[1]Department of Mechanical Engineering National University of Singapore 9 Engineering Drive 1 Singapore 117575;
[2]College of Aerospace Engineering Chongqing University Chongqing 400044 PR China;
[3]AGH University of Science and Technology Faculty of Energy and Fuels al Mickiewicza 30 30-059 Krakow Poland;
[4]National University of Singapore (Suzhou) Research Institute Suzhou PR China;
Sodium ion battery; Ionic conductivity; Inorganic solid electrolyte; Solid polymer electrolyte; Ceramic-polymer composite electrolyte;