12V sodium ion battery and preparation method thereof

Abstract

The invention provides a 12V sodium ion battery and a preparation method thereof, the battery comprises: a battery shell, the interior of the battery shell is hollow; the battery cover covers the opening of the battery shell; the battery cell group is arranged in a cavity formed by the battery shell and the battery cover and is formed by four 3V sodium ion battery cells in a 1P4S connection mode; the signal acquisition component is connected with the battery cell group and is used for acquiring functional signals of each sodium ion battery cell, and the functional signals of the sodium ion battery cells comprise voltage, current and temperature; and the battery management module is connected with the signal acquisition assembly and the battery cell group, receives the function signals acquired by the signal acquisition assembly, and controls and manages the function safety of each sodium ion battery cell. The battery provided by the invention has the characteristics of high performance, long service life and high safety, and can provide a lightweight solution for a 12V low-voltage battery system of a new energy automobile.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile starting batteries, and in particular to a 12V sodium ion battery and a preparation method thereof. Background Art

[0002] As a key component of a vehicle's powertrain, the performance of a starting battery directly impacts its starting efficiency, service life, and safety. Currently, the core performance indicators for starting batteries primarily focus on high-current discharge performance over a wide temperature range, cycle life, and safety.

[0003] Lead-acid batteries, with approximately 90% market share, are the mainstream choice for automotive starting batteries. However, these batteries face numerous technical bottlenecks that are difficult to overcome. First, their short cycle life makes them unable to meet the growing demands of modern vehicles. Second, their charging capacity decreases significantly in low-temperature environments, and their high-current discharge performance degrades significantly, severely impacting vehicle starting performance in cold climates. Third, their high self-discharge rate makes them prone to battery depletion after prolonged parking. Furthermore, their high weight hinders lightweight vehicle design. More critically, lead-acid batteries contain harmful substances such as sulfuric acid and heavy metal lead, making them highly polluting during production, use, and recycling. With the implementation of environmental policies such as the European "lead ban," the application prospects of lead-acid batteries in automotive starting batteries have been significantly limited.

[0004] Meanwhile, while the 12V lithium-ion battery low-voltage system has improved energy density and cycle life to some extent, it also faces new technical challenges. On the one hand, the high production cost of lithium-ion batteries has led to a significant increase in vehicle assembly costs, weakening market competitiveness. On the other hand, in low-temperature environments, lithium-ion batteries are at risk of lithium dendrite growth, which not only seriously affects the battery's cycle performance but can also puncture the battery separator, causing a short circuit and posing a serious safety hazard.

[0005] With the accelerated advancement of automotive electrification and intelligence, the number of electronic components such as sensors and chips integrated into vehicles is increasing. The power load of the 12V on-board power supply has increased significantly, and the "depth of power consumption" has continued to increase. This situation has further exacerbated the performance degradation of lead-acid batteries and lithium-ion batteries, resulting in a significant shortening of battery life, making it difficult to meet the high-performance and long-life requirements of modern automobiles for starting batteries. Therefore, the development of a new starting battery that combines excellent wide-temperature range, high-current discharge performance, long cycle life, high safety performance, controllable cost, and environmental friendliness has become a technical challenge that needs to be urgently addressed in the field of automotive starting batteries. Summary of the Invention

[0006] The purpose of the present invention is to provide a 12V sodium ion battery and a preparation method thereof to solve the above problems. The battery has the characteristics of high performance, long life and high safety, and can provide a lightweight solution for the 12V low-voltage battery system of new energy vehicles.

[0007] The present invention provides a 12V sodium ion battery, comprising:

[0008] a battery housing, wherein the interior of the battery housing is hollow;

[0009] a battery cover, mounted on the opening of the battery housing;

[0010] A battery cell group is arranged in the cavity formed by the battery housing and the battery cover, and is composed of four 3V sodium ion battery cells connected in a 1P4S manner;

[0011] A signal acquisition component connected to the battery cell group to collect functional signals of each sodium ion battery cell, wherein the functional signals of the sodium ion battery cell include voltage, current, and temperature;

[0012] The battery management module is connected to the signal acquisition component and the battery cell group, receives the functional signals collected by the signal acquisition component, and controls and manages the functional safety of each sodium ion battery cell.

[0013] In one embodiment, the sodium ion battery cell is a polyanion compound / amorphous carbon system square shell battery cell.

[0014] In one embodiment, the sodium ion battery cells of the battery cell group are separated by fireproof foam.

[0015] In one embodiment, the battery cell group is fixed to the battery housing by structural adhesive, and the space between the battery cell group and the battery housing is filled with structural adhesive.

[0016] In one embodiment, the signal acquisition component includes an FPC, a PCB, and an FFC, and the signal acquisition component is fixed in the battery housing through a plastic structural member.

[0017] In one embodiment, the battery management module is a BMS controller, which is arranged in the cavity formed by the battery shell and the battery cover, and is located on one side of the battery cell group. Fireproof foam is provided on both sides of the BMS controller. The BMS controller controls the cell balancing of each sodium ion cell in the battery cell group, monitors SOX, MOS charging and discharging separately, and performs overvoltage, undervoltage, overtemperature and overcurrent protection on the sodium ion cells.

[0018] In one embodiment, end plates are respectively provided at both ends of the battery cell group, and the end plates are made of PP material.

[0019] In one embodiment, the sodium ion battery cells of the battery cell group are connected by electrical connecting bars, which are copper bars or aluminum bars.

[0020] The present invention also proposes a method for preparing a 12V sodium ion battery, comprising the following steps:

[0021] Paste fireproof foam on both sides of the sodium ion battery cell;

[0022] Four sodium ion cells are stacked and connected in a 1P4S connection method and then fixed to form a cell group;

[0023] Spray structural adhesive on the bottom of the battery shell, place the battery cell group into the battery shell, and adhere the battery cell group to the structural adhesive on the bottom of the battery shell;

[0024] After the structural adhesive is completely cured, pour the structural adhesive into the battery shell;

[0025] Install the signal acquisition component and the battery management module, and connect the signal acquisition component and the battery management module to the battery cell group;

[0026] The battery cover is sealed at the opening of the battery case.

[0027] In one embodiment, before the fireproof foam is pasted on both sides of the sodium ion battery cells, the capacity, voltage, and internal resistance of the grouped battery cells are tested separately, so that the capacity deviation between the sodium ion battery cells in the battery cell group is less than 0.2Ah, the voltage deviation is less than 0.1V, and the internal resistance deviation is less than 0.1mΩ.

[0028] Compared with the prior art, the 12V sodium ion battery and the preparation method thereof of the present invention have the following beneficial effects:

[0029] 1) Through the CTP integration method, the present invention can simplify the redundant structural components inside the battery pack, improve the integration of the battery system, effectively reduce the battery weight, and increase the energy density, providing a lightweight solution for the 12V low-voltage battery system of new energy vehicles, thereby reducing the weight of the entire vehicle, optimizing the vehicle's energy consumption performance, and achieving a dual increase in cruising range and battery capacity.

[0030] 2) Compared with traditional batteries, the 12V sodium-ion battery of the present invention can extend its life by 50%, reduce system weight by 60%, and perform better at low temperatures of -20°C. It solves the shortcomings of lead-acid batteries such as short life, low low-temperature charging capacity, heavy weight, and high environmental pollution, and combines high efficiency and environmental protection characteristics.

[0031] 3) Compared with the traditional 12V lead-acid battery that uses a BDM controller to monitor battery current and voltage, which cannot meet the requirements of automotive functional safety standards, the sodium-ion battery in the present invention uses a BMS controller, which can achieve ASIL B functional safety level, ensuring system safety from battery cell monitoring to charge and discharge control, and providing reliable protection for vehicle operation.

[0032] 4) Compared with lead-acid batteries, which need to avoid over-discharge and cause deep battery loss and damage, the sodium ion system battery of the present invention can be discharged to 0V, which broadens the battery's usage boundaries, greatly reduces battery maintenance costs and failure rates, and significantly improves user experience and the value of the battery throughout its life cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 12V sodium ion battery manufacturing method according to an embodiment of the present invention;

[0034] Figure 2 This is a flow chart for preparing a 12V sodium ion battery according to one embodiment of the present invention;

[0035] Figure 3 This is the schematic diagram of the BMS controller.

[0036] Reference numerals

[0037] 1. Battery case; 2. Battery cell group; 201. Sodium ion battery cell; 202. Positive terminal; 203. Negative terminal; 3. Battery management module; 4. Battery cover; 5. Fireproof foam; 6. Structural adhesive; 7. Electrical connection bar. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention more understandable, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that many specific details are set forth in the following description to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] Next, the present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for ease of illustration, cross-sectional views illustrating device structures may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of protection of the present invention. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.

[0040] Furthermore, the phrases "one embodiment" or "an embodiment" in this application refer to specific features, structures, or characteristics that may be included in at least one implementation of the present invention. The phrases "in one embodiment" or "an embodiment" appearing in different places in this specification do not necessarily refer to the same embodiment, nor do they refer to separate or selective embodiments that are mutually exclusive with other embodiments. The terms "including" and "comprising" indicate the presence of the claimed features, but do not exclude the presence of one or more other features. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0041] This invention primarily develops a novel chemistry-based 12V sodium-ion battery system through CTP integration. CTP (Cell to Pack) is a battery system integration technology that eliminates the traditional module layer in battery packs and integrates cells directly into the battery pack, thereby increasing energy density, reducing weight, and optimizing space utilization.

[0042] The present invention proposes a 12V sodium ion battery, see Figure 2 , including a battery shell 1, a battery cover 4, a cell group 2, a signal acquisition component and a battery management module 3. The interior of the battery shell 1 is hollow and has an opening on one side. The battery cover 4 is installed on the opening of the battery shell 1. The cell group 2 is arranged in the cavity formed by the battery shell 1 and the battery cover 4, and is composed of four 3V sodium ion batteries 201 connected in a 1P4S manner, that is, it is composed of 3V sodium ion batteries connected in series. The positive terminal 202 and the negative terminal 203 of the cell group are connected from the outside of the battery cover 4. The signal acquisition component is connected to the cell group 2 to collect functional signals of each sodium ion battery 201. The functional signals of the sodium ion battery 201 include voltage, current, temperature, etc. The battery management module 3 is connected to the signal acquisition component and the cell group 2, receives the functional signals collected by the signal acquisition component, and controls and manages the functional safety of each sodium ion battery 201.

[0043] The battery housing 1 of one embodiment of the present invention follows the standard outer housing of an H1 lead-acid battery with dimensions of 207*175*190 mm in length*width*height.

[0044] The sodium ion battery cell 201 of one embodiment of the present invention is a polyanion compound / amorphous carbon system square shell battery cell, that is, the positive electrode material of the sodium ion battery cell is a polyanion compound, and the negative electrode material is amorphous carbon, and they are encapsulated in a metal square shell. Polyanion compounds are a class of compounds containing polyatomic anion groups such as phosphates and sulfates. Anion groups such as PO43- form a strong skeleton. The structure is not easy to collapse during charging and discharging, has a long life, is more resistant to high temperatures, is not prone to thermal runaway, has good safety, and can provide a stable discharge voltage. Amorphous carbon is a non-crystalline carbon material. Sodium ions can be embedded in the chaotic pores of carbon, with a strong sodium storage capacity. The disordered structure also allows sodium ions to enter and exit more freely, with good low-temperature performance and fast charging performance.

[0045] In one embodiment of the present invention, the individual sodium-ion battery cells 201 of the battery cell group 2 are separated by fireproof foam 5 to provide cushioning and shock absorption, prevent heat diffusion, and provide fireproof and heat insulation. This protects the battery cell structure, balances temperature differences between cells, and extends battery life. The fireproof foam 5 can be made of materials such as flame-retardant polyurethane foam or ceramic silicone rubber foam. The fireproof foam of the present invention is preferably 2 mm thick.

[0046] In one embodiment of the present invention, the sodium ion cells 201 of the cell group 2 are connected via electrical connection bars 7 to achieve series and parallel connection between the cells. The electrical connection bars 7 are preferably copper or aluminum bars.

[0047] In one embodiment of the present invention, the cell pack 2 is secured to the bottom of the battery case 1 via structural adhesive 6, filling the gap between the cell pack 2 and the battery case 1. Structural adhesive 6 is a key material used for bonding, fixing, and sealing. It must meet requirements such as high bond strength, high temperature resistance, insulation, and flame retardancy. Epoxy resin structural adhesives, polyurethane (PU) structural adhesives, and silicone structural adhesives are commonly used.

[0048] In one embodiment of the present invention, end plates are provided at both ends of the battery cell group 2, respectively. The end plates are made of PP material, and the battery cell group 2 is fixed using steel cable ties.

[0049] In one embodiment of the present invention, anti-collision beams are also designed on both sides of the interior of the battery housing 1 to maximize the power supply capacity of the 12V low-voltage sodium ion battery system after the vehicle is hit, thereby ensuring the safety of personnel.

[0050] The battery management module 3 of one embodiment of the present invention is a BMS controller, which is arranged in the cavity formed by the battery shell 1 and the battery cover 4, and is located on one side of the battery cell group 2. Fireproof foam is provided on both sides of the BMS controller. The BMS controller controls the cell balancing of each sodium ion cell in the battery cell group, monitors the SOX and MOS charging and discharging, and performs overvoltage, undervoltage, overtemperature and overcurrent protection on the sodium ion cells. Compared with the BDM (Battery Diagnostic Module) of traditional lead-acid batteries, the BMS (Battery Management System) has more powerful intelligent management capabilities and can meet functional safety levels (such as ASIL B) to ensure safe and reliable operation of the battery system.

[0051] Cell balancing involves balancing the charge between cells through active or passive methods, such as resistor energy dissipation and charge transfer, to extend battery life and improve charge and discharge efficiency. SOX refers to SOC (State of Charge), SOH (State of Health), and SOP (State of Power). The BMS controller can estimate the remaining battery charge, monitor battery degradation, predict remaining life, and calculate the battery's charge and discharge power in real time to optimize performance. MOS (Metal Oxide Semiconductor) charge and discharge control means the BMS can independently control the MOS transistors in the charge and discharge circuits to achieve precise switching between charge and discharge, avoiding the risks of shared charge and discharge switches in traditional circuits and improving safety and reliability. Overvoltage and undervoltage protection prevent individual cell voltages from exceeding their limits. Overtemperature protection monitors cell temperature and reduces power or disconnects the battery when it exceeds a threshold. Overcurrent protection limits the charge and discharge current to prevent internal heating and damage to the battery due to excessive current.

[0052] Specifically, the BMS control principle diagram is as follows Figure 3As shown in the figure, Cell 1-Cell 4 represent four sodium-ion battery cells connected in series, connected to the AFE (Analog Front-End) module via a voltage detection circuit (ADC). The AFE collects analog signals such as voltage and current from the sodium-ion battery cells and converts them into digital signals. It also performs cell balancing. The AFE communicates with the MCU (Microcontroller Unit) via the SPI interface, transmitting the collected data to the MCU. The MCU receives the data from the AFE, processes and analyzes it, such as calculating the battery's SOC (State of Charge) and SOH (State of Health). It also manages the battery's charge and discharge processes by controlling the MOSFET driver circuit. It also monitors the MOSFET status and implements protection functions such as overvoltage, undervoltage, overcurrent, and overtemperature. The MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) serves as the switch in the battery's charge and discharge circuit. The MCU controls its on and off state to control the battery's charge and discharge currents.

[0053] The signal acquisition assembly of one embodiment of the present invention includes an FPC, a PCB, and an FFC, which is fixed to the battery housing 1 via a plastic structural member. The FPC (Flexible Printed Circuit) is fixed to the surface of the sodium-ion battery cell by conductive glue or welding. The metal contacts of the FPC are connected to the positive and negative electrodes of the sodium-ion battery cell to collect signals such as voltage, current, and temperature. The PCB (Printed Circuit Board) is connected to the FPC / FFC by welding or plugging. The FPC signals of multiple sodium-ion battery cells can be aggregated on a small PCB for processing. The FFC (Flexible Flat Cable) connects the FPC and the PCB / BMS controller to transmit the detection signals of the sodium-ion battery cell from the FPC to the PCB / BMS controller. The plastic structural member is generally an injection-molded bracket or frame that wraps around the battery cell group 2 and is fixed by snaps, screws, or hot melt. The signal acquisition components such as the FPC and FFC can be embedded in the grooves of the plastic structural member to avoid wear.

[0054] Compared with traditional lead-acid batteries, the weight of the 12V sodium-ion battery of the present invention can be reduced from the original 15.5kg to 6.5kg, achieving the goal of reducing the weight of the entire vehicle; the battery life can be increased from 4 years to 8 years; compared with lead-acid batteries, which need to avoid excessive discharge that causes deep battery loss and damage, sodium-ion system batteries can be discharged to 0V.

[0055] The present invention also proposes a method for preparing a 12V sodium ion battery, see Figure 1 、 Figure 2 , including the following steps:

[0056] Step S1, battery cell testing: the capacity, voltage, and internal resistance of the grouped battery cells are tested respectively, so that the capacity deviation between each sodium ion battery cell in the battery cell group is less than 0.2Ah, the voltage deviation is less than 0.1V, and the internal resistance deviation is less than 0.1mΩ, so as to ensure the consistency of the grouped battery cells.

[0057] Step S2, pasting fireproof foam on both sides of the battery cell: clean the surface of the screened battery cell, and paste fireproof foam on both sides of the sodium ion battery cell. The thickness of the fireproof foam is preferably 2 mm.

[0058] Step S3, cell grouping: stack four 3V sodium ion cells in a 1P4S connection mode to form a cell group, place PP end plates at both ends of the cell group, and use steel cable ties to secure the cell group.

[0059] Step S4, coating the bottom of the shell with glue and inserting the module into the shell: spray structural glue on the bottom of the battery shell, squeeze the foam on both sides of the battery cell group and place the battery cell group into the battery shell, so that the battery cell group and the structural glue at the bottom of the battery shell are bonded to achieve fixation of the battery cell group and the battery shell.

[0060] Step S5, fixing the shell with glue: After the structural glue at the bottom of the battery cell group is completely cured, the structural glue is poured into the battery shell to achieve overall fixation of the battery cell group, foam and battery shell.

[0061] Step S6, CCS (integrated busbar) installation: Connect the signal acquisition components (FPC, PCB, FFC, etc.) to the battery cell group and fix them in place with plastic structural parts. Complete the series and parallel connection between the sodium ion battery cells through the electrical connection bar (copper and aluminum bar). Connect the various components in the battery case into a whole through processes such as hot pressing synthesis or riveting to achieve battery cell series and parallel control, as well as battery temperature sampling and battery cell voltage sampling functions for BMS control.

[0062] Step S7, BMS installation: Install the BMS controller on one side of the battery housing, connect it to the signal acquisition component and the battery cell group, and place foam on both sides of the BMS to prevent collision.

[0063] Step S8, system assembly: encapsulate the battery cover at the opening of the battery housing to form a 12V sodium ion battery system.

[0064] It should be noted that the orientations or positional relationships indicated by terms such as "inside", "outside", and "bottom" are all based on the orientations or positional relationships shown in the accompanying drawings. Such expressions are only intended to make the description of the present invention simpler and more convenient, and do not indicate or imply that the referred parts must have a specific orientation or be constructed and operated in a specific orientation.

[0065] In addition, in this application, unless otherwise clearly specified and limited, "connection", "setting" and other similar terms should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or a connection between two components. Technicians in the field can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0066] The present invention has the following beneficial effects:

[0067] 1) Through the CTP integration method, the present invention can simplify the redundant structural components inside the battery pack, improve the integration of the battery system, effectively reduce the battery weight, and increase the energy density, providing a lightweight solution for the 12V low-voltage battery system of new energy vehicles, thereby reducing the weight of the entire vehicle, optimizing the vehicle's energy consumption performance, and achieving a dual increase in cruising range and battery capacity.

[0068] 2) Compared with traditional batteries, the 12V sodium-ion battery of the present invention can extend its life by 50%, reduce system weight by 60%, and perform better at low temperatures of -20°C. It solves the shortcomings of lead-acid batteries such as short life, low low-temperature charging capacity, heavy weight, and high environmental pollution, and combines high efficiency and environmental protection characteristics.

[0069] 3) Compared with the traditional 12V lead-acid battery that uses a BDM controller to monitor battery current and voltage, which cannot meet the requirements of automotive functional safety standards, the sodium-ion battery in the present invention uses a BMS controller, which can achieve ASIL B functional safety level, ensuring system safety from battery cell monitoring to charge and discharge control, and providing reliable protection for vehicle operation.

[0070] 4) Compared with lead-acid batteries, which need to avoid over-discharge and cause deep battery loss and damage, the sodium ion system battery of the present invention can be discharged to 0V, which broadens the battery's usage boundaries, greatly reduces battery maintenance costs and failure rates, and significantly improves user experience and the value of the battery throughout its life cycle.

[0071] Although the above methods are illustrated and described as a series of acts for simplicity of explanation, it is to be understood and appreciated that these methods are not limited by the order of the acts, as some acts may occur in a different order and / or concurrently with other acts from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art according to one or more embodiments.

[0072] The configuration and arrangement of the present application shown in a number of different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., size, structure, shape, and proportion, as well as parameter values, mounting arrangements, use of materials, changes in orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application. For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of an element may be inverted or otherwise changed, and the nature, number, or position of discrete elements may be altered or changed. Therefore, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover the structures described herein that perform the functions described, and not only structural equivalence but also equivalent structures. Without departing from the spirit and substance of the present invention, those skilled in the art may make various corresponding modifications and variations based on the present invention, but these corresponding modifications and variations should all fall within the scope of protection of the present invention.

Claims

1. A 12V sodium ion battery, characterized in that: include: a battery housing, wherein the interior of the battery housing is hollow; a battery cover, mounted on the opening of the battery housing; A battery cell group is arranged in the cavity formed by the battery housing and the battery cover, and is composed of four 3V sodium ion battery cells connected in a 1P4S manner; A signal acquisition component connected to the battery cell group to collect functional signals of each sodium ion battery cell, wherein the functional signals of the sodium ion battery cell include voltage, current, and temperature; The battery management module is connected to the signal acquisition component and the battery cell group, receives the functional signals collected by the signal acquisition component, and controls and manages the functional safety of each sodium ion battery cell.

2. The 12V sodium ion battery according to claim 1, characterized in that The sodium ion battery core is a polyanion compound / amorphous carbon system square shell battery core.

3. The 12V sodium ion battery according to claim 1, characterized in that The sodium ion battery cells in the battery cell group are separated by fireproof foam.

4. The 12V sodium ion battery according to claim 1, characterized in that The battery cell group is fixed to the battery housing by structural adhesive, and the space between the battery cell group and the battery housing is filled with structural adhesive.

5. The 12V sodium ion battery according to claim 1, characterized in that The signal acquisition component includes an FPC, a PCB, and an FFC, and the signal acquisition component is fixed in the battery housing through a plastic structural member.

6. The 12V sodium ion battery according to claim 1, characterized in that The battery management module is a BMS controller, which is arranged in the cavity formed by the battery shell and the battery cover, and is located on one side of the battery cell group. Fireproof foam is provided on both sides of the BMS controller. The BMS controller controls the cell balancing of each sodium ion cell in the battery cell group, monitors SOX, MOS charging and discharging separately, and protects the sodium ion cells from overvoltage, undervoltage, overtemperature and overcurrent.

7. The 12V sodium ion battery according to claim 1, characterized in that End plates are provided at both ends of the battery cell group, and the end plates are made of PP material.

8. The 12V sodium ion battery according to claim 1, characterized in that The sodium ion cells in the cell group are connected via electrical connecting bars, which are copper bars or aluminum bars.

9. A method for preparing a 12V sodium ion battery, characterized in that: The steps include: Paste fireproof foam on both sides of the sodium ion battery cell; Four sodium ion cells are stacked and connected in a 1P4S connection method and then fixed to form a cell group; Spray structural adhesive on the bottom of the battery shell, place the battery cell group into the battery shell, and adhere the battery cell group to the structural adhesive on the bottom of the battery shell; After the structural adhesive is completely cured, pour the structural adhesive into the battery shell; Install the signal acquisition component and the battery management module, and connect the signal acquisition component and the battery management module to the battery cell group; The battery cover is sealed at the opening of the battery case.

10. The method for preparing a 12V sodium ion battery according to claim 9, wherein: Before pasting fireproof foam on both sides of the sodium-ion battery cells, the capacity, voltage and internal resistance of the grouped battery cells are tested separately to ensure that the capacity deviation between the sodium-ion battery cells in the battery group is less than 0.2Ah, the voltage deviation is less than 0.1V, and the internal resistance deviation is less than 0.1mΩ.

Images