The benefits of incorporating lead-free ferroelectric materials in high energy density Li- and Li-free batteries

Demand for energy storage is increasing day by day and developing a pollution free environment necessitates new battery technologies. However, the existing energy storage technologies like lithium (Li)-ion batteries cannot fulfil the future needs alone. In this regard, Li-free batteries such as sodium (Na), potassium (K), zinc (Zn) and magnesium (Mg) ion batteries have attracted significant attention due to their unique properties, large abundance in the earth's crust, and economic feasibility. Both Li-based and Li-free batteries suffer from drawbacks such as low ionic conductivity, irregular nucleation, poor interfacial stability, volume expansion, etc. Recently, the incorporation of ferroelectrics in batteries has emerged as a viable solution to mitigate some of the problems. However, in most cases environmentally unfriendly conventional lead-based ferroelectrics have been studied. This review investigates the role of emerging lead-free ferroelectrics incorporated in Li- and Li-free batteries.