Covalent organic frameworks (COFs) are revolutionizing the solid-state ionics by programming backbone, incorporating functional groups, and chelating with specific ions in structural units to facilitate rapid ion transport. More encouragingly, topology diagrams enable COFs with tremendous possibilities in structural design from two-dimensional (2D) to three-dimensional (3D) polygonal network, thus positioning themselves as promising ionic solid-state electrolytes for energy storage and conversion. This review summarizes recent advances in COF electrolytes from 2D to 3D, focusing on how pore topology, framework functionality, and composite designs regulate Li⁺ conduction. Mechanistic insights including anion immobilization, backbone–ion interactions, and solvent- or polymer-assisted transport are discussed to elucidate the structure–transport correlations that govern ionic conductivity and interfacial behavior. Key limitations, such as modest intrinsic conductivity, electrode interfacial resistance, and mechanical fragility, are critically examined. Beyond lithium systems, the broader potential of COFs as versatile solid-state ionic conductors for emerging metal-ion batteries is highlighted. Finally, future opportunities are outlined, including ionic-backbone engineering, nanochannel ordering, quasi-solid architectures, dendrite-regulating interfaces, and scalable membrane processing. We earnestly expect that this review will further elucidate pathways for the advancement of COF-based electrolytes toward practical and high-performance solid-state rechargeable batteries.

Lithium-sulfur (Li-S) batteries have gained significant success as next-generation energy sources, but the slow conversion speed of polysulfides and resultant notorious shuttle effect still limit its practical utilization. Metal nitrides (MNs) with high chemical affinity and remarkable catalytic activity have been verified as highly-efficient electrocatalysts in addressing these remaining challenges. However, there is a lack of comprehensive review that clarifying the detailed working principles of MNs in Li-S batteries. This study first summarizes the recent advances in the utilization of MNs for Li-S batteries, especially in sulfur hosts, separator coating layers, and interlayers. Typical MNs in each category were then introduced, by analyzing their material designs, catalytic effects, and modulation strategies. Important perspectives on the future developments of MN-based electrocatalysts and Li-S batteries are given, possible challenges and potential research directions are outlined. This work supplies precious insights into the use of MNs and their key roles in promoting the conversions of sulfur species.

The sluggish kinetics of sulfur redox reactions and the potential of polysulfide shuttling pose significant challenges to the practical application of metal–sulfur batteries (MSBs). Heterostructured materials that integrate the advantages of various components serve as ideal electrocatalysts to address these issues. This review first summarizes and analyzes the engineering strategies and the proposed working principles for heterostructures. Recent advancements in the utilizations of heterostructures in sulfur hosts, separator coating layers, and interlayers are then concluded. The material designs, preparation approaches, and the crucial roles played by heterostructures are subsequently discussed, elucidating the relationship between their structural characteristics and MSB performance. Finally, the remaining challenges are identified, and the future research directions are outlined in this promising area. This work provides invaluable insights into the development of highly efficient heterostructured electrocatalysts and the regulation of sulfur conversion processes in MSBs.

Aqueous zinc (Zn)-based batteries with high cyclic stability, exceptional safety, and low cost hold great promise as next-generation energy storage devices. However, Zn metal anode suffers from serious dendrite growth, hydrogen evolution, and Zn corrosion during plating/stripping cycles, hampering its practical utilization. Herein, we report a multicore–shell structure of bismuth (Bi) nanoparticles embedded within N-doped porous carbon nanorods (NPCN) (Bi@NPCN) to regulate Zn deposition behavior. Theoretical simulation and in situ optical microscopy revealed that the abundant Bi nanoparticles with high zincophilic property strongly adsorbed Zn²⁺, enabling rapid and massive Zn deposition. Meanwhile, NPCN with porous feature provides sufficient space for accommodating Zn volume expansion. Electrochemical tests demonstrated an ultra-stable dendrite-free Zn deposition behavior for 1500 h, high rate capability up to 20 mA·cm⁻², and an exceptional Coulombic efficiency of ~ 100% after 1200 cycles. The Zn-ion batteries coupled with ammonium vanadate cathode exhibit a highly-stable cyclic performance for 3000 cycles at 5.0 A·g⁻¹, with a high capacity retention of 66.7%. Impressively, a remarkable long-term cyclic performance over 10,000 cycles was realized when employing active carbon cathode. This study offers a new strategy of utilizing multicore–shell structure with zincophilic seeds to achieve dendrite-free Zn metal anode.

The rapid evolution of flexible wearable electronics has spurred a growing demand for energy storage devices, characterized by low-cost manufacturing processes, high safety standards, exceptional electrochemical performance and robust mechanical properties. Among novel flexible devices, fiber-shaped batteries (FSBs) have emerged as prominent solutions exceptionally suited to future applications, owing to their unique one-dimensional (1D) architecture, remarkable flexibility, potential for miniaturization, adaptability to deformation and compatibility with the conventional textile industry. In the forefront research on fiber-shaped batteries, zinc-based FSBs (ZFSBs) have garnered significant attentions, featured by the promising electrochemical properties of metallic Zn. This enthusiasm is driven by the impressive capacity of Zn (820 mAh·g⁻¹) and its low redox potential (Zn/Zn²⁺: −0.76 V vs. standard hydrogen electrode). This review aims to consolidate recent achievements in the structural design, fabrication processes and electrode materials of flexible ZFSBs. Notably, we highlight three representative structural configurations: parallel type, twisted type and coaxial type. We also place special emphasis on electrode modifications and electrolyte selection. Furthermore, we delve into the promising development opportunities and anticipate future challenges associated with ZFSBs, emphasizing their potential roles in powering the next generation of wearable electronics.

Lithium-sulfur (Li-S) batteries, known for their high energy density, are attracting extensive research interest as a promising next-generation energy storage technology. However, their widespread use has been hampered by certain issues, including the dissolution and migration of polysulfides, along with sluggish redox kinetics. Metal sulfides present a promising solution to these obstacles regarding their high electrical conductivity, strong chemical adsorption with polysulfides, and remarkable electrocatalytic capabilities for polysulfide conversion. In this review, the recent progress on the utilization of metal sulfide for suppressing polysulfide shuttling in Li-S batteries is systematically summarized, with a special focus on sulfur hosts and functional separators. The critical roles of metal sulfides in realizing high-performing Li-S batteries have been comprehensively discussed by correlating the materials’ structure and electrochemical performances. Moreover, the remaining issues/challenges and future perspectives are highlighted. By offering a detailed understanding of the crucial roles of metal sulfides, this review dedicates to contributing valuable knowledge for the pursuit of high-efficiency Li-S batteries based on metal sulfides.

Lithium-sulfur (Li-S) batteries with the merits of high theoretical capacity and high energy density have gained significant attention as the next-generation energy storage devices. Unfortunately, the main pressing issues of sluggish reaction kinetics and severe shuttling of polysulfides hampered their practical application. To overcome these obstacles, various strategies adopting high-efficient electrocatalysts have been explored to enable the rapid polysulfide conversions and thereby suppressing the polysulfide shuttling. This review first summarizes the recent progress on electrocatalysts involved in hosts, interlayers, and protective layers. Then, these electrocatalysts in Li-S batteries are analyzed by listing representative works, from the viewpoints of design concepts, engineering strategies, working principles, and electrochemical performance. Finally, the remaining issues/challenges and future perspectives facing electrocatalysts are given and discussed. This review may provide new guidance for the future construction of electrocatalysts and their further utilizations in high-performance Li-S batteries.