All-solid-state lithium ion battery and formation method thereof
By pressing, heating, and gradual adjustment of the charging power of the full -solid lithium -ion battery, the problem of turning the processing period and poor performance of the process is solved, and the effect of shortening into time and improving circulation performance.
Patent Information
- Application Number
- CN202411588086.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-08
- Publication Date
- 2025-01-28
AI Technical Summary
The chemical process of all-solid-state lithium-ion batteries takes a long time, and the cell ratio and cycle performance after chemical production is poor.
A method that includes compression, heating, and gradual adjustment of charging rate. Pubse a constant pressure on the battery, adjust the temperature and perform constant current charging and discharge processing to ensure the strict control of the charging status and temperature.
The duration of the process is shortened, which improves the circulation performance and stability of the battery, and improves the overall performance and safety of the battery.
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of solid-state batteries, and in particular to an all-solid-state battery and a formation method thereof. Background Art
[0002] As lithium-ion battery technology continues to develop, battery safety has attracted people's attention, and all-solid-state lithium-ion batteries have emerged. Due to the advantages of all-solid-state lithium-ion batteries, such as high safety, wide operating temperature range, and high energy density, the development of all-solid-state lithium-ion batteries will become a major direction for the future development of lithium-ion batteries.
[0003] At present, there is still no fixed and standard process flow for the preparation of all-solid-state lithium-ion batteries, especially for the middle and later stages of battery production, where the processes of various manufacturers are different. Among them, special attention should be paid to the formation process in the production process of lithium-ion batteries, which involves the process of activating the battery from the raw material state and converting it into a usable state. It is of vital importance to ensure the initial performance, long-term stability and safety of the battery, and the performance test of the battery in the later stage.
[0004] However, all-solid-state lithium-ion batteries are still in the development stage, and the interface resistance between the solid electrolyte and the positive and negative electrodes is not well studied. At present, there is no suitable formation process for all-solid-state lithium-ion batteries. Most of the existing technologies continue to use liquid battery processes, and no corresponding measures are taken to address the interface problems of solid-state batteries. Most manufacturers use small current step-by-step charging activation or intermittent pulse charging. After the formation is completed, it needs to be aged at high temperature for a long time before capacity division. This process cannot fully play the advantages of all-solid-state lithium-ion batteries. Therefore, it is necessary to develop a formation method for all-solid-state lithium-ion batteries to solve the problems of long formation process and poor performance of the battery cell rate and cycle after formation. Summary of the invention
[0005] The purpose of the present application is to provide a formation method for an all-solid-state lithium-ion battery, which is used to shorten the formation process time and improve the cycle performance of the battery.
[0006] In a first aspect, the present application provides a formation method of an all-solid-state lithium-ion battery, characterized in that it comprises: S1, applying constant pressure to the all-solid-state lithium-ion battery through a fixture; S2, adjusting the temperature of the all-solid-state lithium-ion battery to T1, maintaining the temperature at T1, charging the all-solid-state lithium-ion battery at a constant current rate of C1, charging to 60%~70% SOC, and setting aside; S3, maintaining the temperature at T1, charging the all-solid-state lithium-ion battery at a constant current rate of C2 to 70%~75% SOC, and then setting aside; S4, adjusting the temperature of the all-solid-state lithium-ion battery to T2, maintaining the temperature at T2, charging the all-solid-state lithium-ion battery at a C3 rate with a constant current, charging to 80%~85% SOC, and setting aside; S5, maintaining the temperature at T2, discharging the all-solid-state lithium-ion battery at a constant current rate of C4 until the DOD is 20% to 30%, and then placing the battery aside to complete the formation of the all-solid-state lithium-ion battery; Among them, T1>T2, T1 is 80~90℃, C3>C2>C1, and C4<C3.
[0007] In the embodiment, since the interface impedance between the solid electrolyte and the electrode material is relatively high, in S1, before the all-solid-state lithium-ion battery begins to be formed, a clamp is used to pressurize it, so that the solid-solid interface contact is closer by pressurization.
[0008] Furthermore, in S2, the all-solid-state lithium-ion battery is heated before formation, and the internal impedance of the battery is reduced by heating, and the kinetic energy of the active substances inside the battery is increased, so that the chemical reaction inside the battery is more uniform, the overall performance of the battery is improved, the internal friction of the battery during the formation process is reduced, and the energy utilization efficiency is improved. In order to prevent excessive temperature from causing damage to the battery material or side reactions, the temperature of T1 is controlled to 80~90℃ to avoid affecting the performance and life of the battery.
[0009] Furthermore, in S2~S4, by gradually increasing the constant current charging rate and coordinating the charging rate, the charging state (SOC) and temperature of the all-solid-state lithium-ion battery during the formation process are strictly controlled, the all-solid-state lithium-ion battery is fully activated, the battery reaches a specific state, and the battery stability and life are improved.
[0010] In S5, proper discharge treatment of the all-solid-state lithium-ion battery is performed to further activate the active substances in the electrode material, while helping to form a stable electrode-electrolyte interface and greatly reducing the polarization of the battery, shortening the subsequent high-temperature static aging time of the battery and improving the battery's cycle performance.
[0011] In some embodiments, in S1, the constant pressure applied by the fixture to the all-solid-state lithium-ion battery is 3-4 MPa.
[0012] In the embodiment, the degree of pressurization needs to be controlled to ensure close contact while avoiding excessive pressure that damages the battery cell.
[0013] In some embodiments, in S2, C1 is 0.1~0.3C.
[0014] Because the battery is in an empty state before formation, the active materials inside the battery have not yet been activated. Therefore, the initial current must be controlled at the beginning of formation to avoid excessive battery temperature and excessive chemical reaction inside the battery, which may lead to electrode damage and battery short circuit explosion, and ensure the safety of the battery during the formation process. In S2, the all-solid-state lithium-ion battery is charged at a low rate constant current to perform preliminary activation of the battery cell.
[0015] In some embodiments, in S3, C2 is 0.3~0.6C.
[0016] In the embodiment, after the initial heating and charging of S2, the active materials in the battery have been gradually activated. In order to increase the reaction rate and shorten the formation time, the charging rate is further increased in S3. However, due to the excessive current, the electrode polarization phenomenon will be aggravated, and polarization will increase the internal resistance of the battery, and even cause the electrolyte to decompose, produce unnecessary side reactions, thereby reducing the charging and discharging efficiency of the battery and affecting the performance of the battery. At the same time, for all-solid-state lithium-ion batteries, an SEI film will be formed during the formation process. If the current is too large, an unstable or uneven SEI film may be formed, affecting the cycle stability and service life of the battery. Therefore, it is necessary to control the charging rate to 0.3~0.6C, while shortening the charging time, controlling the internal reaction of the battery.
[0017] In some embodiments, in S4, C3 is 0.6~0.8C.
[0018] In the embodiment, through S1~S3, the battery has reached 70%~75% SOC, and the battery has a higher charging efficiency at a lower SOC. As the SOC increases, the rechargeability of the battery gradually decreases, resulting in a decrease in charging efficiency. Therefore, in order to complete the formation process of the battery as soon as possible, it is necessary to further increase the charging rate. At the same time, in order to control the influence of the increased polarization degree of the battery caused by the high current, the temperature of the all-solid-state lithium-ion battery needs to be reduced to T2 in S4.
[0019] In some embodiments, in S5, C4 is 0.2~0.4C.
[0020] Compared with the charging rate C3 in S4, the discharge rate C4 in S4 is lower than C3. The lower discharge rate is used to weaken the polarization degree of the battery, shorten the high-temperature static aging process after formation, and enable the battery to directly enter the battery capacity division process after completing the formation process, thereby shortening the total time of the battery formation process and improving the battery production efficiency.
[0021] In some embodiments, the T2 is 60-70°C.
[0022] In order to balance the battery overheating caused by high-rate charging, the battery temperature needs to be lowered in advance to ensure the safety of the formation process.
[0023] In some embodiments, the holding time in S2-S5 is 10-15 minutes.
[0024] When switching between steps, the battery needs to be left alone for a period of time to allow the battery to fully react.
[0025] In a second aspect, the present application further provides an all-solid-state lithium-ion battery, including an all-solid-state lithium-ion battery prepared by the formation method described in the first aspect of the present application.
[0026] The beneficial effects of the all-solid-state lithium-ion battery and the formation method thereof provided in the present application include but are not limited to the following: 1) The formation method of the present application is designed for all-solid-state lithium-ion batteries. By pressurizing and heating the all-solid-state lithium-ion batteries, the solid-solid interface contact is made closer, the internal impedance of the battery is reduced, the kinetic energy of the active substances inside the battery is increased, and the internal friction of the battery during the formation process is reduced, thereby making the chemical reaction inside the battery more uniform and improving the overall performance of the battery.
[0027] 2) The formation method of the present application activates the all-solid-state lithium-ion battery by gradually increasing the battery charging rate and strictly controlling the charge state (SOC) and temperature of the all-solid-state lithium-ion battery during the formation process in accordance with the size of the charging rate, thereby improving the stability and life of the battery and having high safety during the process. After the battery prepared by this method was cycled for 500 weeks at 0.5C / 0.5C at 60°C, the capacity retention rate was still greater than 80%.
[0028] 3) After the initial charging activation, the formation method of the present application performs appropriate discharge treatment on the all-solid-state lithium-ion battery to further activate the active substances in the electrode material, while helping to form a stable electrode-electrolyte interface inside the battery and greatly reducing the polarization degree of the battery, further improving the battery's cycle performance. At the same time, it greatly shortens the duration of the all-solid-state lithium-ion battery formation process, which is conducive to the industrial production of all-solid-state lithium-ion batteries. DETAILED DESCRIPTION
[0029] The following description provides specific application scenarios and requirements of the present application, with the purpose of enabling those skilled in the art to make and use the content in the present application. It will be apparent to those skilled in the art that various local modifications to the disclosed embodiments are apparent, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but to the widest scope consistent with the claims.
[0030] The present application provides a formation method for an all-solid-state lithium-ion battery, characterized by comprising: S1, applying constant pressure to the all-solid-state lithium-ion battery through a fixture; S2, adjusting the temperature of the all-solid-state lithium-ion battery to T1, maintaining the temperature at T1, charging the all-solid-state lithium-ion battery at a constant current rate of C1, charging to 60%~70% SOC, and setting aside; S3, maintaining the temperature at T1, charging the all-solid-state lithium-ion battery at a constant current rate of C2 to 70%~75% SOC, and then setting aside; S4, adjusting the temperature of the all-solid-state lithium-ion battery to T2, maintaining the temperature at T2, charging the all-solid-state lithium-ion battery at a C3 rate with a constant current, charging to 80%~85% SOC, and setting aside; S5, maintaining the temperature at T2, discharging the all-solid-state lithium-ion battery at a constant current rate of C4 until the DOD is 20% to 30%, and then placing the battery aside to complete the formation of the all-solid-state lithium-ion battery; Among them, T1>T2, T1 is 80~90℃, C3>C2>C1, and C4<C3.
[0031] This application applies constant pressure to the all-solid-state lithium-ion battery through a clamp, which is beneficial to strengthen the contact tightness of the solid-solid interface. By heating the all-solid-state lithium-ion battery during the formation process, the internal impedance of the battery is reduced, the kinetic energy of the active substances inside the battery is increased, and the chemical reaction inside the battery is made more uniform, the overall performance of the battery is improved, the internal consumption of the battery during the formation process is reduced, and the energy utilization efficiency is improved. Further, by designing the constant current charging and discharging rates, and strictly controlling the charge state (SOC), discharge state (DOD) and temperature of the all-solid-state lithium-ion battery during the formation process, the all-solid-state lithium-ion battery is fully activated, helping to form a stable electrode-electrolyte interface inside the battery, so that the battery reaches a specific state, and greatly reduces the polarization of the battery, thereby improving the stability and life of the battery.
[0032] The all-solid-state lithium-ion battery and its formation method provided by the present application will be described in detail below in conjunction with specific embodiments.
[0033] The present application provides a formation method for an all-solid-state lithium-ion battery, characterized by comprising: S1, applying constant pressure to the all-solid-state lithium-ion battery through a fixture; S2, adjusting the temperature of the all-solid-state lithium-ion battery to T1, maintaining the temperature at T1, and charging the all-solid-state lithium-ion battery at a constant current rate of C1 to 60% to 70% SOC, for example, 60% SOC, 61% SOC, 62% SOC, 63% SOC, 64% SOC, 65% SOC, 66% SOC, 67% SOC, 68% SOC, 69% SOC or 70% SOC, and setting aside; S3, maintaining the temperature at T1, charging the all-solid-state lithium-ion battery at a constant current rate of C2 to 70% to 75% SOC, for example, 70% SOC, 71% SOC, 72% SOC, 73% SOC, 74% SOC or 75% SOC, and then placing on hold; S4, adjusting the temperature of the all-solid-state lithium-ion battery to T2, maintaining the temperature at T2, and charging the all-solid-state lithium-ion battery at a C3 rate to 80% to 85% SOC, for example, 80% SOC, 81% SOC, 82% SOC, 83% SOC, 84% SOC or 85% SOC, and setting aside; S5, maintaining the temperature at T2, discharging the all-solid-state lithium-ion battery at a constant current rate of C4 to 20% to 30% DOD, for example, 20% DOD, 21% DOD, 22% DOD, 23% DOD, 24% DOD, 25% DOD, 26% DOD, 27% DOD, 28% DOD, 29% DOD or 30% DOD, and completing the formation of the all-solid-state lithium-ion battery after shelving; Among them, T1>T2, T1 is 80~90℃, C3>C2>C1, and C4 is less than C3.
[0034] For example, T1 is 80°C, 85°C or 90°C.
[0035] In some embodiments, in S1, the constant pressure applied by the clamp to the all-solid-state lithium-ion battery is 3-4 MPa, for example, 3 MPa, 3.1 MPa, 3.2 MPa, 3.3 MPa, 3.4 MPa, 3.5 MPa, 3.6 MPa, 3.7 MPa, 3.8 MPa, 3.9 MPa or 4 MPa.
[0036] In some embodiments, in S2, C1 is 0.1-0.3C, for example, 0.1C, 0.2C or 0.3C.
[0037] In some embodiments, in S3, C2 is 0.3~0.6C, for example, 0.3C, 0.4C, 0.5C or 0.6C.
[0038] In some embodiments, in S4, C3 is 0.6~0.8C, for example, 0.6C, 0.7C or 0.8C.
[0039] In some embodiments, in S5, C4 is 0.2-0.4C, for example, 0.2C, 0.3C or 0.4C.
[0040] In some embodiments, T2 is 60-70°C, for example, T1 is 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C.
[0041] In some embodiments, the holding time in S2-S5 is 10-15 min, for example, 10 min, 11 min, 12 min, 13 min, 14 min or 15 min.
[0042] In some embodiments, the positive electrode material of the all-solid-state lithium-ion battery is any one of ternary, lithium iron phosphate, and lithium cobalt oxide, the solid electrolyte of the all-solid-state lithium-ion battery is sulfide, and the negative electrode material of the all-solid-state lithium-ion battery is any one of graphite, silicon-carbon negative electrode, and lithium metal. Example
[0043] In this embodiment, the all-solid-state lithium-ion battery is subjected to a formation treatment using the formation method designed for the all-solid-state lithium-ion battery in this application. The specific parameters of the all-solid-state lithium-ion battery are as follows: the positive electrode material of the battery is lithium iron phosphate, the solid electrolyte is sulfide, the negative electrode material is graphite, the capacity is 100mAh, the full-charge voltage is 4.25V, and the maximum support is 1C charging and 0.5C discharging; the specific steps are as follows: S1. Before the battery is formed, a clamp is used to pressurize it. The clamp structure consists of two stainless steel plates, the battery is located between the two plates, and the pressure between the plates is 4MPa.
[0044] S2. Place the battery in the formation cabinet and connect the positive and negative terminals to the positive and negative terminals. Leave it for 15 minutes. At 80°C, charge the battery at a constant current of 0.1C until the voltage reaches 2.81V (66% SOC) and set the time to 65 minutes. Leave the battery for 10 minutes.
[0045] S3. At 80°C, the battery was charged at a constant current of 0.5C until the voltage reached 3.06V (72% SOC) for 37 minutes. The battery was left for 10 minutes.
[0046] S4. At 60°C, the battery is charged at a constant current of 0.7C until the voltage reaches 3.57V (84% SOC) and the charging time is set to 45 minutes. The battery is left for 10 minutes.
[0047] S5. At 60℃, the battery is discharged at a constant current of 0.3C until the voltage reaches 3.19V (25% DOD) and the time is set to 45min. Finally, it is left for 15min to complete the formation process. After the formation, the battery can be directly divided.
[0048] In this comparative example, the all-solid-state lithium-ion battery is subjected to a formation treatment using a conventional solid-state battery formation step based on a liquid battery formation step. The specific parameters of the all-solid-state lithium-ion battery are as follows: the positive electrode material of the battery is lithium iron phosphate, the solid electrolyte is sulfide, the negative electrode material is graphite, the capacity is 100mAh, the full-charge voltage is 4.25V, and the maximum support is 1C charging and 0.5C discharging; the specific steps are as follows: S1. Before the battery is formed, a clamp is used to pressurize it. The clamp structure consists of two stainless steel plates, the battery is located between the two plates, and the pressure between the plates is 4MPa.
[0049] S2. Place the battery in the formation cabinet and connect the positive and negative terminals to the positive and negative terminals. Leave it for 15 minutes. At 80°C, charge the battery at a constant current of 0.1C until the voltage reaches 2.81V (66% SOC) and set the time to 65 minutes. Leave the battery for 10 minutes.
[0050] S3. At 80°C, the battery is charged at a constant current of 0.25C until the voltage reaches 2.98V (70% SOC) and the charging time is set to 80 minutes. The battery is left for 20 minutes.
[0051] S4. At 80℃, the battery is charged at a constant current of 0.4C until the voltage reaches 3.40V (80% SOC) and the time is set to 96 minutes. Finally, it is left for 15 minutes to complete the formation process. After the formation, the battery needs to be left at high temperature for 24 hours before the capacity can be divided. Example
[0052] In this embodiment, the all-solid-state lithium-ion battery is subjected to a formation treatment using the formation method designed for the all-solid-state lithium-ion battery in this application. The specific parameters of the all-solid-state lithium-ion battery are as follows: the positive electrode material of the battery is lithium cobalt oxide, the solid electrolyte is sulfide, the negative electrode material is lithium metal, the capacity is 50mAh, the full-charge voltage is 4.4V, and the maximum support is 1C charging and 1C discharging; the specific steps are as follows: S1. Before the battery is formed, a clamp is used to pressurize it. The clamp structure consists of two stainless steel plates, the battery is located between the two plates, and the pressure between the plates is 4MPa.
[0053] S2. Place the battery in the formation cabinet and connect the positive and negative terminals to the positive and negative terminals. Leave it for 15 minutes. At 80°C, charge the battery at a constant current of 0.2C until the voltage reaches 2.73V (62% SOC) and set the time to 70 minutes. Leave the battery for 10 minutes.
[0054] S3. At 80°C, the battery is charged at a constant current of 0.6C until the voltage reaches 3.21V (73% SOC) and the charging time is set to 45 minutes. The battery is left for 10 minutes.
[0055] S4. At 60°C, the battery is charged at a constant current of 0.8C until the voltage reaches 3.74V (85% SOC) and the charging time is set to 45 minutes. The battery is left for 10 minutes.
[0056] S5. At 60℃, the battery is discharged at a constant current of 0.3C until the voltage reaches 3.08V (30% DOD) and the time is set to 45min. Finally, it is left for 15min to complete the formation process. After the formation, the battery can be directly divided.
[0057] In this comparative example, the all-solid-state lithium-ion battery is subjected to a formation treatment using a conventional solid-state battery formation step based on a liquid battery formation step. The specific parameters of the all-solid-state lithium-ion battery are as follows: the positive electrode material of the battery is lithium cobalt oxide, the solid electrolyte is sulfide, the negative electrode material is lithium metal, the capacity is 50mAh, the full-charge voltage is 4.4V, and the maximum support is 1C charging and 1C discharging; the specific steps are as follows: S1. Before the battery is formed, a clamp is used to pressurize it. The clamp structure consists of two stainless steel plates, the battery is located between the two plates, and the pressure between the plates is 4MPa.
[0058] S2. Place the battery in the formation cabinet and connect the positive and negative terminals to the positive and negative terminals. Leave it for 15 minutes. At 80°C, charge the battery at a constant current of 0.2C until the voltage reaches 2.73V (62% SOC) and set the time to 70 minutes. Leave the battery for 10 minutes.
[0059] S3. At 80°C, the battery is charged at a constant current of 0.25C until the voltage reaches 3.08V (70% SOC) and the time is set to 90min. The battery is left for 20min.
[0060] S4. At 80℃, the battery is charged at a constant current of 0.5C until the voltage reaches 3.52V (80% SOC) and the time is set to 95min. Finally, it is left for 15min to complete the formation process. After the formation, the battery needs to be left at high temperature for 24h before capacity division can be performed.
[0061] The prepared all-solid-state lithium-ion battery was subjected to a cycle test, and the test method is as follows: In Example 1 and Comparative Example 1, the test charge and discharge voltage was 2.5-4.25 V, the cycle temperature was 60° C., the first cycle was 0.5° C., and 2000 charge and discharge cycles were performed at 0.5° C. starting from the second cycle.
[0062] In Example 2 and Comparative Example 2, the test charge and discharge voltage was 2.75-4.4 V, the cycle temperature was 60° C., the first cycle was 0.5° C., and 2000 charge and discharge cycles were performed at 0.5° C. starting from the second cycle.
[0063] The indicators for evaluating cyclability are the capacity retention rate after 100, 200, 300, 400 and 500 cycles.
[0064] The results of the above tests are shown in Table 1.
[0065] Table 1 Performance test results of Examples 1-2 and Comparative Examples 1-2 sample Capacity retention rate after 100 cycles Capacity retention rate after 200 cycles Capacity retention rate after 300 cycles Capacity retention rate after 400 cycles Capacity retention rate after 500 cycles Example 1 98.21% 94.86% 90.33% 86.23% 80.13% Example 2 98.01% 93.11% 90.58% 85.68% 80.17% Comparative Example 1 98.77% 91.37% 87.23% 80.01% 72.21% Comparative Example 2 98.23% 92.87% 88.65% 81.77% 72.56% From the test data in Table 1, it can be seen that the all-solid-state lithium-ion batteries prepared by the formation method of the present application in Examples 1 and 2 have similar capacity retention rates when the number of cycles is less than 100, compared with the all-solid-state lithium-ion batteries prepared by the conventional solid-state battery formation steps based on the liquid battery formation steps in Comparative Examples 1 and 2. When the number of cycles is greater than 100, the capacity retention rate of the all-solid-state lithium-ion batteries prepared in Examples 1 and 2 is significantly higher than that of Comparative Examples 1 and 2. When the number of cycles reaches 500, the capacity retention rate of the all-solid-state lithium-ion batteries prepared in Comparative Examples 1 and 2 is significantly lower than that at 400, which is about 90% of that in Examples 1 and 2.
[0066] In Comparative Examples 1 and 2, although the method of gradually increasing the charging rate is also adopted, the temperature inside the battery cannot be well controlled because the appropriate state of charge (SOC) and temperature are not matched according to different charging rates. The battery is not properly discharged, and the all-solid-state lithium-ion battery cannot be fully activated, which affects the stability and life of the battery. At the same time, the batteries after formation in Comparative Examples 1 and 2 also need to be left at high temperature for a long time before they can be divided into different capacities. The process time is too long, which is not conducive to industrial production.
[0067] The beneficial effects of the all-solid-state lithium-ion battery and the formation method thereof provided in the present application include but are not limited to the following: 1) The formation method of the present application is designed for all-solid-state lithium-ion batteries. By pressurizing and heating the all-solid-state lithium-ion batteries, the solid-solid interface contact is made closer, the internal impedance of the battery is reduced, the kinetic energy of the active substances inside the battery is increased, and the internal friction of the battery during the formation process is reduced, thereby making the chemical reaction inside the battery more uniform and improving the overall performance of the battery.
[0068] 2) The formation method of the present application activates the all-solid-state lithium-ion battery by gradually increasing the battery charging rate and strictly controlling the charge state (SOC) and temperature of the all-solid-state lithium-ion battery during the formation process in accordance with the size of the charging rate, thereby improving the stability and life of the battery and having high safety during the process. After the battery prepared by this method was cycled for 500 weeks at 0.5C / 0.5C at 60°C, the capacity retention rate was still greater than 80%.
[0069] 3) After the initial charging activation, the formation method of the present application performs appropriate discharge treatment on the all-solid-state lithium-ion battery to further activate the active substances in the electrode material, while helping to form a stable electrode-electrolyte interface inside the battery and greatly reducing the polarization degree of the battery, further improving the battery's cycle performance. At the same time, it greatly shortens the duration of the all-solid-state lithium-ion battery formation process, which is conducive to the industrial production of all-solid-state lithium-ion batteries.
[0070] In summary, after reading the contents of this application, those skilled in the art will appreciate that the aforementioned application contents may be presented only in an exemplary manner and may not be restrictive. Although not explicitly stated herein, those skilled in the art will appreciate that this application is intended to encompass various reasonable changes, improvements and modifications to the embodiments. These changes, improvements and modifications are within the spirit and scope of the exemplary embodiments of this application.
Claims
1. A formation method for an all-solid-state lithium-ion battery, characterized in that: include: S1, applying constant pressure to the all-solid-state lithium-ion battery through a fixture; S2, adjusting the temperature of the all-solid-state lithium-ion battery to T1, maintaining the temperature at T1, charging the all-solid-state lithium-ion battery at a constant current rate of C1, charging to 60%~70% SOC, and setting aside; S3, maintaining the temperature at T1, charging the all-solid-state lithium-ion battery at a constant current rate of C2 to 70%~75% SOC, and then setting aside; S4, adjusting the temperature of the all-solid-state lithium-ion battery to T2, maintaining the temperature at T2, charging the all-solid-state lithium-ion battery at a C3 rate with a constant current, charging to 80%~85% SOC, and setting aside; S5, maintaining the temperature at T2, discharging the all-solid-state lithium-ion battery at a constant current rate of C4 until the DOD is 20% to 30%, and then placing the battery aside to complete the formation of the all-solid-state lithium-ion battery; Among them, T1>T2, T1 is 80~90℃, C3>C2>C1, and C4<C3.
2. The formation method of an all-solid-state lithium-ion battery according to claim 1, characterized in that: In S1, the constant pressure applied by the fixture to the all-solid-state lithium-ion battery is 3-4 MPa.
3. The formation method of an all-solid-state lithium-ion battery according to claim 1, characterized in that: In the S2, C1 is 0.1~0.3C.
4. The formation method of an all-solid-state lithium-ion battery according to claim 3, characterized in that: In the S3, C2 is 0.3~0.6C.
5. The formation method of an all-solid-state lithium-ion battery according to claim 4, characterized in that: In the S4, C3 is 0.6~0.8C.
6. The formation method of an all-solid-state lithium-ion battery according to claim 5, characterized in that: In the S5, C4 is 0.2~0.4C.
7. The formation method of an all-solid-state lithium-ion battery according to claim 1, characterized in that: The T2 is 60-70°C.
8. The formation method of an all-solid-state lithium-ion battery according to claim 1, characterized in that: The holding time in S2~S5 is 10~15min.
9. An all-solid-state lithium-ion battery, characterized in that: A fully solid-state lithium-ion battery prepared by the formation method of any one of claims 1 to 8.