Lithium ion battery pre-charging box and pre-charging and forming device and method

Abstract

This invention discloses a lithium-ion battery pre-charge formation box, pre-charge formation device, and pre-charge formation method. The device includes a pre-charge box, a power supply junction box, and a monitoring computer. The pre-charge box has uniformly arranged charging bars, and the power supply junction box includes junction boxes. The charging electrodes on the charging bars correspond to the charging pile positions on the junction boxes, and indicator lights show the battery charging status. This systematizes the lithium-ion battery pre-charge formation process and increases the number of lithium-ion batteries that can be pre-charged at one time. Data from the pre-charge process can be viewed on the monitoring computer, facilitating data recording during the pre-charge formation process. Using the pre-charge formation method of this invention for lithium-ion battery pre-charge formation results in a stable and uniformly thick SEI film formed inside the battery, and shortens the pre-charge formation time, thus improving the efficiency of pre-charge formation.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery production technology, and specifically relates to a lithium-ion battery precharge box, precharge formation device, and precharge formation method. Background Technology

[0002] Lithium-ion batteries, as a green and environmentally friendly high-tech product, are widely used in various fields such as consumer electronics and automobiles. With the increasing demand for lithium-ion batteries, lithium-ion battery manufacturers need to improve production efficiency to meet market demand on the one hand, and optimize production processes to improve product quality on the other. As the degree of automation in the lithium battery industry becomes higher and higher, pre-charging and high-temperature aging processes have become important links that restrict production speed and product quality.

[0003] For lithium-ion batteries, pre-charge formation, also known as the first charge, involves an electrochemical reaction where the electrolyte is reduced on the negative electrode surface. Insoluble reduction products deposit on the negative electrode surface, forming a passivation film covering the graphite surface, known as the solid electrolyte interface (SEI) film. During the SEI film formation process, side reactions produce gases, leading to inconsistent uniformity and stability. High-temperature aging is typically required to reform and repair the SEI film, significantly increasing its stability. Conversely, the worse the stability of the SEI film formed during pre-charge, the greater the consumption of active lithium for repair during high-temperature aging, resulting in a higher capacity loss. Therefore, the formation of a stable and uniformly thick SEI film during pre-charge is crucial for the cell's capacity, cycle life, safety, and other performance aspects. Thus, pre-charge is a critical stage in lithium-ion battery cell production efficiency.

[0004] The current pre-charging process typically involves charging at room temperature with a low current for over ten hours to obtain a good SEI film, followed by 3 days of high-temperature aging for reforming and repair to maintain stable battery performance. However, the long pre-charging and high-temperature aging processes result in low production efficiency.

[0005] While existing technologies include battery pre-charging devices for pre-charging batteries, their efficiency is low and cannot solve the efficiency problem in mass battery production. The existing utility model patent with patent application number 201720736597.5, entitled "A Lithium Battery Pre-charging Device," is applicable to various battery models, but it does not improve battery productivity. The efficiency of battery pre-charging formation has become a bottleneck in battery production.

[0006] To address the aforementioned issues, it is necessary to design a lithium-ion battery pre-charge formation device to improve the efficiency of battery pre-charge formation and solve the bottleneck problem in battery production. Summary of the Invention

[0007] To address the shortcomings of the prior art, this invention provides a lithium-ion battery pre-charge box, a pre-charge formation device, and a pre-charge formation method. The device includes a pre-charge box, a power supply junction box, and a monitoring computer. The pre-charge box has evenly arranged charging bars, and the power supply junction box includes junction boxes. The charging electrodes on the charging bars correspond to the charging pile positions on the junction boxes, and an indicator light is provided to indicate the charging status of the battery. This systematizes the pre-charge formation of lithium-ion batteries and increases the number of lithium-ion batteries that can be pre-charged at one time. The data of the pre-charge process can be viewed through the monitoring computer, facilitating data recording of the pre-charge formation process of lithium-ion batteries.

[0008] The pre-charge formation method of this invention is used to pre-charge and form lithium-ion batteries, which makes the SEI film formed inside the battery stable and uniform in thickness, and shortens the pre-charge formation time, thereby improving the efficiency of pre-charge formation.

[0009] The technical effects to be achieved by this invention are accomplished through the following solutions:

[0010] A lithium-ion battery pre-charge box is provided, wherein the pre-charge box contains a uniformly arranged charging bar, the charging bar has a charging negative terminal and a charging positive terminal, a heating coil for temperature control is provided on the inner periphery of the box, and a fan is provided on the side of the heating coil away from the charging bar; a monitoring module for controlling data inside the pre-charge box is provided at the upper end of the pre-charge box.

[0011] A heating coil located on the inner periphery of the pre-charge box is used to control the temperature of the battery pre-charge formation. A fan is located on the side of the heating coil away from the charging pad. When the heating coil heats up, the fan blows the heat evenly into the space of the charging pad, ensuring a uniform temperature in the pre-charge box and preventing damage to lithium-ion batteries near the heating coil due to overheating. The control module at the top of the pre-charge box controls data such as temperature, airflow, current, and voltage inside the box, making the battery pre-charge formation process controllable.

[0012] Furthermore, the negative charging electrode and the positive charging electrode are respectively disposed on two corresponding charging bars, and the lithium-ion batteries are neatly arranged during pre-charging, making the pre-charging of lithium-ion batteries more systematic and intuitive.

[0013] Furthermore, the monitoring module includes a timer, an ammeter, a temperature controller, a flow switch, a heating switch, and a power switch, and the timer, the ammeter, the temperature controller, the flow switch, the heating switch, and the power switch are connected to the circuit board; the monitoring module also includes a fault alarm and an over-temperature alarm.

[0014] A timer calculates the time for each stage of battery pre-charge formation; an ammeter displays the pre-charge current; a temperature controller monitors the temperature inside the pre-charge box; a flow switch controls the speed of the fan inside the pre-charge box; similarly, a heating switch controls the operation of the heating coil; and a power switch controls the operation of the pre-charge box. To ensure the operation of the various components within the pre-charge box is interconnected, the timer, ammeter, temperature controller, flow switch, heating switch, and power switch are further connected to a circuit board (not shown in the diagram). The circuit board integrates these components and provides unified control over their operation. For example, the temperature inside the pre-charge box can be set differently for different time periods, requiring the coordinated operation of the timer, temperature controller, heating coil, flow switch, and fan.

[0015] Furthermore, the pre-charge box is equipped with a sealed door and a bolt running through the sealed door. The sealed door is located on one side of the pre-charge box body, and sealant is applied to the periphery of the door frame. To ensure a sealed space inside the pre-charge box during operation, a bolt and sealant are provided. The bolt exerts force on the sealed door, causing it to adhere tightly to the sealant. The sealed space design of the pre-charge box during operation facilitates temperature control within it.

[0016] A lithium-ion battery pre-charge formation device includes a pre-charge box, a power supply junction box connected to the pre-charge box, and a monitoring computer; the power supply junction box includes a terminal block, the terminal block is provided with terminal posts, the terminal posts are connected to cables, the cables include a positive cable and a negative cable, the positive cable is connected to the charging positive terminal, and the negative cable is connected to the charging negative terminal; the lower end of the terminal block is provided with an indicator light corresponding to the terminal post.

[0017] The power supply cabinet provides power to the pre-charged batteries in the pre-charge box. The terminal block has terminals that connect to cables, which in turn connect to the positive and negative charging terminals. Each terminal connects to a pair of positive and negative charging terminals via two cables, providing the power required for battery pre-charging. To indicate the battery pre-charging status, a corresponding indicator light is located at the lower end of the terminal block. This indicator light shows the pre-charging formation status of the battery connected to its corresponding terminal. The indicator light can be set to be on when pre-charging is incomplete and off when pre-charging is complete; alternatively, it can be set to be off when pre-charging is incomplete and on when pre-charging is complete. The indicator light settings are determined during the connection to the internal circuitry of the battery pre-charging formation device, meaning that the indicator light's status is set during manufacturing based on production needs.

[0018] The monitoring computer is connected to the pre-charge box and the power supply junction box respectively, and collects the pre-charge data generated by them.

[0019] Furthermore, the positions of the terminal blocks in the power supply junction box correspond to the positions of the positive and negative charging terminals in the pre-charge box. This design aims to ensure that the pre-charge status of each battery is clearly visible to monitoring personnel based on the indicator lights at each location. When the indicator light at the bottom of the terminal block is always on or off, monitoring personnel can locate the corresponding battery after pre-charge formation, facilitating the sorting and testing of faulty batteries and reducing the probability of defective products in the final battery pack.

[0020] A method for pre-charging and forming a lithium-ion battery includes the following steps:

[0021] S01: Place the lithium-ion battery into the pre-charge box, with the negative electrode of the lithium-ion battery connected to the negative charging electrode and the positive electrode connected to the positive charging electrode.

[0022] S02: Precharge the lithium-ion battery at a rate of 0.01-0.1C for 8-40 minutes;

[0023] S03: Static aging for 24-48 hours;

[0024] S04: Charge the lithium-ion battery at a rate of 0.05-0.15C for 0.5-2 hours until the battery's charging capacity accounts for 5%-10% of the total capacity of the lithium-ion battery;

[0025] S05: Charge the lithium-ion battery at a constant current rate of 0.25-0.35C until the battery voltage is 4.2V;

[0026] S06: Place the battery in the precharge box for 1-2 days for formation, and then remove the lithium-ion battery after formation.

[0027] The steps S02-S05 described above are all carried out at a temperature of 35-55℃, and the formation temperature of step S06 is 40-55℃.

[0028] Furthermore, the positive electrode active material of the lithium-ion battery is a ternary lithium nickel cobalt manganese oxide.

[0029] Furthermore, in the positive electrode active material of the lithium-ion battery, the Ni:Co:Mn ratio is 4-6:1.6-2.4:2.4-3.6.

[0030] Furthermore, step S05 also includes charging the lithium-ion battery at a constant voltage of 4.2V to a current of 52mA.

[0031] The present invention has the following advantages:

[0032] 1. The charging and power connectors of the device of this invention systematize battery pre-charge formation and increase the number of batteries that can be pre-charged in a single operation. A heating coil and a fan are located on the inner periphery of the pre-charge box, and the data within the box is controlled by a control module. Data is set on the control module, and the entire pre-charge formation process of the lithium-ion battery takes place within the pre-charge box, simplifying the pre-charge formation process.

[0033] 2. The lithium-ion battery pre-charge formation method of the present invention places the lithium-ion battery inside a pre-charge box at a temperature of 35-55℃, and by controlling the charging rate, charging time and charging voltage, a stable and uniformly thick SEI film is formed inside the battery, thereby improving battery reliability, shortening the pre-charge formation time and improving the efficiency of pre-charge formation. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the lithium-ion battery pre-charge formation apparatus of the present invention;

[0035] Figure 2 This is a schematic diagram of the pre-filling box in this invention;

[0036] Figure 3 This is a schematic diagram of the internal structure of the pre-charge box of the present invention;

[0037] Figure 4 This is a schematic diagram of the power supply junction box in this invention;

[0038] Explanation of symbols in the attached diagram: 1. Pre-charge box; 2. Power supply junction box; 3. Monitoring computer; 11. Charging strip; 111. Negative charging terminal; 112. Positive charging terminal; 12. Heating coil; 13. Fan; 14. Sealant; 151. Ammeter; 152. Temperature controller; 153. Timer; 154. Fault alarm; 155. Power switch; 156. Airflow switch; 157. Heating switch; 158. Over-temperature alarm; 16. Sealing door; 17. Door bolt; 21. Terminal block; 22. Terminal post; 23. Cable; 24. Indicator light. Detailed Implementation

[0039] To better explain the present invention and to highlight its advantages and structure, the following description is provided in conjunction with the appendix. Figure 1-4 The present invention will be described in detail with reference to the embodiments.

[0040] In this invention, the lithium-ion battery pre-charge formation device includes a pre-charge box 1; the lithium-ion battery pre-charge formation device may also include a pre-charge box 1 and a power connection cabinet 2 connected to the pre-charge box 1; the lithium-ion battery pre-charge formation device may also include a pre-charge box 1, a monitoring computer 3, and a power connection cabinet 2, the specific composition of the lithium-ion battery pre-charge formation device depending on actual needs. In this embodiment, a lithium-ion battery pre-charge formation device including a pre-charge box, a monitoring computer, and a power connection cabinet is taken as an example.

[0041] In this embodiment, the lithium-ion battery pre-charge formation apparatus is as shown in the attached diagram. Figure 1 As shown, it includes a connected pre-charge box, a power wiring cabinet, and a monitoring computer.

[0042] As attached Figure 3 As shown, the pre-charge box is provided with a uniformly arranged charging bar 11. The charging bar is provided with a charging negative electrode 111 and a charging positive electrode 112. A heating coil 12 for temperature control is provided on the inner periphery of the box. A fan 13 is provided on the side of the heating coil 12 away from the charging bar 11. A monitoring module for controlling the data inside the pre-charge box is provided at the upper end of the pre-charge box 1.

[0043] As attached Figure 4 As shown, the power supply junction box 2 includes a junction box 21, which is provided with terminal blocks 22. The terminal blocks 22 are connected to cables 23, which include a positive cable and a negative cable. The positive cable is connected to the charging positive terminal 112, and the negative cable is connected to the charging negative terminal 111. The lower end of the junction box 21 is provided with an indicator light 24 corresponding to the terminal block 22.

[0044] The monitoring computer 3 is connected to the pre-charge box 1 and the power supply junction box 2 respectively, and collects the pre-charge data generated by them.

[0045] Connect the positive terminal of the lithium-ion battery to the charging positive terminal 112 and the negative terminal to the charging negative terminal 111. Set the data in the control module and start the pre-charge box 1. The battery will then charge in the pre-charge box 1. It should be noted that the distance between the charging negative terminal 111 and the charging positive terminal 112 on the two corresponding charging bars is equal to the length of the battery. That is, after the battery is connected to the charging positive terminal 112 and the charging negative terminal 111, the two corresponding charging bars exert a certain clamping force on the battery, so that the lithium-ion battery is held in place by the two corresponding charging bars, which serves to fix it.

[0046] A heating coil 12 is located on the inner periphery of the pre-charge box 1 to control the temperature of the battery pre-charge formation. A fan 13 is located on the side of the heating coil 12 away from the charging pad. When the heating coil 12 heats up, the fan 13 blows the heat from the heating coil 12 evenly into the space of the charging pad 11, making the temperature of the pre-charge box 1 uniform and preventing the lithium-ion batteries near the heating coil 12 from being damaged due to overheating. The control module at the top of the pre-charge box is used to control the temperature, airflow, current, and voltage inside the pre-charge box, making the battery pre-charge formation process controllable.

[0047] The power supply cabinet 2 provides power to the pre-charged batteries in the pre-charge box 1. The terminal block 21 has terminals 22 connected to cables 23, which are respectively connected to the positive charging terminal 112 and the negative charging terminal 111. Each terminal 22 is connected to a pair of positive and negative charging terminals 112 via two cables 23, providing the power required for battery pre-charging. To indicate the battery pre-charging status, an indicator light 24 corresponding to the terminal 22 is provided at the lower end of the terminal block 21. The indicator light 24 indicates the pre-charging status of the battery connected to its corresponding terminal 22. The indicator light 24 can be set to be on when pre-charging is incomplete and off when pre-charging is complete; alternatively, it can be set to be off when pre-charging is incomplete and on when pre-charging is complete. The setting of indicator light 24 is determined when connecting to the internal circuit of the battery precharge formation device. That is, when manufacturing the battery precharge formation device, the indicator light is set to indicate the status of the precharged battery according to the production needs.

[0048] The monitoring computer 3 records data generated by the pre-charging box 1 and the power junction box 2 during the pre-charging process, such as the temperature inside the pre-charging box, the battery pre-charging current, the battery pre-charging voltage, and data on wind speed and time; and data on the voltage, current, and indicator light status of the power junction box 2. Monitoring personnel can view all the data generated during battery pre-charging on the monitoring computer for better control of the battery pre-charging status.

[0049] This implementation example is attached. Figure 2As shown, the monitoring module includes a timer 153, an ammeter 151, a temperature controller 152, a flow switch 156, a heating switch 157, and a power switch 155. The timer 153 calculates the time for each stage of battery pre-charge formation; the ammeter 151 displays the pre-charge current; the temperature controller 152 monitors the temperature inside the pre-charge box 1; the flow switch 156 controls the speed of the fan inside the pre-charge box; similarly, the heating switch 157 controls the operation of the heating coil 12; and the power switch 155 controls the operation of the pre-charge box 1. To ensure the operation of the components within the pre-charge box 1 is interconnected, the timer 153, ammeter 151, temperature controller 152, flow switch 156, heating switch 157, and power switch 155 are further connected to a circuit board (not shown in the figure). The circuit board integrates these components and provides unified control over their operation. For example, the temperature inside the pre-charge box 1 can be set to different times, which requires the joint operation of the timer 153, temperature controller 152, heating coil 12, airflow switch 156 and fan 13.

[0050] Further improvements were made to the pre-charge box, with the negative and positive charging terminals located on two corresponding charging bars. The lithium-ion batteries are neatly arranged during pre-charging, making the pre-charging of lithium-ion batteries more systematic and intuitive.

[0051] To promptly alert supervisory personnel in the event of a malfunction in precharge box 1, the monitoring module also includes a fault alarm 154 and an over-temperature alarm 158. When precharge box 1 malfunctions, fault alarm 154 will sound an alarm, alerting supervisory personnel involved in battery precharge formation to inspect precharge box 1. Similarly, when the temperature inside precharge box 1 exceeds a preset value, over-temperature alarm 158 will sound an alarm, alerting supervisory personnel involved in battery precharge formation to inspect the precharge box.

[0052] Based on the connection of the positive and negative charging terminals 111 and 112 on the charging strip 11 to the terminal blocks 22, the positions of the positive charging terminal 112 and the negative charging terminal 111 in the pre-charge box 1 correspond to the positions of the terminal blocks 22 in the power supply cabinet 2. The purpose of this design is to ensure that the pre-charge status of the battery at each location is clearly visible to monitoring personnel using the indicator lights 24 at each location. When the indicator light at the lower end of the terminal block 22 is either always on or off, monitoring personnel can locate the corresponding battery based on the position of the indicator light 24 after pre-charge formation, facilitating the sorting out and testing of faulty batteries and reducing the probability of defective products in the finished battery pack.

[0053] Please refer to the attached document. Figure 2In this embodiment, the pre-filling box preferably has a sealing door 16 and a bolt 17 running through the sealing door 16. The sealing door 16 is located on one side of the pre-filling box 1, and sealant 14 is provided around the door frame of the sealing door 16. The sealing door 16 facilitates the loading and unloading of materials into the pre-filling box 1. To ensure that the interior of the pre-filling box is a sealed space during operation, the bolt 17 and sealant 14 are provided. The bolt 17 exerts a force on the sealing door 16, causing the sealing door 16 to be tightly sealed against the sealant. The sealed space of the pre-filling box 1 during operation facilitates the control of its internal temperature.

[0054] A method for pre-charging and forming a lithium-ion battery includes the following steps:

[0055] S01: Place the lithium-ion battery into the pre-charge box, with the negative electrode of the lithium-ion battery connected to the negative charging electrode and the positive electrode connected to the positive charging electrode.

[0056] S02: Precharge the lithium-ion battery at a rate of 0.01-0.1C for 8-40 minutes;

[0057] S03: Static aging for 24-48 hours;

[0058] S04: Charge the lithium-ion battery at a rate of 0.05-0.15C for 0.5-2 hours until the battery's charging capacity accounts for 5%-10% of the total lithium-ion battery capacity;

[0059] S05: Charge the lithium-ion battery at a constant current rate of 0.25-0.35C until the battery voltage is 4.2V;

[0060] S06: Place the battery in the precharge box for 1-2 days for formation, and then remove the lithium-ion battery after formation.

[0061] The above steps S02-S05 are all carried out at a temperature of 35-55℃, and the formation temperature of step S06 is 40-55℃.

[0062] In this embodiment, the positive electrode active material of the lithium-ion battery is preferably a ternary lithium nickel cobalt manganese oxide (LCA) material. Positive electrodes made from LCA materials exhibit high structural stability and safety, resulting in a highly stable and uniformly thick SEI film.

[0063] Based on the ternary lithium-cobalt-manganese oxide (LCO) active material for lithium-ion batteries, the Ni:Co:Mn ratio in the active material of the lithium-ion battery positive electrode is 4-5:1.6-2.4:2.4-3.6. The higher the nickel content in the ternary material, the higher its reversible specific capacity. However, increasing the nickel content significantly reduces the material's stability and safety, makes it more sensitive to moisture, and worsens electrode processing performance. The nickel content is generally controlled below 50%. In contrast, LCO ternary materials with lower nickel content (nickel content below 50%) have better safety, mainly due to the presence of manganese. Within a certain range, the higher the manganese content, the higher the structural stability and safety of the material. In this invention, when the active material Ni:Co:Mn ratio is 4-5:1.6-2.4:2.4-3.6, its structural stability and safety are relatively high, which is beneficial for the formation of a highly stable and uniformly thick SEI film in lithium-ion batteries.

[0064] In this embodiment, step S05 further includes charging the lithium-ion battery at a constant voltage of 4.2V until the current reaches 52mA. In step S05, the battery is charged at a constant current rate of 0.25-0.35C until the battery voltage reaches 4.2V, at which point the battery capacity is essentially fully charged. However, to ensure that the battery capacity has reached the required level, the lithium-ion battery is charged again at a constant voltage of 4.2V, and the current is tested until the voltage and current across the lithium-ion battery reach the required level. Only then is the battery capacity truly fully charged. While most batteries have reached the required capacity when the constant current charging reaches 4.2V in step S05, the purpose of adding constant voltage charging is to ensure that the capacity of all batteries reaches the required level.

[0065] The following are examples of embodiments of the method of the present invention under different conditions, and these embodiments are compared.

[0066] The following table shows a comparative example where only the conditions of steps S02 and S03 were changed in a pre-charge chamber at a temperature of 45°C:

[0067]

[0068] As shown in the table above, when the charging current in step S02 is the same, a charging time of 8-40 minutes and a resting time of 24-48 hours in step S03 result in a relatively low self-discharge rate. Similarly, when the charging time in step S02 and the resting time in step S03 are the same, a charging current in step S02 within the range of 0.05-0.15C also results in a relatively low self-discharge rate. The self-discharge rate of a battery is its ability to retain the stored charge under certain conditions in an open-circuit state. Since the raw materials used in battery manufacturing cannot be 100% pure, impurities are inevitable, leading to self-discharge. Therefore, given the same battery materials, efforts should be made to minimize the self-discharge rate through advanced manufacturing processes.

[0069] Under the same conditions as step S02 and step S03, the lithium-ion battery is pre-charged using the pre-charge scheme in the table below:

[0070]

[0071] Under the above pre-charge conditions, the pre-charged battery was aged, and its resistance was tested. The results are shown in the table below:

[0072]

[0073] The above data shows that the average resistance measured at 25℃ is lower than other values, and the resistance increases accordingly with increasing temperature. This indicates that a temperature range of 35-60℃ is conducive to the formation of a stable and dense SEI film. Therefore, the internal resistance of cells pre-charged within this temperature range will be slightly higher than that pre-charged at other temperatures. The thickness of the SEI film affects the battery's internal resistance; the thicker the SEI film, the greater its internal resistance. The thickness of the SEI film needs to be limited within a certain range to ensure a long battery life and stable battery performance. In this embodiment, the pre-charge temperature is 25-60℃. However, since the internal resistance formed during pre-charging at 60℃ is the highest, posing a certain risk to battery use, the pre-charge temperature is preferably controlled between 35-55℃. The SEI film formed after pre-charging with a formation time controlled within 1-2 days has a more stable structure, and its resistance value is relatively normal. Compared to the traditional formation process which takes 2-3 days, the formation time of the method of this invention is 1-2 days. The SEI film formed by this method is not only structurally stable and uniform in thickness, but also has a shorter formation time, which can greatly reduce the battery production time and improve battery production efficiency.

[0074] To ensure the accuracy of the above experiments, performance tests were conducted on the lithium-ion batteries with a formation time of 1 day in the examples. The test results are shown in the table below:

[0075]

[0076] In the above embodiments, lithium-ion batteries pre-charged using the method of the present invention were tested at temperatures of 25°C and 45°C. Since 25°C and 45°C are more consistent with the ambient temperatures of batteries in daily use, they were chosen as the test temperatures. After 500 cycles, the internal resistance of the lithium-ion batteries was tested. The test results show that the resistance of lithium-ion batteries pre-charged at 25°C is significantly lower than that of lithium-ion batteries pre-charged at other temperatures after 500 cycles at either 25°C or 45°C. Therefore, the structure of the internal SEI film is less stable compared to lithium-ion batteries pre-charged at other temperatures. Furthermore, after 1100 cycles, the retention rate of lithium-ion batteries pre-charged at 25°C is lower than that of lithium-ion batteries pre-charged at other temperatures. Lithium-ion batteries pre-charged at 35-55°C exhibit better performance in all tests than those pre-charged at 25°C. The retention rate mentioned here refers to the battery capacity retention rate.

[0077] The lithium-ion battery pre-charge formation apparatus and the pre-charge formation method using the apparatus of the present invention can be applied not only to lithium-ion batteries but also to other types of batteries. From the perspective of battery pre-charge formation effect, the pre-charge formation effect of lithium-ion batteries is better, therefore lithium-ion batteries are the preferred solution.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and not to limit them. Although the embodiments of the present invention have been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the embodiments of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for pre-charging and forming a lithium-ion battery, characterized in that, The process includes the following steps: S01: Place the lithium-ion battery into a pre-charge box, connecting the negative electrode of the lithium-ion battery to the negative charging electrode and the positive electrode to the positive charging electrode; S02: Pre-charge the lithium-ion battery at a rate of 0.01-0.1C for 8-40 minutes; S03: Allow the battery to stand for 24-48 hours; S04: Charge the lithium-ion battery at a rate of 0.05-0.15C for 0.5-2 hours until the battery's charging capacity accounts for 5%-10% of the total capacity of the lithium-ion battery; S05: Charge the lithium-ion battery at a constant current rate of 0.25-0.35C until the battery voltage is 4.2V; S06: Allow the battery to stand for 1-2 days for formation, and then remove the lithium-ion battery from the pre-charge box; Steps S02-S05 are all performed at a temperature of 35-55℃, and the formation temperature of step S06 is 40-55℃. The positive electrode active material of the lithium-ion battery is a ternary material of lithium nickel cobalt manganese oxide.

2. The pre-charge formation method as described in claim 1, characterized in that, The positive electrode active material of the lithium-ion battery has a Ni:Co:Mn ratio of 4-6:1.6-2.4:2.4-3.

6.

3. The pre-charge formation method as described in claim 1, characterized in that, Step S05 further includes charging the lithium-ion battery at a constant voltage of 4.2V to a current of 52mA.

Images