Long-cycle Life Sodium-ion Battery Fabrication via Unique Chemical Bonding Interface Mechanism.

Titanates have been widely reported as anode materials for sodium-ion batteries (SIBs). However, their wide temperature suitability and cycle life remain fundamental issues that hinder their practical application. Herein, we report a novel hollow Na 2 Ti 3 O 7 microsphere (H-NTO) with a unique chemically bonded NTO/C(N) interface. Theoretical calculations demonstrated that the NTO/C(N) interface stabilized the crystal structure, and the optimized interface enabled the H-NTO anode to stably operate for 80,000 cycles in a conventional ester electrolyte with negligible capacity loss. Optimizing the electrolyte allows the H-NTO electrode to cycle stably for 200 calendar days without capacity degradation at -40°C. The excellent cycling stability was attributed to the NTO/C(N) interface and the stable solid electrolyte interphase formed by the highly adaptable electrolyte/electrode interface. Titanate exhibits solvent co-intercalation behavior in ether-based electrolytes, and its robust structure ensures that it can adapt to large volume changes at low temperatures. This study provides a unique perspective on the long-cycle mechanism of titanate anodes and highlights the critical importance of manipulating the interfacial chemistry in SIBs, including the material and electrode/electrolyte interfaces. This article is protected by copyright. All rights reserved.