Sodium‐ion batteries (SIBs) are potential candidates for the replacement of lithium‐ion batteries to meet the increasing demands of electrical storage systems due to the low cost and high abundance of sodium. Sodium superionic conductor (NASICON) structured materials have attracted enormous interest in recent years as electrode materials for safer and long‐term performance of SIBs for electric energy storage smart grids. These materials have a three‐dimensional robust framework, high redox potential, thermal stability, and a fast Na⁺‐ion diffusion mechanism. However, NASICON has low intrinsic electronic conductivity, which limits the electrochemical performance. This review describes the structural features of NASICONs to illustrate the ion storage mechanism and electrochemical performance of SIBs. Details of the NASICON crystal structure, the affiliated Na⁺‐ion diffusion mechanism, morphology, and electrochemical performance of these materials in sodium‐ion half‐cells as well as full cells are described. In addition to the application as electrode materials, the use of NASICONs as solid electrolytes is also elaborated in solid‐state SIBs. Based on these aspects, we have provided more perspectives in terms of the commercialization of SIBs and strategies to overcome the limitations of NASICONs. Hence, this review is expected to provide the researchers of energy storage with an in‐depth understanding of NASICON materials with the knowledge of structural features, which will provide a new avenue on the practicality of SIBs.

Designing multifunctional nanomaterials for high performing electrochemical energy conversion and storage devices has been very challenging. A number of strategies have been reported to introduce multifunctionality in electrode/catalyst materials including alloying, doping, nanostructuring, compositing, etc. Here, we report the fabrication of a reduced graphene oxide (rGO)-based ternary composite NiO/MnO₂/rGO (NMGO) having a range of active sites for enhanced electrochemical activity. The resultant sandwich structure consisted of a mesoporous backbone with NiO and MnO₂ nanoparticles encapsulated between successive rGO layers, having different active sites in the form of Ni-, Mn-, and C-based species. The modified structure exhibited high conductivity owing to the presence of rGO, excellent charge storage capacity of 402 F·g⁻¹ at a current density of 1 A·g⁻¹, and stability with a capacitance retention of ~93% after 14,000 cycles. Moreover, the NMGO//MWCNT asymmetric device, assembled with NMGO and multi-wall carbon nanotubes (MWCNTs) as positive and negative electrodes, respectively, exhibited good energy density (28 Wh·kg⁻¹), excellent power density (750 W·kg⁻¹), and capacitance retention (88%) after 6000 cycles. To evaluate the multifunctionality of the modified nanostructure, the NMGO was also tested for its oxygen evolution reaction (OER) activity. The NMGO delivered a current density of 10 mA·cm⁻² at the potential of 1.59 V versus RHE. These results clearly demonstrate high activity of the modified electrode with strong future potential.

Entropy engineering offers a promising strategy for constructing multicomponent electrocatalysts, yet its role in nitrate‐to‐ammonia electroreduction remains insufficiently understood. Herein, we design a series of Fe‐based oxide two‐dimensional sheets with low‐, medium‐, and high‐entropy compositions by incorporating Cu, Co, Mn, and Zn into Fe ₃ O ₄ frameworks. This compositional series enables a comparative evaluation of how elemental combination, oxidation‐state distribution, local electronic environment, and electrochemically accessible interfaces influence nitrate reduction reaction (NO ₃ RR) performance. The FeCuCoMnZnO _x catalyst delivers an ammonia yield rate of 10.9 mgh ⁻¹ mg _cat ⁻¹ and a Faradaic efficiency of 94% at −0.55 V vs. reversible hydrogen electrode. Integrated experimental and theoretical analyses suggest that the catalytic behaviour is associated with the combined effects of composition‐dependent electronic structure, mixed‐valence metal centres, and heteroatomic bridge‐site configurations. These features are associated with a calculated d‐band centre in a favourable range for balancing NO ₃ RR intermediate adsorption and desorption, while selected heteroatomic configurations lower key reaction barriers compared with the corresponding homoatomic sites. Post‐cyclic‐stability characterization further indicates partial surface reduction and oxidation‐state redistribution under NO ₃ RR operating conditions. In situ Fourier‐transform infrared and Raman spectroscopy provide potential‐dependent evidence for NO ₃ RR‐related surface intermediates on FeCuCoMnZnO _x .