Long‐Cycle‐Life Sodium‐Ion Battery Fabrication via a Unique Chemical Bonding Interface Mechanism

Abstract

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, a novel hollow Na 2 Ti 3 O 7 microsphere (H-NTO) with a unique chemically bonded NTO/C(N) interface is reported. Theoretical calculations demonstrated that the NTO/C(N) interface stabilizes the crystal structure, and the optimized interface enables 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 is 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.

Building a Stable Plateau-Type Na2Ti3O7 Anode Interface toward Advanced Sodium-Ion Batteries

“…As shown in Figure 1f, the fitting curves of the O 1s signal for NTO can be deconvoluted into three regions at 534.5, 530.8, and 529.6 eV, which are ascribed to O−H, Ti−O−H, and Ti− O bonds, respectively. 31,34 To investigate the feasibility of incorporating TEOS as an additive, we constructed Na-ion half-cells using the NTO sample as the working electrode. The initial galvanostatic charge and discharge (GCD) curve exhibited four distinct voltage plateaus, which corresponded to different processes: electrolyte decomposition, irreversible reaction between sodium ions and Ketjen black, insertion of Na + into Na 2 Ti 3 O 7 , and formation of Na 4 Ti 3 O 7 (Figure 2a).…”

“…As a result, there is an urgent requirement to develop a straightforward and convenient method to enhance the interfacial stability of NTO anode materials, aiming to significantly improve the electrochemical performance of Na 2 Ti 3 O 7 anodes. 31 In this work, a silicon-containing film-forming additive, tetraethyl orthosilicate (TEOS), is introduced into the ether electrolyte (1.0 M NaPF 6 in dimethoxyethane, DME) for optimizing the interface stability of NTO anode materials. The presence of a more stable SEI layer enhances the cycling stability of NTO.…”

“…Poly(ethylene oxide) and alkyl carbonates were discovered to be partially dissolved among these components, contributing to the instability of the SEI layer and negatively influencing battery performance. As a result, there is an urgent requirement to develop a straightforward and convenient method to enhance the interfacial stability of NTO anode materials, aiming to significantly improve the electrochemical performance of Na 2 Ti 3 O 7 anodes …”

Enabling Further Organic Electrolyte Infiltration of Cellulose-Based Separators via Defect-Rich Polypyrrole Modification for High Sodium Ion Transport in Sodium Metal Batteries

“…Metallic sodium possessing enormous theoretical capacity (1166 mA h g –1 ), low redox potential (−2.714 V versus standard hydrogen electrode), and abundant natural occurrence has been desirable due to its gigantic energy density and cost-effectiveness as an anode in promising next-generation rechargeable batteries. − Nevertheless, its uneven solid electrolyte interphase (SEI) and uncontrollable dendritic growth result in some problems such as microshorts, confined cyclability, and poor rate performance, which suppress their actual applications. , Many battery design strategies have been employed to address these challenges. , One of the efforts is dedicated to the exploration of electrolytes containing fluorine to enhance the interfacial stability by their sacrificial decomposition to form a robust NaF-containing SEI layer, which is profitable to inhibit dendrite growth. , Unfortunately, implementing this strategy can lead to the formation of corrosive and environmentally unfriendly hydrofluoric acid (HF) and cost escalation. , Except for utilizing fluorine-containing electrolytes, regulating ion flux and boosting the anion transfer number have been likewise considered as practical strategies to suppress dendrite growth but remain challenging to implement …”

Highly Crystalline Poly(heptazine imide)-Based Carbonaceous Anodes for Ultralong Lifespan and Low-Temperature Sodium-Ion Batteries

“…The increasing demands of energy storage from portable electronics, electrical vehicles, and other applications require the development of advanced battery technologies with high energy and power densities. − The commercialized lithium-ion batteries (LIBs) have limitations due to the shortage of natural reserves, and the pursuit of low-cost alternatives is in great necessity. Sodium-ion batteries (SIBs), with similar chemical properties and working mechanism to LIBs, are viewed as one of the most promising commercializable choices for large-scale energy storage. − Electrode material is the key component to determine the performances of batteries, while the larger ionic radius of Na + leads to the unfeasibility of conventional graphite materials used in LIBs for SIBs.…”