Performance test method of self-baking electrode paste
As a key material in the field of electrochemistry, self-baking electrode paste, its performance is directly related to the overall performance and stability of the electrode.In order to ensure the quality of the electrode paste and optimize its use effect, a set of scientific and systematic performance testing methods is particularly important.This article will elaborate on the preparation of electrode paste, the self-baking process, and the performance test method from three aspects.
1. Preparation of electrode paste
The preparation of electrode paste is the basis for performance testing.Generally speaking, electrode pastes are made of a mixture of conductive materials, binders and active substances in a certain proportion.Specific steps include：
Raw material preparation: Measure the specific quality of raw materials according to the mass ratio of conductive carbon black: binder: active substance =20:5:75.The conductive carbon black is added to an appropriate amount of absolute ethanol, and it is evenly dispersed by ultrasonic dispersion.
Mixed grinding: Add the binder (such as PTFE) and the ground active substance to the mortar, mix with the dispersed conductive carbon black, and grind for 30 minutes until a uniform paste is formed.
Coating and drying: The prepared electrode paste is coated on nickel foam according to a certain area (such as 1×1cm2), and then placed in a constant temperature drying oven (such as 80°C) and dried for 12 hours to ensure that the electrode paste is completely cured and attached to the collector.
2. Self-baking process
Self-baking is a key step in the formation of a stable electrode structure of the electrode paste.Through baking, the solvent in the electrode paste evaporates and the binder solidifies to form a dense electrode layer.The self-baking process generally needs to be carried out under specific temperature and time conditions to ensure the baking effect of the electrode paste.
3. Performance test method
The performance test of self-baking electrode paste mainly includes two parts: electrochemical performance test and physical performance test.
1. Electrochemical performance test
Electrochemical performance testing is an important index for evaluating the performance of electrode pastes, including cyclic voltammetry testing (CV), constant current charge and discharge testing (CP), and AC impedance testing (EIS).
Cyclic voltammetry test (CV): Within a specific voltage range, control a constant voltage change speed, and collect the response value of the current to the voltage change during the electrochemical process.The CV curve can be used to investigate the cyclic performance of the electrode material and whether the redox reaction occurs.During the test, the working electrode is placed in an aqueous electrolyte (such as 30wt% KOH solution), and the infiltration is vacuumed for 30 minutes to ensure sufficient infiltration.
Constant current charge and discharge test (CP): The electrode is charged and discharged through a constant current to evaluate its capacity, cycle stability, coulomb efficiency and other properties.This test helps to understand the performance of the electrode in actual use.
AC impedance test (EIS): By measuring the impedance spectrum of the electrode at different frequencies, the internal structure and interface reaction characteristics of the electrode are analyzed.EIS testing can provide information such as electrode dynamics parameters and interface resistance.
2. Physical performance test
The physical performance test mainly includes the morphology observation, structural analysis and mechanical performance testing of the electrode.
Morphology observation: Use scanning electron microscopy (SEM) and other instruments to observe the surface morphology and microstructure of the electrode, and evaluate the coating uniformity and density of the electrode paste.
Structural analysis: Analyze the crystal structure of the electrode through X-ray diffraction (XRD) and other means to understand the composition of the electrode material and the phase transition process.
Mechanical performance test: Measure the tensile strength, hardness and other mechanical performance indicators of the electrode, and evaluate the stability and durability of the electrode during use.
The performance testing method of self-baking electrode paste involves many aspects, including electrochemical performance testing and physical performance testing.Through scientific and systematic testing methods, the performance of electrode pastes can be comprehensively evaluated, and strong support can be provided for the preparation and application of electrodes.In actual operation, the appropriate test methods and parameters should be selected according to specific needs and conditions to ensure the accuracy and reliability of the test results.
