Research Projects

Lithium-ion batteries currently dominate the portable energy storage market. However, despite their superior performance characteristics, the battery technology does face some challenges in their application as large-scale energy storage. Zinc-ion batteries can offer a viable alternative to the current state-of-the-art lithium-ion battery technology. The major advantages of a zinc ion-based battery are (a) reducing manufacturing complexities, (b) availability in the nation, (c) cost, and (d) safety. Of course, the energy density and power density are expected to be significantly lower than that of a lithium-ion battery. Nonetheless, very preliminary experiments performed at the PIs laboratory indicate the stable and good performance (see Annexure -I) of a non-aqueous rechargeable Zn ion battery based on a dual electrolyte and electrodes composed of Prussian blue analogs of Zn, Fe, and Cu and their compounds. In this context, the project thus has the following main objectives: (a) zinc/alkali cation insertion type cathode material for high capacity, high voltage, and long-term cyclability (more than 1000 cycles) and (b) the development of an efficient electrolyte system consisting of more than one cation. The synthesis of the analogs is fairly simple and solution-based techniques will be used. The synthesized materials will undergo a host of characterization both material and electrochemical. However, the focus will be on two primary aspects (a) cyclic stability and kinetics of intercalation/deintercalation in non-aqueous (glycol-based) electrolytes and (b) a fundamental understanding of the effect of other cations on intercalation/deintercalation. The studies on electrolytes will focus on binary and ternary solutions with an eye for solution resistivity, kinetics, and morphology (dendritic/non-dendritic) of Zn plating/stripping reactions. Other than the technological component of the development of a working prototype, the project will have a strong scientific component as far as the understanding of the properties of the non-aqueous electrolyte and cation intercalation in non-aqueous media on Prussian blue analogs is concerned. Further, it is hypothesized that it is possible to have selective intercalation of cations from a mix of several cations by careful control of applied voltage and to have an electrolyte with high ionic conductivity. This is of fundamental importance and can be used in a variety of applications such as sensors, membranes, etc. On the technology side, it is envisioned that the Zn-ion battery may be useful for small-scale energy storage applications based on low-cost cathode materials.