Yang Tao, Xu Xijun, Chen Suping, Yang Yan, Li Fangkun, Fan Weizhen, Wu Yanxue, Zhao Jingwei, Liu Jun, Huo Yanping
School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, PR China.
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, China.
Angew Chem Int Ed Engl. 2025 Feb 24;64(9):e202420973. doi: 10.1002/anie.202420973. Epub 2025 Jan 9.
As traditional lithium-ion batteries near their theoretical limits, the advancement of lithium-metal batteries (LMBs) becomes crucial for achieving higher energy densities. However, uncontrolled ion transport and unstable solid electrolyte interface (SEI) layer are key factors inducing lithium dendrite growth, hindering the development of LMBs. Separator modification is an effective strategy to address the challenges of LMBs. To tackle the issues, a donor-acceptor polymer (ArMT) consisting of benzene rings and triazine was successfully synthesized and modified onto commercial polypropylene (ArMT@PP) as separators for LMBs. Benefitting from the highly lithiophilic triazine organic units, this ArMT exhibits affinity towards Li and simplifies the solvation structure of Li during the diffusion process, thus decreasing the ion diffusion activation energy, thereby accelerating the migration of Li. Furthermore, triazine organic units with appropriate pore size regulate the plating/stripping behavior of lithium metal anodes, thereby facilitating the formation of a stable solid electrolyte interface (SEI) layer. As a result, the assembled Li|ArMT@PP|Li symmetric cells exhibit stable plating/stripping over 800 h. Moreover, the LiFePO|ArMT@PP|Li cells achieved excellent cycling stability with 127.3 mAh g after 1200 cycles at 1 C and a high capacity retention of 90.58 %. This design strategy ensures a durable and dendrite-free anode and paves the way for the development of high-energy-density LMBs.
随着传统锂离子电池接近其理论极限，锂金属电池（LMBs）的发展对于实现更高的能量密度至关重要。然而，不受控制的离子传输和不稳定的固体电解质界面（SEI）层是诱导锂枝晶生长的关键因素，阻碍了LMBs的发展。隔膜改性是解决LMBs挑战的有效策略。为了解决这些问题，一种由苯环和三嗪组成的给体-受体聚合物（ArMT）被成功合成并修饰在商用聚丙烯（ArMT@PP）上作为LMBs的隔膜。受益于高度亲锂的三嗪有机单元，这种ArMT对Li表现出亲和力，并在扩散过程中简化了Li的溶剂化结构，从而降低了离子扩散活化能，进而加速了Li的迁移。此外，具有适当孔径的三嗪有机单元调节锂金属负极的电镀/剥离行为，从而促进形成稳定的固体电解质界面（SEI）层。结果，组装的Li|ArMT@PP|Li对称电池在800 h以上表现出稳定的电镀/剥离。此外，LiFePO|ArMT@PP|Li电池在1 C下经过1200次循环后实现了优异的循环稳定性，容量为127.3 mAh g，高容量保持率为90.58%。这种设计策略确保了耐用且无枝晶的负极，为高能量密度LMBs的发展铺平了道路。
