Amorphous Aluminum Oxide-Coated NaFe_0.33Ni_0.33Mn_0.33O₂ Cathode Materials: Enhancing Interface Charge Transfer for High-Performance Sodium-Ion Batteries

Abstract

Layered cathode materials for sodium-ion batteries (SIBs) have gained considerable attention as promising candidates owing to their high capacity and potential for industrial scalability. Nonetheless, challenges arise from stress and structural degradation resulting from the deposition of larger ion radius species, leading to diminished cyclic stability and rate performance. In this study, we present a novel and straightforward strategy that combines the synergistic effects of an amorphous aluminum oxide coating and aluminum ion doping. This approach effectively addresses the issues of grain cracking and expands the interlayer spacing of alkali metal ions in SIB materials, thereby enhancing their overall performance. Consequently, it optimizes the diffusion of charge carriers and facilitates interfacial charge transfer, leading to remarkable improvements in the performance of the NaNi 0.33 Mn 0.33 Fe 0.33 O 2 material with 0.4 wt % amorphous aluminum oxide coating (NNMF-0.4A), which exhibits reversible

Regulating Interfacial Compositions to Build a Stable Superlattice Structure of Layered Oxide Cathode Materials for Sodium-Ion Batteries

“…It is worth noting that the (002) diffraction peak shifted to a smaller angle and the layer spacing gradually increased with increasing Si content, indicating that some Si was introduced into the TM layer. Due to the stronger bonding force between Si and O (Si–O is 798 kJ·mol –1 , Ni–O is 391.6 kJ·mol –1 , Mn–O is 402 kJ·mol –1 ), when Si is introduced into the TM layer, the average bond length of TM–O becomes shorter and the TMO 6 structure becomes more stable . Accordingly, the distance between adjacent TMO 2 layers increases, which is conducive to the reversible transfer of Na + between the layers.…”

“…), when Si is introduced into the TM layer, the average bond length of TM−O becomes shorter and the TMO 6 structure becomes more stable. 38 Accordingly, the distance between adjacent TMO 2 layers increases, which is conducive to the reversible transfer of Na + between the layers. The above conclusions were confirmed by X-ray diffraction (XRD) Rietveld refinement (Figure S4; refinement results are shown in Table S1).…”

Sodium layered oxide cathodes: properties, practicality and prospects

“…An amorphous aluminum oxide-coated NaFe 0.33 Ni 0.33 Mn 0.33 O 2 cathode was found to effectively reduce the interfacial charge transfer resistance, thereby improving the overall battery performance. 179 Additionally, this coating layer could alleviate the issue of particle cracking that arises due to non-uniform stress distribution. In addition, the in situ -formed NaF and C–O-rich cathode electrolyte interphase (CEI) film on the cathode surface exhibited high mechanical strength and ionic conductivity.…”

Slow-Released Cationic Redox Activity Promoted Stable Anionic Redox and Suppressed Jahn–Teller Distortion in Layered Sodium Manganese Oxides

“…With the increased demand for new energy storage, the expansion of lithium-ion batteries (LIBs) industry has intensified the exploitation of limited lithium resources and their rising cost. − Sodium-ion batteries (SIBs) are considered a promising alternative to LIBs for energy storage due to their similar electrochemistry principle, rich sodium resources, and relatively low cost. − Developing high-performance cathode materials is one of the keys to further commercial applications of SIBs. Among the numerous cathode candidates reported so far, the layered transition metal (TM) oxides family (Na x TMO 2 ), especially manganese-based layered oxides (Na x MnO 2 ), have been deeply studied owing to their high theoretical capacity, extremely low cost, and environmental sustainability. − However, these layered Na x MnO 2 compounds usually undergo serious MnO 6 octahedral distortion induced by the typical Jahn–Teller effect of high-spin Mn 3+ ions during the electrochemical cycle, which results in structural deterioration and severe capacity fade. − To suppress the Jahn–Teller effect of the Mn 3+ ion, various electrochemically inactive cationic ions (such as Mg 2+ , Zn 2+ , Al 3+ , and Mo 6+ ) were introduced into TM ion sites to regulate the electron and band structure of MnO 6 octahedra. − Also, cationic B 3+ ions with a small radius were introduced into the tetrahedral interstitial sites in the TM layer to effectively mitigate the Jahn–Teller effect …”