Xinhua News Agency, Hefei, Nov. 15 (Reporter Xu Haitao) If an electric vehicle crashes, it may cause the on-board lithium battery to burst into flames. Recently, scholars from the University of Science and Technology of China were inspired by the mother of pearl layer in the natural mussel shell, and bionic construction of a new type of "imitation mother of pearl layer diaphragm" protection material, experiments show that it can effectively reduce the possibility of short circuit of lithium batteries when impacted, and improve safety. Advanced Materials, a top international academic journal in the field of materials, recently published the results.

At present, the mainstream commercial lithium batteries on the market widely use porous polyolefin materials as battery diaphragm protection materials. When the diaphragm is subjected to external impact, this pore structure is easy to deform and crack, resulting in the disturbance of the ion flow inside the battery, and then a short circuit or even a fire and explosion.

Mother of pearl in mussel shells in nature is a kind of "hard without losing toughness" excellent performance material. Recently, the research team of professors Yao Hongbin, Ni Yong and Yu Shuhong from the University of Science and Technology of China built a new material with a "layer of brick and mud" structure on the surface of the polyethylene diaphragm.

The experiment shows that the lithium battery using commercial diaphragm protection material has a transient voltage fluctuation range of 60% when it is impacted, while the battery voltage fluctuation range using "imitation mother-of-pearl diaphragm" material is less than 20%, and the voltage recovery speed is faster.

"Like a punch to cotton, the unique structure of the new material can dissipate the force on both sides, reducing the impact force transmitted internally." According to Professor Yao Hongbin, experiments have shown that this new material has a better protective effect on batteries, while its production cost is not high, the coating thickness is comparable to existing commercial materials, and it has a good application prospect. At present, the research team has applied for a patent.