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Zinc-ion batteries (ZIBs) emerge as leading candidates for a flexible energy storage system, distinguished by high capacity, affordability, and inherent safety. The integration of hydrogel electrolytes, particularly those with saturated aqueous solvents, has significantly enhanced the electrochemical performance of ZIBs while preserving their essential flexibility. Nonetheless, challenges in electrochemical performance under specific conditions highlight the nascent stage of this technology, with numerous technical hurdles awaiting resolution. Addressing these challenges, recent investigations have leveraged the unique properties of cellulose hydrogel—namely, its exceptional toughness, tensile strength, extreme temperature resilience, stimulus responsiveness, and self-healing capabilities—to innovate multifunctional flexible zinc-based batteries. This paper conducts a comprehensive review of the physicochemical attributes of cellulose hydrogel electrolytes within ZIBs. We thoroughly analyze their performance under diverse environmental conditions, offering insights into the current landscape and their future potential. By examining these aspects, we aim to underscore the developmental prospects and the challenges that lie ahead for hydrogel electrolytes in ZIBs, paving the way for further advancement in this promising field. [ABSTRACT FROM AUTHOR]

Ultrafine ruthenium nanoparticles are encapsulated by single-atom Ni-bonded graphitic carbon nitride (g-C3N4) layers anchored on carbon nanotubes (Ru/Ni-CNCT). The enhanced electronic interaction between Ru nanoparticles and Ni–N(O)–C sites anchored in g-C3N4 layers promotes water adsorption/dissociation and hydrogen evolution. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries, because of their sustainability and low cost, provide an attractive alternative to Li-ion technology for large-scale energy storage. However, their applicability still faces a large challenge due to the lack of high energy density and cycling-stable Na-based positive materials. Here, we design and synthesize a P2-type Na0.7Li0.1Mg0.2Mn0.7O2 material exhibiting synergistic anionic and cationic redox activity. This material exhibits a high reversible capacity of 217 mA h g−1 which is attributed to Mn3+ − e− = Mn4+ and O2− − ne− = O(2−n)− demonstrated by combined spectrum and DFT calculations. Not only high energy density, NLMMO also exhibits high cycling stability with a reversible capacity of 183 mA h g−1 (84.3%) for 50 cycles. These findings, rationalized by DFT calculations, reveal the effect of interlayer Li+ migration on regulating structural stability, achieving a high reversible capacity. The present study offers a new strategy for designing high-performance cathode materials with synergistic anionic and cationic redox reactions. [ABSTRACT FROM AUTHOR]

Room‐temperature sodium–sulfur batteries are potential candidate for sustainable large‐scale energy storage systems due to their high energy density and low cost. However, the shuttling effect of high‐order polysulfides (Na2Sn, 4 < n ≤ 8) usually leads to rapid capacity fading, while the reaction kinetics of low‐order polysulfides (Na2Sn, 1 ≤ n ≤ 4) are slow. In this work, microporous‐mesoporous carbon derived from mangosteen peels is reported as cathode materials for RT Na–S batteries. The designed micro‐mesoporous structure not only effectively suppresses the shuttling effect of sodium polysulfides (NaPS), but also has high electrical conductivity and porosity, which facilitates electron/ion diffusion. Oxygen functional groups on the surface provide high catalytic activity for efficient low‐order NaPS conversion. The obtained Na–S battery exhibits high reversible capacity with excellent long‐term cycle performance (526.1 mAh g−1 at 4 A g−1 after 1000 cycles) and outstanding rate performance (676.59 mAh g−1 at 16 A g−1). This work demonstrates a novel activation strategy of biomass‐derived carbons for high‐performance Na–S batteries. [ABSTRACT FROM AUTHOR]

Urea electrolysis can convert urea from urea‐rich wastewater to hydrogen for environmental protection and sustainable energy production. However, the sluggish kinetics of urea oxidation reaction (UOR) requires valence‐variable sites that are generally active at high anodic overpotentials. Herein, a robust ceramic coating is constructed with coupled tungsten nitride (WN)/nickel carbide (Ni3C) nanoparticles to achieve valence‐stable catalytic sites with outstanding UOR performance. Various characterization results indicate strong interfacial electron transfer from WN to Ni3C in coupled nanoparticles, which enables reservation of Ni2+ sites without self‐oxidation during UOR, quite distinct from the kinetically slow Ni3+OOH‐catalyzed UOR pathway. Theoretical calculations show that the coupled effect in WN/Ni3C leads to enhanced electron transfer from catalytic sites to adsorbed urea, and W sites are thermodynamically favorable for UOR. This efficiently lowers the barrier of rate‐determining step (RDS: *CO‐N2 → *CO·OH), thus enabling fast UOR kinetics and a low potential of 1.336 V at 100 mA cm−2, which identifies this ceramic coating as one of the best UOR electrocatalysts. This work opens a new avenue for design of stable and active sites in ceramics coatings toward advanced electrocatalytic applications. [ABSTRACT FROM AUTHOR]

An "inside-out regulation" strategy is proposed to improve the Zn2+ storage of MnO by Ni doping into the lattice and graphene wrapping outside the nanoparticles. The as-prepared Ni-MnO@rGO exhibits 112 mA h g−1 at 2.0 A g−1 over 800 cycles, due to the improved transport of electrons and ions from the synergistical function of intrinsic doping and external graphene encapsulation. [ABSTRACT FROM AUTHOR]

In this study, a Cu NPs-incorporated carbon-containing mesoporous SiO2 (Cu/C-SiO2) was successfully synthesized through a grinding-assisted self-infiltration method followed by an in situ reduction process. The obtained Cu/C-SiO2 was then employed as a Fenton-like catalyst to remove tetracycline (TC) from aqueous solutions. TEM, EDS, XRD, N2 adsorption–desorption, FTIR, and XPS methods were used to characterize the crystal structure, morphology, porosity, chemical composition, and surface chemical properties of the catalyst. The effects of initial TC concentration, catalyst dosage, H2O2 dosage, solution pH, HA addition, and water media on the TC degradation over Cu/C-SiO2 were investigated. Scavenging and electrochemical experiments were then carried out to analyze the TC degradation mechanism. The results show that the Cu/C-SiO2 can remove 99.9% of the concentrated TC solution (C0 = 500 mg·L−1), and it can be used in a wide pH range (R.E. = 94–99%, pH = 3.0–11.0). Moreover, hydroxyl radicals (•OH) were detected to be the dominant reactive species in this catalytic system. This study provides a simple and promising method for the synthesis of heteroatom-containing mesoporous catalysts for the decomposition of antibiotics in wastewater. [ABSTRACT FROM AUTHOR]

Compared to traditional modulation by metal cations doping, oxyanions offer a higher possibility of mediating the performance of electrocatalysts toward oxygen evolution reaction (OER) due to their special polyanion configurations and large electronegativity. However, the mechanism and rules of oxyanions mediation remain poorly understood. Herein, an in situ electrochemical oxyanion (NO3−, PO43−, SO42−, or SeO42−) steering strategy to study the variation and rules of OER performance for transition‐metal (TM = Ni, Fe, Co) hydroxide electrocatalysts is reported. Electrocatalytic experiments indicate both activity and stability of oxyanion‐modified TM hydroxides follow the order of PO43− > NO3− > SO42− > SeO42−. Electrochemical incorporation of PO43− or NO3− improves activity and stability of TM hydroxides. Conversely, SO42− or SeO42− doping significantly accelerates TM leaching and thus impairs OER performance. Theoretical calculations reveal that electrochemical oxyanion doping simultaneously modulates TM‐O covalency and TM‐3d band centers, correlating with TM stability and OER activity of TM hydroxides. This research constructs an oxyanion‐mediated rule for designing high‐performance electrocatalysts toward energy transformation. [ABSTRACT FROM AUTHOR]

Li metal anode is considered as one of the most desirable candidates for next‐generation battery due to its lowest electrochemical potential and high theoretical capacity. However, undesirable dendrite growth severely exacerbates the interfacial stability, thus damaging battery performance and bringing safety concerns. Here, an efficient strategy is proposed to stabilize Li metal anode by digesting dendrites sprout using a 3D flexible superlithiophilic membrane consisting of poly(vinylidene fluoride) (PVDF) and ZnCl2 composite nanofibers (PZEM) as a protective layer. Both the experimental studies and theoretical calculations show the origin of superlithiophilicity ascribed to a strong interaction between ZnCl2 and PVDF to form the ZnF bonds. The multifield physics calculation implies effective removal of local dendrite hotspots by PZEM via a more homogeneous Li+ flux. The PZEM‐covered Li anode (PZEM@Li) exhibits superior Li deposition/stripping performance in a symmetric cell over 1100 cycles at a high current density of 5 mA cm−2. When paired with LiFePO4 (LFP), PZEM@Li|LFP full cell remains stable over 1000 cycles at 2 C with a degradation rate of 0.0083% per cycle. This work offers a new route for efficient protection of Li metal anode for practical applications. [ABSTRACT FROM AUTHOR]

Oxygen electrocatalysts are of great importance for the air electrode in zinc—air batteries (ZABs). Owing to large surface area, high electrical conductivity and ease of modification, two-dimensional (2D) materials have been widely studied as oxygen electrocatalysts for the rechargable ZABs. The elaborately modified 2D materials-based electrocatalysts, usually exhibit excellent performance toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), which have attracted extensive interests of worldwide researchers. Given the rapid development of bifunctional electrocatalysts toward ORR and OER, the latest progress of non-noble electrocatalysts based on layered double hydroxides (LDHs), graphene, and MXenes are intensively reviewed. The discussion ranges from fundamental structure, synthesis, electrocatalytic performance of these catalysts, as well as their applications in the rechargeable ZABs. Finally, the challenges and outlook are provided for further advancing the commercialization of rechargeable ZABs. [ABSTRACT FROM AUTHOR]