Glass cathode crystallization with optimized cyclability towards energy storage technology

Currently, the production of economical and effective electrodes is fundamental to the technological advancement of all energy devices. Hence, here, the 20Na2O−35Fe2O3−45P2O5 glassy electrode was prepared using the melt-quenching technique, accompanied by crystallization to obtain the crystallized glass electrodes (denoted as GCHT2h and GCHT5h). The microstructural and spectroscopic properties of the prepared glass, GCHT2h, and GCHT5h cathodes were systematically investigated via XRD, FTIR, TEM/EDX, and Mössbauer techniques. Interestingly, the electrochemical performances of these crystallized glass samples were examined by galvanostatic charge/discharge and cyclic voltammetry (CV) methods. The glass, GCHT2h, and GCHT5h cathodes exhibited initial discharge capacities of 29.26, 58.20, and 64.10 mAh g−1, respectively. In addition, after 100 cycles, the GCHT5h cathode has a substantially optimized capacity retention rate (92.0%) compared to that of the glass cathode (56.1%) and the GCHT2h cathode (90.8%). The initial coulombic efficiency of the GCHT2h and GCHT5h cathodes was ~ 103.7 % and then was relatively stable at ~ 97.9 % over all cycles, reflecting excellent cycle reversibility and stability. The CV profile of the GCHT5h cathode demonstrated the highest level of redox current. These findings highlight the potential of sodium iron phosphate crystallized glass for developing cathodes, a vital step towards improving energy storage technology.