Battery cell and battery pack

Abstract

The utility model relates to the technical field of new energy batteries, and discloses a battery cell and a battery pack, the battery cell comprises a shell, the shell is provided with a containing cavity and an electrode assembly, and the electrode assembly is assembled in the containing cavity; the top cover covers and seals the accommodating cavity, and the top cover is provided with an assembling surface; the protective cover is fixedly connected with the assembly surface, the protective cover is a corrosion-resistant material piece or the side, away from the assembly surface, of the protective cover is provided with a corrosion-resistant layer, and a pressure measuring cavity is defined between the protective cover and the assembly surface; the circuit board is fixedly connected with the top cover; the pressure sensor is fixedly connected with the circuit board, the top cover is further provided with a detection hole communicated with the pressure measuring cavity, and the pressure sensor is embedded in the detection hole. The protective cover protects the pressure sensor, the pressure in the pressure measuring cavity changes in the charging and discharging process of the battery cell, the pressure sensor can detect the pressure change in the pressure measuring cavity or the extrusion force change of the protective cover in real time, and a dynamic and real-time pressure feedback mechanism is provided for monitoring the health condition of the electrode assembly.

Description

TECHNICAL FIELD

[0001] The utility model relates to new energy battery technical field especially relates to a kind of battery cell and battery pack. BACKGROUND

[0002] In the equipment such as electric vehicle, power tool that depends on battery power supply, battery management system (BATTERY MANAGEMENT SYSTEM, simply BMS) is the key technology to ensure the safety and stability of battery.BMS is through monitoring voltage, temperature and current and other key parameters in battery pack, carries out comprehensive management to battery pack.However, the abnormality of these traditional parameters often indicates that battery cell is in failure state, and early warning is difficult to realize.

[0003] In order to improve the accuracy of monitoring, the pressure change in the battery cell becomes an important indicator for monitoring the safety of the battery cell.However, the internal space of the battery cell is limited, and the size of the electrolyte-resistant sensor on the market is large, while the small sensor is difficult to withstand the corrosion of electrolyte. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of battery cell to solve the problem that the space of battery cell in prior art is limited and it is difficult to arrange sensor detection;The utility model further provides a kind of battery pack using the battery cell.

[0005] In order to achieve the above purpose, the utility model provides a kind of battery cell, comprising:

[0006] Shell, the shell has accommodating cavity,

[0007] Electrode assembly, the electrode assembly is assembled in the accommodating cavity;

[0008] Top cover, the top cover covers the accommodating cavity, the top cover has assembly surface, and the assembly surface is located at the side of the top cover towards the shell;

[0009] Protective cover, the protective cover is fixedly connected with the assembly surface, the protective cover is corrosion-resistant material piece or the side of the protective cover away from the assembly surface has anticorrosive layer, the protective cover is deformable flexible piece, and the protective cover and the assembly surface are surrounded to form pressure measuring cavity;

[0010] Circuit board, the circuit board is arranged on the side of the top cover away from the assembly surface, and the circuit board is fixedly connected with the top cover;

[0011] Pressure sensor, the pressure sensor is fixedly connected with the circuit board, the top cover is further provided with detection hole in communication with the pressure measuring cavity, and the pressure sensor is embedded in the detection hole.

[0012] Preferably, the protective cover comprises a cover body and a flange connected with the cover body, the flange is welded with the assembly surface, and the pressure sensor is located between the cover body and the assembly surface.

[0013] Preferably, the pressure sensor has a spacing with the cover body, and the pressure sensor is used for detecting the air pressure of the pressure measuring cavity.

[0014] Preferably, the pressure sensor is in contact with the cover body, and the pressure sensor is used for detecting the pressure transmitted by the cover body.

[0015] Preferably, the protective cover is an aluminum foil piece.

[0016] Preferably, one side of the top cover away from the assembly surface has a groove, the circuit board is fixedly assembled in the groove, the groove has a groove bottom, and the detection hole penetrates the groove bottom.

[0017] Preferably, a sealing ring is further included, and the sealing ring is assembled between the pressure sensor and the detection hole.

[0018] Preferably, the battery cell further comprises a second positive pole, a third positive pole, a second negative pole and a third negative pole, the groove bottom is further provided with a through hole penetrating through, the second positive pole, the third positive pole, the second negative pole and the third negative pole are respectively assembled in the through hole, one end of the second positive pole, the third positive pole, the second negative pole and the third negative pole is respectively electrically connected with the electrode assembly, and the other end of the second positive pole, the third positive pole, the second negative pole and the third negative pole is respectively electrically connected with the circuit board.

[0019] The battery cell further comprises a first positive pole and a first negative pole, and the first positive pole and the first negative pole are respectively fixedly connected with the top cover.

[0020] Preferably, the battery cell further comprises a positive pole capacitor sensor and a negative pole capacitor sensor, the positive pole capacitor sensor is electrically connected with the first positive pole, the second positive pole and the third positive pole, and the negative pole capacitor sensor is electrically connected with the first negative pole, the second negative pole and the third negative pole.

[0021] The utility model further provides a battery pack which comprises the battery cell of any one of the above technical solutions.

[0022] The utility model discloses an electrode core and battery pack compared with prior art, its beneficial effect lies in: the assembly surface on the top cover fixedly connected with the protective cover, and the assembly surface between the protective cover and top cover encloses the pressure measuring cavity, and the pressure measuring cavity provides the assembly space for pressure sensor, because the protective cover is corrosion -resistant material piece or has anticorrosive layer, has improved corrosion resistance, and the protection is formed to pressure sensor, because the protective cover is the flexible piece of variability, and the electrode core is in the process of charge and discharge, and the protective cover is extruded, and the pressure in the pressure measuring cavity changes, and pressure sensor can real -time detection pressure change or extrusion pressure change of the protective cover in the pressure measuring cavity, and the dynamic, real -time pressure feedback mechanism is provided for monitoring the health condition of electrode assembly, and the accuracy, efficiency and safety of electrode core failure early warning are improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the structural schematic diagram of the electrode core of the utility model;

[0024] Figure 2 It is the front view of the electrode core of Figure 1 ;

[0025] Figure 3 It is the explosion schematic diagram of the electrode core of Figure 1 ;

[0026] Figure 4 It is the structural schematic diagram of the top cover of the electrode core of Figure 3 ;

[0027] Figure 5 It is the assembly schematic diagram of the circuit board, pressure sensor and protective cover of the electrode core of Figure 3 ;

[0028] Figure 6 It is the assembly schematic diagram of the top cover and electrode assembly of the electrode core of the utility model.

[0029] In the drawing, 1, electrode assembly, 2, top cover, 21, assembly surface, 22, recess, 221, groove bottom, 222, detection hole, 3, protective cover, 31, cover body, 32, flange, 4, pressure measuring cavity, 5, pressure sensor, 6, circuit board, 7, sealing ring, 8, shell, 81, containing cavity, 10, second positive pole column, 20, third positive pole column, 30, second negative pole column, 40, third negative pole column, 50, first positive pole column, 60, first negative pole column, 70, positive pole capacitor sensor, 80, negative pole capacitor sensor. DETAILED DESCRIPTION

[0030] The utility model discloses an electrode core and battery pack compared with prior art, its beneficial effect lies in: the assembly surface on the top cover fixedly connected with the protective cover, and the assembly surface between the protective cover and top cover encloses the pressure measuring cavity, and the pressure measuring cavity provides the assembly space for pressure sensor, because the protective cover is corrosion -resistant material piece or has anticorrosive layer, has improved corrosion resistance, and the protection is formed to pressure sensor, because the protective cover is the flexible piece of variability, and the electrode core is in the process of charge and discharge, and the protective cover is extruded, and the pressure in the pressure measuring cavity changes, and pressure sensor can real -time detection pressure change or extrusion pressure change of the protective cover in the pressure measuring cavity, and the dynamic, real -time pressure feedback mechanism is provided for monitoring the health condition of electrode assembly, and the accuracy, efficiency and safety of electrode core failure early warning are improved.

[0031] A preferred embodiment of the battery cell of this utility model is as follows: Figures 1 to 6 As shown, the battery cell includes a housing 8, an electrode assembly 1, a top cover 2, a protective cover 3, a circuit board 6, and a pressure sensor 5.

[0032] The housing 8 has a receiving cavity 81, in which the electrode assembly 1 is assembled. The top cover 2 seals the receiving cavity 81. The top cover 2 has a mounting surface 21, which is located on the side of the top cover 2 facing the housing 8. That is, in this embodiment, the mounting surface 21 of the top cover 2 and the electrode assembly 1 are arranged opposite to each other.

[0033] The protective cover 3 is fixedly connected to the mounting surface 21 of the top cover 2, and the protective cover 3 and the mounting surface 21 form a pressure measuring chamber 4. After the protective cover 3 is connected to the top cover 2, the pressure measuring chamber 4 becomes a sealed absolute pressure environment. The protective cover 3 is a deformable flexible part. During the charging and discharging process of the battery cell, the air pressure inside the electrode assembly 1 will pressurize the protective cover 3. The protective cover 3 deforms under pressure, and the pressure inside the pressure measuring chamber 4 changes.

[0034] The protective cover 3 is made of a corrosion-resistant material, giving it corrosion-resistant properties; alternatively, the side of the protective cover 3 facing away from the mounting surface 21 has an anti-corrosion layer, which increases its corrosion resistance. When the electrolyte in the electrode assembly 1 comes into contact with the protective cover 3, the protective cover 3 is protected from corrosion, thus protecting the pressure sensor 5 in the pressure measuring chamber 4.

[0035] The circuit board 6 is located on the side of the top cover 2 away from the assembly surface 21. The circuit board 6 is fixedly connected to the top cover 2. The pressure sensor 5 is fixedly connected to the circuit board 6. The pressure sensor 5 can transmit the measured pressure data to the circuit board 6. In this embodiment, the circuit board 6 and the pressure sensor 5 are integrated and welded to the top cover 2.

[0036] The top cover 2 is also provided with a detection hole 222 that communicates with the pressure measuring chamber 4. The pressure sensor 5 is embedded in the detection hole 222. When the air pressure change of the electrode assembly 1 squeezes the protective cover 3, the protective cover 3 deforms. At this time, the pressure in the pressure measuring chamber 4 changes. The pressure sensor 5 can detect the air pressure change in the pressure measuring chamber 4, or it can directly contact the protective cover 3 to detect the pressure change transmitted by the protective cover 3.

[0037] In this embodiment, the pressure sensor 5 can take various forms, including strain gauge, piezoelectric, capacitive, inductive, and resonant types, which can be selected according to user needs to adapt to different application requirements and environmental conditions.

[0038] In the charging and discharging process of the battery cell, the pressure change in the electrode assembly 1 extrudes the protective cover 3, thereby increasing the pressure in the pressure measuring cavity 4. As the pressure increases, when a certain threshold is reached, the shell 8 of the battery cell begins to expand, and at this time the growth rate of the pressure will slow down accordingly. Further, when the pressure P grows to a critical value, the explosion-proof valve is triggered to explode, and the pressure will quickly decrease to atmospheric pressure. This process not only ensures the safety of the battery cell during charging and discharging, but also provides real-time monitoring and early warning for the health status of the battery cell.

[0039] The battery cell is fixedly connected with the protective cover 3 on the assembly surface 21 of the top cover 2, and the protective cover 3 and the assembly surface 21 of the top cover 2 form a pressure measuring cavity 4 therebetween, which provides an assembly space for the pressure sensor 5. Since the protective cover 3 is a corrosion-resistant material or has a corrosion-resistant layer, the corrosion resistance is improved, and the pressure sensor 5 is protected. Since the protective cover 3 is a flexible piece with variability, the protective cover 3 is extruded during the charging and discharging of the battery cell, and the pressure in the pressure measuring cavity 4 changes. The pressure sensor 5 can detect the pressure change in the pressure measuring cavity 4 or the extrusion force change of the protective cover 3 in real time, thereby providing a dynamic and real-time pressure feedback mechanism for monitoring the health status of the electrode assembly 1, and improving the accuracy, efficiency and safety of the failure warning of the battery cell.

[0040] Preferably, the protective cover 3 includes a cover body 31 and a flange 32 connected with the cover body 31, and the flange 32 is welded and fixed with the assembly surface 21, and the pressure sensor 5 is located between the cover body 31 and the assembly surface 21.

[0041] The flange 32 increases the contact area between the protective cover 3 and the top cover 2, ensures the stability of the welding between the protective cover 3 and the assembly surface 21 of the top cover 2, and also increases the sealing performance of the pressure measuring cavity 4 between the cover body 31 and the assembly surface 21, thereby ensuring the accuracy of the detection result of the pressure sensor 5. In the embodiment, the flange 32 is laser welded on the assembly surface 21 of the top cover 2, and has air tightness and corrosion resistance.

[0042] Preferably, the pressure sensor 5 has a space with the cover body 31, and the pressure sensor 5 is used to detect the air pressure of the pressure measuring cavity 4.

[0043] In the embodiment, the pressure sensor 5 detects the air pressure change in the pressure measuring cavity 4 to reflect the air pressure change in the electrode assembly 1.

[0044] Preferably, the pressure sensor 5 is in contact with the cover body 31, and the pressure sensor 5 is used to detect the pressure transmitted by the cover body 31.

[0045] In the embodiment, the pressure sensor 5 is in direct contact with the cover 31 of the protective cover 3, and when the air pressure inside the electrode assembly 1 changes, the protective cover 3 is pressed, and the protective cover 3 directly transmits the pressure to the pressure sensor 5, and the pressure sensor 5 detects the change of the pressure transmitted by the protective cover 3 to reflect the change of the air pressure inside the electrode assembly 1.

[0046] Preferably, the protective cover 3 is an aluminum foil piece.

[0047] The aluminum foil piece naturally forms a corrosion-resistant oxide film on the outside, and there is no need to add a corrosion-resistant layer on the outside of the protective cover 3, which simplifies the process and reduces the cost, and the aluminum foil piece also has the advantage of light weight. In other embodiments, the protective cover 3 can also be made of polyester material, and the outside of the polyester material is coated with a corrosion-resistant material to form a corrosion-resistant layer.

[0048] Preferably, the side of the top cover 2 away from the assembly surface 21 has a groove 22, and the circuit board 6 is fixedly assembled in the groove 22, and the groove 22 has a groove bottom 221, and a detection hole 222 penetrates the groove bottom 221.

[0049] The groove 22 on the top cover 2 provides space for the assembly of the circuit board 6, and also avoids the height of the circuit board 6 exceeding the top surface of the top cover 2. The detection hole 222 penetrates the groove bottom 221 and communicates with the pressure measuring cavity 4, and the pressure sensor 5 is embedded in the detection hole 222, so that the pressure sensor 5 can also enter the pressure measuring cavity 4 through the detection hole 222 to detect the air pressure in the pressure measuring cavity 4 or contact the cover 31 of the protective cover 3.

[0050] Preferably, a sealing ring 7 is further included, and the sealing ring 7 is assembled between the pressure sensor 5 and the detection hole 222.

[0051] The sealing ring 7 arranged between the pressure sensor 5 and the detection hole 222 can increase the sealing between the pressure sensor 5 and the hole wall of the detection hole 222, thereby increasing the sealing of the pressure measuring cavity 4, so that the pressure measuring cavity 4 forms an internal sealed absolute pressure environment, and the accuracy of the detection result of the pressure sensor 5 is improved.

[0052] Preferably, the battery further includes a second positive electrode column 10, a third positive electrode column 20, a second negative electrode column 30, and a third negative electrode column 40, the groove bottom 221 is further provided with a through hole penetrating therethrough, the second positive electrode column 10, the third positive electrode column 20, the second negative electrode column 30, and the third negative electrode column 40 are respectively assembled in the through hole, one end of the second positive electrode column 10, the third positive electrode column 20, the second negative electrode column 30, and the third negative electrode column 40 are respectively electrically connected with the electrode assembly 1, and the other end of the second positive electrode column 10, the third positive electrode column 20, the second negative electrode column 30, and the third negative electrode column 40 are respectively electrically connected with the circuit board 6; the battery further includes a first positive electrode column 50 and a first negative electrode column 60, and the first positive electrode column 50 and the first negative electrode column 60 are respectively fixedly connected with the top cover 2.

[0053] The second positive pole 10, the third positive pole 20, the second negative pole 30 and the third negative pole 40 are electrically connected with the electrode assembly 1 and the circuit board 6, the electrode assembly 1 can supply electricity to the circuit board 6, and the first positive pole 50 and the first negative pole 60 are fixedly connected with the top cover 2 and can discharge outward. In assembly, the top cover 2 can be provided with a solder pad or a buckle to be connected with the second positive pole 10, the third positive pole 20, the second negative pole 30 and the third negative pole 40.

[0054] Preferably, the electric core further comprises a positive pole capacitor sensor 70 and a negative pole capacitor sensor 80, the positive pole capacitor sensor 70 is electrically connected with the first positive pole 50, the second positive pole 10 and the third positive pole 20, and the negative pole capacitor sensor 80 is electrically connected with the first negative pole 60, the second negative pole 30 and the third negative pole 40.

[0055] The positive pole capacitor sensor 70 and the negative pole capacitor sensor 80 can detect the current, voltage and temperature of the battery.

[0056] In conclusion, the electric core and the battery pack provided by the embodiment of the present application have the following advantages: the protective cover is fixedly connected with the assembly surface of the top cover, a pressure measuring cavity is formed between the protective cover and the assembly surface of the top cover, and the pressure measuring cavity provides an assembly space for the pressure sensor; since the protective cover is made of a corrosion-resistant material or has a corrosion-resistant layer, the corrosion resistance is improved, and the pressure sensor is protected; since the protective cover is a flexible piece with variability, the protective cover is extruded in the process of charging and discharging of the electric core, the pressure in the pressure measuring cavity changes, the pressure sensor can detect the pressure change in the pressure measuring cavity or the extrusion force change of the protective cover in real time, a dynamic and real-time pressure feedback mechanism is provided for monitoring the health condition of the electrode assembly, and the accuracy, efficiency and safety of the failure warning of the electric core are improved.

[0057] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and replacements can be made, and these improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. An electric cell, characterized by, The application relates to a pressure sensor protection device for a lithium battery, which comprises the following parts: a shell (8) with a containing cavity (81); an electrode assembly (1) assembled in the containing cavity (81); a top cover (2) covering the containing cavity (81), the top cover (2) having an assembling surface (21) on the side of the top cover (2) facing the shell (8); a protective cover (3) fixedly connected with the assembling surface (21), the protective cover (3) being made of a corrosion-resistant material or having a corrosion-resistant layer on the side of the protective cover (3) facing away from the assembling surface (21), the protective cover (3) being a flexible part capable of being deformed, and a pressure measuring cavity (4) being formed between the protective cover (3) and the assembling surface (21); a circuit board (6) arranged on the side of the top cover (2) facing away from the assembling surface (21) and fixedly connected with the top cover (2); a pressure sensor (5) fixedly connected with the circuit board (6), the top cover (2) being further provided with a detection hole (222) in communication with the pressure measuring cavity (4), and the pressure sensor (5) being embedded in the detection hole (222).

2. The electric cell of claim 1, wherein, The protective cover (3) comprises a cover body (31) and a flange (32) connected with the cover body (31), the flange (32) is welded and fixed with the assembling surface (21), and the pressure sensor (5) is located between the cover body (31) and the assembling surface (21).

3. The electric cell of claim 2, wherein, The pressure sensor (5) is spaced apart from the cover body (31), and the pressure sensor (5) is used for detecting the air pressure of the pressure measuring cavity (4).

4. The cell of claim 2, wherein, The pressure sensor (5) is in contact with the cover body (31), and the pressure sensor (5) is used for detecting the pressure transmitted by the cover body (31).

5. The cell of any of claims 1-4, wherein, The protective cover (3) is an aluminum foil part.

6. The cell of any of claims 1-4, wherein, The side of the top cover (2) facing away from the assembling surface (21) is provided with a recess (22), the circuit board (6) is fixedly assembled in the recess (22), the recess (22) has a groove bottom (221), and the detection hole (222) penetrates through the groove bottom (221).

7. The electric cell of claim 6, wherein, The application further comprises a sealing ring (7) assembled between the pressure sensor (5) and the detection hole (222).

8. The electric cell of claim 6, wherein, The electrode assembly further comprises a second positive pole (10), a third positive pole (20), a second negative pole (30) and a third negative pole (40), the groove bottom (221) is further provided with a through hole, the second positive pole (10), the third positive pole (20), the second negative pole (30) and the third negative pole (40) are respectively assembled in the through hole, one end of the second positive pole (10), the third positive pole (20), the second negative pole (30) and the third negative pole (40) is respectively electrically connected with the electrode assembly (1), and the other end of the second positive pole (10), the third positive pole (20), the second negative pole (30) and the third negative pole (40) is respectively electrically connected with the circuit board (6). The electric core further comprises a first positive pole post (50) and a first negative pole post (60), the first positive pole post (50) and the first negative pole post (60) are fixedly connected with the top cover (2) respectively.

9. The electric cell of claim 8, wherein, The electric core further comprises a positive pole capacitor sensor (70) and a negative pole capacitor sensor (80), the positive pole capacitor sensor (70) is electrically connected with the first positive pole post (50), the second positive pole post (10) and the third positive pole post (20), and the negative pole capacitor sensor (80) is electrically connected with the first negative pole post (60), the second negative pole post (30) and the third negative pole post (40).

10. A battery pack, characterized by, An electric core comprising any one of claims 1-9.

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