%0 Journal Article %A Wei Yin %A Judith Alvarado %A Gözde Barim %A M C Scott %A Xinxing Peng %A Marca M Doeff %B MRS Energy & Sustainability %D 2021 %G eng %N 2 %P 88 - 97 %R 10.1557/s43581-021-00008-6 %T A layered nonstoichiometric lepidocrocite-type sodium titanate anode material for sodium-ion batteries %U https://link.springer.com/10.1557/s43581-021-00008-6 %V 8 %8 09/2021 %! MRS Energy & Sustainability %X

A lepidocrocite-structured sodium titanate prepared by ion-exchange of a Cs-containing precursor shows promise as an anode material for sodium ion batteries, with a discharge capacity of up to 229 mAh g−1 at an average potential of about 0.6 V vs. Na+/Na. Titanium vacancies in the metal oxide layers provide additional sites for sodium intercalation in addition to interlayer sites, which accounts for the higher capacity compared to other previously reported lepidocrocite-structured titanates. By screening a series of electrolyte formulations and binders, we were able to improve the first-cycle coulombic efficiency to 81.8% and 94.7% respectively using CMC/SBR-based and binder-free electrodes in ether electrolytes. The electrochemical consequences of short-term air-exposure on the electrodes are also discussed.