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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Characterizing degraded visual environments with scanning lenses to improve contrast recovery

Atmospheric aerosols, such as fog and smoke, degrade optical signals via the scattering and absorption of light, making it difficult to recover information from the surrounding environment. Here, we present a technique that measures the angular distribution of light in scattering environments to help recover these degraded optical signals. This is done by passing a collimated beam through the aerosol environment and collecting the scattered and unscattered light with an f-theta scan lens. The lens transforms the angular distribution of the scattered light into the linear domain, mapping the collected light onto a detector. The measured angular scattering distribution is then used to estimate the point spread function of the environment at an arbitrary stand-off distance. This point spread function can be used to deconvolve images blurred by the aerosol environment in which the angular scattering distribution was initially measured. With this approach, we demonstrate improvements in the effective resolution of deblurred images up to 26% over a 120-cm stand-off distance. Experimentation was performed in the Sandia National Laboratories tabletop fog chamber, a platform that generates aerosol environments analogous to real-world fogs. We intend to leverage this technique in future work to develop a low-SWaP system for the in situ characterization of aerosol environments.

Aerosols↗
DOE OSTI2025

In situ Raman investigation of Dy complexation in Cl-bearing aqueous solutions at 20–300 °C

Raman spectroscopy provides a versatile tool for in situ characterization of aqueous rare earth elements (REE) speciation at the molecular level. Complexation of REE with ligands such as Cl – and OH – is of particular interest for understanding the mobility of REE in NaCl-bearing hydrothermal fluids responsible for enriching REE to economic levels in nature. Raman spectroscopic studies of REE speciation in Cl-bearing aqueous fluids are primarily conducted at ambient temperature, whereas natural systems indicate temperatures of >100–600 °C. In this study, the speciation of Dy in acidic chloride-bearing hydrothermal solutions was investigated using confocal Raman spectroscopy with a new capillary Raman heating stage at 20–300 °C. Background solutions (pure water, NaCl-solutions) and solutions with 0.14–1.8 mol kg –1 dissolved DyCl 3 were sealed in quartz capillary cells. Comparison of the spectra for Dy chloride solutions with those for background solutions and the spectra for reference Dy-bearing solids was used to identify Raman bands specific to Dy–O and Dy–Cl bonds. The Raman band for the Dy–O stretching mode of hydrated Dy 3+ aqua ions was measured at 365–384 cm –1 and a Raman band for the Dy–Cl stretching modes of Dy chloride complexes was measured near 240 cm –1 . The Dy–O band decreases systematically with temperature, whereas the Dy–Cl band systematically increases, indicating a systematic increase in the stability of Dy chloride complexes with temperature. Here, this study provides the framework for expanding the use of in situ Raman spectroscopy to investigate the speciation of REE in aqueous solutions to hydrothermal conditions.

58 GEOSCIENCES↗
DOE OSTI2025

Controlling Reaction Pathways of Ethylene Hydroformylation Using Isolated Bimetallic Rhodium–Cobalt Sites

Designing efficient ligand-free heterogeneous catalysts for ethylene hydroformylation to produce C 3 oxygenates is of importance for both fundamental research and practical applications, but it is often hindered by insufficient catalytic activity and selectivity. Here, this work designs isolated rhodium–cobalt (Rh–Co) sites confined within a ZSM-5 zeolite to enhance ethylene hydroformylation rates and selectivity while maintaining catalyst stability. By adjusting the Co/Al ratio in Co-ZSM-5, different sizes of Co are formed; subsequent Rh introduction produces isolated Rh 1 Co x clusters with different Rh–Co coordination numbers (CNs). In-situ characterizations and density functional theory calculations reveal that a Rh–Co CN of 3, corresponding to an isolated Rh 1 Co 3 site, provides optimal bindings to reaction intermediates and thus achieves the highest hydroformylation rates among supported Rh-based catalysts. This study demonstrates the role of coordination-tuning via a secondary metal in effectively controlling the reaction pathway over single Rh atom catalysts.

03 NATURAL GAS↗
DOE OSTI2024

Electrochemical Control of the Ultrafast Lattice Response of a Layered Semimetal

The unique layer-stacking in two-dimensional (2D) van der Waals materials facilitates the formation of nearly degenerate phases of matter and opens novel routes for the design of low-power, reconfigurable functional materials. Electrochemical ion intercalation between stacked layers offers a promising approach to stabilize bulk metastable phases and to explore the effects of extreme carrier doping and strain. However, in situ characterization methods to study the structural evolution and dynamical functional properties of these intercalated materials remains limited. Here a novel experimental platform is presented capable of simultaneously performing electrochemical lithium-ion intercalation and multimodal ultrafast characterization of the lattice using both electron diffraction and nonlinear optical techniques. Using the layered semimetal WTe 2 as a model system, the interlayer shear phonon mode that modulates stacking between 2Dlayers is probed, showing that small amounts of lithiation enhance the amplitude and lifetime of the phonon, contrary to expectations. This results from the dynamically fluctuating and anharmonic structure between nearly degenerate phases at room temperature, which can be stabilized by electronic carriers accompanying the inserted lithium ions. At high lithiation, the T d ’ structure emerges and quenches the phonon response. This work defines new approaches for using electrochemistry to engineer the dynamic structure of 2D materials.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Anion Vacancies Coupling with Heterostructures Enable Advanced Aerogel Cathode for Ultrafast Aqueous Zinc‐Ion Storage

As a potential cathode material, manganese-based sulfide has recently attracted increasing interest due to its many advantages in aqueous zinc-ion storage. Unfortunately, some challenges such as sluggish kinetics, unstable structure, and controversial phase transition mechanism during the energy storage process hinder its practical application. Herein, inspired by density functional theory (DFT) calculations, a novel 3D sulfur vacancy-rich and heterostructured MnS/MXene aerogel is designed, and used as a cathode for aqueous Zn-ion batteries/hybrid capacitors (ZIBs/ZICs) for the first time. Thanks to the synergistic modification strategy of sulfur vacancies and heterostructures, the as-constructed MnS/MXene//Zn ZIBs exhibit significantly enhanced electrochemical properties, especially outstanding rate capability and cyclic stability. More encouragingly, the as-assembled MnS/MXene//porous carbon (PC) ZICs exhibit an ultrahigh energy density, a high power density, and a splendid cycling lifespan. Most notably, systematic kinetic analyses, ex situ characterizations, and DFT calculations illustrate that MnS/MXene first irreversibly converts into MnO x @ZnMnO 3 /MXene, and then undergoes a reversible conversion from MnO x @ZnMnO 3 /MXene to MnOOH@ZnMn 2 O 4 /MXene, accompanied by the co-insertion/extraction of H + and Zn 2+ . Further, the synergistic modification strategy of sulfur vacancies and heterostructures and the thorough mechanistic study proposed in this work offer valuable guidance for designing and exploiting high-performance cathodes in aqueous zinc-based energy storage devices.

25 ENERGY STORAGE↗
DOE OSTI2025

Mitigating Battery Cell Failure: Role of Ag‐Nanoparticle Fillers in Solid Electrolyte Dendrite Suppression

Abstract The development of solid‐state batteries (SSBs) with lithium Li metal anodes holds significant promise for enhancing the energy density and safety of next‐generation energy storage systems. However, their commercialization is hindered by challenges related to Li dendrite formation, which can lead to short circuits and battery failure. In this study, the role of Ag nanoparticles embedded within solid electrolytes (SE) is investigated in suppressing dendrite propagation. The results demonstrate that Ag nanoparticles effectively mitigate two key failure mechanisms: (1) dendrite growth within porous networks at low current densities and (2) stress intensification‐induced SE fracture at higher current densities (12 mA cm −2 ). Ex situ characterization using focused‐ion beam – scanning electron microscopy (FIB–SEM) and energy dispersive X‐ray spectroscopy (EDS,) reveals that Ag nanoparticles migrate alongside advancing Li dendrites, promoting homogeneous dendrite growth and reducing the likelihood of localized stress concentrations. Additionally, the incorporation of Ag nanoparticles is shown to facilitate a more uniform Li distribution toward the anode side, which can potentially enable the use of higher charging rates in SSBs. This study provides a new perspective on Li dendrite suppression and presents new opportunities for enhancing the performance and safety of SSBs.

Diallo, Mouhamad Said↗
DOE OSTI2025

AI‐Driven Robot Enables Synthesis‐Property Relation Prediction for Metal Halide Perovskites in Humid Atmosphere

Materials Acceleration Platforms (MAPs) – also known as self-driving laboratories– present a new paradigm for materials science and promise an order of magnitude accelerated materials discovery compared to the traditional trial-and-error approach. Metal halide perovskites (MHPs) are an emerging class of materials for optoelectronic applications but are plagued by irreproducible optoelectronic quality, particularly for films fabricated in a humid atmosphere. Here, in this work, a machine learning (ML)-guided closed-loop platform is developed with a multimodal data fusion approach to predict synthesis–property relations for the optical quality of MHP thin films in relative humidities (RHs) ranging from 5–55%. The efficiency of this approach is confirmed by the fast-dropping learning rate to 2% after experimentally sampling less than 1% of the possible 5,000+ combinations. The prediction of synthesis–property relations is done by optical and imaging characterizations. In situ photoluminescence characterization revealed the origin of thin film quality variation at different RH. These insights provide an avenue for controlling the MHP crystallization by fine-tuning the synthesis parameters and RH for a given chemistry, thus lifting the need for stringent atmosphere control. The MAP enables an accelerated screening and understanding of the synthesis design space, facilitating rational synthesis recipe choice for a wide range of materials.

AI-driven robot↗
DOE OSTI2024

Uncovering the Size-dependent Thermal Solid Transformation of Akaganéite

Investigating the structural evolution and phase transformation of iron oxides is crucial for gaining a deeper understanding of geological changes on diverse planets and preparing oxide materials suitable for industrial applications. In this study, we employed in-situ heating techniques in conjunction with transmission electron microscopy (TEM) observations and ex-situ characterization to thoroughly analyze the thermal solid-phase transformation of akaganéite one-dimensional (1D) nanostructures with varying diameters. Our findings offer compelling evidence for a size-dependent morphology evolution in akaganéite 1D nanostructures, which can be attributed to the transformation from akaganéite to maghemite (?-Fe2O3) and subsequent crystal growth. Specifically, we observed that akaganéite nanorods with a diameter of around 50 nm transformed into hollow polycrystalline maghemite nanorods, which demonstrated remarkable stability without arresting crystal growth under continuous heating. In contrast, smaller akaganéite nanoneedles or nanowires with a diameter ranging from 20 to 8 nm displayed a propensity for forming single-crystal nanoneedles or nanowires through phase transformation and densification. By manipulating the size of the precursors, we have developed a straightforward method for the synthesis of single-crystal and polycrystalline maghemite nanowires through solid-phase transformation. These significant findings provide new insights into the size-dependent structural evolution and phase transformation of iron oxides at the nanoscale.

Wang, Xiang↗
DOE OSTI2025

A simple centrifuge cell method for ex situ quantification of electrical conductivity of slurry electrode materials

We present the design, experimental procedure, and experimental evaluation of a system for fast, simple, and ex situ characterization of electrical conductivity of slurry electrode materials. The system uses a custom-designed electrochemical cell compatible with centrifugation in a swing-bucket centrifuge. The cell features cylindrical graphite electrodes that are partially sheathed so as to expose only 2 mm of the electrode surface to the bottom region of the packed particulate pellet. Also presented is a conduction model that provides a shape factor for estimating effective conductivity. We tested aqueous solutions of carbon black (CB), activated carbon (AC), and mixtures thereof. These particles were dispersed in 0.0 and 0.5 M NaCl solutions. Measurements show that the effective conductivity initially increases linearly with pellet mass and then saturates at higher masses. Notably, CB exhibited a fivefold increase in conductivity than AC at equal pellet masses. CB/AC mixtures at a fixed pellet mass were tested with CB mass fractions of 0 to 100%. Interestingly, the mixture conductivity was found to be a non-monotonic function of CB mass fraction, with a maximum conductivity at about 60 % CB mass fraction. At this maximum, the mixture conductivity is approximately 30 % higher than pure CB. NaCl concentration in the slurry solution had no effects on conductivity. These results highlight the interactions between slurry electrode composition and compaction, offering insights for optimizing slurry electrodes. Furthermore, the system and results may also be applicable to evaluation of particulate materials (including slurries) used for Li-ion batteries, capacitive deionization, fuel cells, and flow electrodes.

Capacitive deionization↗
DOE OSTI2024

High-entropy Li-rich layered oxide cathode for Li-ion batteries

High-entropy oxides (HEOs) are emerging as promising cathode materials for Li-ion batteries (LIBs) due to their stable solid-state phase and compositional flexibility. Herein, we investigate the structural and electrochemical properties of a novel non-equimolar high-entropy cathode material, termed high-entropy Li-rich layered oxide (HE-LLO, Li 1.15 Na 0.05 Ni 0.19 Mn 0.56 Fe 0.02 Mg 0.02 Al 0.02 O 1.97 F 0.03 ), in comparison to a pristine Li-rich layered oxide (PR-LLO, Li1.2Ni0.2Mn0.6O2). The incorporation of multiple cations (Na + , Al 3+ , Mg 2+ , Fe 3+ ) and anion (F - ) into HE-LLO introduces compositional diversity, enhancing structural stability through the entropy stabilization effect. Theoretical calculations confirm a significantly higher configurational entropy in HE-LLO compared to PRLLO, supporting its high-entropy nature. Electrochemical evaluations demonstrate that HE-LLO exhibits considerable capacity retention, preserving 76.8 % of its discharge capacity at 0.5C after 200 cycles, compared to only 36.2 % for PR-LLO. Even under high-temperature conditions, HE-LLO outperformed PR-LLO, maintaining 76.1 % of its discharge capacity after 100 cycles at 5C, while PR-LLO retained only 12.4 %. These enhancements are attributed to the improved phase reversibility and higher Li + ion diffusion coefficients of HE-LLO, validated by ex-situ characterizations using a synchrotron X-ray technique, along with density functional theory (DFT) calculations. In conclusion, these findings highlight the promise of non-equimolar HEOs as a novel design strategy for highperformance cathode materials.

25 ENERGY STORAGE↗
DOE OSTI2026

In situ TEM annealing of neutron-irradiated Ti reveals a two-stage mechanism for elevated temperature radiation damage recovery

Understanding how irradiation-induced defects evolve at elevated temperatures is of critical importance to predicting materials' behavior under steady-state and accident scenarios. However, such mechanistic insight into microstructural evolution is limited by the nature of ex situ annealing and subsequent imaging. Here we show direct observation and quantification of defect recovery in neutron-irradiated Ti using in situ transmission electron microscopy (TEM) annealing experiments. In agreement with our prior work, and at temperatures below the irradiation temperature (T irr = 300 °C), dislocation loops are observed to glide. At elevated temperatures (>500 °C), dislocation lines become mobile and promote significant recovery of the microstructure. These mechanisms challenge the established electron irradiation-based model for radiation damage recovery, which originally suggests dissolution of static defect clusters, and demonstrates the importance of in situ characterization in understanding defect evolution in irradiated materials.

Hirst, Charles A. [Univ. of Michigan, Ann Arbor, M↗
DOE OSTI2025

Probing the Effects of the First Atomic Layer on the Dynamic Behavior of Sub-2 nm MgO/Al 2 O 3 Memristors

As electronic devices continue to scale down from the current sub-5 nm range, atomic-scale control of defects becomes increasingly crucial to suppressing their impact on the physical properties of the devices. Memristors present an excellent example as a nonlinear and dynamic device with high speed and endurance required for electronic applications ranging from neuromorphic computing to nonvolatile memories. Herein we investigate the impact of atomic defects in sub-2 nm thick MgO/Al 2 O 3 atomic layer stack (ALS) memristors that use an M1 (switching layer)/M2 (oxygen vacancy reservoir layer) bilayer structure grown using in vacuo atomic layer deposition (iALD). Intriguingly, we revealed a direct correlation of the atomic defects in the M2 layer with the memristor dynamic behavior using a combined analysis of in situ scanning tunneling spectroscopy (iSTS) on the M2 layer and ex situ characterization on the memristors. Specifically, incomplete coverage of the 1st ALD atomic layer of M2 on the electrode yields defects at the M2/electrode interface. Despite the monotonic increase of ALD coverage, by almost three-fold from ~30% to >90%, at completion of the M2 layer of ~ 0.7 nm in thickness, the impact of the defects on the M2/electrode interface has been found detrimental to both memristor switching speed and endurance. Guided by atomistic simulation, we addressed the issue of interface defects via tuning of the Al surface hydroxylation to increase the first atomic layer ALD coverage to ~75%, leading to improved memristor switching speed and endurance by several orders of magnitude. In conclusion, these findings shed light on the correlation between the atomic defects and the dynamic behavior of sub-2 nm memristors and the importance of minimizing the atomic defects in memristors for future electronic applications.

Atomic Layer Deposition↗
DOE OSTI2025

Effect of Networking Density on the Patterning Performance of Molecular Layer Deposited Alucone Electron Beam/EUV Resists

One of the main barriers to continued device scaling in the era of extreme ultraviolet (EUV) lithography is the need for improved photoresist chemistries to address challenges such as poor EUV sensitivity, inadequate etch resistance, and pattern collapse. Metal-organic photoresists are a promising class of materials that can address many of these challenges, and among them, resists deposited via hybrid molecular layer deposition (MLD) have attracted interest for their unique advantages in thickness control, chemical homogeneity, and compatibility with vacuum processing. However, despite many successful demonstrations of patterning, little is known about how the molecular design of hybrid MLD resists affects their lithographic performance. In this work, we study the effect of the network structure, a common feature among all hybrid MLD resists, via a series of aluminum alkoxide ("alucone") negative tone resists with varying networking density. Their patterning mechanism is investigated via electron beam lithography (EBL)─a common proxy for EUV─and compared to their EUV-induced reactions studied via flood exposure and in situ characterization. In conclusion, we show that the resist with the least networking density demonstrates the best sensitivity and resolution, with the ability to resolve dense line/space gratings as small as 14 nm half pitch via EBL.

electron beam lithography↗
DOE OSTI2025

Electrochemical Activation of Ni–Fe Oxides for the Oxygen Evolution Reaction in Alkaline Media

The oxygen evolution reaction (OER) is essential to many key electrochemical devices, including H 2 O electrolyzers, CO 2 electrolyzers, and metal−air batteries. NiFe oxides have been historically identified as active for the OER, though they have been less studied in their more commercially relevant bulk oxide forms, such as NiFe 2 O 4 . Past works have demonstrated that the initial starting phase of Ni(Fe) precatalysts can influence their activation to the Ni(Fe)OOH active phase, including the rate and degree of conversion, pointing to the necessity of understanding activation protocols and in situ characteristics of catalyst materials at the device level. In this work, we investigate the characteristics of commercially relevant NiFe bulk oxides (NiFe 2 O 4 and a physical mixture of NiO and γ-Fe 2 O 3 ) during multiple activation procedures. Our results demonstrate that significant performance enhancement is observed for these bulk oxides regardless of the Fe incorporation in the initial form (i.e., atomically or macroscopically integrated), leading to significant performance enhancement (up to 30×) over time on stream. We hypothesize that this activation is due to the formation of NiFeOOH active sites on the surface, supported by in situ cyclic voltammetry and Raman spectroscopy results. We further show that not only the starting material but also the method of activation influences the number of Ni(Fe)OOH active sites formed and suggest that these sites can be quantified from the Ni 2+ to Ni 3+ redox transition using cyclic voltammetry. Broadly, this work demonstrates the necessity of in situ characterization of catalyst materials for cell-level design and testing.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Enhancing Acidic Oxygen Evolution Activity by Supporting Iridium Electrocatalysts on Tantalum Carbide

For a high-performance proton exchange membrane water electrolyzer (PEMWE), acidic oxygen evolution reaction (OER) electrocatalysts require highly dispersed iridium oxide (IrO x ) nanoparticles. Although carbon-based materials have been explored as promising supports for IrO x nanoparticles, their limited stability under harsh oxidative and acidic PEMWE conditions remains a significant challenge. Here, in this study, we report the synthesis and in situ characterization of active and durable IrOx electrocatalysts supported on electrochemically stable and electrically conducting tantalum carbide (TaC). When applied in a PEMWE, the IrO x /TaC electrocatalyst achieves a cell voltage of 1.71 V at 1.0 A cm –2 , outperforming the commercial IrO 2 catalyst (1.82 V at 1.0 A cm –2 ). Furthermore, the IrO x /TaC catalyst maintains a stable operation for 200 h at 0.5 A cm –2 with a low degradation rate of 36 μV h –1 . Density functional theory calculations further confirm that Ir–O–Ta bond formation at the IrO x /TaC interface reduces the overpotential of the OER compared to IrO 2 . This study underscores the pivotal role of supporting IrO x over stable and conducting metal carbides, providing guidance for the design of advanced acidic OER catalysts.

58 GEOSCIENCES↗
DOE OSTI2025

Achieving Higher Activity of Acidic Oxygen Evolution Reaction Using an Atomically Thin Layer of IrO x over Co 3 O 4

The development of electrocatalysts with reduced iridium (Ir) loading for the oxygen evolution reaction (OER) is essential to produce low-cost green hydrogen from water electrolysis under acidic conditions. Herein, an atomically thin layer of iridium oxide (IrO x ) has been uniformly dispersed onto cobalt oxide (Co 3 O 4 ) nanocrystals to improve the efficient use of Ir for acidic OER. In situ characterization and theoretical calculations reveal that compared to the conventional IrOx cluster, the atomically thin layer of IrO x shows stronger interaction with the Co 3 O 4 and consequently higher OER activity due to the Ir-O-Co bond formation at the interface. Equally important, the facile synthetic method and the promising activity in the proton exchange membrane water electrolyzer, reaching 1 A cm -2 at 1.7 V with remarkable durability, enable potential scale-up applications. In conclusion, these findings provide a mechanistic understanding for designing active, stable and lower-cost electrocatalysts with well-defined structures for acidic OER.

58 GEOSCIENCES↗
DOE OSTI2026

In Situ Insights into Enhanced Cooperative Ligand Exchange Kinetics via Solvent-Induced Restacking in a 2D Metal–Organic Framework

Understanding the reaction kinetics at catalytically active sites is crucial for integrating catalytic two-dimensional (2D) materials into industrial processes. This study focuses on in situ observation of ligand exchange kinetics and solvent-assisted structural restacking transition in the 2D paddle wheel-based MOF [Cu 2 (dttc) 2 ] n (DUT-134(Cu), dttc = dithieno[3,2-b:2′,3′- d]thiophene-2,6-dicarboxylate). The ligand exchange process, involving the replacement of dimethylformamide (DMF) with nitriles such as acetonitrile (ACN), pentanenitrile, and heptanenitrile, was investigated using advanced in situ characterization techniques with high temporal resolution, including powder X-ray diffraction and Raman spectroscopy. The larger analytes exhibited reduced exchange rates, consistent with enhanced steric hindrance and greater diffusion constraints. Interestingly, the study revealed that the exchange of DMF with ACN induces a structural transition to higher symmetry within few seconds, a transition from AB to AA stacking mode of the layers, and a widening of the interlayer distance. Crucially, this structural transition dramatically accelerates the solvent exchange process through cooperative effects, offering critical advantages for catalytic applications. Notably, the reverse exchange from ACN to DMF proceeds more slowly and does not reverse the structural changes, but a new phase is formed with preserved AA stacking. By isotope labeling of linker molecules in combination with two complementary theoretical vibrational simulation methods, the precise assignment of Raman bands and the vibrational modes associated with the ligand exchange process could be achieved. These pioneering insights into the dynamic behavior of 2D MOFs, coupled with ligand exchange, establish a highly promising and transformative approach to achieving enhanced tunability and responsiveness in future catalytic applications.

Layers↗
DOE OSTI2025

Scalable mechanochemical synthesis of high-quality Prussian blue analogues for high-energy and durable potassium-ion batteries

Prussian blue analogues (PBAs) are recognized as promising cathode materials for potassium-ion batteries (PIBs), particularly the low-cost and high-energy K 2 Mn[Fe(CN) 6 ](KMnF). However, conventional solution-based synthesis inevitably introduces [Fe(CN) 6 ] 4− defects and lattice water while suffering low synthesis efficiency, unfavorable to the improvement of electrochemical performance and scalability. Here, in this work, we report a simple solvent-free mechanochemical strategy for the synthesis of a wide variety of K 2 M[Fe(CN) 6 ] (M = Mn, Mg, Ca, etc.) with negligible defects and water, and it is unprecedented to achieve kilogram-level products of high-quality KMnF within just 10 minutes. The as-prepared KMnF delivers a high energy density of 590 Wh kg −1 at 0.2 C and exhibits an astonishing stability over 10 000 cycles and rate ability up to 50 C in a potassium metal half-cell. Encouragingly, a high-areal-capacity pouch cell with 2.2 mAh cm −2 (16.5 mg cm −2 ) exhibits a capacity retention of 80.7% after 500 cycles. Furthermore, systematic in situ characterization reveals underlying mechanism insights into structure–performance relationships. Specifically, the fully coordinated Mn–N 6 octahedral configuration effectively suppresses Mn 3+ Jahn–Teller distortion, enabling reversible phase transitions under both high-voltage and long-term cycling conditions. In addition, minimal defects provide sufficient redox centers, while the continuous three-dimensional framework facilitates rapid K + diffusion kinetics. This work provides a new opportunity for the ultrafast, universal and scalable synthesis of high-quality PBAs, facilitating the practical application of PIBs while enabling precise structural and compositional design of novel PBAs.

Mechanochemical method↗