Affiliation:
1. Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China
2. Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing 100049 China
3. Center for Hydrogenergy College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 Jiangsu China
4. Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
5. NIST Center for Neutron Research National Institute of Standards and Technology Gaithersburg MD 20899–6102 USA
6. Pacific Northwest National Laboratory Richland WA 99352 USA
Abstract
AbstractReplacing widely used organic liquid electrolytes with solid‐state electrolytes (SSEs) could effectively solve the safety issues in sodium‐ion batteries. Efforts on seeking novel solid‐state electrolytes have been continued for decades. However, issues about SSEs still exist, such as low ionic conductivity at ambient temperature, difficulty in manufacturing, low electrochemical stability, poor compatibility with electrodes, etc. Here, sodium carbazolide (Na‐CZ) and its THF‐coordinated derivatives are rationally fabricated as Na+ conductors, and two of their crystal structures are successfully solved. Among these materials, THF‐coordinated complexes exhibit fast Na+ conductivities, i.e., 1.20×10−4 S cm−1 and 1.95×10−3 S cm−1 at 90 °C for Na‐CZ‐1THF and Na‐CZ‐2THF, respectively, which are among the top Na+ conductors under the same condition. Furthermore, stable Na plating/stripping is observed even over 400 h cycling, showing outstanding interfacial stability and compatibility against Na electrode. More advantages such as ease of synthesis, low‐cost, and cold pressing for molding can be obtained. In situ NMR results revealed that the evaporation of THF may play an essential role in the Na+ migration, where the movement of THF creates defects/vacancies and facilitates the migration of Na+.
Funder
National Natural Science Foundation of China
Dalian National Laboratory for Clean Energy
Biological and Environmental Research