近日，南开大学曹鹏飞及其团队的最新研究报道了，氰基丙烯酸乙酯作为锂金属电池凝胶电解质的共聚行为。该项研究成果发表在2025年1月9日出版的《德国应用化学》上。

具有强吸电子基团的聚合物（如含氰聚合物）由于其高介电常数，和优异的电化学稳定性而在广泛的应用中具有吸引力。然而，这类单体的聚合很难控制，因为微量的水可以提供即时反应，而与其他单体的共聚在没有强酸的情况下更具有挑战性。

该研究展示了一种简单的方法，可以在不添加有害添加剂的情况下，实现氰基丙烯酸酯乙酯（ECA）的高效可控共聚，实现机械稳健和高离子导凝胶聚合物电解质（GPE），作为安全和长循环寿命锂金属电池（LMB）的基础。加入的双锂盐，即二氟(草酸)硼酸锂（LiDFOB）和二氟(三氟甲烷磺酰基)亚胺锂（LiTFSI），不仅通过抑制ECA单体的阴离子聚合促进自由基聚合，而且还促进了高离子导电GPE的形成。

加入的甲基丙烯酸甲酯（MMA）单体加速了ECA的自由基聚合（经DFT计算证实），实现了ECA基共聚物的可控共聚。由ECA共聚物制成的机械稳健聚合物网络，使LFP阴极和高压LCO阴极（4.5 V）的LMB可以在不同的温度下工作，在1℃下具有超长的循环寿命（1000次循环后容量保持率分别为81.1%和83.8%）。

附：英文原文

Title: Mastering the Copolymerization Behavior of Ethyl Cyanoacrylate as Gel Polymer Electrolyte for Lithium-metal Battery Application

Author: Weixing Min, Lengwan Li, Mingli Wang, Shuaijiang Ma, Hao Feng, Weirong Wang, Hang Ding, Tianhui Cheng, Zhenxi Li, Tomonori Saito, Huabin Yang, Peng-Fei Cao

Issue&Volume: 2025-01-09

Abstract: Polymers with strong electron-withdrawing groups (e.g., cyano-containing polymers) are attractive for a wide range of applications due to their high dielectric constant and outstanding electrochemical stability. However, the polymerization of such monomers is difficult to control with trace of water affording instant reactions, and copolymerization with other monomers without using strong acid is even more challenging. The present study demonstrates a facile approach enabling efficient and controllable copolymerization of ethyl cyanoacrylate (ECA) without adding undesired additives, achieving mechanically robust and high ion-conduction gel polymer electrolyte (GPE) for safe and long cycle-life lithium-metal batteries (LMBs). The incorporated dual-lithium salts, i.e., lithium difluoro(oxalato)borate (LiDFOB) and lithium bis(trifluoromethanesulphonyl)imide (LiTFSI) not only facilitate radical polymerization of ECA monomers by suppressing their anionic polymerization, but also promote the formation of high-ionic conducting GPE. The incorporated methyl methacrylate (MMA) monomer accelerates the radical polymerization of ECA (confirmed by DFT calculations), achieving controlled copolymerization of ECA-based copolymers. The mechanically robust polymer network made by the ECA copolymer enables LMBs with both LFP cathodes and high-voltage LCO cathodes (4.5 V) operatable at different temperatures with ultra-long cycle life at 1 C (capacity retention of 81.1% and 83.8%, respectively, over 1000 cycles).

DOI: 10.1002/anie.202422510

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202422510