Bimetallic catalysts offer enhanced catalytic performance through synergistic interactions between the two metals, allowing them to break the linear scaling relations and reach high electrocatalytic activity. This study presents bimetallic aerogel-based catalyst synthesized as a covalent, three-dimensional framework containing neighboring iron and manganese sites. The aerogel structure provides a high surface area and porosity, facilitating an ultra-high active site density and efficient mass transport. The MnFe porphyrrole's unique structure is obtained by alternately linking Mn-porphyrin and Fe-corrole complexes. It exhibited outstanding performance with an onset potential of 0.99 V_RHE. Comparative studies with a free-base Fe porphyrrole catalyst (E_onset 0.97 V_RHE) revealed that while Mn incorporation led to only a slight improvement in half-cell performance, it resulted in significantly enhanced performance in anion exchange membrane fuel cell. The MnFe catalyst achieved an OCV of 0.97 V and a peak power density of 0.27 W cm⁻², outperforming the free-base Fe counterpart. Using density functional theory calculations, we show that the higher ORR activity of MnFe-porphyrrole is due to charge transfer between Mn and Fe atoms, which is absent in the reference free-base Fe-porphyrrole. These findings underscore the advantages of bimetallic catalysts in improving ORR activity and fuel cell efficiency by leveraging synergistic effects.

Anode-less sulfide-based all-solid-state batteries (ASSBs) have emerged as promising candidates for next-generation energy storage, offering high energy density, enhanced safety, and simplified cell design. By eliminating excess lithium (Li) metal and relying solely on Li extracted from the cathode, these systems significantly improve gravimetric and volumetric performance. However, the absence of a Li reservoir introduces critical challenges, particularly at the Li|solid electrolyte (Li|SE) interface. This review first outlines the fundamental interfacial and electrochemical challenges in anode-less sulfide systems, including unstable Li plating/stripping, void formation, interfacial contact loss, and parasitic reactions that lead to poor reversibility and early failure. Drawing from recent experimental studies, the second part of this review discusses material and structural strategies developed to stabilize these systems. These include current collector modifications, lithiophilic and alloying interlayers, cathode prelithiation, and artificial interphase engineering, each aiming to suppress dendrite growth, enhance interfacial integrity, and manage Li inventory. The review concludes by highlighting future research directions and design principles essential for realizing scalable and commercially viable anode-less sulfide-based ASSBs. By critically evaluating the latest progress, this work aims to provide a comprehensive framework to guide the rational development of robust and high-performance solid-state battery architecture.

All-solid-state lithium-ion batteries (ASSLBs) are a promising next-generation energy storage technology for their enhanced safety and high energy density. In this study, we develop high-performance ASSLBs utilizing a Ni-rich single-crystalline NCM811 (SC-NCM811) cathode and a Li₆PS₅Br argyrodite solid electrolyte. By optimizing the cathode material and stack pressure, we demonstrate an exceptional areal capacity exceeding 4 mAh/cm² with a high cathode loading of ∼21 mg/cm². Electrochemical performance comparisons between SC-NCM811 and polycrystalline NCM811 (PC-NCM811) reveal the superior capacity retention and rate performance of SC-NCM811-based ASSLBs, particularly at an optimized stack pressure. Our findings underscore the potential of SC-NCM811 as a highly efficient cathode material for next-generation ASSLBs, offering both increased energy density and operational safety. This work highlights the importance of cathode engineering and pressure optimization in advancing the implementation of ASSLBs.

Although the enzymatic mechanisms of terpene synthases have been extensively characterized through experimental and computational studies, the atomistic details underlying the product release process have remained elusive. In this study, we present the first atomistic simulations of the initial stages of product release in a terpene synthase, using the bacterial diterpene cyclase CotB2 as a model system. CotB2 catalyzes the complex cyclization of geranylgeranyl diphosphate (GGDP) to the tricyclic diterpene cyclooctat-9-en-7-ol in a single active site through an 11-step reaction cascade. Our MD simulations focus on three model systems representing CotB2 with bound GGDP and cyclooctat-9-en-7-ol, the latter in two states—with the diphosphate fully deprotonated (P₂O₇⁴⁻) and protonated diphosphate (HP₂O₇³⁻). Analysis of the MD trajectories clearly shows that product release is initiated by the dislocation of the diphosphate group, which in turn triggers active site opening via coordinated C-terminal motions. Notably, protonation of the diphosphate moiety appears to be the key event that weakens its interactions with the active site and enables product release. These findings provide crucial mechanistic insight into the final phase of terpene biosynthesis and open new avenues for rational enzyme engineering targeting product release.

Various carbonaceous anode materials have been developed to improve both the rate and capacity characteristics of Li-ion batteries (LIBs), and yet the performances of the anodes depend on the quality of the inevitable and uncontrollable growth of the solid–electrolyte interphase (SEI), resulting from the electrolyte reduction and decomposition during the initial cycles. Here, we propose the fabrication of an artificial SEI (Art-SEI), enabling tuning of specific properties, such as the chemical composition, electrochemical impedance, and thickness of the interfacial film. In this work, a genuine Art-SEI was conformally fabricated via molecular layer deposition (MLD), utilizing as one of the precursors a commercial battery electrolyte itself, with a cross-linker-functionalized film grown on the surface of the carbonaceous anode materials, along with a Li-ion source. This type of air- and moisture-stable Art-SEI possesses enhanced protective characteristics, and it mitigates the irreversible capacity loss associated with the SEI buildup during the formation cycles while substantially improving Li-ion battery cycling performances.

Zinc–bromine batteries (ZBBs) are promising candidates for large-scale energy storage due to their low cost, inherent safety, and high theoretical energy density. However, conventional flow-based ZBBs suffer from low system-level energy density and operational complexity. Recent interest has shifted toward flowless ZBBs (FL-ZBBs) configuration, yet these face critical challenges associated with uncontrolled diffusion and self-discharge (SD) of bromine species at the cathode. One of the holy grails in addressing these challenges is the use of quaternary ammonium salts (NR₄⁺), which interact with bromine species to inhibit their diffusion. In this work, we demonstrate the first ever reported utilization of phosphonium-based bromine-complexing agents (BCAs) in FL-ZBBs. We do so by impregnation of the BCAs into porous carbon cathodes, particularly tetrabutylphosphonium bromide (TBP), outperform traditional ammonium-based analogs in FL-ZBBs. TBP enables high Coulombic efficiency (>98.5%, 1 A g⁻¹) for 145 mAh g⁻¹, reduces the SD phenomenon, and achieves long-term cycling stability of over 500 cycles with >97% CE (1.5 A g⁻¹, 145 mAh g⁻¹), even under low electrolyte concentrations (0.5M ZnBr2). The enhanced performance is attributed to faster 2Br⁻/Br₂ redox kinetics, as demonstrated by cyclic voltammetry, and improved molecular polybromide∙∙∙PR₄⁺ interactions, highlighting phosphonium salts as more attractive BCA compounds for high-performance FL-ZBBs.

Achieving high capacity, long-term stability, and fast charge–discharge capability remains a central challenge in the development of advanced anode materials for lithium-ion batteries. In this work, we present nickel vanadium oxyphosphide (NVOP) nanosheets synthesized via controlled thermal phosphorization of NiV-layered double hydroxide (NiV-LDH). The resulting multiphase structure, composed of conductive Ni₂P and redox-active vanadium oxides, delivers an initial discharge capacity of 1345 mAh/g and retains 442 mAh/g after 200 cycles at 0.1 A/g, with Coulombic efficiency stabilizing near 99.5%. NVOP also demonstrates excellent rate performance, maintaining 359 mAh/g at a high current density of 1.0 A/g. Electrochemical and structural characterization suggest that the improved cycling stability and rate capability may stem from the multiphase architecture, which integrates conductive and redox-active components within a porous nanosheet framework. These findings underscore the potential of direct phosphorization of mixed-metal layered hydroxide precursors as an effective strategy for constructing high-performance, durable anode materials for next-generation lithium-ion batteries.

Solid polymer electrolytes (SPEs) present a promising alternative for rechargeable batteries with aprotic liquids. Although SPEs were extensively researched for several decades, recent studies have gained momentum in response to growing demand for safer battery options. While various electrochemical and spectral methods for characterizing polymeric electrolytes were proposed, a comprehensive guide to support future investigations appears lacking. Here, we propose a working protocol to derive parameters that characterize SPEs as crucial components of battery systems. An overview of various methods is provided, with particular emphasis on simple impedance measurements for extracting electrochemical parameters. We underscore the significance of considering the interfaces within the battery, specifically the electrolyte-anode and electrolyte-cathode interfaces. Post-mortem analysis is discussed along with the challenges it entails. A summary table detailing the extracted parameters, the corresponding characterization methods, and their applications is provided.

Ion exchange membranes are essential components in electrochemical systems, playing a crucial role in energy and environmental applications. These membranes are broadly classified into proton exchange membranes (PEMs) and anion exchange membranes (AEMs). Despite being a relatively young technology, AEMs have attracted considerable attention for energy applications due to their potential to achieve a significant reduction in materials and device costs thanks to their alkaline character. This cost reduction facilitates mass production and commercialization, thereby expanding the applicability of electrochemical energy technologies.

Electrocatalytic hydrazine oxidation holds great promise for enabling fuel cell-powered transportation since hydrazine hydrate (N₂H₄·H₂O) has the highest energy density of all liquid, CO₂-free fuels (3.45 kWh/L), and the highest fuel cell voltage (1.56 V vs O₂). Inspired by the ruffling of catalytic centers in oxidative enzymes, we designed a twisted single-atom nanozyme comprising twisted FeN₂₊₂C₄₊₄ sites, enabling high accessibility of N₂H₄ and OH^– reactants. Experimental evidence shows that this nanozyme catalyst achieves the lowest oxidation overpotential of all Fe–N–C materials, both in the lab and in direct hydrazine fuel cells, with an open-circuit voltage of 0.95 V, unprecedented for an Fe-based anode. The structure of the catalytic site is elucidated through a combination of electrochemistry, ⁵⁷Fe Mössbauer spectroscopy, high-resolution transmission electron microscopy, and X-ray absorption spectroscopy with crystal field multiplet simulations and fits of the pre-edge features, as well as density functional theory calculations and theoretical simulations of X-ray absorption near edge structure. The experimental and theoretical methods reveal that twisting the active site also shifts its oxidation potential positively and improves N₂ bubble removal while limiting ammonia production to less than 10 ppm. This work demonstrates the potential of active site twisting to enhance the oxidation of energy-rich and liquid substrates, representing a crucial step toward building a sustainable society.