Electrolyte wettability test system

Definition and importance:

Electrolyte wettability refers to the ability of the interface formed by the electrolyte on the electrode surface to effectively cover the entire electrode surface, which is an important electrochemical characteristic because it directly affects the performance and life of the battery. Therefore, electrolyte wettability testing is an essential step in battery development and production. Accurate evaluation of the infiltration behavior of electrolyte on the surface of battery components under different temperatures, volumes and pressures can provide a strong basis for the optimization of battery performance.

Test method:

Electrolyte wettability test methods are generally divided into static wettability test and dynamic wettability test, and it is also an important means to detect and evaluate the influence of different containers and battery components on electrolyte wettability. Traditional test methods include:

Contact Angle measurement method: The electrolytic drop is added to the surface of the electrode or diaphragm, and the infiltration of the electrolyte is judged according to the contact Angle between the electrolyte and the electrode or diaphragm. In the test of this method, the electrolyte spreading speed on the surface of the electrode plate or diaphragm is fast, usually the test requires high-speed camera equipment, and the overall test cost and difficulty are high, and the complete soaking time and soaking speed of the electrolyte on the electrode plate or diaphragm are difficult to investigate.

Infiltration time method: A certain amount of electrolytic drops is added to the surface of the pole sheet to test the length of the complete penetration time of the electrolyte, and the difference of the electrolyte infiltration of the pole sheet is evaluated by the time difference.

Infiltration height method: The fixed size of the pole plate is completely immersed or one end is immersed in the electrolyte, and the electrolyte infiltration performance of the pole plate is evaluated according to the quality of the immersed electrolyte in the pole plate within a certain time.

However, the traditional test methods have the problem of poor repeatability and can not accurately evaluate the real infiltration of the electrolyt

e. To address these limitations, some advanced test systems have been developed.

Advanced test system:

Capillary infiltration test system:

Principle: Based on the principle of capillary diffusion of electrolyte between anode and diaphragm, capillary infiltration method was adopted, equipped with high-precision mechanical control system and visual acquisition system to quantitatively evaluate the difference of electrolyte infiltration between different positive and negative electrode plates and diaphragm.

Operation: The electrolyte is injected into the capillary tube. After the capillary glass tube is in vertical contact with the surface of the pole sheet, the wave surface of the capillary tube decreases continuously as the electrolyte wets the coating. The visual recognition system records the capillary liquid level in real time. The dynamic evolution process of liquid level height is the real-time process of electrolyte infiltration, and the height change is the amount of electrolyte infiltration.

Advantages: This method overcomes the limitations of the traditional wetting balance method and can better understand the migration of the electrolyte in the porous electrode, so it helps to optimize the composition of the electrolyte and the microstructure design of the electrode to achieve rapid and complete wetting, reduce battery production costs, and improve product quality.

Battery electrolyte wettability analyzer:

Principle: Based on the process of electrolyte adsorption in the diaphragm, the infiltration difference of electrolyte in the diaphragm is quantitatively evaluated by the principle of gradually enhanced solid-liquid interface

Advantages: Fast test （less than two minutes）， accurate results and quantifiable characterization, easy operation and simple processing.