P-025

Skirmantė Tutlienė

skirmante.tutliene@ftmc.lt

Jurgis Pilipavičius, Jurga Juodkazytė, Linas Vilčiauskas

Center for Physical Sciences and Technology (FTMC), Lithuania

Electrochemical Performance ant Stability Analysis of Zirconium and Hafnium Substituted NaTi2-xMx(PO4)3 Anodes for Aqueous Sodium Ion Batteries

The growing global energy demand requires transitioning to renewable energy systems, which in turn require development of efficient energy storage technologies to ensure stable grids and reliable power supply. A significant challenge in this transition is the geopolitical tensions associated with dependence on rare and difficult-to-extract elements necessary for current energy storage technologies. This reliance on scarce materials, such as lithium, cobalt, and other critical raw materials, can lead to supply chain disruptions and price volatility, hindering extensive adoption of renewable energy systems. Additionally, the disproportionate global distribution of these critical materials fuels geopolitical tensions and resource-based conflicts, thereby undermining the stability and long-term prospect of the energy transition. This unequal access to essential components poses a serious challenge to the widespread adoption of renewable energy systems. Sodium-ion water batteries, as a promising alternative, offer a sustainable solution to address both the storage demands and concerns associated with the use of scarce materials. Among the materials for sodium-ion battery electrodes, the NASICON (sodium superionic conductor) structure has gained attention. However, the stability and cycle life of these electrodes remain limiting factors for their widespread adoption. This study explores the potential of improving the stability and extending the lifespan of NASICON-based electrodes by substituting titanium with alternative elements such as zirconium (Zr) and hafnium (Hf), which are recognized for their enhanced structural stability and resistance to degradation. For this purpose, two series of anodes were prepared with the composition NaTi2-xZrx(PO4)3 and NaTi2-xHfx(PO4)3, where x ranges from 0 to 1. Detailed electrochemical cycling tests, including galvanostatic charge-discharge cycling and self-discharge measurements, are presented, demonstrating the superior performance and stability of the modified electrodes. Furthermore, structural and morphological analyses are conducted to assess the effects of these substitutions on the materials' integrity. The findings of this study provide insight into the development of more stable and durable energy storage systems, contributing to the broader adoption of renewable energy technologies.