The role of sodium in the electrochemical tuning of Li2TiSiO5 anodes across ceramic and glass phases

Abstract

This study investigates the enhancement of Li2TiSiO5 anode material through Na doping via two routes: melt-quenching (route I) and subsequent heat treatment (route II). A 5 % Na-doped ceramic sample significantly improves Li-ion mobility and discharge capacity (215 mA h g−1 at 10 mA g−1), sustaining 45 mA h g−1 at a high rate of 1 A g−1. However, higher doping levels hinder performance, indicating Li-ion path obstruction and non-conductive impurities. Intriguingly, undoped Li2TiSiO5 glass exhibits superior electrochemical performance, with a discharge capacity of 340 mA h g−1 at 10 mA g−1 and high-rate endurance (81 mA h g−1 at 1 A g−1). This research provides insights into phase-dependent optimization, highlighting the glass phase's inherent benefits for Li-ion diffusion. It addresses a significant research gap, offering critical understanding for advancing high-energy-density anode materials in next-generation batteries.

Keywords

• Li2-xNaxTiSiO5
• Na-doping
• Electrochemical performance
• XAS