Fast Lithium Ion Conductivity in Layered (Li–Ag)CrS<sub>2</sub>
Jing Peng, Yuhua Liu, Yu Pan, Jiajing Wu, Yueqi Su, Yuqiao Guo, Xiaojun Wu, Changzheng Wu, Yi Xie
Abstract
Fast ionic conductors are of great importance for novel technologies in high-performance and rechargeable energy storage components with reliable safety and thermal stability. Here, we demonstrate a new concept of the pillar effect to construct two-dimensional (2D) fast Li+ conductors. Our developed layered LixAg1–xCrS2 (0 < x < 0.4) structure, with larger-radius Ag+ served as “pillars” to effectively rigidify the interlayer ionic channel, leads to multi-ion concerted migration behavior and thus contributes to low activation energy and fast Li+ diffusion. Consequently, the room-temperature ionic conductivity in (Li–Ag)CrS2 system reaches up to 19.6 mS·cm–1 for x is 0.31, which is comparable to that of currently best Li-ion conductors. Furthermore, the pillared structure exhibits unique ionic transport that the conductivity decreases as temperature elevated, which can be ascribed to the competition between Li+ and Ag+ migration through tetrahedral viods in 2D channel. We anticipated that pillar effect would pave a new way to explore new catalogue of Li superionic conductors.