Layered Structure Na2Ti3O7 as a Promising Anode Material for Sodium-Ion Batteries

Sodium-ion batteries (SIBs), as next-generation energy storage devices, can be made by a similar production process to lithium-ion batteries (LIBs). The key to accelerating their commercialization is to discover appropriate high-performance electrode materials with low cost, nontoxicity, and simple synthetic features. Herein, layered-structure Na 2 Ti 3 O 7 , with the advantages of appropriate charge/discharge plateaus, superior stability, environmental friendliness, and ease of preparation using cheap raw materials, is selected for assembly in full-cell battery packs to evaluate its suitability for practical application. When evaluated in a coin cell, it has a capacity of 77.2 mAh g −1 at 1 A g −1 after 10 000 cycles with capacity retention of 99.9%, demonstrating its excellent stability. In the case of a soft-pack battery, it retains 22.3 mAh g −1 at 0.1 A g −1 and 18.1 mAh g −1 at 0.05 A g −1 after 50 cycles. After cycling, there is no sodium dendrite formation or active material shedding, further confirming its safety in practical application. Therefore, Na 2 Ti 3 O 7 as another intercalation/deintercalation mechanism material has application potential in the future.