NASICON-Structured NaTi₂(PO₄)₃ for Sustainable Energy Storage

Several emerging energy storage technologies and systems have been demonstrated that feature low cost, high rate capability, and durability for potential use in large-scale grid and high-power applications. Owing to its outstanding ion conductivity, ultrafast Na-ion insertion kinetics, excellent structural stability, and large theoretical capacity, the sodium superionic conductor (NASICON)-structured insertion material NaTi₂(PO₄)₃ (NTP) has attracted considerable attention as the optimal electrode material for sodium-ion batteries (SIBs) and Na-ion hybrid capacitors (NHCs). On the basis of recent studies, NaTi₂(PO₄)₃ has raised the rate capabilities, cycling stability, and mass loading of rechargeable SIBs and NHCs to commercially acceptable levels. In this comprehensive review, starting with the structures and electrochemical properties of NTP, we present recent progress in the application of NTP to SIBs, including non-aqueous batteries, aqueous batteries, aqueous batteries with desalination, and sodium-ion hybrid capacitors. After a thorough discussion of the unique NASICON structure of NTP, various strategies for improving the performance of NTP electrode have been presented and summarized in detail. Further, the major challenges and perspectives regarding the prospects for the use of NTP-based electrodes in energy storage systems have also been summarized to offer a guideline for further improving the performance of NTP-based electrodes.