Man Yuanxin, Nan Hui, Ma Jianzhe, Li Zhike, Zhou Jingyuan, Wang Xianlan, Li Heqi, Xue Caihong, Yang Yongchun
Qinghai Provincial Key Laboratory of New Light Alloys, School of Mechanical Engineering, Qinghai University, Xining 810016, China.
Qinghai Beijie New Material Technology Co., Ltd., Xining 810016, China.
Materials (Basel). 2024 May 6;17(9):2162. doi: 10.3390/ma17092162.
In the field of lithium-ion batteries, the challenges posed by the low melting point and inadequate wettability of conventional polyolefin separators have increased the focus on ceramic-coated separators. This study introduces a highly efficient and stable boehmite/polydopamine/polyethylene (AlOOH-PDA-PE) separator. It is crafted by covalently attaching functionalized nanosized boehmite (γ-AlOOH) whiskers onto polyethylene (PE) surfaces. The presence of a covalent bond increases the stability at the interface, while amino groups on the surface of the separator enhance the infiltration of the electrolyte and facilitate the diffusion of lithium ions. The PE-PDA-AlOOH separator, when used in lithium-ion batteries, achieves a discharge capacity of 126 mAh g at 5 C and retains 97.1% capacity after 400 cycles, indicating superior cycling stability due to its covalently bonded ceramic surface. Thus, covalent interface modification is a promising strategy to prevent delamination of ceramic coatings in separators.
在锂离子电池领域，传统聚烯烃隔膜的低熔点和润湿性不足所带来的挑战，使得人们对陶瓷涂层隔膜的关注度不断提高。本研究介绍了一种高效且稳定的勃姆石/聚多巴胺/聚乙烯（AlOOH-PDA-PE）隔膜。它是通过将功能化的纳米级勃姆石（γ-AlOOH）晶须共价连接到聚乙烯（PE）表面而制成的。共价键的存在增加了界面处的稳定性，而隔膜表面的氨基增强了电解质的浸润，并促进锂离子的扩散。PE-PDA-AlOOH隔膜在锂离子电池中使用时，在5C下的放电容量为126 mAh g，400次循环后保留97.1%的容量，这表明由于其共价键合的陶瓷表面，具有优异的循环稳定性。因此，共价界面改性是防止隔膜中陶瓷涂层分层的一种有前景的策略。
