超离子导体Li3-xNaxZr2Si2PO12中的Li+/Na+混合离子传导机制OA
Li+/Na+Hybrid Ion Conduction Mechanism in the Superionic Conductor Li3-xNaxZr2Si2PO12
混合离子导体能够同时传导多种离子,为探究单一相中混合离子传输对离子电导调控机制提供了重要支持.然而,多种可迁移离子在固态电解质中的可控引入及其在晶体骨架内的迁移机理仍面临挑战.本文采用一种骨架保持的 Li+↔Na+阳离子交换策略,在 NASICON 型 Li3-xNaxZr2Si2PO12(0<x<3)的骨架中同时引入 Li+和 Na+.研究表明,NaO6 和 NaO8 配位多面体的相互贯通对混合离子导体的离子电导率具有显著影响.计算分析显示,Na+更倾向于从八面体配位的 NaO6 位点迁移至八配位的 NaO8 位点,同时伴随 Li+从 NaO8 位点向原 NaO6 位点处的四面体 LiO4 环境迁移,从而促进 Li+/Na+位点分离.随着 Na+在 NaO8 位点占据比例的增加,瓶颈效应限制了 Na+的迁移,同时阻碍了连续 Li+迁移网络的形成,导致离子电导率由 1.78 mS·cm-1 降低至 0.50 mS·cm-1.经再次离子交换后,NaO8 环境中的 Na+被 Li+所取代,形成五配位的 LiO5,从而重建 Li+的渗透传输通道,实现体电导的可逆恢复.该研究揭示了基于 Li+与 Na+在可用位点间分散占据的快速双离子传导机制,为进一步发展固态混合离子导体开辟了新途径.
Hybrid ion conductors that transport multiple ionic conductive species provide a useful platform for understanding how mixed-ion transport governs ionic conductivity within a single phase.However,the controlled introduction of mul-tiple mobile ions into solid-state electrolytes and a mechanistic understanding of their migration within the framework remain challenging.Herein,a skeleton-retained Li+↔Na+cationic exchange was used to simultaneously induce Li+and Na+cations into the NASICON-type framework of Li3-xNaxZr2Si2PO12(0<x<3).We show that the interpenetration of NaO6 and NaO8 coordination polyhedra significantly influences the ionic conductivity of hybrid ion conductors.Computational anal-ysis indicates that Na+transfer from octahedral NaO6 sites to octa-coordinated NaO8 sites is thermodynamically favorable,accompanied by Li+relocation from NaO8 to tetrahedral LiO4 environments at former NaO6 sites,thereby promoting Li+/Na+site segregation.The increased occupation of Na+at NaO8 sites not only suppresses Na+mobility due to bottleneck lim-itations but also hinders the formation of a continuous Li+migration network,thereby reducing the room-temperature ionic conductivity from 1.78 to 0.50 mS·cm-1.Upon re-exchange,Na+in the NaO8 sites is replaced by Li+in penta-coordinated LiO5,which re-establish percolating ion-transport pathways for Li+and enable reversible recovery of the overall conduc-tivity.These results reveal a fast dual-ion conduction mechanism enabled by the interpenetrating occupation of Li+and Na+across the available sites.This work opens a new avenue for the development of hybrid ion conductors.
吴艺弘;谢霞;朱蕾;于沐冉;张果泰;陈俊超;孙淑英;王有伟;汤卫平
华东理工大学资源与环境工程学院,上海 200237中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海 200050||中国科学院大学材料科学与光电技术学院,北京 100049上海空间电源研究所,上海 200245上海交通大学化学化工学院,上海 200240上海交通大学化学化工学院,上海 200240上海交通大学化学化工学院,上海 200240华东理工大学资源与环境工程学院,上海 200237中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海 200050||中国科学院大学材料科学与光电技术学院,北京 100049上海交通大学化学化工学院,上海 200240
混合离子导体锂/钠阳离子交换双离子传导机制渗透占据
Hybrid ion conductorLi+/Na+cationic exchangeDual-ion transport mechanismInterpenetrating occupation
《电化学（中英文）》 2026 (6)
1-9,9
This work was financially supported by the Na-tional Natural Science Foundation of China,NSFC(22402119,22509129,92372103 and U25A20243),Puji-ang Project of the Shanghai Baiyulan Talent Program(24PJD049),Natural Science Foundation of Shang-hai(25ZR1402376),Open Foundation of Shanghai Jiao Tong University Shaoxing Research Institute of Renewable Energy and Molecular Engineering(JDSX2023011),and Opening Project of State Key Laboratory of Space-Power Sources(24-1533).
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