Optimization method of positive electrode lithium supplement battery formation process

Abstract

The invention provides an optimization method for a formation process of a positive pole lithium supplement battery. The method comprises the following steps: placing the positive pole lithium supplement battery after liquid injection in a first given temperature environment for a first duration; performing a formation charging activation process on the positive electrode lithium supplement battery in a second given temperature environment to obtain formation data corresponding to the positive electrode lithium supplement battery; based on the formation data, generating a formation curve which takes the charging capacity as a horizontal axis and takes the ratio of the charging capacity variation to the battery voltage variation as a longitudinal axis; and based on the formation curve, evaluating the gas production performance of the positive electrode lithium supplement battery treated by the formation charging activation process during high-temperature application. The gas production performance of the battery under high-temperature application is evaluated through the characteristics of the formation curve corresponding to the battery, so that the evaluation process of the gas production performance is simpler and more efficient, resources and time are saved, and the process development efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of positive electrode lithium supplementation formation process, and in particular to a method for optimizing positive electrode lithium supplementation battery formation process. Background Art

[0002] Positive electrode lithium replenishment technology improves the energy density and life of lithium-ion batteries by replenishing the irreversible losses of the first charge of lithium-ion batteries. It has been widely used in the power and energy storage fields. However, since the positive electrode lithium replenisher releases oxygen when the active lithium is first released, oxygen will cause the ethylene carbonate in the electrolyte to oxidize and decompose to form carbon dioxide and water, which will trigger a series of side reactions, causing the subsequent lithium-ion battery to produce serious gas under high temperature conditions, affecting its performance.

[0003] Patent CN116666791A proposes a formation method to solve the problem of battery gas production. The traditional method of evaluating high-temperature gas production of positive-electrode lithium-ion batteries is mainly to charge the positive-electrode lithium-ion batteries to 100% SOC and then place them at high temperatures or conduct actual cycle tests to evaluate gas production. This method is time-consuming, seriously affecting the time and cost of battery development and reducing R&D efficiency. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide at least a method for optimizing the formation process of positive lithium-ion battery, by evaluating the gas production behavior of the battery under high-temperature application through the characteristics of the formation curve corresponding to the battery, so as to make the evaluation process of the gas production behavior more concise and efficient, save resources and time, and improve process development efficiency.

[0005] This application mainly includes the following aspects: In a first aspect, an embodiment of the present application provides a method for optimizing the formation process of a positive lithium-ion battery, the method comprising: placing the positive lithium-ion battery after liquid injection for a first period of time in a first given temperature environment; performing a formation charging activation process on the positive lithium-ion battery under a second given temperature environment to obtain formation data corresponding to the positive lithium-ion battery; based on the formation data, generating a formation curve with charging capacity as the horizontal axis and the ratio between the change in charging capacity and the change in battery voltage as the vertical axis; based on the formation curve, estimating the gas production performance of the positive lithium-ion battery after the formation charging activation process in subsequent high-temperature applications.

[0006] In one possible embodiment, the formation charge activation process includes: charging the positive electrode lithium-supplementing battery to a first preset voltage and a cut-off charge rate through a given multi-stage charging strategy to complete the first charge activation of the positive electrode lithium-supplementing battery; placing the positive electrode lithium-supplementing battery after the first charge activation for a second period of time; charging the positive electrode lithium-supplementing battery after the placement to a second preset voltage according to a preselected constant current charging method to complete the second charge activation of the positive electrode lithium-supplementing battery.

[0007] In a possible implementation, the given multi-stage charging strategy comprises: charging the positive electrode lithium supplement battery at a first charging rate for a first charging duration; charging the positive electrode lithium supplement battery at a second charging rate for a second charging duration; and charging the positive electrode lithium supplement battery at a third charging rate for a constant-voltage charging to a first preset voltage and up to a third charging rate.

[0008] In a possible implementation, the first charging rate belongs to a first preset charging rate interval, the second charging rate belongs to a second preset charging rate interval, and the third current belongs to a third preset charging rate interval, wherein a lower limit value of the second preset charging rate interval is greater than an upper limit value of the first preset charging rate interval, and a lower limit value of the third preset charging rate interval is greater than or equal to an upper limit value of the second preset charging rate interval.

[0009] In a possible implementation, the preselected constant-current charging mode comprises: charging the positive electrode lithium supplement battery at a fourth charging rate to a second preset voltage after being shelved, and the fourth charging rate belongs to a third preset charging rate interval; or charging the positive electrode lithium supplement battery to the second preset voltage in a step-by-step manner according to the third preset charging rate interval.

[0010] In a possible implementation, the formation data comprises a corresponding charging capacity and a battery voltage of the positive electrode lithium supplement battery at each unit collection time during the second charging activation process, wherein the formation curve is generated by: determining a corresponding charging capacity change amount and a battery voltage change amount of the positive electrode lithium supplement battery at each unit collection time during the second charging activation process according to the formation data; and generating the formation curve by taking the corresponding charging capacity of the positive electrode lithium supplement battery at each unit collection time during the second charging activation process as the horizontal axis and taking the ratio between the corresponding charging capacity change amount and the battery voltage change amount of the positive electrode lithium supplement battery at each unit collection time during the second charging activation process as the vertical axis.

[0011] In a possible implementation, the gas generation performance of the positive electrode lithium supplement battery after being processed by the formation charging activation process in subsequent high-temperature applications is estimated by: calculating an integral area of a second peak in the formation curve, taking the integral area as a gas generation index of the positive electrode lithium supplement battery; comparing the gas generation index of the positive electrode lithium supplement battery under the formation charging activation process with a standard gas generation index; and according to the comparison result, estimating the gas generation performance of the positive electrode lithium supplement battery after being processed by the formation charging activation process in subsequent high-temperature applications and optimizing the formation charging activation process.

[0012] In a possible implementation, the gas generation index is consistent with the gas generation amount change of the positive electrode lithium supplement battery after the formation charging activation process, and the step of estimating the gas generation performance of the positive electrode lithium supplement battery after the formation charging activation process and optimizing the formation charging activation process according to the comparison result includes: if the gas generation index is lower than the standard gas generation index, it is determined that the positive electrode lithium supplement battery after the current formation charging activation process has good gas generation performance in the subsequent high-temperature application; if the gas generation index is higher than the standard gas generation index, it is determined that the positive electrode lithium supplement battery after the current formation charging activation process has poor gas generation performance in the subsequent high-temperature application, and an optimization prompt for the formation charging activation process is generated.

[0013] In a possible implementation, the method further includes: obtaining a plurality of preset formation charging activation processes and a plurality of positive electrode lithium supplement batteries of a target model, the plurality of preset formation charging activation processes corresponding to the plurality of positive electrode lithium supplement batteries one by one; for each positive electrode lithium supplement battery, determining a gas generation index of the positive electrode lithium supplement battery under the corresponding preset formation charging activation process and any target parameter reflecting the active lithium release performance of the positive electrode lithium supplement battery; building a formation process matrix diagram of the positive electrode lithium supplement battery of the target model under the plurality of formation charging activation processes from the two dimensions of the gas generation index and the target parameter; and selecting an optimal formation charging activation process for the positive electrode lithium supplement battery of the target model based on the formation process matrix diagram.

[0014] In a second aspect, the embodiments of the present application further provide an electronic device, including: a processor, a memory and a bus, the memory stores machine readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, and the machine readable instructions are executed by the processor to perform the steps of the optimization method of the positive electrode lithium supplement battery formation process in the first aspect or any possible implementation of the first aspect.

[0015] The optimization method of the positive electrode lithium supplement battery formation process provided by the embodiments of the present application includes: placing the positive electrode lithium supplement battery after liquid injection in a first given temperature environment for a first time length; performing a formation charging activation process on the positive electrode lithium supplement battery in a second given temperature environment to obtain corresponding formation data of the positive electrode lithium supplement battery; generating a formation curve with the charging capacity as the horizontal axis and the ratio between the charging capacity change and the battery voltage change as the vertical axis based on the formation data; and estimating the gas generation performance of the positive electrode lithium supplement battery after the formation charging activation process in subsequent high-temperature applications according to the formation curve. The gas generation performance of the battery in high-temperature applications is evaluated by the characteristics of the corresponding formation curve of the battery, which makes the evaluation process of the high-temperature application gas generation of the positive electrode lithium supplement battery more concise and efficient, saves resources and time, and improves the process development efficiency.

[0016] In order to make the above objectives, characteristics and advantages of the present application more apparent, more comprehensible, the following preferred embodiments are specifically described in detail below, and the accompanying drawings are referred to. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0018] Figure 1 A flowchart of an optimization method of a positive electrode lithium supplementing battery formation process provided by an embodiment of the present application is shown; Figure 2 A flowchart of a formation charging activation process provided by an embodiment of the present application is shown; Figure 3 A formation curve schematic diagram of a positive electrode lithium supplementing battery under different formation charging activation processes provided by an embodiment of the present application is shown; Figure 4 A gas production index schematic diagram of a positive electrode lithium supplementing battery under different formation charging activation processes provided by an embodiment of the present application is shown; Figure 5 A gas production amount schematic diagram obtained in actual tests of different formation charging activation processes provided by an embodiment of the present application is shown; Figure 6 A formation curve schematic diagram of a positive electrode lithium supplementing battery under different formation charging activation processes provided by an embodiment of the present application is shown; Figure 7 A gas production index schematic diagram of a positive electrode lithium supplementing battery under different formation charging activation processes provided by an embodiment of the present application is shown; Figure 8 A gas production amount schematic diagram obtained in actual tests of different formation charging activation processes provided by an embodiment of the present application is shown; Figure 9 A formation curve schematic diagram of a positive electrode lithium supplementing battery under different formation charging activation processes provided by an embodiment of the present application is shown; Figure 10 A gas production index schematic diagram of a positive electrode lithium supplementing battery under different formation charging activation processes provided by an embodiment of the present application is shown; Figure 11 A gas production amount schematic diagram obtained in actual tests of different formation charging activation processes provided by an embodiment of the present application is shown; Figure 12 A formation process matrix diagram provided by an embodiment of the present application is shown; Figure 13 A structural schematic diagram of an electronic device provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and superiorities of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application merely serve the purpose of illustrating and describing and are not intended to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present application show the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowcharts can not be implemented in sequence, and the steps without logical context relationship can be reversed in sequence or implemented simultaneously. In addition, one or more other operations can be added to the flowcharts or one or more operations can be removed from the flowcharts under the guidance of the content of the present application.

[0020] In addition, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0021] Lithium ion batteries have high energy density and long cycle life, and are widely used in new energy vehicles, home energy storage, backup power, industrial and commercial energy storage, and large-scale energy storage fields. With the increasing demand for energy, the energy density and life of power batteries for new energy vehicles and energy storage batteries gradually fail to meet people's daily needs. It is urgent to improve the energy density and cycle life of lithium ion batteries.

[0022] Positive electrode lithium supplement technology supplements the irreversible loss of lithium ion batteries during the first charge, thereby achieving the effect of improving the energy density and life of lithium ion batteries. It has been widely used in the fields of power and energy storage. However, when the positive electrode lithium supplement agent releases oxygen during the first active lithium extraction, the oxygen will cause the oxidative decomposition of ethylene carbonate in the electrolyte to form carbon dioxide and water, and then trigger a series of side reactions, resulting in serious gas production of the subsequent lithium ion battery under high temperature conditions, affecting performance.

[0023] The high-temperature gas production of the positive electrode lithium supplement battery formation process is very important. The patent CN116666791A proposes a formation method for solving battery gas production. The traditional method for evaluating the high-temperature gas production of the positive electrode lithium supplement battery is mainly to charge the positive electrode lithium supplement battery to 100% SOC (State of Charge) and then store it at high temperature or actually cycle test to evaluate the gas production performance after the formation process. This method is time-consuming and seriously affects the time and cost of battery development, further delays the optimization progress of the positive electrode lithium supplement battery formation process, and reduces the research and development efficiency of the positive electrode lithium supplement battery formation process.

[0024] Therefore, the embodiment of the present application provides a positive electrode lithium supplement battery formation process optimization method. The gas production behavior of the battery under high temperature application is evaluated by the characteristics of the corresponding formation curve of the battery, which makes the evaluation process of the gas production behavior more concise and efficient, saves resources and time, and improves the process development efficiency. Specifically as follows: Please refer to Figure 1 , Figure 1 The flowchart of the positive electrode lithium supplement battery formation process optimization method provided by the embodiment of the present application is shown. As Figure 1 shown, the method provided by the embodiment of the present application includes the following steps: S100, the positive electrode lithium supplement battery after liquid injection is stored at a first given temperature environment for a first time length.

[0025] S200, the positive electrode lithium supplement battery is subjected to a formation charging activation process in a second given temperature environment, and the corresponding formation data of the positive electrode lithium supplement battery is obtained.

[0026] S300, based on the formation data, a formation curve is generated with the charging rate as the horizontal axis and the ratio between the charging rate change and the battery voltage change as the vertical axis.

[0027] S400, according to the formation curve, the gas production performance of the positive electrode lithium supplement battery after the formation charging activation process is estimated in subsequent high temperature application.

[0028] In the method provided in steps S100-S400, the positive electrode lithium supplement battery does not need to be stored at high temperature or actually cycled to test the gas production. Instead, the gas production performance of the positive electrode lithium supplement battery under high temperature application is determined by the characteristics of the formation curve. Compared with the traditional test and determination process of the gas production behavior, it is more concise and efficient, can quickly form a conclusion and be applied to production and manufacturing, saves resources and time, and improves the process development efficiency.

[0029] In step S100, before the positive lithium-ion battery is subjected to the formation charging activation process, the positive lithium-ion battery after injection needs to be placed in a first given temperature environment for a first period of time to ensure that the electrolyte is fully infiltrated into the positive electrode sheet, negative electrode sheet, and diaphragm of the battery. In a specific example, the first given temperature environment is 40°C~50°C, and the first period of time belongs to a time range of 24h~48h.

[0030] In step S200, the positive lithium battery is clamped by a fixture and placed in a second given temperature environment to perform a predetermined formation charging and activation process to obtain corresponding formation data. Preferably, the second given temperature environment is 40°C to 50°C.

[0031] In step S300, refer to Figure 2 , Figure 2 The flowchart of a formation charge activation process provided by the embodiment of the present application is shown. Figure 2 As shown, the formation charge activation process includes: S3001. By providing a multi-stage charging strategy, the positive electrode lithium battery is charged to a first preset voltage and a cut-off charging rate to complete the first charging activation of the positive electrode lithium battery.

[0032] S3002: The positive lithium battery activated after the first charge is placed for a second period of time.

[0033] S3003: charging the positive electrode replenishing lithium battery after being put on hold to a second preset voltage according to a preselected constant current charging method, so as to complete the second charging activation of the positive electrode replenishing lithium battery.

[0034] In a preferred embodiment, in step S3001, the first preset voltage is 3.65V, and the end charging rate is 0.05C, where C is the abbreviation of Capacity, which represents the rated capacity of the positive lithium battery. Furthermore, the given multi-stage charging strategy specifically includes: a.1. The positive electrode lithium battery is charged at a first charging rate and a first charging time.

[0035] Preferably, the first charging rate belongs to a first preset charging rate range, the first preset charging rate range is 0.02C~0.05C, the first charging rate is any charging rate in the first preset charging rate range of 0.02C~0.05C, and the first charging time belongs to a time range of 100min~150min.

[0036] a.2 The positive electrode lithium battery is charged with a constant current at a second charging rate for a second charging time.

[0037] The second charging rate belongs to a second preset charging rate interval, the second preset charging rate interval is 0.1C-0.2C, the second charging rate is any charging rate in the second preset charging rate interval 0.1C-0.2C, and the second charging time length belongs to a time range of 100 minutes to 150 minutes.

[0038] a.3 charging the positive electrode lithium supplement battery at a third charging rate to a first preset voltage and cutting off the charging rate.

[0039] In the present application, the lower limit value of the second preset charging rate interval is greater than the upper limit value of the first preset charging rate interval, and the lower limit value of the third preset charging rate interval is greater than or equal to the upper limit value of the second preset charging rate interval.

[0040] Preferably, the third charging rate belongs to a third preset charging rate interval, the third preset charging rate interval is 0.2C-0.5C, and the third charging rate is any charging rate in the third preset charging rate interval 0.2C-0.5C.

[0041] Returning to step S3002, the second time length belongs to a time range of 30 minutes to 60 minutes.

[0042] In step S3003, the second preset voltage is any voltage value in 3.9V-4.2V.

[0043] In a preferred embodiment, the preselected constant current charging mode in step S3003 includes: The shelved positive electrode lithium supplement battery is charged to the second preset voltage at a fourth charging rate, the fourth charging rate belongs to the third preset charging rate interval, or the shelved positive electrode lithium supplement battery is charged to the second preset voltage in a step-by-step manner according to the third preset charging rate interval.

[0044] Specifically, the fourth charging rate is any charging rate in the third preset charging rate interval 0.2C-0.5C, and in step S3003 provided by the present application, the positive electrode lithium supplement battery can be directly charged to the second preset voltage at the fourth charging rate, or the positive electrode lithium supplement battery can be charged to the second preset voltage in a step-by-step manner, and either of the two modes can be selected.

[0045] In a preferred embodiment, the formation data includes the charging capacity and the battery voltage of the positive electrode lithium supplement battery at each unit collection time in the second charging activation process. The charging capacity refers to the total amount of electric charge transferred from the external power source to the battery during the battery charging process.

[0046] Returning to Figure 1 , step S300 includes: According to the formation data, the corresponding charge capacity change dQ and the battery voltage change dV of the positive electrode lithium supplement battery at each unit collection time during the second charging activation process are determined, the corresponding charge capacity Q of the positive electrode lithium supplement battery at each unit collection time during the second charging activation process is taken as the horizontal axis, and the ratio dQ / dV between the corresponding charge capacity change dQ and the battery voltage change dV of the positive electrode lithium supplement battery at each unit collection time during the second charging activation process is taken as the vertical axis, to generate a formation curve.

[0047] In a preferred embodiment, step S400 comprises: The integral area of the second peak in the formation curve is calculated, and the integral area is taken as the gas generation index of the positive electrode lithium supplement battery. The gas generation index can reflect the gas generation performance of the positive electrode lithium supplement battery after the corresponding formation charging activation process.

[0048] Through pre-experiments, it is determined that the gas generation index is consistent with the gas generation performance of the positive electrode lithium supplement battery under high temperature storage, that is, the gas generation behavior of the positive electrode lithium supplement battery after the specific formation charging activation process can be reflected by the gas generation index.

[0049] In a specific embodiment, for steps S100-S400 provided in the present application, an embodiment one is provided, comprising: Ten positive electrode lithium supplement batteries BAT1-BAT10 of the same model after liquid injection are taken, and are placed at 45°C (a first given temperature environment) for 24h (a first time length).

[0050] BAT1-BAT10 are divided into five battery groups (BAT1, BAT2), (BAT3, BAT4), (BAT5, BAT6), (BAT7, BAT8), and (BAT9, BAT10) in pairs.

[0051] Five formation charging activation processes are provided, and the five battery groups are one-to-one correspondingly associated to the five formation charging activation processes ①-⑤, and the formation data of each positive electrode lithium supplement battery under the corresponding formation charging activation process is obtained by respectively performing the corresponding formation charging activation process on each battery group at 45°C (a second given temperature environment).

[0052] Among them, the formation charging activation processes ①-⑤ are specifically: The formation charging activation process ① comprises: The positive electrode lithium supplement batteries BAT1 and BAT2 are charged at a first charging rate of 0.05C for 120min; The positive electrode lithium supplement batteries BAT1 and BAT2 are charged at a second charging rate of 0.2C for 120min; The positive electrode lithium supplement battery BAT1 and BAT2 are charged at a third charging rate of 0.5C to a first preset voltage of 3.65V and cut off at a charging rate of 0.05C in a constant current and constant voltage mode; The positive electrode lithium supplement battery BAT1 and BAT2 are left for 30 minutes (second time length); The positive electrode lithium supplement battery BAT1 and BAT2 are charged at a fourth charging rate of 0.025C to 3.95V in a constant current mode.

[0053] The formation charge activation process ② includes: The positive electrode lithium supplement battery BAT3 and BAT4 are charged at a first charging rate of 0.05C in a constant current mode for 120 minutes; The positive electrode lithium supplement battery BAT3 and BAT4 are charged at a second charging rate of 0.2C in a constant current mode for 120 minutes; The positive electrode lithium supplement battery BAT3 and BAT4 are charged at a third charging rate of 0.5C to a first preset voltage of 3.65V and cut off at a charging rate of 0.05C in a constant current and constant voltage mode; The positive electrode lithium supplement battery BAT3 and BAT4 are left for 30 minutes (second time length); The positive electrode lithium supplement battery BAT3 and BAT4 are charged at a fourth charging rate of 0.05C to 3.95V in a constant current mode.

[0054] The formation charge activation process ③: The positive electrode lithium supplement battery BAT5 and BAT6 are charged at a first charging rate of 0.05C in a constant current mode for 120 minutes; The positive electrode lithium supplement battery BAT5 and BAT6 are charged at a second charging rate of 0.2C in a constant current mode for 120 minutes; The positive electrode lithium supplement battery BAT5 and BAT6 are charged at a third charging rate of 0.5C to a first preset voltage of 3.65V and cut off at a charging rate of 0.05C in a constant current and constant voltage mode; The positive electrode lithium supplement battery BAT5 and BAT6 are left for 30 minutes (second time length); The positive electrode lithium supplement battery BAT5 and BAT6 are charged at a fourth charging rate of 0.1C to 3.95V in a constant current mode.

[0055] The formation charge activation process ④: The positive electrode lithium supplement battery BAT7 and BAT8 are charged at a first charging rate of 0.05C in a constant current mode for 120 minutes; The positive electrode lithium supplement battery BAT7 and BAT8 are charged at a second charging rate of 0.2C in a constant current mode for 120 minutes; The positive electrode lithium supplement battery BAT7 and BAT8 are charged at a third charging rate of 0.5C to a first preset voltage of 3.65V and cut off at a charging rate of 0.05C in a constant current and constant voltage mode; The positive electrode lithium supplement battery BAT7 and BAT8 are left for 30 min (the second time length); The positive electrode lithium supplement battery BAT7 and BAT8 are charged at a fourth charge rate 0.2C to 3.95V.

[0056] Formation charge activation process ⑤: The positive electrode lithium supplement battery BAT9 and BAT10 are charged at a first charge rate 0.05C for 120 min; The positive electrode lithium supplement battery BAT9 and BAT10 are charged at a second charge rate 0.2C for 120 min; The positive electrode lithium supplement battery BAT9 and BAT10 are charged at a third charge rate 0.5C to a first preset voltage 3.65V and the charge rate is 0.05C; The positive electrode lithium supplement battery BAT9 and BAT10 are left for 30 min (the second time length); The positive electrode lithium supplement battery BAT9 and BAT10 are charged at a fourth charge rate 0.3C to 3.95V.

[0057] The formation curves of the positive electrode lithium supplement battery BAT1-BAT10 under the corresponding formation charge activation processes are plotted with the charge capacity Q as the horizontal axis and the ratio dQ / dV between the charge capacity change dQ and the battery voltage change dV as the vertical axis. For details, please refer to Figure 3 , Figure 3 The formation curve schematic diagram of the positive electrode lithium supplement battery under different formation charge activation processes is shown.

[0058] As shown in Figure 3 , the formation curve of the positive electrode lithium supplement battery BAT1 or BAT2 under the formation charge activation process ①, the formation curve of the positive electrode lithium supplement battery BAT3 or BAT4 under the formation charge activation process ②, the formation curve of the positive electrode lithium supplement battery BAT5 or BAT6 under the formation charge activation process ③, the formation curve of the positive electrode lithium supplement battery BAT7 or BAT8 under the formation charge activation process ④, and the formation curve of the positive electrode lithium supplement battery BAT9 or BAT10 under the formation charge activation process ⑤ are respectively given.

[0059] Further, for each of the positive electrode lithium supplement battery BAT1-BAT10, the integral area of the second peak in the formation curve obtained under the corresponding formation charge activation process is calculated. For details, please refer to Figure 4 , Figure 4 The gas production index schematic diagram of the positive electrode lithium supplement battery under different formation charge activation processes is shown.

[0060] As shown in Figure 4As shown, the positive electrode lithium supplement battery BAT1 has a gas production index of 0.58 under the formation charge activation process 1, the positive electrode lithium supplement battery BAT2 has a gas production index of 0.56 under the formation charge activation process 1, the positive electrode lithium supplement battery BAT3 has a gas production index of 0.44 under the formation charge activation process 2, the positive electrode lithium supplement battery BAT4 has a gas production index of 0.46 under the formation charge activation process 2, the positive electrode lithium supplement battery BAT5 has a gas production index of 0.35 under the formation charge activation process 3, the positive electrode lithium supplement battery BAT6 has a gas production index of 0.34 under the formation charge activation process 3, the positive electrode lithium supplement battery BAT7 has a gas production index of 0.20 under the formation charge activation process 4, the positive electrode lithium supplement battery BAT8 has a gas production index of 0.19 under the formation charge activation process 4, the positive electrode lithium supplement battery BAT9 has a gas production index of 0.13 under the formation charge activation process 5, and the positive electrode lithium supplement battery BAT10 has a gas production index of 0.15 under the formation charge activation process 5.

[0061] In addition, please refer to Figure 5 , Figure 5 The figure shows the gas production of different formation charge activation processes provided by the embodiment one of the present application in actual tests. As shown in the figure, Figure 5 , the present application obtains the corresponding gas production of each positive electrode lithium supplement battery BAT1-BAT10 under high-temperature storage at 70°C and 100% SOC for 21 days, specifically, the corresponding gas production of the positive electrode lithium supplement batteries BAT1-BAT10 is 14.1ml, 14.2ml, 11.7ml, 11.4ml, 9.7ml, 9.7ml, 8.2ml, 7.5ml, 7.1ml, and 7.8ml, respectively, which shows that the gas production index is consistent with the gas production performance of the positive electrode lithium supplement battery under high-temperature storage, further proving that the scheme provided by the present application can accurately predict the battery gas production behavior under different formation charge activation processes. Figure 4 and Figure 5

[0062] In a specific embodiment, for the steps S100-S400 provided by the present application, an embodiment two is provided, including: Take six positive electrode lithium supplement batteries BAT1A-BAT6A of the same model after liquid injection, and place them at 45°C (a first given temperature environment) for 24h (a first time length).

[0063] ​BAT1A~BAT6A are divided into three groups (BAT1A, BAT2A), (BAT3A, BAT4A), (BAT5A, BAT6A) in twos, three different formation charging activation processes ⑥~⑧ are provided, the three groups of batteries are one-to-one corresponding associated to the three formation charging activation processes ⑥~⑧, and the formation charging activation process of each group is executed at 45°C (the second given temperature environment) respectively, to obtain the formation data of each positive electrode lithium supplement battery under the corresponding formation charging activation process.

[0064] The formation charging activation process ⑥~⑧ is specifically: The formation charging activation process ⑥ includes: The positive electrode lithium supplement batteries BAT1A and BAT2A are charged at a first charging rate of 0.05C for 120 minutes; The positive electrode lithium supplement batteries BAT1A and BAT2A are charged at a second charging rate of 0.2C for 120 minutes; The positive electrode lithium supplement batteries BAT1A and BAT2A are charged at a third charging rate of 0.5C to a first preset voltage of 3.65V and cut off at a charging rate of 0.05C; The positive electrode lithium supplement batteries BAT1A and BAT2A are left for 30 minutes (the second time length); The positive electrode lithium supplement batteries BAT1A and BAT2A are charged at a fourth charging rate of 0.1C to 3.95V.

[0065] The formation charging activation process ⑦ includes: The positive electrode lithium supplement batteries BAT3A and BAT4A are charged at a first charging rate of 0.05C for 120 minutes; The positive electrode lithium supplement batteries BAT3A and BAT4A are charged at a second charging rate of 0.2C for 120 minutes; The positive electrode lithium supplement batteries BAT3A and BAT4A are charged at a third charging rate of 0.5C to a first preset voltage of 3.65V and cut off at a charging rate of 0.05C; The positive electrode lithium supplement batteries BAT3A and BAT4A are left for 30 minutes (the second time length); The positive electrode lithium supplement batteries BAT3A and BAT4A are charged at a fourth charging rate of 0.1C to 4.05V.

[0066] The formation charging activation process ⑧: The positive electrode lithium supplement batteries BAT5A and BAT6A are charged at a first charging rate of 0.05C for 120 minutes; The positive electrode lithium supplement batteries BAT5A and BAT6A are charged at a second charging rate of 0.2C for 120 minutes; The anode lithium supplement battery BAT5A and BAT6A are charged at a third charging rate 0.5C to a first preset voltage 3.65V and cut off at a charging rate 0.05C in a constant current and constant voltage mode; The anode lithium supplement battery BAT5A and BAT6A are left for 30 minutes (a second time length); The anode lithium supplement battery BAT5A and BAT6A are charged at a fourth charging rate 0.1C to 4.2V in a constant current mode.

[0067] The formation curves of the anode lithium supplement battery BAT1A-BAT6A under the corresponding formation charge activation processes are plotted with the charging capacity Q as the horizontal axis and the ratio dQ / dV between the charging capacity change dQ and the battery voltage change dV as the vertical axis. For details, please refer to Figure 6 , Figure 6 The formation curve schematic diagrams of the anode lithium supplement battery provided in Embodiment Two of the present application under different formation charge activation processes are shown.

[0068] As shown in Figure 3 , the formation curves of the anode lithium supplement battery BAT1A or BAT2A under the formation charge activation process ⑥, the formation curves of the anode lithium supplement battery BAT3A or BAT4A under the formation charge activation process ⑦, and the formation curves of the anode lithium supplement battery BAT5A or BAT6A under the formation charge activation process ⑧ are respectively given.

[0069] Further, for each of the anode lithium supplement battery BAT1A-BAT6A, the integral area of the second peak in the formation curve obtained under the corresponding formation charge activation process is calculated respectively. As shown in Figure 7 , Figure 7 The gas production index schematic diagrams of the anode lithium supplement battery provided in Embodiment Two of the present application under different formation charge activation processes are shown.

[0070] As shown in Figure 7 , the gas production indexes of the anode lithium supplement battery BAT1A and BAT2A under the formation charge activation process ⑥ are 0.35 and 0.34 respectively, the gas production indexes of the anode lithium supplement battery BAT3A and BAT4A under the formation charge activation process ⑦ are 0.43 and 0.41 respectively, and the gas production indexes of the anode lithium supplement battery BAT5A and BAT6A under the formation charge activation process ⑧ are 0.44 and 0.42 respectively.

[0071] In addition, please refer to Figure 8 , Figure 8 The gas production amount schematic diagrams of different formation charge activation processes obtained in actual tests provided in Embodiment Two of the present application are shown. As shown in Figure 8As shown, the present application is directed to the positive electrode lithium supplement battery BAT1A~BAT6A treated by the above corresponding formation charging activation process, under 70℃, 100% SOC, high temperature storage for 21 days, to obtain the corresponding gas production of each positive electrode lithium supplement battery, specifically, the corresponding gas production of the positive electrode lithium supplement battery BAT1A~BAT6A is 9.7ml, 9.7ml, 10.5ml, 10.6ml, 11.1ml, 11.8ml respectively, and similarly, the gas production index is consistent with the gas production performance of the positive electrode lithium supplement battery under high temperature storage, which further illustrates that the scheme provided by the present application can accurately predict the battery gas production behavior under different formation charging activation processes. Figure 7 and Figure 8 It can be seen that the gas production index is consistent with the gas production performance of the positive electrode lithium supplement battery under high temperature storage, which further illustrates that the scheme provided by the present application can accurately predict the battery gas production behavior under different formation charging activation processes.

[0072] In a specific embodiment, for the steps S100~S400 provided by the present application, an embodiment three is provided, including: Take 4 positive electrode lithium supplement batteries BAT7A~BAT10A of the same model after liquid injection, and place them at 45℃ (a first given temperature environment) for 24h (a first time length).

[0073] BAT7A~BAT10A are divided into two groups (BAT7A, BAT8A) and (BAT9A, BAT10A), 2 different formation charging activation processes ⑥~⑧ are provided, and the two groups of batteries are one-to-one correspondingly associated to the 3 formation charging activation processes ⑨~⑩, and each group of batteries is executed under 45℃ (a second given temperature environment) respectively. The formation data of each positive electrode lithium supplement battery under the corresponding formation charging activation process is obtained.

[0074] Among them, the formation charging activation processes ⑨~⑩ are specifically: The formation charging activation process ⑨ includes: Constant current charging the positive electrode lithium supplement batteries BAT7A and BAT8A at a first charging rate of 0.05C for 120min; Constant current charging the positive electrode lithium supplement batteries BAT7A and BAT8A at a second charging rate of 0.2C for 120min; Constant current and constant voltage charging the positive electrode lithium supplement batteries BAT7A and BAT8A at a third charging rate of 0.5C to a first preset voltage of 3.65V and a cut-off charging rate of 0.05C; The positive electrode lithium supplement batteries BAT7A and BAT8A are placed for 30min (a second time length); Constant current charging the positive electrode lithium supplement batteries BAT7A and BAT8A at a fourth charging rate of 0.05C to 3.95V.

[0075] The formation charging activation process ⑩ includes: Charge the anode lithium supplement battery BAT9A and BAT10A at a first charging rate of 0.05C for 120 min; Charge the anode lithium supplement battery BAT9A and BAT10A at a second charging rate of 0.2C for 120 min; Charge the anode lithium supplement battery BAT9A and BAT10A at a third charging rate of 0.5C for 120 min until a first preset voltage of 3.65V is reached and the charging rate is 0.05C; Place the anode lithium supplement battery BAT9A and BAT10A for 30 min (second time length); Charge the anode lithium supplement battery BAT9A and BAT10A at a fourth charging rate of 0.3C until 3.95V is reached.

[0076] Draw the formation curves of the anode lithium supplement battery BAT7A-BAT10A under the corresponding formation charge activation processes with the charging capacity Q as the horizontal axis and the ratio dQ / dV between the charging capacity change dQ and the battery voltage change dV as the vertical axis. For details, please refer to Figure 9 , Figure 9 The figure shows the formation curve of the anode lithium supplement battery under different formation charge activation processes.

[0077] As shown in Figure 9 , it respectively shows the formation curve of the anode lithium supplement battery BAT7A or BAT8A under the formation charge activation process 9 and the formation curve of the anode lithium supplement battery BAT9A or BAT10A under the formation charge activation process 10.

[0078] Further, for each of the anode lithium supplement batteries BAT7A-BAT10A, the integral area of the second peak in the formation curve obtained under the corresponding formation charge activation process is calculated respectively. As shown in Figure 10 , Figure 10 The figure shows the gas production index of the anode lithium supplement battery under different formation charge activation processes.

[0079] As shown in Figure 10 , the gas production indexes of the anode lithium supplement batteries BAT7A and BAT8A under the formation charge activation process 9 are 0.44 and 0.46 respectively, and the gas production indexes of the anode lithium supplement batteries BAT9A and BAT10A under the formation charge activation process 10 are 0.33 and 0.35 respectively.

[0080] In addition, please refer to Figure 11 , Figure 11 The figure shows the gas production amount of different formation charge activation processes obtained in actual tests. As shown in Figure 11As shown, the present application is directed to the positive electrode lithium supplement battery BAT7A~BAT10A treated by the above corresponding formation charging activation process, at 70℃, 100% SOC, high temperature storage for 21 days, to obtain the corresponding gas production of each positive electrode lithium supplement battery. Specifically, the corresponding gas production of the positive electrode lithium supplement battery BAT7A~BAT10A is 11.7ml, 11.4ml, 10.3ml, and 10.4ml, respectively. Similarly, it can be seen that the gas production index is consistent with the gas production performance of the positive electrode lithium supplement battery under high temperature storage, further indicating that the scheme provided by the present application can accurately predict the battery gas production behavior under different formation charging activation processes. Figure 10 and Figure 11 It can be seen that the gas production index is consistent with the gas production performance of the positive electrode lithium supplement battery under high temperature storage, further indicating that the scheme provided by the present application can accurately predict the battery gas production behavior under different formation charging activation processes.

[0081] Step S400 further includes: Comparing the gas production index of the positive electrode lithium supplement battery under the formation charging activation process with the standard gas production index, according to the comparison result, evaluating the gas production performance of the positive electrode lithium supplement battery under the formation charging activation process and optimizing the formation charging activation process.

[0082] Further, for example, a standard gas production index can be pre-set according to actual conditions, and the standard gas production index is used as a dividing line for evaluating the pros and cons of the gas production behavior of the positive electrode lithium supplement battery under the formation charging activation process. By comparing the gas production index calculated under the formation charging activation process with the standard gas production index, the pros and cons of the gas production of the positive electrode lithium supplement battery treated by the formation charging activation process in subsequent high temperature application can be estimated, to provide a basis for adjusting the formation charging activation process.

[0083] In a specific embodiment, step S400 further includes: If the gas production index is lower than the standard gas production index, it is determined that the positive electrode lithium supplement battery treated by the current formation charging activation process has good gas production performance in subsequent high temperature application, and if the gas production index is higher than the standard gas production index, it is determined that the positive electrode lithium supplement battery treated by the current formation charging activation process has poor gas production performance in subsequent high temperature application, and an optimization prompt for the formation charging activation process is generated.

[0084] In a preferred embodiment, the method provided by the present application further includes: A plurality of preset formation charge activation processes and a plurality of positive electrode lithium supplement batteries of a target model are obtained, the plurality of preset formation charge activation processes correspond to the plurality of positive electrode lithium supplement batteries one by one, for each positive electrode lithium supplement battery, a gas generation index of the positive electrode lithium supplement battery under the corresponding preset formation charge activation process and any target parameter reflecting the active lithium release performance of the positive electrode lithium supplement battery are determined, a formation process matrix diagram of the positive electrode lithium supplement battery of the target model under the plurality of formation charge activation processes is built from the two dimensions of the gas generation index and the target parameter, and the optimal formation charge activation process for the positive electrode lithium supplement battery of the target model is screened out based on the formation process matrix diagram.

[0085] In a specific embodiment, the target parameter is the total charge capacity or the lithium supplement agent gram capacity exertion of the positive electrode lithium supplement battery in the formation charge activation process. In daily product manufacturing and process development, the active lithium release performance of the positive electrode lithium supplement battery and the gas generation inhibition of the battery under high temperature application need to be considered. Therefore, the method provided in the application can determine the gas generation performance and the target parameter of the positive electrode lithium supplement battery after being treated by different formation charge activation processes for the same model positive electrode lithium supplement battery under the corresponding plurality of preset formation charge activation processes, establish a corresponding formation process matrix diagram, and quickly screen out the optimal formation charge activation process for the positive electrode lithium supplement battery of the target model based on the formation process matrix diagram, thereby saving time and avoiding resource waste.

[0086] Specifically, the formation charge activation process with the maximum target parameter and the lowest gas generation index is selected from the formation process matrix diagram as the optimal formation charge activation process for the positive electrode lithium supplement battery of the target model.

[0087] Please refer to Figure 12 , Figure 12 A formation process matrix diagram provided by an embodiment of the application is shown. As shown in Figure 12 , the formation process matrix diagram horizontally represents the gas generation index and vertically represents the target parameter. Each point on the formation process matrix diagram corresponds to the target parameter and the gas generation index of the positive electrode lithium supplement battery of a target model under a certain formation charge activation process. Figure 12 As shown in the formation process matrix diagram, the position close to the upper left corner means that the active lithium release of the positive electrode lithium supplement battery can effectively reduce the gas generation behavior of the lithium supplement battery under high temperature, and the position close to the lower right corner is the opposite.

[0088] Based on the same application concept, please refer to Figure 13 , Figure 13 A structure schematic diagram of an electronic device provided by an embodiment of the application is shown. As shown in Figure 13As shown, the electronic device 500 comprises a processor 510, a memory 520 and a bus 530, the memory 520 stores machine readable instructions executable by the processor 510, when the electronic device 500 is running, the processor 510 and the memory 520 communicate through the bus 530, and the machine readable instructions are executed by the processor 510 to perform the steps of the optimization method of the positive electrode lithium supplement battery formation process provided in any of the above embodiments.

[0089] Based on the same application concept, the embodiment of the present application further provides a computer readable storage medium, the computer readable storage medium stores a computer program, and the computer program is executed by a processor to perform the steps of the optimization method of the positive electrode lithium supplement battery formation process provided in the above embodiments.

[0090] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described system and device can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here. In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. The above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some communication interface, device or unit, which can be electrical, mechanical or other forms.

[0091] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on a plurality of network units. According to actual needs, some or all of the units can be selected to achieve the purpose of the embodiment scheme.

[0092] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0093] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a nonvolatile computer readable storage medium executable by a processor. Based on this understanding, the technical solutions of the present application or the parts of the present application that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of software products. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0094] The above merely describes the specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for optimizing the formation process of a positive lithium-ion battery, characterized in that: The method comprises: placing the positive lithium-ion battery after injection at a first given temperature for a first period of time; Performing a formation charging activation process on the positive electrode lithium battery under a second given temperature environment to obtain formation data corresponding to the positive electrode lithium battery; Based on the formation data, generating a formation curve with the charge capacity as the horizontal axis and the ratio between the charge capacity change and the battery voltage change as the vertical axis; According to the formation curve, the gas production performance of the positive lithium battery after the formation charge activation process in subsequent high-temperature applications is estimated.

2. The method according to claim 1, characterized in that The formation charge activation process comprises: By giving a multi-stage charging strategy, charging the positive electrode lithium battery to a first preset voltage and a cut-off charging rate, so as to complete the first charging activation of the positive electrode lithium battery; The positive lithium battery after the first charge activation is set aside for a second period of time; The positive electrode lithium-ion battery that has been put aside is charged to a second preset voltage according to a preselected constant current charging method to complete the second charging activation of the positive electrode lithium-ion battery.

3. The method according to claim 2, characterized in that The given multi-stage charging strategy includes: charging the positive lithium battery at a first charging rate and at a constant current for a first charging time; Constant current charging of the positive electrode lithium battery for a second charging period at a second charging rate; The positive electrode lithium battery is charged at a third charging rate with a constant current and constant voltage to a first preset voltage and a cut-off charging rate.

4. The method according to claim 3, characterized in that The first charging rate belongs to a first preset charging rate range, the second charging rate belongs to a second preset charging rate range, and the third current belongs to a third preset charging rate range. Among them, the lower limit value of the second preset charging rate interval is greater than the upper limit value of the first preset charging rate interval, and the lower limit value of the third preset charging rate interval is greater than or equal to the upper limit value of the second preset charging rate interval.

5. The method according to claim 3, characterized in that The preselected constant current charging mode includes: charging the idle positive lithium battery at a fourth charging rate constant current to a second preset voltage, wherein the fourth charging rate belongs to the third preset charging rate range; Alternatively, the idle positive lithium battery is charged in stages to the second preset voltage according to the third preset charging rate range.

6. The method according to claim 2, characterized in that The formation data includes the charging capacity and battery voltage corresponding to each unit collection time during the second charging activation process of the positive lithium battery. Wherein, the formation curve is generated by the following method: Determine, based on the formation data, the charge capacity change and battery voltage change corresponding to each unit acquisition time during the second charge activation process of the positive lithium battery; The formation curve is generated by taking the charge capacity corresponding to each unit sampling time in the second charging and activation process of the positive electrode lithium-supplemented battery as the horizontal axis and the ratio between the charge capacity change corresponding to each unit sampling time in the second charging and activation process of the positive electrode lithium-supplemented battery as the vertical axis.

7. The method according to claim 1, characterized in that The following methods are used to estimate the gas production performance of the positive lithium battery after the formation charge activation process in subsequent high temperature applications: Calculating the integrated area of ​​the second peak in the formation curve, and using the integrated area as the gas production index of the positive electrode lithium-supplemented battery; Comparing the gas production index of the positive electrode lithium supplemented battery under the formation charge activation process with the standard gas production index; According to the comparison results, the gas production performance of the positive lithium battery treated by the formation charge activation process in subsequent high-temperature applications is estimated and the formation charge activation process is optimized.

8. The method according to claim 7, characterized in that The gas production index is consistent with the change in gas production of the positive lithium battery after the formation charge activation process during subsequent high-temperature applications. The steps of estimating the gas production performance of the positive lithium battery after the formation charge activation process in subsequent high-temperature applications and optimizing the formation charge activation process according to the comparison results include: If the gas production index is lower than the standard gas production index, it is determined that the positive electrode lithium battery after the current formation charge activation process has good gas production performance in subsequent high temperature applications; If the gas production index is higher than the standard gas production index, it is determined that the positive electrode lithium battery treated by the current formation charge activation process has poor gas production performance in subsequent high-temperature applications, and an optimization prompt for the formation charge activation process is generated.

9. The method according to claim 1, characterized in that The method further comprises: Obtain multiple preset formation charging activation processes and multiple positive electrode lithium-ion batteries of target models, where the multiple preset formation charging activation processes correspond one to one to the multiple positive electrode lithium-ion batteries; For each positive lithium-ion battery, determining a gas production index of the positive lithium-ion battery under a corresponding preset formation charge activation process and any target parameter reflecting the active lithium release performance of the positive lithium-ion battery; From the two dimensions of gas production index and target parameters, a formation process matrix diagram of the target model of positive electrode lithium-ion battery under multiple formation, charging and activation processes is constructed; Based on the formation process matrix diagram, the optimized formation and charging activation process for the target model of positive lithium battery is screened out.

10. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor and the memory communicate through the bus. When the processor is running, the machine-readable instructions execute the steps of the method for optimizing the formation process of a positive electrode lithium-supplemented battery as described in any one of claims 1 to 9.

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