Porous crystalline materials such as covalent organic frameworks and metal-organic frameworks have garnered considerable attention as promising ion conducting media. However, most of them additionally incorporate lithium salts and/or solvents inside the pores of frameworks, thus failing to realize solid-state single lithium-ion conduction behavior. Herein, we demonstrate a lithium sulfonated covalent organic framework (denoted as TpPa-SO3Li) as a new class of solvent-free, single lithium-ion conductors. Benefiting from well-designed directional ion channels, a high number density of lithium-ions, and covalently tethered anion groups, TpPa-SO3Li exhibits an ionic conductivity of 2.7 × 10-5 S cm-1 with a lithium-ion transference number of 0.9 at room temperature and an activation energy of 0.18 eV without additionally incorporating lithium salts and organic solvents. Such unusual ion transport phenomena of TpPa-SO3Li allow reversible and stable lithium plating/stripping on lithium metal electrodes, demonstrating its potential use for lithium metal electrodes.
Bibliographical noteFunding Information:
This work was supported by the Basic Science Research Program (2018R1A2A1A05019733, 2018M3D1A1058624, and 2017R1D1A1B03033699) and the Wearable Platform Materials Technology Center (2016R1A5A1009926) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education and the Ministry of Science, ICT and Future Planning. This work was also supported by the Samsung Research Funding Center of Samsung Electronics under project no. SRFC-MA1702-04. S.K.K. acknowledges financial support from an NRF grant funded by the Korean government (MSIT) (NRF-2018M1A2A2063341) and computational resources from UNIST-HPC.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry