South Korea’s research and development of multifunctional separators is expected to significantly reduce battery costs

The 2020 Nobel chemist was awarded to researchers who developed lithium-ion rechargeable batteries, which are also a basic source of energy for small IT equipment, electric vehicles and other Electronic devices. Tesla, a leading US automaker, also recently emphasized the need to establish an innovative battery production system and reduce battery costs, because the price of batteries accounts for a large proportion of electric vehicles, and reducing the cost of batteries is critical to popularizing electric vehicles.

To this end, according to foreign media reports, a joint research team established by South Korea’s Pohang University of Science and Technology (POSTECH) and South Korea’s Ulsan College (Ulsan College) has developed a multi-functional separator that can assemble cells even under ambient conditions. The battery still works. The group was led by Professor Soojin Park and Ph.D. candidate Hye Bin Son from the Department of Chemistry at Pohang University of Science and Technology, with the participation of Professor Seungmin Yoo from Ulsan University.

Using multifunctional separators to make batteries in ambient environment (Image credit: Pohang University of Science and Technology)

Because the electrolyte inside the battery reacts with moisture and degrades, lithium-ion batteries are usually assembled in a dry room that needs to be kept below 1% humidity. However, maintaining a dry room is expensive.

To solve this problem, researchers have injected additives into the electrolyte to suppress impurities such as moisture or hydrofluoric acid. However, such behavior can cause unwanted side effects when running on battery. In fact, when the battery is activated at high temperatures (50 degrees Celsius or above), even a little moisture can cause the battery’s performance to deteriorate rapidly. Therefore, there is a need for a material that can trap moisture and impurities in batteries without adversely affecting the electrochemical reactions of additives.

Therefore, the joint research team introduced functional materials capable of trapping moisture on the battery separator to increase the thermal stability and performance of the battery. The multifunctional separator exhibits excellent heat resistance (only 10% shrinkage at 140°C for 30 minutes, compared to 50% for conventional separators) and optimized electrochemistry at 55°C Performance, 100 times of charging still retains 79% of the original capacity.

In addition, the researchers also confirmed that the functional material in the electrolyte is still effective in an environment full of impurities. The silane compound on the surface of this synthetic functional ceramic battery can capture moisture well and maintain the ceramic structure of the battery, but the general ceramic material is corroded by the acidified electrolyte. In addition, through this study, the team demonstrated that the multifunctional membrane produced in ambient conditions has a longer lifespan than conventional membranes, and that it provides stability performance beyond simple membranes.

“This newly developed multifunctional separator exhibits great stability, excellent electrochemical performance, and high energy density,” said the researchers. “This is the first case of a battery successfully fabricated in an ambient environment, which is expected to reduce battery power consumption.” play an important role in terms of cost.”

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