A test method for cathode additives that accelerate formation and improve battery performance

Abstract

This invention discloses a testing method for cathode additives that accelerate formation and improve battery performance. The specific steps of the testing method are as follows: Step 1: Preparation, selecting several groups of batteries of the same specifications and dividing them into experimental and control groups; Step 2: Adding additives, adding the cathode additive to be tested to the cathode material of the experimental group batteries in a certain proportion; Step 3: Formation test, placing the batteries of the experimental and control groups in a constant temperature and humidity environment; Step 4: Performance test, specifically including the following tests: cycle performance test, rate performance test, internal resistance test, and thermal stability test; Step 5: Data analysis. The testing method of this invention covers multiple aspects such as formation test, cycle performance test, rate performance test, internal resistance test, and thermal stability test, which can comprehensively evaluate the impact of cathode additives on battery performance and provide comprehensive data support for the research and optimization of additives.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to a test method for cathode additives that accelerate formation and improve battery performance. Background Technology

[0002] With the continuous development of technology, batteries are being used more and more widely in many fields, and the requirements for battery performance are also increasing. Formation is a key step in the battery manufacturing process, which directly affects the battery's initial charge-discharge efficiency, cycle life, and energy density. During the formation process, an SEI film forms on the surface of the negative electrode. This process consumes some lithium ions in the positive electrode material, leading to irreversible capacity loss of the positive electrode material and a decrease in initial coulombic efficiency.

[0003] To address the aforementioned issues, introducing cathode additives during battery production has become an effective approach. However, current testing methods for cathode additives have several shortcomings. Existing methods often only detect the impact of additives on a single battery performance aspect, failing to comprehensively assess their combined effect on battery formation and overall performance. Moreover, these methods are mostly complex to operate, requiring expensive equipment and specialized technicians, resulting in high testing costs and hindering large-scale application. Furthermore, existing testing methods cannot accurately simulate the operating conditions of batteries in actual use, leading to discrepancies between test results and real-world application scenarios, and failing to provide reliable data for optimized battery design and production. Therefore, developing a comprehensive, accurate, easy-to-operate, and low-cost testing method for cathode additives that accelerate formation and improve battery performance is of significant practical importance. Summary of the Invention

[0004] The purpose of this invention is to provide a testing method for cathode additives that accelerate formation and improve battery performance. The specific steps of this testing method for cathode additives that accelerate formation and improve battery performance are as follows:

[0005] Step 1: Preparation. Select several groups of batteries of the same specifications and divide them into experimental and control groups. The number of batteries in each group is determined according to statistical requirements, generally no less than 5. Prepare the positive electrode additive to be tested, ensuring that the purity and quality of the additive meet the requirements. Prepare the battery testing equipment.

[0006] Step 2: Adding additives. The positive electrode additive to be tested is added to the positive electrode material of the experimental group battery in a certain proportion. The additive is evenly dispersed in the positive electrode material by high-speed stirring and ultrasonic dispersion. No additives are added to the positive electrode material of the control group battery. Other preparation processes are the same as those of the experimental group.

[0007] Step 3: Formation test. The batteries of the experimental group and the control group are placed in a constant temperature and humidity environment and formed according to the set formation regime. A multi-stage constant current charging method is adopted. During the formation process, the battery voltage, current, capacity and other parameters are monitored in real time using a battery charge and discharge tester and the data is recorded.

[0008] Step 4: Performance testing, which includes the following tests:

[0009] Cyclic performance test: The formed battery is subjected to cyclic charge and discharge test using standard charge and discharge rates, such as 1C charge and 1C discharge, and multiple cycles are performed within the voltage range of 2.5V - 4.2V. The charge and discharge capacity, coulombic efficiency and other parameters of each cycle are recorded, and the changes in battery cycle performance are observed.

[0010] Rate performance testing: The battery is charged and discharged at different rates, such as 0.5C, 1C, 2C, and 5C, to measure the discharge capacity and charge acceptance of the battery at different rates and to evaluate the impact of additives on the rate performance of the battery.

[0011] Internal resistance testing: Using an electrochemical workstation or a high-precision internal resistance tester, the internal resistance of the battery is measured under different conditions, such as after formation and after a certain number of cycles, to analyze the effect of additives on the battery's internal resistance.

[0012] Thermal stability test: The battery is placed in an environment with different temperatures, such as -20℃, 25℃, 50℃, and 80℃, and charge and discharge tests are carried out to observe the changes in battery performance with temperature and evaluate the effect of additives on battery thermal stability.

[0013] Step 5: Data Analysis: Perform statistical analysis on the test data, using the mean and standard deviation statistical methods to evaluate the differences in battery performance between the experimental and control groups. Visually demonstrate the impact of additives on battery performance by plotting charts such as capacity-cycle count curves and rate-discharge capacity curves. Use correlation analysis to explore the relationship between additive content and battery performance, and determine the optimal additive addition ratio.

[0014] Preferably, the electrical testing equipment in step 1 includes a high-precision battery charge-discharge tester, an electrochemical workstation, etc., and the equipment is calibrated and debugged to ensure the accuracy of the test data.

[0015] Preferably, the multi-stage constant current charging method in step 2 is as follows: in the first stage, the battery is charged with a current of 0.1C until the battery voltage reaches a certain value, such as 3.0V; in the second stage, the battery is charged with a current of 0.05C until the battery voltage reaches 3.5V; and finally, the battery is charged with a current of 0.02C until it is fully charged.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. Comprehensive performance evaluation: The testing methods of this invention cover multiple aspects such as formation testing, cycle performance testing, rate performance testing, internal resistance testing, and thermal stability testing, which can comprehensively evaluate the impact of cathode additives on battery performance and provide comprehensive data support for the research and optimization of additives.

[0018] 2. Easy to operate: The equipment used in the test is common battery testing equipment. The operation process is simple and clear, requiring no professional technicians or complicated operating skills, which reduces the difficulty and cost of testing.

[0019] 3. High accuracy: By strictly controlling test conditions, such as temperature, humidity, and charge / discharge regimes, and by adopting scientific data statistical analysis methods, test errors are reduced, and the accuracy and reliability of test results are improved, making the test results closer to the performance of the battery in actual use.

[0020] 4. Low cost: It eliminates the need for expensive special equipment and reagents, reducing testing costs and facilitating large-scale application, providing an economical and practical testing method for battery manufacturers and research institutions. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] Example 1

[0023] 1. Preparation: Select 10 lithium-ion batteries of the same specifications, divided into an experimental group and a control group, with 5 batteries in each group. Prepare the positive electrode additive A to be tested, with a purity of 99%. Calibrate and debug the battery charge-discharge tester and electrochemical workstation.

[0024] 2. Additive addition: 5% (mass fraction) of additive A was added to the positive electrode material of the experimental group batteries. The additive was uniformly dispersed by high-speed stirring for 30 minutes and ultrasonic dispersion for 15 minutes. No additive was added to the positive electrode material of the control group batteries.

[0025] 3. Formation test: Place the two sets of batteries in an environment with a temperature of 25℃ and a humidity of 50%, and perform formation according to the formation process of charging to 3.0V at 0.1C in the first stage, charging to 3.5V at 0.05C in the second stage, and finally charging to full at 0.02C. Record the voltage, current and capacity data during the formation process.

[0026] 4. Performance Testing

[0027] - Cyclic performance test: 100 cycles were performed with 1C charge and 1C discharge in a voltage range of 2.5V - 4.2V, and the charge / discharge capacity and coulombic efficiency were recorded for each cycle.

[0028] - Rate performance testing: Tests were conducted at charge / discharge rates of 0.5C, 1C, 2C, and 5C to measure discharge capacity and charge acceptance.

[0029] - Internal resistance test: The battery internal resistance was measured using an electrochemical workstation after formation and after 50 cycles.

[0030] - Thermal stability test: The battery was placed in environments of -20℃, 25℃, 50℃ and 80℃ for charge and discharge tests, and the performance changes were observed.

[0031] 5. Data Analysis: Perform statistical analysis on the test data, calculate the mean and standard deviation, and draw charts such as capacity-cycle count curves and rate-discharge capacity curves to analyze the impact of additive A on battery performance.

[0032] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A test method for a cathode additive that accelerates formation and improves battery performance, characterized in that: The specific steps of the test method for the cathode additive that accelerates formation and improves battery performance are as follows: Step 1: Preparation. Select several groups of batteries of the same specifications and divide them into experimental and control groups. The number of batteries in each group is determined according to statistical requirements, generally no less than 5. Prepare the positive electrode additive to be tested, ensuring that the purity and quality of the additive meet the requirements. Prepare the battery testing equipment. Step 2: Adding additives. The positive electrode additive to be tested is added to the positive electrode material of the experimental group battery in a certain proportion. The additive is evenly dispersed in the positive electrode material by high-speed stirring and ultrasonic dispersion. No additives are added to the positive electrode material of the control group battery. Other preparation processes are the same as those of the experimental group. Step 3: Formation test. The batteries of the experimental group and the control group are placed in a constant temperature and humidity environment and formed according to the set formation regime. A multi-stage constant current charging method is adopted. During the formation process, the battery voltage, current, capacity and other parameters are monitored in real time using a battery charge and discharge tester and the data is recorded. Step 4: Performance testing, which includes the following tests: Cyclic performance test: The formed battery is subjected to cyclic charge and discharge test using standard charge and discharge rates, such as 1C charge and 1C discharge, and multiple cycles are performed within the voltage range of 2.5V - 4.2V. The charge and discharge capacity, coulombic efficiency and other parameters of each cycle are recorded, and the changes in battery cycle performance are observed. Rate performance testing: The battery is charged and discharged at different rates, such as 0.5C, 1C, 2C, and 5C, to measure the discharge capacity and charge acceptance of the battery at different rates and to evaluate the impact of additives on the rate performance of the battery. Internal resistance testing: Using an electrochemical workstation or a high-precision internal resistance tester, the internal resistance of the battery is measured under different conditions, such as after formation and after a certain number of cycles, to analyze the effect of additives on the battery's internal resistance. Thermal stability test: The battery is placed in an environment with different temperatures, such as -20℃, 25℃, 50℃, and 80℃, and charge and discharge tests are carried out to observe the changes in battery performance with temperature and evaluate the effect of additives on battery thermal stability. Step 5: Data Analysis: Perform statistical analysis on the test data, using the mean and standard deviation statistical methods to evaluate the differences in battery performance between the experimental and control groups. Visually demonstrate the impact of additives on battery performance by plotting charts such as capacity-cycle count curves and rate-discharge capacity curves. Use correlation analysis to explore the relationship between additive content and battery performance, and determine the optimal additive addition ratio.

2. The test method for a cathode additive that accelerates formation and improves battery performance according to claim 1, characterized in that: In step 1, the electrical testing equipment includes a high-precision battery charge-discharge tester, an electrochemical workstation, etc. The equipment is calibrated and debugged to ensure the accuracy of the test data.

3. The test method for a cathode additive that accelerates formation and improves battery performance according to claim 1, characterized in that: The multi-stage constant current charging method in step 2 is as follows: in the first stage, the battery is charged with a current of 0.1C until the battery voltage reaches a certain value, such as 3.0V; in the second stage, the battery is charged with a current of 0.05C until the battery voltage reaches 3.5V; and finally, the battery is charged with a current of 0.02C until it is fully charged.