the starting winding end of the separator, and the other areas of the positive tab and the negative tab except the starting winding end are double-sided coated.

9. The battery of claim 1, wherein, The electrode assembly is in a Z-shaped laminated structure, the tab comprises n positive tabs and n+1 negative tabs, n being greater than or equal to 2; wherein the positive tab and the negative tab on both sides of the separator provided with the sheet-shaped sensor are single-sided coated, and the other tabs are double-sided coated.

10. The battery according to claim 7 or 9, characterized in that, The sheet-shaped sensor is embedded in the blank area of the tab along the thickness direction, and the spacing between the side edge of the sheet-shaped sensor and the active material layer of the tab is 0 mm to 0.01 mm.

11. The battery of claim 1, wherein, The battery further comprises an optical fiber sensor which is located in the separator gap at the side edge of the electrode assembly.

12. The battery of claim 11, wherein, The diameter of the optical fiber sensor is 0.02 mm to 0.2 mm.

13. A battery module, characterized by The battery module comprises the battery of any one of claims 1 to 12.

14. A terminal device, comprising: The battery module comprises the battery of claim 13.

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