High-power sodium titanate anodes; a comparison of lithium vs sodium-ion batteries

Sodium titanate nanopowder (nominal formula Na1.5H0.5Ti3O7) was directly synthesized using a continuous hydrothermal flow synthesis process using a relatively low base concentration (4 M NaOH) in process. The as made titanate nanomaterials were characterised using powder X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, Brunauer-Emmett-Teller analysis and transmission electron microscopy, and evaluated as potential electrode materials for Li-ion and Na-ion batteries. Cyclic voltammetry studies on half-cells revealed that the sodium titanate nanomaterial stored charge primarily through a combination of pseudocapacitive and diffusion-limited processes in both systems. Electrochemical cycling tests at a high specific current of 1000 mA g(-1), revealed that the Li-ion and Na-ion cells retained relatively high specific capacities after 400 cycles of 131 and 87 mAh g(-1), respectively. This study demonstrates the potential of CHFS-made sodium titanate nanopower as an anode material for both Li- and Na-ion cell chemistries.