Method for manufacturing energy storage battery, energy storage battery and device

Abstract

This application relates to a method for manufacturing an energy storage battery, an energy storage battery, and an apparatus. Applied to the capacity grading stage of a semi-finished energy storage battery, the manufacturing method includes: in a first capacity grading stage, charging the semi-finished energy storage battery with a first preset current to a first preset value higher than the delivery voltage, and discharging the semi-finished energy storage battery with a second preset current to the delivery voltage; in a second capacity grading stage, charging the semi-finished energy storage battery with a first preset stepped current to the upper voltage limit; in a third capacity grading stage, discharging the semi-finished energy storage battery with a second preset stepped current to the lower voltage limit; and in a fourth capacity grading stage, charging the semi-finished energy storage battery with a third preset current to a second preset value higher than the delivery voltage, and discharging the semi-finished energy storage battery with a fourth preset current to the delivery voltage. Using the above manufacturing method can improve the uniformity of cell capacity decay and the uniformity of storage voltage difference.

Description

Technical Field

[0001] This application relates to the field of photovoltaic cell technology, and in particular to a method for preparing an energy storage battery, an energy storage battery, a battery device, an electrical device, and an energy storage device. Background Technology

[0002] Battery capacity grading involves charging and discharging the battery under fixed conditions to determine the capacity of each cell, and then categorizing the cells by capacity. Subsequently, during module assembly, cells within the same capacity grading group are paired to improve cell consistency. Higher consistency in cell capacity within a module results in superior module performance during subsequent use.

[0003] As battery energy density continues to increase, relying solely on the performance of the materials themselves and employing a one-time capacity grading process can easily lead to poor stability of the SEI (Solid Electrolyte Interphase) formed in the cell (potentially resulting in lithium plating due to SEI damage during charging). This, in turn, results in poor consistency in the voltage performance after capacity grading and before shipment. Therefore, specific control during capacity grading is needed to stabilize the SEI film and ensure consistent cell capacity decay and storage voltage drop. Summary of the Invention

[0004] Therefore, it is necessary to provide a method for preparing an energy storage battery, an energy storage battery, a battery device, an electrical device, and an energy storage device battery to address the problems of inconsistent cell capacity decay and poor storage voltage difference.

[0005] In a first aspect, this application provides a method for preparing an energy storage battery, applied to the capacity grading stage of a semi-finished energy storage battery. The capacity grading stage includes four sub-stages—a first, a second, a third, and a fourth—that are distinct from each other and executed sequentially; including:

[0006] In the first capacity-dividing stage, the semi-finished energy storage battery is charged to a first set value higher than the delivery voltage with a first preset current, and then the semi-finished energy storage battery is discharged to the delivery voltage with a second preset current, wherein the first preset current and the second preset current are currents of different magnitudes;

[0007] In the second capacity-dividing stage, the semi-finished energy storage battery is charged to the upper voltage limit with a first preset step current;

[0008] In the third capacity-dividing stage, the semi-finished energy storage battery is discharged to the lower voltage limit using a second preset step current;

[0009] In the fourth capacity stage, the semi-finished energy storage battery is charged to a second set value higher than the delivery voltage using a third preset current, and then discharged to the delivery voltage using a fourth preset current.

[0010] Secondly, this application also provides an energy storage battery, which is prepared from a semi-finished energy storage battery using the above-described energy storage battery preparation method, and is used to form one or more of a battery module and a battery pack.

[0011] Thirdly, this application also provides a battery device, which includes an energy storage battery as described above, and the battery device includes one or more of a battery module and a battery pack.

[0012] Fourthly, this application also provides an electrical device, which includes a battery device as described above, the battery device being used to provide electrical energy.

[0013] Fifthly, this application also provides an energy storage device, which includes a battery device as described above, the battery device being used to store electrical energy.

[0014] The aforementioned method for preparing the energy storage battery, the energy storage battery, the battery device, the power consumption device, and the energy storage device divide the capacity grading stage of the semi-finished energy storage battery into four different and sequentially executed sub-stages: a first capacity grading stage, a second capacity grading stage, a third capacity grading stage, and a fourth capacity grading stage. Specifically, in the first capacity grading stage, the semi-finished energy storage battery is first charged to a first preset value higher than the delivery voltage using different first preset currents and second preset currents, and then discharged to the delivery voltage. This allows the stability of the SEI film already formed in the semi-finished energy storage battery to be enhanced through an electrochemical regulation method of charging before discharging in the first capacity grading stage. Furthermore, in the second capacity grading stage, a step-wise first preset current is used... The step-current charges the semi-finished energy storage battery to the upper voltage limit, thereby avoiding interface damage caused by a single large current surge. Then, in the third capacity stage, the semi-finished energy storage battery is discharged to the lower voltage limit with a second preset step-current, thereby balancing the compatibility between the SEI film and the semi-finished energy storage battery discharge process. Finally, in the fourth capacity stage, the semi-finished energy storage battery is charged to a second preset value higher than the delivery voltage with a third preset current, and then discharged to the delivery voltage with a fourth preset current. This solves the problem of incomplete release of battery residual capacity and ensures the stability of storage voltage difference. Therefore, the energy storage battery preparation method of this embodiment can improve the capacity grading effect of semi-finished energy storage batteries. Attached Figure Description

[0015] Figure 1 This is a schematic flowchart of a method for preparing an energy storage battery in one embodiment;

[0016] Figure 2 This is a schematic flowchart of a method for preparing an energy storage battery in another embodiment;

[0017] Figure 3 This is a schematic diagram of the voltage and current change curves during the charging process of a semi-finished energy storage battery with a first preset stepped current in one embodiment of the energy storage battery preparation method.

[0018] Figure 4 This is a flowchart illustrating the preparation method of an energy storage battery in yet another embodiment;

[0019] Figure 5 This is a schematic diagram of the voltage and current changes during the discharge of a semi-finished energy storage battery with a second preset stepped current in one embodiment of the energy storage battery preparation method.

[0020] Figure 6 This is a schematic diagram of the voltage and current variation curves during the capacity testing stage of a semi-finished energy storage battery in one embodiment of the energy storage battery preparation method. Detailed Implementation

[0021] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0022] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0023] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0026] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0027] First, it should be understood that with the comprehensive upgrading of core materials for positive and negative electrodes, the optimization of electrolyte and interface technologies, and the continuous improvement of manufacturing processes, battery energy density is continuously increasing. Currently, it usually relies on the performance of the materials themselves and adopts a one-time capacity grading process to activate and calibrate the battery cell for the first charge and discharge. For example, in the charging stage, the energy storage battery is first charged to 3.65V with a constant current of 0.5C. After reaching this voltage, the constant voltage of 3.65V is maintained and charging continues until the charging current drops to 0.05C and charging is stopped. Then, in the discharging stage, the battery is first discharged to 2.5V with a constant current of 0.5C, and then discharged to 2.5V with a constant small current of 0.05C. Finally, in the adjustment stage, the battery is charged to the delivery voltage with a constant current of 0.5V, thus completing the entire capacity grading stage. Understandably, this one-time capacity grading process features constant current and constant voltage. First, the battery is charged with a constant current of 0.5C. Once the voltage reaches 3.65V, it switches to a constant voltage charging mode of 3.65V. During the constant voltage phase, the charging current gradually decreases as the battery is fully charged, decreasing from the initial 0.5C to 0.45C, 0.4C, etc., until the cutoff conditions of 3.65V voltage and 0.05C current are met. However, under these cutoff conditions, the SEI film formed in the cell is prone to insufficient stability. This leads to poor consistency in the shipped voltage of the cells after capacity grading, resulting in inconsistent capacity decay and poor storage voltage differential. Therefore, specific control measures are needed to ensure stable SEI film formation during the capacity grading process. This application provides a method for preparing an energy storage battery.

[0028] like Figure 1 As shown, a method for preparing an energy storage battery is provided, applied to the capacity grading stage of a semi-finished energy storage battery. The capacity grading stage includes a first capacity grading sub-stage, a second capacity grading sub-stage, a third capacity grading stage, and a fourth capacity grading sub-stage, which are different from each other and executed sequentially; including steps 202 to 208:

[0029] Step 202: In the first capacity division stage, the semi-finished energy storage battery is charged to a first set value higher than the delivery voltage with a first preset current, and then the semi-finished energy storage battery is discharged to the delivery voltage with a second preset current, wherein the first preset current and the second preset current are currents of different magnitudes.

[0030] It should be noted that semi-finished energy storage batteries refer to energy storage battery cells that have completed basic processes such as core electrode manufacturing and cell assembly, but have not yet undergone post-processing processes such as capacity testing, aging, and consistency screening. This means that semi-finished energy storage batteries have not completed the stable formation of the SEI film through the first charge-discharge cycle, their key electrochemical parameters such as capacity and internal resistance have not been calibrated, and their performance stability and consistency have not met the finished product shipment standards. However, after the capacity testing process and subsequent testing steps of the energy storage battery preparation method in this embodiment, qualified energy storage batteries at the finished product stage can be obtained. The capacity testing stage of the semi-finished energy storage battery includes four different and sequentially executed capacity testing sub-stages: the first capacity testing sub-stage, the second capacity testing sub-stage, the third capacity testing stage, and the fourth capacity testing stage. These four sub-stages correspond to different charge-discharge operation steps in the capacity testing process of the semi-finished energy storage battery. Together, these four sub-stages constitute a complete capacity testing process, and are executed sequentially in chronological order.

[0031] It should be noted that the first preset current refers to the fixed current value used to charge the semi-finished energy storage battery in the first capacity-sensing stage. Specifically, it can be 0.3C, 0.4C, or 0.5C, etc. By controlling the first preset current, it is possible to avoid the violent interface reaction caused by large current impact, and ensure that lithium ions are stably embedded into the electrode, thereby providing a basis for the initial formation of a uniform SEI film. The delivery voltage refers to the standard voltage value maintained by the cell during the delivery stage of the energy storage battery. Specifically, it can be 3.2V or 3.3V, etc. The first set value can be customized according to the manufacturing process, specifically 3.6V, 3.62V, or 3.65V, etc. In the first capacity-sensing stage, the semi-finished energy storage battery is first charged to a value higher than the delivery voltage using the first preset current. This allows the electrolyte and electrode to fully contact and react, thereby ensuring the initial growth of the SEI film and avoiding insufficient capacity utilization during subsequent charging and discharging processes.

[0032] It should be noted that the second preset current refers to a fixed current value for discharging the semi-finished energy storage battery, specifically 0.2C, 0.3C, or 0.4C, etc. The second preset current and the first preset current are different magnitudes, and by differentiating the charge and discharge rates, the electrode surface reaction can be more complete, reducing interface defects and lowering capacity loss during the first charge and discharge. For example, in one feasible implementation, the first preset current is 0.5C, and the second preset current is 0.2C, where C refers to the ratio of the battery's charge and discharge current to its rated capacity. During the charging phase, C can be expressed as... (Charging rate), which is the ratio of charging current to the battery's rated capacity, can be expressed as C during the discharge phase. (Discharge rate) is the ratio of discharge current to rated current capacity. The purpose of discharging the semi-finished energy storage battery to the delivery voltage is to bring the cell voltage of the semi-finished energy storage battery to a uniform baseline at the end of the first capacity grading stage.

[0033] It is understandable that the charge and discharge times differ at different charge and discharge rates. For example, a semi-finished energy storage battery has a rated capacity of 1000mAh, and the first preset current is expressed as 0.5... That is, the first preset current is specifically 500mA (0.5). *1000mAh), then the ideal charging time is 2 hours (1000mAh / 500mA), if the first preset current is expressed as 0.2. That is, the first preset current is specifically 200mA (0.2). If the capacity is *1000mAh, then the ideal charging time is 5 hours (1000mAh / 200mA); if the second preset current is expressed as 0.5... That is, the second preset current is specifically 500mA (0.5). *1000mAh), then the ideal discharge time is 2 hours (1000mAh / 500mA), if the second preset current is expressed as 0.2. That is, the second preset current is specifically 200mA (0.2). If the capacity is 1000mAh, then the ideal discharge time is 5 hours (1000mAh / 200mA).

[0034] As an example, step 202 includes: using 0.5 The constant current charges the semi-finished energy storage battery to a first set value higher than the shipment voltage, and then charges it at 0.05... The constant current discharges the semi-finished energy storage battery to the delivery voltage.

[0035] Step 204, in the second capacity stage, the semi-finished energy storage battery is charged to the upper voltage limit using the first preset step current.

[0036] It should be noted that the second capacity grading stage refers to the second step in the multi-stage capacity grading process of semi-finished energy storage batteries. It is used to optimize the density and uniformity of the SEI film through stepped charging and simultaneously increase the cell voltage to a fully charged state. It can be understood that the first and second preset currents can be constant currents, while the first preset stepped current is non-constant current. Constant current refers to a current whose magnitude remains constant during charging and discharging, which can be understood as the amount of charge passing through the battery per unit time remaining consistent. The upper voltage limit is the charging termination voltage of the second capacity grading stage, specifically 3.65V or 3.7V, etc. By charging the semi-finished energy storage battery to the upper voltage limit with the first preset stepped current in the second capacity grading stage, its function is to fully activate the electrochemical activity of the semi-finished energy storage battery cells within a safe voltage range. The first preset stepped current refers to a pre-set charging current that gradually changes according to a fixed rule. This fixed rule can be a stepped increase or a stepped decrease; for example, the first preset stepped current can be 0.2V. 0.4 and 0.6 Or it could be 0.6 0.5 and 0.2 .

[0037] As an example, step 204 includes: in the second capacity stage, charging the semi-finished energy storage battery to 3.65V with a first preset step current.

[0038] Step 206: In the third stage of the capacitor, the semi-finished energy storage battery is discharged to the lower voltage limit using the second preset step current.

[0039] It should be noted that the third capacity grading stage refers to the third step in the multi-stage capacity grading process of semi-finished energy storage batteries, used to further optimize the stability of the SEI film through stepped discharge; the second preset stepped current refers to a pre-set discharge current that gradually changes according to a fixed rule, where the fixed rule can be a stepped increase or a stepped decrease, for example, the second preset stepped current can be 0.2. 0.4 and 0.6 Or it could be 0.6 0.5 and 0.2 The second preset step current and the first preset step current can be the same or different; the lower voltage limit is the discharge termination voltage of the third capacity stage, which can be 2.5V or 2.7V, etc. By discharging the semi-finished energy storage battery to the lower voltage limit with the second preset step current in the third capacity stage, its function is to enable the cells of the semi-finished energy storage battery to fully release their capacity within the safe voltage range and further stabilize the structure of the SEI film.

[0040] As an example, step 206 includes: in the third stage of the cell, discharging the semi-finished energy storage battery to 2.5V with a second preset step current.

[0041] Step 208: In the fourth capacity stage, the semi-finished energy storage battery is charged to a second set value higher than the delivery voltage using a third preset current, and then the semi-finished energy storage battery is discharged to the delivery voltage using a fourth preset current.

[0042] It should be noted that the fourth capacity grading stage refers to the fourth step in the multi-stage capacity grading process of the semi-finished energy storage battery. It is used to finally reinforce and repair the SEI film and ensure that the cell voltage of the semi-finished energy storage battery is regulated to the shipping standard. The third preset current refers to the fixed current value for charging the semi-finished energy storage battery in the fourth capacity grading stage. Specifically, it can be 0.3C, 0.4C, or 0.5C, etc. Through the controllable third preset current, it is possible to avoid secondary damage to the formed SEI film caused by large current impact, control the lithium ion insertion rate, reduce the local concentration gradient, and reduce the risk of lithium dendrite precipitation. The second set value can be customized according to the preparation process. Specifically, it can be 3.6V, 3.62V, or 3.65V, etc. The first set value and the second set value are different. In the fourth capacity grading stage, the semi-finished energy storage battery is first charged to the second set value, which is higher than the shipping voltage, with the third preset current. This allows the micro-defects in the formed SEI film to be fully repaired and promotes further densification and uniformity of the film layer, thereby improving the interface stability.

[0043] It should be noted that the fourth preset current refers to a fixed current value for discharging the semi-finished energy storage battery, specifically 0.2C, 0.3C, or 0.4C, etc. The third and fourth preset currents can be the same or different. For example, in one feasible embodiment, the third preset current can be set to be the same as the first preset current, and the fourth preset current can be set to be the same as the second preset current, i.e., the third and fourth preset currents are set to different magnitudes. In this way, the SEI film structure is made more stable by setting differentiated charge and discharge rates, reducing the risk of damage and lithium deposition, and simultaneously enhancing the cell's adaptability to rate changes, thereby improving the integrity of capacity utilization and the consistency of parameters after capacity grading. For example, in one feasible embodiment, the first preset current is 0.5C. The second preset current is 0.2. .

[0044] As an example, step 208 includes: using 0.5 The constant current charges the semi-finished energy storage battery to a second set value higher than the shipment voltage, and then charges it at 0.05... The constant current discharges the semi-finished energy storage battery to the delivery voltage.

[0045] The aforementioned method for preparing the energy storage battery divides the capacity grading stage of the semi-finished energy storage battery into four different and sequentially executed sub-stages: a first capacity grading stage, a second capacity grading stage, a third capacity grading stage, and a fourth capacity grading stage. Specifically, in the first capacity grading stage, the semi-finished energy storage battery is first charged to a first set value higher than the delivery voltage using different first and second preset currents, and then discharged to the delivery voltage. This allows the stability of the SEI film already formed in the semi-finished energy storage battery to be enhanced through an electrochemical regulation method of charging before discharging in the first capacity grading stage. Then, in the second capacity grading stage, the semi-finished energy storage battery is discharged using a stepped first preset current. The battery is charged to the upper voltage limit, thus avoiding interface damage caused by a single large current surge. Then, in the third capacity stage, the semi-finished energy storage battery is discharged to the lower voltage limit with a second preset step current, thereby balancing the compatibility between the SEI film and the semi-finished energy storage battery discharge process. Finally, in the fourth capacity stage, the semi-finished energy storage battery is charged to a second preset value higher than the delivery voltage with a third preset current, and then discharged to the delivery voltage with a fourth preset current. This solves the problem of incomplete release of battery residual capacity and ensures the stability of storage voltage difference. Therefore, the energy storage battery preparation method of this embodiment can improve the capacity grading effect of semi-finished energy storage batteries.

[0046] In one embodiment, refer to Figure 2 The first preset step current includes multiple fifth preset currents arranged in descending order of magnitude; the semi-finished energy storage battery is charged to the upper voltage limit using the first preset step current, including steps 302 and 304:

[0047] Step 302, Perform the charging step: Charge the semi-finished energy storage battery with a single fifth preset current.

[0048] It should be noted that, in order to rapidly activate the active material during the high-current stage and finely control the SEI film growth during the low-current stage, thereby avoiding uneven reactions caused by a single current and forming a denser and more uniform interface film layer, the first preset step current can be set as multiple fifth preset currents arranged in descending order of magnitude. In the stepped charging mode, the semi-finished energy storage battery is gradually charged to the upper voltage limit using a single fifth preset current. For example, in one feasible approach, refer to... Figure 3 , Figure 3 To illustrate the voltage and current changes during the charging process of a semi-finished energy storage battery with a first preset stepped current, the first preset stepped current includes 0.5... 0.3 and 0.2 First, use 0.5 The semi-finished energy storage battery is charged from the shipping voltage (3.5V) to the first preset charging voltage (3.55V), and then charged at 0.3... The semi-finished energy storage battery is charged to the second preset charging voltage (3.6V), and finally charged at 0.2V. The semi-finished energy storage battery is charged to the upper voltage limit (3.65V). The first preset step charging voltage, the second preset step charging voltage and the upper voltage limit increase sequentially. The first preset step charging voltage and the second preset step charging voltage are the voltage values ​​that should be reached when the semi-finished energy storage battery is charged by a single preset fifth current.

[0049] As an example, step 302 includes: performing a charging step: charging the semi-finished energy storage battery to the corresponding preset tiered charging voltage with a single fifth preset current.

[0050] Step 304: According to the decreasing order of the magnitude of the multiple fifth preset currents, the fifth preset currents for charging the semi-finished energy storage battery are switched sequentially, and the charging steps are continued until the semi-finished energy storage battery is charged to the upper voltage limit with the smallest fifth preset current; wherein any fifth preset current is greater than the preset current threshold value.

[0051] It should be noted that after a single fifth preset current completes the charging of the semi-finished energy storage battery, the fifth preset current used to charge the semi-finished energy storage battery needs to be switched. Multiple fifth preset currents participate in the charging stage of the semi-finished energy storage battery in descending order of magnitude. This is because switching between different fifth preset currents sequentially allows the battery cells to complete lithium-ion intercalation in stages under different current intensities, thus avoiding over- or under-reaction in certain areas under a single current and improving interface uniformity. The stepped charging mode terminates after the semi-finished energy storage battery is charged to the upper voltage limit using the minimum fifth preset current. Setting the minimum fifth preset current to complete the final charging during the process of charging the semi-finished energy storage battery to the upper voltage limit minimizes the polarization effect when the voltage approaches the upper limit, thereby reducing the risk of lithium dendrite precipitation and ensuring the stability of the upper voltage limit and the integrity of the SEI film.

[0052] It should be noted that the preset current threshold is a pre-set minimum current threshold. By setting any fifth preset current greater than the preset current threshold, a sufficiently large current intensity can be maintained during the charging process of the finished energy storage battery to ensure that lithium ions are effectively inserted into the electrode, so as to ensure sufficient interface reaction and avoid the occurrence of long capacity grading time. The preset current threshold can be 0.05C or 0.1C, etc.

[0053] As an example, step 304 includes: sequentially switching the fifth preset current for charging the semi-finished energy storage battery in descending order of magnitude of multiple fifth preset currents, and continuing to perform the charging step until the semi-finished energy storage battery is charged to the upper voltage limit with the smallest fifth preset current; wherein any fifth preset current is greater than a preset current threshold value.

[0054] In one feasible approach, it is assumed that the preset current threshold value is 0.05. Then, the first preset step current includes multiple fifth preset currents arranged in descending order of magnitude, which can be 0.4 in sequence. 0.3 0.2 and 0.1 The specific steps for charging the semi-finished energy storage battery to its upper voltage limit using a first preset step current can be as follows: first, charge it with a 0.4... The semi-finished energy storage battery is charged to the first preset charging voltage. Once the real-time charging voltage of the semi-finished energy storage battery reaches the first preset charging voltage, the fifth preset current is increased from 0.4... Switch to 0.3 Then add 0.3 The semi-finished energy storage battery is charged to the second preset charging voltage. Once the real-time charging voltage of the semi-finished energy storage battery reaches the second preset charging voltage, the fifth preset current is increased from 0.3... Switch to 0.2 Then with 0.2 The semi-finished energy storage battery is charged to the third preset charging voltage. Once the real-time charging voltage of the semi-finished energy storage battery reaches the third preset charging voltage, the fifth preset current is increased from 0.2... Switch to 0.1 Ultimately, it was 0.1 Charge the semi-finished energy storage battery to its maximum voltage limit.

[0055] In this way, by setting multiple fifth preset currents arranged in descending order of magnitude, and charging the semi-finished energy storage battery to the upper voltage limit in a stepwise manner according to the descending order of the fifth preset currents, the charging rate of the semi-finished energy storage battery is gradually reduced while ensuring a certain charging rate. This allows the SEI film to grow uniformly and densely, reducing the risk of polarization and lithium deposition. At the same time, by precisely controlling the charging time of the semi-finished energy storage battery by different fifth preset currents through preset step charging voltages, the electrochemical reaction at each current level can be ensured to be sufficient, thereby avoiding the situation of insufficient utilization of local active materials caused by constant current charging. Therefore, the cycle stability and voltage consistency of the cell can be improved without affecting the capacity.

[0056] In one embodiment, a plurality of fifth preset currents satisfy the following condition: the first current difference between two adjacent fifth preset currents is greater than the second current difference between any two adjacent fifth preset currents.

[0057] It should be noted that, to further optimize the smoothness of the charging rate and reduce the impact of sudden current changes on the SEI film, the magnitude correlation between multiple fifth preset currents can be limited. Specifically, the first current difference between the first two adjacent fifth preset currents can be set to be greater than the second current difference between any two adjacent fifth preset currents. That is, during the process of charging the semi-finished energy storage battery to the upper voltage limit with the first preset step current, the semi-finished energy storage battery is first charged with a large current, and then charged with a decreasing small current. This allows for precise control of the interface reaction while ensuring the charging rate. The second current difference between different adjacent fifth preset currents can be the same or different. For example, in one feasible approach, the preset current threshold value is assumed to be 0.05. The first preset step current includes multiple fifth preset currents arranged in descending order of magnitude, each of which can be 0.5. 0.3 0.2 and 0.1 That is, the first current difference is 0.2. The second current difference is 0.1. The specific steps for charging the semi-finished energy storage battery to its upper voltage limit using a first preset step current can be as follows: first, charge it with a 0.5... The semi-finished energy storage battery is charged to the first preset charging voltage. Once the real-time charging voltage of the semi-finished energy storage battery reaches the first preset charging voltage, the fifth preset current is increased from 0.5... Switch to 0.3 Then add 0.3 The semi-finished energy storage battery is charged to the second preset charging voltage. Once the real-time charging voltage of the semi-finished energy storage battery reaches the second preset charging voltage, the fifth preset current is increased from 0.3... Switch to 0.2 Then with 0.2 The semi-finished energy storage battery is charged to the third preset charging voltage. Once the real-time charging voltage of the semi-finished energy storage battery reaches the third preset charging voltage, the fifth preset current is increased from 0.2... Switch to 0.1 Ultimately, it was 0.1 Charge the semi-finished energy storage battery to its maximum voltage limit.

[0058] In this way, by controlling the first current difference between the first two adjacent fifth preset currents to be greater than the second current difference between any two adjacent fifth preset currents, a certain charging efficiency can be ensured in the early stage of charging through a large current. Then, the interface response can be precisely controlled through a small current, so that after the active material of the cell is quickly activated, the SEI film can grow uniformly and become dense under the gradually decreasing current intensity. Therefore, while further improving the capacity grading efficiency, the cycle performance and consistency of the semi-finished energy storage battery cell can be improved.

[0059] In one embodiment, the plurality of fifth preset currents are sequentially: , , and ; satisfy: ,in, This refers to the charging rate. The total number of multiple fifth preset currents.

[0060] It should be noted that, based on the differences in manufacturing requirements, the magnitudes of multiple fifth preset currents can be adaptively set. However, by limiting the magnitude of the minimum fifth preset current, the voltage upper limit calibration of the semi-finished energy storage battery can always be completed with an effective and relatively small current intensity during the use of the stepped charging mode. This can avoid the impact of excessive current on the interface reaction in the final stage, and also prevent situations such as low charging efficiency or insufficient reaction due to insufficient current. Therefore, it can ensure the consistency and stability of the performance of the semi-finished energy storage battery cells after the capacity grading process.

[0061] In one possible implementation, The value is 5, and the multiple fifth preset currents are sequentially 5. , , , and ,in, It is 0.6 , It is 0.4 , It is 0.3 , It is 0.2 , It is 0.1 .

[0062] In another feasible approach The value is 4, and the multiple fifth preset currents are as follows: , , and ,in, It is 0.6 , It is 0.3 , It is 0.05 , It is 0.02 .

[0063] In one embodiment, refer to Figure 4 The second preset step current includes the sixth preset current and the seventh preset current; the semi-finished energy storage battery is discharged to the lower voltage limit using the second preset step current, including steps 402 to 404:

[0064] Step 402: Perform the first discharge step: discharge the semi-finished energy storage battery with the sixth preset current.

[0065] It should be noted that, in order to quickly screen for defects and deeply stabilize the interface, while ensuring discharge efficiency and taking into account the fine-tuning of cell performance, the second preset step current can be set as the sixth and seventh preset currents. In the stepped charging mode, the semi-finished energy storage battery is gradually discharged to the lower voltage limit using the sixth and seventh preset currents. The second preset step current includes the sixth and seventh preset currents, where the sixth preset current is greater than the preset current threshold and the seventh preset current is less than the preset current threshold. For example, in one feasible method, refer to... Figure 5 , Figure 5 To illustrate the voltage and current changes of the semi-finished energy storage battery during the discharge process using the second preset stepped current, it is assumed that the preset current threshold value is 0.1. Therefore, the sixth preset current can be 0.2. The seventh preset current can be 0.05. First, use 0.2 The semi-finished energy storage battery is discharged from its upper voltage limit (3.65V) to a preset stepped discharge voltage (3.2V), and then discharged at 0.05... The semi-finished energy storage battery is discharged from a preset stepped discharge voltage (3.2V) to the lower voltage limit (2.5V), wherein the preset stepped discharge voltage is greater than the lower voltage limit.

[0066] As an example, step 402 includes: performing a first discharge step: discharging the semi-finished energy storage battery to a preset stepped discharge voltage with a sixth preset current.

[0067] Step 404: After the first discharge step is completed, the second discharge step is performed: the semi-finished energy storage battery is discharged to the lower voltage limit with the seventh preset current; wherein, the sixth preset current is greater than the preset current threshold value, and the seventh preset current is less than the preset current threshold value.

[0068] It should be noted that after the sixth preset current has finished discharging the semi-finished energy storage battery, the sixth preset current needs to be switched to the seventh preset current for discharging the semi-finished energy storage battery. It can be understood that, firstly, a large current is used to quickly release most of the capacity, so as to achieve efficient screening of hidden micro-defects inside the cell. Then, a small current is used to fully extract and insert the residual lithium ions in the electrode to ensure the accuracy of the capacity calibration. At the same time, it can also avoid polarization accumulation and SEI film damage caused by excessively fast discharge rate.

[0069] As an example, step 404 includes: when the real-time discharge voltage of the semi-finished energy storage battery is a preset stepped discharge voltage, switching the sixth preset current to the seventh preset current, and performing the second discharge step: discharging the semi-finished energy storage battery to the lower voltage limit with the seventh preset current.

[0070] In one feasible approach, it is assumed that the preset current threshold value is 0.05. Then the second preset step current includes the sixth preset current 0.2. And the seventh preset current 0.05 The specific steps for discharging the semi-finished energy storage battery to its lower voltage limit using a second preset step current can be as follows: [The steps are described in the original text, but the provided excerpt ends here.] Discharge the semi-finished energy storage battery to a preset stepped discharge voltage. When the real-time discharge voltage of the semi-finished energy storage battery is equal to the preset stepped discharge voltage, discharge at a rate of 0.05... Discharge the semi-finished energy storage battery to its lower voltage limit.

[0071] In this way, in the third stage of cell discharge, the semi-finished energy storage battery is first discharged with a sixth preset current greater than the preset current threshold, and then discharged to the lower voltage limit with a seventh preset current less than the preset current threshold. This achieves the purpose of first discharging the semi-finished energy storage battery quickly and then discharging it slowly. This can efficiently screen for micro-defects inside the cell, while allowing lithium ions to be fully inserted and extracted, reducing the risk of polarization and SEI film damage, and accurately calibrating the lower capacity limit. Therefore, it improves the stability and consistency of cell performance.

[0072] In one embodiment, the sixth preset current is The seventh preset current is ; and Each to their own satisfaction: , ,in, This represents the discharge rate.

[0073] It should be noted that, based on the differences in preparation requirements, the magnitudes of the sixth and seventh preset currents can be adaptively limited to specific ranges. This allows for the release of capacity with an effective and relatively large current intensity during the use of a stepped discharge mode, while using a small current to complete the voltage lower limit calibration of the semi-finished energy storage battery. This not only improves the efficiency of the capacity grading process and fully exposes cell defects, but also ensures the complete deintercalation and intercalation of lithium ions in the active material, providing a reliable benchmark for capacity calibration and consistency screening.

[0074] In one feasible approach It is 0.2 , It is 0.02 .

[0075] In another feasible approach It is 0.2 , It is 0.1 .

[0076] In another feasible approach It is 0.5 , It is 0.02 .

[0077] In another feasible approach It is 0.5 , It is 0.1 .

[0078] In one embodiment, the method further includes:

[0079] After the second capacity-classification stage is completed, the semi-finished energy storage battery is left to stand, and after the semi-finished energy storage battery has been left to stand, the third capacity-classification stage is carried out.

[0080] It should be noted that, since the second and third capacity sub-stages are between the formation of the SEI film and the discharge stage, in order to improve the stability of the SEI film, the semi-finished energy storage battery is left to stand between the second and third capacity sub-stages. This standing operation can strengthen and repair the SEI film, preventing damage to the film layer during subsequent discharge. At the same time, it can also provide a stable initial state for the stepped discharge in the third capacity sub-stage.

[0081] As an example, after the second capacity grading stage is completed, the semi-finished energy storage battery is left to rest for a preset time. After the preset resting time, the third capacity grading stage is then performed. This resting period between the second and third capacity grading stages strengthens and repairs the formed SEI film, preventing damage during subsequent discharge. Simultaneously, it provides a stable initial state for the stepped discharge in the third capacity grading stage, thus laying a foundation for further improving the capacity grading effect of the semi-finished energy storage battery.

[0082] In one embodiment, a static semi-finished energy storage battery includes:

[0083] The semi-finished energy storage battery is left to stand for a preset time within the preset temperature range.

[0084] It should be noted that by controlling the temperature and time during the resting process of the semi-finished energy storage battery, the pace of repairing and reinforcing the SEI film can be precisely controlled. Specifically, the preset temperature range and preset time can be adaptively set according to the requirements of the preparation process. The resting can be carried out at a constant temperature value within the preset temperature range or at a varying temperature value within the preset temperature range.

[0085] As an example, the semi-finished energy storage battery was left to stand at 55°C for 30 minutes.

[0086] In one embodiment, the first preset current is The second preset current is ; and They respectively satisfy: , ,in, This refers to the charging rate. This represents the discharge rate.

[0087] It should be noted that, to ensure rate matching during charging and discharging, and to avoid the accumulation of internal stress or repeated damage to the SEI film in the semi-finished energy storage battery due to excessive differences in charge and discharge rates, the first preset current and the second preset current can be limited to their respective rate ranges. The first preset current is greater than the second preset current; that is, a large current rapidly activates the active materials during the charging phase, while a small current reduces interfacial impact during the discharging phase through a lower discharge rate. This balances the cell's activation effect and structural stability. This refers to the charging rate. This refers to the discharge rate. and They can be the same or different; it is understood that when the first preset current and the second preset current are respectively limited to the corresponding multiplier range, the third preset current and the first preset current can be limited to be the same, and the fourth preset current and the second preset current can be limited to be the same.

[0088] In one feasible approach It is 0.2 , It is 0.02 .

[0089] In another feasible approach It is 0.2 , It is 0.1 .

[0090] In another feasible approach It is 0.5 , It is 0.02 .

[0091] In another feasible approach It is 0.5 , It is 0.1 .

[0092] In one embodiment, the voltage upper limit is The lower voltage limit is ; and Each to their own satisfaction: , .

[0093] It should be noted that by limiting the upper and lower voltage limits of semi-finished energy storage batteries, the problem of excessive SEI film growth due to overcharging can be avoided, and irreversible damage to the active material structure due to over-discharging can also be prevented; specifically, the upper voltage limit... satisfy: Lower voltage limit satisfy: .

[0094] In one feasible approach It is 3.65V. It is 2V.

[0095] In another feasible approach It is 3.65V. It is 2.5V.

[0096] In another feasible approach It is 3.7V. It is 2V.

[0097] In another feasible approach It is 3.7V. It is 2.5V.

[0098] In one embodiment, both the first setting value and the second setting value are... The shipping voltage is ; and The following conditions must be met: U 1 ∈ [ 101 % U 2 ， 10 3%U 2 ] .

[0099] It should be noted that the first setting value and the second setting value can be set to the same fixed value. This ensures that the shipment voltage calibration benchmark for cells after the same capacity grading is maintained, thereby avoiding some cells having a shipment voltage that is too high or too low due to differences in setting values; specifically, the first setting value and the second setting value are set within a range of 1% to 3% higher than the shipment voltage, that is, The minimum value is 101%. , The maximum value is 103%. The purpose of setting this range is to both reserve a small amount of residual charge for the finished battery cell and prevent risks such as increased self-discharge and SEI film aging caused by excessive charge.

[0100] In one embodiment, the voltage upper limit is The lower voltage limit is ; and Each to their own satisfaction: , .

[0101] It should be noted that, based on the chemical system characteristics and safety threshold requirements of semi-finished energy storage battery cells, the upper and lower voltage limits can be defined separately; specifically, the upper voltage limit... The minimum value is 3.65V, and the maximum voltage is... The maximum value is 3.7V, and the lower voltage limit is... The minimum value is 2V, lower voltage limit The maximum value is 2.5V; in this way, the semi-finished energy storage battery can be anchored in a safe and effective charge and discharge range during the capacity grading process, thereby providing a reliable voltage boundary for the regulation of the SEI film and capacity calibration.

[0102] In one embodiment, the semi-finished energy storage battery is composed of multiple battery cells connected in series, and the capacity testing stage is an overall capacity testing stage composed of multiple battery cells.

[0103] It should be noted that a semi-finished energy storage battery can be a single battery cell or a combination of multiple battery cells. When a semi-finished battery is composed of multiple battery cells connected in series, the capacity testing stage is the overall capacity testing stage of the multiple battery cells. That is, the capacity testing stage includes the same charge and discharge test process for the entire series connection, as well as the individual capacity testing stages for each of the multiple battery cells. In this way, the actual series operation state of the finished battery can be directly simulated, and the charge and discharge characteristics under real application scenarios can be accurately matched.

[0104] In one feasible approach, refer to Figure 6 , Figure 6 This diagram illustrates the voltage and current variations during the capacity grading stages of a semi-finished energy storage battery. Specifically, it includes diagrams of voltage and current variations in the first, second, third, and fourth capacity grading stages. The specific steps of the capacity grading process for the semi-finished energy storage battery are as follows: First, in the first capacity grading stage, with a voltage of 0.5... The constant current charges the semi-finished energy storage battery from its initial voltage (3.25V) to 3.57V (3.5V*102%), and then charges it at a constant current of 0.1... The constant current discharges the semi-finished energy storage battery from 3.57V to the delivery voltage (3.5V). The initial voltage refers to the voltage before the capacity grading process begins, and its specific value can range from 3.25V to 3.33V. Then, in the second capacity grading stage, four fifth preset currents (0.5V each) arranged in descending order of magnitude are used. 0.3 0.2 and 0.1 The first preset step current, consisting of 0.5V, charges the semi-finished energy storage battery to its upper voltage limit. Specifically, it first charges it with a current of 0.5V. The constant current charges the semi-finished energy storage battery from the delivery voltage (3.5V) to the first preset step charging voltage (3.60V). Once the real-time charging voltage of the semi-finished energy storage battery reaches the first preset step charging voltage, the fifth preset current is increased from 0.5V. Switch to 0.3 And then with 0.3 A constant current charges the semi-finished energy storage battery from a first preset charging voltage (3.60V) to a second preset charging voltage (3.62V). Once the real-time charging voltage of the semi-finished energy storage battery reaches the second preset charging voltage, the fifth preset current is increased from 0.3V. Switch to 0.2 Then with 0.2 A constant current charges the semi-finished energy storage battery from the second preset charging voltage (3.62V) to the third preset charging voltage (3.64V). Once the real-time charging voltage of the semi-finished energy storage battery reaches the third preset charging voltage, the fifth preset current is increased from 0.2V. Switch to 0.1 (The minimum fifth preset current), ultimately at 0.1 The semi-finished energy storage battery is charged from the third preset step charging voltage (3.624V) to the upper voltage limit (3.65V) using a constant current. Then, after the second capacity assessment stage, the semi-finished energy storage battery is left to stand at 55°C for 30 minutes. After this standing period, the third capacity assessment stage is performed, that is, the semi-finished energy storage battery is discharged to the lower voltage limit using the second preset step current composed of the sixth and seventh preset currents. Specifically, it is first discharged at 0.5V... The constant current discharges the semi-finished energy storage battery from its upper voltage limit (3.65V) to a preset stepped discharge voltage (3.62V). Once the real-time discharge voltage of the semi-finished energy storage battery reaches the preset stepped discharge voltage, it discharges at a rate of 0.1... The constant current discharges the semi-finished energy storage battery from a preset stepped discharge voltage (3.62V) to the lower voltage limit (2.5V); finally, in the fourth capacity stage, it is discharged at 0.5V. (The third preset current is the same as the first preset current) Charge the semi-finished energy storage battery from the lower voltage limit (2.5V) to 3.57V (the second preset value is the same as the first preset value), and then charge it at 0.1V. (The fourth preset current is the same as the second preset current) The constant current discharges the semi-finished energy storage battery from 3.57V to 3.5V; wherein, the semi-finished energy storage battery is composed of multiple battery cells, which are connected in series, and the capacity testing stage is the overall capacity testing stage composed of multiple battery cells.

[0105] In this way, the stability of the SEI film formed in the semi-finished energy storage battery can be enhanced through electrochemical regulation of charging followed by discharging in the first capacity grading stage. Then, in the second capacity grading stage, the semi-finished energy storage battery is charged to the upper voltage limit with a stepped first preset current, thereby avoiding interface damage caused by a single large current surge. Then, in the third capacity grading stage, the semi-finished energy storage battery is discharged to the lower voltage limit with a second preset current, thereby balancing the compatibility between the SEI film and the discharge process of the semi-finished energy storage battery. Finally, in the fourth capacity grading stage, the semi-finished energy storage battery is charged to a second preset value higher than the delivery voltage with a third preset current, and then discharged to the delivery voltage with a fourth preset current. This solves the problem of incomplete release of residual battery capacity and ensures the stability of storage voltage difference. Therefore, the energy storage battery preparation method of this embodiment can improve the capacity grading effect of semi-finished energy storage batteries.

[0106] This embodiment also provides an energy storage battery, which is prepared from a semi-finished energy storage battery by any of the methods described above, and is used to form one or more of battery modules and battery packs.

[0107] This embodiment also provides a battery device, which includes the energy storage battery as described above. The battery device includes one or more of a battery module and a battery pack. The battery device can be used, but is not limited to, in electrical devices or energy storage devices such as vehicles, ships, or aircraft. The power system of the electrical device or energy storage device can be composed of battery cells, energy storage batteries, etc. disclosed in this embodiment.

[0108] This embodiment also provides an electrical device, which includes the battery device described above, used to provide electrical energy. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, and spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0109] This embodiment also provides an energy storage device that uses a battery device as a power source to store electrical energy; the energy storage device can be, but is not limited to, an energy storage container, an energy storage cabinet, an energy storage power station, an energy storage battery pack, or a portable energy storage system.

[0110] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0111] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing an energy storage battery, characterized in that, This method is applied to the capacity assessment stage of semi-finished energy storage batteries. The capacity assessment stage includes four sub-stages—a first capacity assessment sub-stage, a second capacity assessment sub-stage, a third capacity assessment sub-stage, and a fourth capacity assessment sub-stage—that are distinct from each other and executed sequentially. The sub-stages include: In the first capacity-dividing stage, the semi-finished energy storage battery is charged to a first set value higher than the delivery voltage with a first preset current, and then the semi-finished energy storage battery is discharged to the delivery voltage with a second preset current, wherein the first preset current and the second preset current are currents of different magnitudes; In the second capacity-dividing stage, the semi-finished energy storage battery is charged to the upper voltage limit with a first preset step current, wherein the first preset step current includes a plurality of fifth preset currents arranged in descending order of size; In the third capacity-dividing stage, the semi-finished energy storage battery is discharged to the lower voltage limit using a second preset step current; In the fourth capacity-classifying stage, the semi-finished energy storage battery is charged to a second set value higher than the delivery voltage using a third preset current, and then discharged to the delivery voltage using a fourth preset current. The first preset current and the third preset current are the same, the second preset current and the fourth preset current are the same, and the second preset step current includes a sixth preset current and a seventh preset current. Discharging the semi-finished energy storage battery to the lower voltage limit using the second preset step current includes: Perform the first discharge step: discharge the semi-finished energy storage battery to the preset step discharge voltage using the sixth preset current; After the first discharge step is completed, the second discharge step is executed: the semi-finished energy storage battery is discharged to the lower voltage limit using the seventh preset current; wherein... The preset stepped discharge voltage is greater than the lower voltage limit, the sixth preset current is greater than the preset current threshold, and the seventh preset current is less than the preset current threshold.

2. The method for preparing an energy storage battery according to claim 1, characterized in that, The step of charging the semi-finished energy storage battery to the upper voltage limit with a first preset step current includes: Perform the charging step: Charge the semi-finished energy storage battery with a single fifth preset current; The fifth preset current is switched sequentially to charge the semi-finished energy storage battery in descending order of magnitude, and the charging steps are continued until the semi-finished energy storage battery is charged to the upper voltage limit with the smallest fifth preset current; wherein any fifth preset current is greater than the preset current threshold value.

3. The method for preparing an energy storage battery according to claim 2, characterized in that, The plurality of fifth preset currents satisfy the following condition: the first current difference between the first two adjacent fifth preset currents is greater than the second current difference between any two adjacent fifth preset currents.

4. The method for preparing an energy storage battery according to claim 3, characterized in that, The plurality of fifth preset currents are sequentially as follows: , , and ; satisfy: ,in, This refers to the charging rate. The total number of the plurality of fifth preset currents.

5. The method for preparing an energy storage battery according to claim 1, characterized in that, The sixth preset current is The seventh preset current is ; and Each to their own satisfaction: , ,in, This represents the discharge rate.

6. The method for preparing an energy storage battery according to claim 1, characterized in that, The method further includes: After the second capacity assessment stage is completed, the semi-finished energy storage battery is left to stand, and after the semi-finished energy storage battery has been left to stand, the third capacity assessment stage is performed.

7. The method for preparing an energy storage battery according to claim 6, characterized in that, The static storage battery includes: The semi-finished energy storage battery is left to stand for a preset time within a preset temperature range.

8. The method for preparing an energy storage battery according to claim 1, characterized in that, The first preset current is The second preset current is ; and They respectively satisfy: , ,in, This refers to the charging rate. This represents the discharge rate.

9. The method for preparing an energy storage battery according to claim 1, characterized in that, Both the first setting value and the second setting value are The shipping voltage is ; and The following conditions must be met: .

10. The method for preparing an energy storage battery according to claim 1, characterized in that, The upper limit of the voltage is The lower voltage limit is ; and Each to their own satisfaction: , .

11. The method for preparing an energy storage battery according to claim 1, characterized in that, The semi-finished energy storage battery is composed of multiple battery cells connected in series, and the capacity testing stage is the overall capacity testing stage of the multiple battery cells.

12. An energy storage battery, characterized in that, The energy storage battery is prepared from a semi-finished energy storage battery by the method described in any one of claims 1 to 11, and the energy storage battery is used to form one or more of battery modules and battery packs.

13. A battery device, characterized in that, The battery device includes the energy storage battery as described in claim 12, and the battery device includes one or more of a battery module and a battery pack.

14. An electrical appliance, characterized in that, The electrical device includes the battery device as described in claim 13, the battery device being used to provide electrical energy.

15. An energy storage device, characterized in that, The energy storage device includes the battery device as described in claim 13, the battery device being used to store electrical energy.

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