Zhang Kai-Lun, Li Na, Li Xu, Huang Jun, Chen Haosen, Jiao Shuqiang, Song Wei-Li
Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing, 100081, P. R. China.
Institute of Theoretical Chemistry, Ulm University, Ulm, 89069, Germany.
Adv Sci (Weinh). 2022 Jun;9(18):e2200213. doi: 10.1002/advs.202200213. Epub 2022 Apr 23.
The ionic conductivity of composite solid-state electrolytes (SSEs) can be tuned by introducing inorganic fillers, of which the mechanism remains elusive. Herein, ion conductivity of composite SSEs is characterized in an unprecedentedly wide frequency range of 10 -10 Hz by combining chronoamperometry, electrochemical impedance spectrum, and dielectric spectrum. Using this method, it is unraveled that how the volume fraction v and surface fluorine content x of TiO fillers tune the ionic conductivity of composite SSEs. It is identified that activation energy E is more important than carrier concentration c in this game. Specifically, c increases with v while E has the minimum value at v = 10% and increases at larger v. Moreover, E is further correlated with the dielectric constant of the SSE via the Marcus theory. A conductivity of 3.1×10 S cm is obtained at 30 °C by tuning v and x , which is 15 times higher than that of the original SSE. The present method can be used to understand ion conduction in various SSEs for solid-state batteries.
复合固态电解质（SSEs）的离子电导率可通过引入无机填料来调节，但其机制仍不清楚。在此，通过结合计时电流法、电化学阻抗谱和介电谱，在前所未有的10⁻¹⁰至10 Hz宽频率范围内对复合SSEs的离子电导率进行了表征。使用该方法，揭示了TiO填料的体积分数v和表面氟含量x如何调节复合SSEs的离子电导率。发现在此过程中活化能E比载流子浓度c更重要。具体而言，c随v增加，而E在v = 10%时具有最小值，并在v更大时增加。此外，根据Marcus理论，E与SSE的介电常数进一步相关。通过调节v和x，在30°C时获得了3.1×10⁻⁵ S cm⁻¹的电导率，比原始SSE高15倍。本方法可用于理解固态电池中各种SSEs的离子传导。
