Li Shuqiang, Lu Xueying, Li Yu, Wang Huaizhi, Sun Yufeng, Zhou Qiannan, Yue Jiasheng, Guo Ruiqi, Wu Feng, Wu Chuan, Bai Ying
Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, 314019, China.
Adv Mater. 2024 Dec;36(49):e2413013. doi: 10.1002/adma.202413013. Epub 2024 Oct 24.
Low-temperature synthesis of polyanionic cathodes for sodium-ion batteries is highly desirable but often plagued by prolonged reaction times and suboptimal crystallinity. To address these challenges, a novel self-adaptive coordination field regulation (SACFR) strategy based on a dynamic lock-and-release (DLR) mechanism is introduced. Specifically, urea is used as a DLR carrier during synthesis, which dynamically "locks" and "releases" vanadium ions for controlled release, simultaneously "locking" H ions to enhance phosphate group release, thereby creating a self-adaptive coordination field that can intelligently respond to real-time demands of the reaction system. This dynamic coordination behavior contributes to both an improvement in reaction kinetics and a significant reduction in Gibbs free energy change (ΔG). As a result, the kinetic efficiency and thermodynamic spontaneity of the reaction are greatly enhanced, enabling the efficient synthesis of high-crystalline NaVO(PO)F (NVOPF) at 90 °C within just 3 hours. The as-prepared NVOPF cathode exhibits exceptional rate performance and ultra-stable cycling stability across a broad temperature range. Furthermore, the successful kilogram-scale synthesis underscores the practical potential of the innovative strategy. This work pioneers the regulation of coordination field chemistry for polyanionic cathode synthesis, providing transformative insights into material design.
钠离子电池聚阴离子阴极的低温合成非常理想，但常常受到反应时间过长和结晶度欠佳的困扰。为应对这些挑战，引入了一种基于动态锁定-释放（DLR）机制的新型自适应配位场调控（SACFR）策略。具体而言，在合成过程中尿素用作DLR载体，它动态地“锁定”和“释放”钒离子以实现可控释放，同时“锁定”氢离子以增强磷酸根离子的释放，从而创建一个能够智能响应反应体系实时需求的自适应配位场。这种动态配位行为有助于反应动力学的改善以及吉布斯自由能变化（ΔG）的显著降低。结果，反应的动力学效率和热力学自发性得到极大提高，能够在90°C下仅3小时内高效合成高结晶度的NaVO(PO)F（NVOPF）。所制备的NVOPF阴极在很宽的温度范围内展现出优异的倍率性能和超稳定的循环稳定性。此外，成功的千克级合成突出了该创新策略的实际潜力。这项工作开创了聚阴离子阴极合成中配位场化学的调控，为材料设计提供了变革性的见解。
