Research Projects

Owing to limited storage of lithium in the earth, the researchers are alternatively thinking about sodium ion batteries (NIBs) because of their availability in large scales and low cost preparation techniques [1-3]. Na2O doped glassy system acts as the electrolyte of NIBs due to their important features in electrochemical stability, sensors, electrochemical devices etc. [4]. Out of two types of Na2O doped electrolytes, liquid electrolyte shows better electrical conductivity [2]. But liquid electrolytes exhibit lower capacitance and their stability is not up to the mark [2]. This shortcoming can be improved by using Na2O doped electrolyte in solid form because of their higher stability and easy accessibility [2]. Efforts [2] have been made to develop Na2O doped solid electrolytes, which show moderate ionic conductivity. This information led us to develop a new Na2O as well as NaI doped solid electrolyte with higher ionic conductivity at ambient temperature. Present work has been done with the following objectives: (i) To develop Na2O and NaI doped solid electrolytes in a very easy and low cost process (ii) To enhance electrical conductivity of the present system at ambient temperature (iii) To establish the relation between ion migration process and the dielectric properties in the present system (iv) To explore nature of conduction mechanism in the present system in a comparative manner with others work (v) To explore the nature of hopping/migration frequency of Na+ ions as well as electrochemical stability of the present system so that the newly developed Na2O or NaIdoped solid electrolytes can be regarded as suitable candidate for NIBs application In particular, this project work will address some unexplored questions----- • What factors do influence the sodium ion conduction in as-prepared glassy system? • Do the present models of DC conductivity and AC relaxation mechanism agree with the experimental data? • How the elctrochemicalstability is related with the conductivity and how it varies with temperature and composition? • How the frequency exponents (in the low and high frequency regime) vary with temperature and composition? • Does the variation of the microscopic parameters with composition obtained from conductivity and modulus formalism tally? • Do the relaxation dynamics in these glassy systems depend on temperature or composition? • What factors do influence the performance of sodium ion conducting glassy system as the Na-ion battery application? References: 1. J. Y. Hwang, S. T. Myung, Y. K. Sun. Chemical Society Reviews, 46(12), (2017) 3529-3614. 2. Glass nanocomposites: synthesis, properties and applications; Basudeb Karmakar, Klaus Rademann, ANDREY Stepanov, Elsevier Publication, 2016 3. L. P. Wang, L. Yu, X. Wang, M. Srinivasan, Z. J. Xu, Journal of Materials Chemistry A, 3(18), (2015) 9353-9378. 4. H. Aono, Y. Sadaoka, Chemistry Letters, 29(1), (2000) 34-35.