Ren Wen, Ng Migo Szeman, Zhang Ye, Lakraychi Alae Eddine, Liang Yanliang, Feng Dawei, Lehmann Michelle, Yang Guang, Jeevarajan Judith, Tang Wan Si, Yao Yan
Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, United States.
Electrochemical Safety Research Institute (ESRI), UL Research Institutes, Houston, Texas 77204, United States.
ACS Nano. 2025 Feb 11;19(5):5781-5788. doi: 10.1021/acsnano.4c17740. Epub 2025 Jan 28.
Magnesium batteries offer a safer alternative for next-generation battery technology due to their insusceptibility to dendrite deposition. Selective membranes tailored for magnesium-ion conduction will unlock further technological advancement. Herein, we demonstrate fluorine-free magnesiated sulfonated poly(ether ether ketone) (Mg-SPEEK) selective membranes capable of facilitating magnesium-ion conduction while effectively rejecting soluble organic species. These membranes demonstrate a reversible Mg plating and stripping Coulombic efficiency (CE) of 85.4% and an ionic conductivity of 3.3 × 10 S cm at room temperature, surpassing those for a Mg-Nafion selective membrane. Theoretical density functional theory (DFT) calculations reveal that SPEEK possesses more localized charge centers along its backbone compared with Nafion, potentially facilitating enhanced ion conduction. Full cells assembled with Mg-SPEEK coupled with the organic cathode pyrene-4,5,9,10-tetraone (PTO) and Mg metal demonstrated significantly improved capacity retention as compared to those assembled with conventional nonselective separators.
镁电池由于不易发生枝晶沉积，为下一代电池技术提供了一种更安全的选择。为镁离子传导量身定制的选择性膜将推动进一步的技术进步。在此，我们展示了无氟的镁化磺化聚醚醚酮（Mg-SPEEK）选择性膜，该膜能够促进镁离子传导，同时有效排斥可溶性有机物种。这些膜在室温下表现出85.4%的可逆镁电镀和剥离库仑效率（CE）以及3.3×10 S cm的离子电导率，超过了镁-纳夫ion选择性膜。理论密度泛函理论（DFT）计算表明，与纳夫ion相比，SPEEK在其主链上具有更多的局域电荷中心，这可能有助于增强离子传导。与使用传统非选择性隔膜组装的全电池相比，使用Mg-SPEEK与有机阴极芘-4,5,9,10-四酮（PTO）和镁金属组装的全电池表现出显著提高的容量保持率。
