The development of green and insensitive primary explosives to replace toxic heavy-metal-based energetic materials (e.g., lead azide) remains a central challenge in the field of modern energetic materials. This work presents a ligand engineering strategy based on site-specific N-methylation to regulate the energy-safety balance in copper perchlorate energetic coordination compounds. By systematically employing four N-methyl-1H-pyrazole-carbohydrazide ligands with distinct methyl substitution patterns (varying in position and number), a series of isostructural congeners (ECC-1 to ECC-4) with identical coordination motifs are successfully constructed, providing ideal platforms for structure-property relationship studies. Multidimensional mechanistic investigations revealed that methylation exerts a finely tuned influence: ortho-methylation enhances thermal stability (e.g., ECC-4, Td = 188 °C), primarily by strengthening the coordination bonds through its electron-donating effect, while meta-methylation facilitates a more uniform molecular surface charge distribution, optimizing the supramolecular interaction network and thereby significantly improving mechanical safety. Owing to its balanced methylation pattern, the complex ECC-3 integrates low mechanical sensitivity (IS = 3.8 J, FS = 9 N), excellent laser ignition capability (El = 5 mJ), and reliable detonation performance, demonstrating the most promising overall practical potential among the studied energetic materials. This study elucidates the feasibility of synergistically tuning the properties of energetic materials at both molecular and supramolecular levels through rational ligand design, offering a new paradigm for developing high-performance and high-safety energetic materials.

Rechargeable alkali metal-sulfur (M–S) batteries, including Li/Na/K–S chemistries, have the potential to utilize abundant and low-cost sulfur cathodes yet offer high theoretical energy densities. However, their practical electrochemical performance is fundamentally limited by the polysulfide shuttle effect. This challenge is particularly exacerbated in Na–S and K–S systems owing to larger metal-ion radii, weaker solvation energies, slower redox kinetics, and greater electrolyte–electrode incompatibilities compared to Li–S batteries. This review presents a comparative analysis of interface engineering strategies designed to suppress the shuttle effect across these three systems. Following a summary of sulfur cathode properties and reaction mechanisms, we systematically examine the origins of polysulfide shuttling. Our analysis progresses from functional separator design and interlayer enhancements to the implementation of solid‑state electrolytes for root-cause inhibition. By evaluating interface engineering research specific to Na–S and K–S batteries, we elucidate both shared principles and unique challenges inherent to alkali M-S systems. Finally, we propose multifaceted solutions to achieve shuttle-free operation and enhance overall battery performance, thereby establishing a foundation for future advancements.

A 2D coordination polymer[Zn(ATRZ)2(H2O)2](ATRZ)(CBH)2 center dot 2H2O, (ZAG) was constructed using 4,4 '-azobis-1,2,4-triazole (ATRZ) as the linker, Zn2+ as the node, and active cyanoborohydride (CBH) as the dissociative anion. Its crystal structure and properties were characterized by X-ray diffraction (XRD), differential scanning calorimetry-thermogravimetry (DSC-TG), oxygen bomb calorimetry, and mechanical sensitivity measurements (X-ray density: 1.548 g center dot cm-3; thermal decomposition temperature, Td: 179.14 degrees C; specific energy, Eg: 15.76 kJ center dot g-1; energy density, Ev: 24.40 kJ center dot cm-3; impact sensitivity, IS: 30 J; friction sensitivity, FS: 288 N). ZAG is characterized by a unique 2D polymer stabilized by the coordination of Zn2+ with linker ATRZ and aqua ligands, while free ATRZ, CBH anion and crystal water are packed in the polymer. The combustion performance of ZAG/ KClO4 (ZAGK) composite was evaluated in detail (Heat of combustion: 5.25 kJ center dot g-1; peak pressure: 3.23 MPa; response time: 11.07 ms; linear burning rate: 124.6 mm center dot s-1). Improved performance relative to conventional BPN (B/KNO3) was observed, highlighting its potential for energetic materials applications.

The design and synthesis of a high-energy-density material (HEDM) that simultaneously possesses high energy and low sensitivity is a challenging task. This study reports an effective strategy for constructing polynitro-substituted bicyclic fused ring frameworks. A series of polynitro [1,2,4] triazolo [4,3-b] pyridazine fused rings with nitrogen-rich NH2/NHNH2/NHOH groups were first synthesized by straightforward routes, and were characterized by chemical (NMR, MS, IR spectroscopy, and single-crystal X-ray diffraction) as well as experimental analysis (sensitivity towards friction, impact, and DSC-TGA test). Their detonation properties (detonation velocity, detonation pressure, etc.) were predicted by the EXPLO5 program. These new polynitro fused ring compounds were found to exhibit high density, high decomposition temperature, and acceptable impact and sensitivity, making them promising high-energy-density materials (HEDM). It is worth noting that the excellent energetic properties (density: 1.932 g cm-3, Vdet: 9585 m s-1; PCJ: 41.8 GPa), superior to those of HMX (1,3,5,7-tetranitrotetraazacyclooctane), highlight compound 5 as the highest-performing bicyclic fused ring energetic compound reported to date. Computational considerations of 5 and 2,4,6-triamino-1,3,5-trinitrobenzene (TATB) suggest that its structural character provides a good balance between energy and safety (sensitivity: 36 J, 324 N). This work demonstrates the effectiveness of introducing polynitro groups into the multi-ring planar skeleton and provides a generalizable design synthesis strategy for developing new HEDMs.

The development of green primary explosives that combine high energy with low sensitivity represents a central challenge in the field of energetic materials. This paper reports a novel energetic complex, Cu(1-MPCA)2(H2O)(ClO4)2, based on 1-methyl-1H-pyrazole-4-carbohydrazide (1-MPCA). Single-crystal X-ray diffraction analysis reveals that the Cu(II) center in this complex adopts a rare square-pyramidal five-coordinate geometry, in sharp contrast to its isomeric analogue based on 3-methyl-1H-pyrazole-4-carbohydrazide (3-MPCA), which exhibits a classic octahedral structure. Theoretical calculations indicate that the Jahn–Teller distortion induced by the five-coordinate geometry, along with the altered intermolecular hydrogen-bonding network, negatively impacts sensitivity characteristics, leading to nonlinear differences in macroscopic performance between the two complexes. Consequently, Cu(1-MPCA)2(H2O)(ClO4)2 displays lower thermal stability (Td = 157°C) and higher mechanical sensitivity (IS = 0.8 J, FS < 5 N). However, this declining trend does not extend to energy-related properties such as laser-ignition capability (El = 9 mJ) and detonation performance. This study clearly demonstrates that the precise position of a substituent in energetic complex can decisively influence the coordination geometry of the metal center, thereby exerting a far-reaching impact on the overall performance balance. These findings provide key insights for the rational design of high-performance energetic materials through “positional isomeric engineering”.

To develop energetic combustion catalysts for solid propellants, two novel energetic metal coordination compounds, Mn(AIM)6(BF4)2 (Mn-ABF) and Ni(AIM)6(BF4)2 (Ni-ABF), were successfully synthesized in this study. These compounds were prepared by coordinating Mn2+ and Ni2+ ions with the ligand 1-allylimidazole (AIM) and the tetrafluoroborate anion. Physicochemical characterization revealed that both compounds exhibit excellent safety performance (IS > 40 J, FS > 360 N) along with favorable energetic properties. Specifically, Mn-ABF and Ni-ABF lowered the decomposition temperature of RDX by 3.7 °C and 9.8 °C, and reduced its apparent activation energy by 32.1 kJ mol-1 and 50.4 kJ mol-1, respectively. For HMX, the decomposition temperatures were decreased by 3.8 °C and 18.3 °C, with corresponding reductions in apparent activation energy of 43.5 kJ mol-1 and 137.7 kJ mol-1, respectively. Combustion experiments based on these findings demonstrated that both compounds significantly promote the combustion process in RDX/AP/Al and HMX/AP/Al composite systems. They reduced the burning times of both AP/RDX/Al (from 33 s to 16 s and 6 s) and AP/HMX/Al (from 31 s to 13 s and 10 s), while also increasing the flame area and intensity. Quantum chemical calculations were conducted to analyze the Hirshfeld surfaces, interatomic interactions, and molecular electrostatic potential of Mn-ABF and Ni-ABF. These analyses revealed the intrinsic reasons, at the electronic structure level, for the superior catalytic performance of Ni-ABF over Mn-ABF. The results indicate that the synthesized Mn-ABF and Ni-ABF possess promising application potential as highly efficient combustion catalysts for solid propellants.

The development of melt-cast explosives with balanced energy, safety, and processability remains a critical challenge due to the inherent trade-offs among these properties. Herein, we report a rationally designed melt-cast explosive carrier, 1,4-dimethyl-3,5-dinitropyrazole (DMDNP), synthesized via a one-step nitration from commercially available precursors. DMDNP exhibits a favorable melting point (101.0 degrees C), high thermal stability (T-d = 300.6 degrees C), and a density of 1.638 g cm(-3) at 118 K. The detonation performance, based on EXPLO5 calculations, reaches a velocity of 7082 m s(-1) and a pressure of 19.2 GPa, outperforming traditional TNT and significantly exceeding DNAN. Notably, DMDNP demonstrates low mechanical sensitivities (IS = 50 J, FS > 360 N, and E-50 = 9.3 J), attributed to a synergistic combination of high bond dissociation energy, herringbone crystal packing, and a low proportion of unfavorable O & ctdot;O and O & ctdot;N intermolecular contacts. With straightforward synthesis, favorable thermal behavior, enhanced detonation performance, and low sensitivity, DMDNP exhibits well-balanced properties and holds promise for further application studies as a next generation melt-cast explosive carrier.

Energetic catalysts combine the catalytic performance and high energy storage, thus showing application potential as composite solid propellant components. In this study, four energetic polymeric complexes, namely [Cu(MAT)DCA2]n (1), [Co(MAT)2DCA2]n (2), [Ni(MAT)2DCA2]n (3), and [Cd(MAT)2DCA2]n (4) (MAT = 1-methyl-5-aminotetrazole, DCA = dicyanamide), were synthesized by a straight and simple route. These complexes were characterized by single-crystal X-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy, and elemental analysis. The thermal stability of these complexes was obtained by differential scanning calorimetry (DSC) and thermogravimetry (TG), and the decomposition temperatures are between 195.3 and 261.7 °C. Their catalytic performances for ammonium perchlorate (AP) decomposition were confirmed by DSC. The obtained results reveal that all the complexes have catalytic performance for AP thermal decomposition. [Cu(MAT)DCA2]n (1) exhibits the best catalytic performance and reduces the decomposition (high-temperature) peak temperature by 110.4 °C compared to pure AP. Moreover, this complex alters the shape of the decomposition peak, which suggests that it speeds up the decomposition process and renders it more intense.

The tetranitroethane (TNE) as a typical representative of polynitroalkanes, exhibits positive oxygen balance (OB = +22.9 %), high nitrogen content and strong electronegativity. In this work, a series of tetranitroethaneimidazole energetic metal complexes with varying coordination functionalities based on tetranitroethane were synthesized. We cultivated and characterized the synthesized compound crystals. Thermal analysis was conducted on the four synthesized compounds. The apparent activation energy of four compounds was calculated using the Kissinger and Ozawa methods, respectively. The thermal explosion critical temperature and thermodynamic parameters were also determined. Moreover, their sensitivities were tested and the explosion properties of the energetic complexes of tetranitroethane were predicted through the EXPLO5 software. The results indicate that the synthesized nickel hexaimidazole tetranitroethane energetic metal complexes (EMC-2) exhibits moderate explosive performance and demonstrates low sensitivity, making it a promising candidate for a novel green and insensitive energetic material.

Achieving high laser sensitivity while maintaining excellent mechanical safety is a pivotal yet challenging goal for the development of advanced laser-ignitable energetic materials. In this work, nitro-functionalization was employed to simultaneously reduce the mechanical sensitivity and enhance the laser sensitivity of energetic coordination compounds (ECCs). Five novel nitro-substituted ECCs were synthesized and characterized. Structural analysis reveals that nitro-functionalization significantly enhances crystal density and thermal stability. The mechanism of nitro functionalization was elucidated through noncovalent interaction (NCI), Hirshfeld surface analysis, electrostatic potential surface, and frontier molecular orbital analysis. Experimental and theoretical investigations attribute this "laser-specific sensitivity" to the nitro group's dual role: it modulates the electronic structure to favor laser initiation while strengthening intermolecular interaction networks to buffer mechanical stimuli. This work provides a new paradigm for designing safe, high-performance laser-sensitive explosives.

Two novel energetic metal coordination compounds, Mn(VIM)(6)(BF4)(2) (Mn-VBF) and Ni(VIM)(6)(BF4)(2) (Ni-VBF), were synthesized as potential combustion catalysts for solid propellants, using 1-vinylimidazole (VIM) as the ligand and transition metals (Mn, Ni) as central ions . Physicochemical characterization confirmed their excellent safety characteristics (IS > 40 J, FS > 360 N) and favorable energetic properties. Their catalytic effects on the thermal decomposition of AP and RDX, as well as on the combustion of AP/RDX-based composites, were systematically studied. Both compounds concurrently catalyzed the decomposition of AP and RDX, lowering their decomposition temperatures and activation energies, and leading to a more concentrated and rapid heat release. Key experimental results show that Mn-VBF and Ni-VBF reduce the high-temperature decomposition peak of AP by 26.2 degrees C and 22.2 degrees C, narrow its peak width by 22.2 degrees C and 20.6 degrees C, and decrease the apparent activation energy by 73.8kJ & centerdot;mol(-)(1) and 64.4 kJ & centerdot;mol(-)(1), respectively. For RDX, the main decomposition peak is lowered to 233.6 degrees C and 236.2 degrees C, with activation energies reduced to 147.8kJ & centerdot;mol(-)(1) and 153.9kJ & centerdot;mol(-)(1). In AP/RDX-based composites, these catalysts shorten the burn time from 74 s to 39 s (Mn-VBF) and 44 s (Ni-VBF) while increasing flame intensity. Quantum chemical calculations, including frontier orbital analysis, reveal that the lower energy gaps (Delta E) for both alpha-spin and beta-spin electrons in Mn-VBF underlie its enhanced catalytic performance relative to Ni-VBF. These findings highlight Mn-VBF and Ni-VBF as promising high-performance combustion catalysts for solid propellants.

In this paper, a novel three-dimensional porous NiB based metallic catalysts with Ce doping were obtained through dealloying treatment of Cu–Ni–Ce–B precursors. It was found that Ce addition had an obvious refinement effect on the microstructure of precursors, in which the thermodynamically stable CeB₆ spherical precipitations were observed. After dealloying, a self-supporting NiB framework enriched with abundant grooves and pores were formed, leading to a significant increase in specific surface area and the exposure number of active sites. Furthermore, electrochemical measurements demonstrated that the catalyst after adding 2 wt% Ce exhibited a relatively low hydrogen evolution overpotential of 135.2 mV @10 mA cm−2 along with the remarkably small radii of Nyquist Plots and the Cdl as high as 49.16 mF cm−2, indicating the adequate electrochemical active sites and excellent charge transfer capability. In addition, it was also found that after the introduction of Ce the B 1 s peaks were detected to be shifted slightly toward lower binding energies through XPS analysis, indicating the remarkable promotion of electron transfers from Ce to B. Based on these, the catalytic performance of the self-supported NiB based catalysts with Ce modification was thereby promoted.

Energetic plasticizers are rarely used in HTPB propellants due to compatibility issues; one strategy is usually adopted is to introduce energetic substituents. In this study, the synthesized high-energy ionic liquids were comprehensively characterized, and showed that they possess extremely low melting points (IL-3h, Tm = –70 °C), good thermal stability (ILs, Tp > 370 °C), and high densities (IL-3a, ρ = 1.637 g/cm3). The high-energy performance exhibited by high detonation velocity (Dv) and pressure (DP) of ionic liquids (Dv: 6600–6800 m/s; Dp: 17–19 MPa) contributes to improved specific impulse in propellant formulations, which significantly surpasses that of conventional triethylene glycol dinitrate (TEGDN). Furthermore, HTPB elastomer cured with TDI were plasticized with ionic liquids, and the results of tensile and dynamic mechanical tests were showed that the HTPB elastomer plasticized with ionic liquids had a maximum tensile strength of 0.883 MPa and a maximum elongation at break of 539.2%, which were comparable to DOA (σt = 0.587 MPa, εt = 479.1%). This work provides an innovative approach for the design of energetic ionic liquid plasticizers in HTPB propellants.

The trade-off between safety and energy content has long been a central challenge in the design of energetic materials. Here we propose a TATB-inspired design strategy for high-energy, insensitive explosives: secure intrinsic safety at the electronic and molecular scales, and achieve synergistic optimization of safety and detonation performance at the crystal scale by enforcing planar packing motifs. Using fused five- and six-membered nitrogen-containing aromatic rings as the scaffold, and combining nitro, amino, and N-coordinated oxygen substituents, we constructed an initial molecular library of 1 00 413 compounds and applied five rounds of high-throughput virtual screening (oxygen balance, substituent counts, synthetic feasibility, planarity, predicted detonation velocity) to progressively down-select targets. Crystal structure prediction was then performed for 100 candidate molecules using USPEX coupled with GFN1-xTB, yielding ten compounds with planar, layered packing motifs. Theoretical evaluation indicates that mol-392 attains a calculated detonation velocity of 8541 m s-1 and a predicted sensitivity at least comparable to TNT, demonstrating excellent overall performance. Furthermore, energy decomposition and correlation analyses identify van der Waals (dispersion) interactions as the dominant determinant of crystal density in these systems. This study validates the practicality of the TATB-like design strategy, provides a route for the rational discovery of insensitive high explosives, elucidates mechanisms governing crystal density in planar layered packings, and highlights the value of combining high-throughput virtual screening with crystal engineering in energetic-materials development.

Quasi-solid-state sodium-ion batteries (SSSIBs) hold great promise for next-generation energy storage owing to their high safety and abundant reserves, but are limited by the low conductivity and interfacial instability of quasi-solid-state electrolytes (SSEs). This study reports a series of porous hyper-crosslinked polymers (HCPs) constructed from heteroaromatic monomers (thiophene, furan, pyrrole) as high-performance quasi-solid electrolytes. Heteroatoms such as sulfur (S), oxygen (O), and nitrogen (N) within the polymer backbone can induce enhanced localized positive charges, strengthening the electrostatic attraction toward ClO4- anions and promoting anion-ordered migration, thereby effectively reducing the energy barrier for Na+ transport. Notably, the S atom in the thiophene structure facilitates Na+ migration while anchoring ClO4- anions, endowing the electrolyte with a high ionic conductivity of 2.75 & times; 10-3 S cm- 1, a low activation energy of 0.15 eV, and a wide electrochemical window of 4.70 V. A Na|TP-HCP-E (thiophene-based HCP electrolyte)| Na3V2(PO4)3 (NVP) full cell exhibits a capacity retention of 62.03% after 4000 cycles at 1C and demonstrates stable charge-discharge performance even at a low temperature of -25 degrees C. This work elucidates the modulation mechanism of heterocyclic structures on ion transport behavior and interfacial stability at the atomic scale, providing an important foundation for designing novel high-performance SSEs.

The pursuit of enhanced combustion performance in solid propellants has stimulated significant research focus on novel aluminum-based fuels. We report the synthesis of a novel copper-based metallic ionic liquid, [Cu (VIM)5](BF4)2 (MetIL-Cu), achieved via fluorine-containing functional group incorporation. Comprehensive physicochemical characterization demonstrated exceptional safety parameters and energetic performance. Employing MetIL-Cu as a coating precursor yielded a core-shell structured fuel (Al@MetIL-Cu) with a dense, homogeneous encapsulation layer. Systematic characterization of composition, morphology, and thermal decomposition behavior validated the structural integrity of Al@MetIL-Cu and coating uniformity. Relative to Al, Al@MetIL-Cu displayed a 6.5 degrees C reduction in primary exothermic peak temperature along with a 118.1 degrees C decrease in exothermic peak width. Propellant applicability assessment commenced with theoretical performance calculations via Chemical Equilibrium with Applications (CEA). Computational results indicate that MetIL-Cu exceeds the efficacy of conventional additives. Propellant (CSP-2) containing Al@MetIL-Cu achieved a 9.5% enhancement in linear burning rate relative to pure aluminum-based counterparts, concurrently exhibiting significant amplification of flame area and intensity. Theory calculations revealed MetIL-Cu possesses: extended positive charge density distribution, a pronounced electropositive region, and a narrow bandgap (1.45 eV). These electronic properties synergistically facilitate electron transfer kinetics and elevate reactivity within Al@MetILCu, establishing the electronic and kinetic mechanism for Al and AP thermal decomposition. Remarkably, Al@MetIL-Cu mediated a reduction in AP's high-temperature decomposition peak from 393.4 degrees C to 336.5 degrees C, compressed the exothermic peak width from 43.2 degrees C to 18.2 degrees C, and lowered apparent activation energy from 198.2 kJ mol- 1 to 136.5 kJ mol- 1. Collectively, Al@MetIL-Cu represents a novel high-performance fuel that concurrently optimizes the efficiency and peak width of Al and AP pyrolysis, delivering fundamental mechanistic insights and implementable strategies for enhancing solid propellant combustion performance.

Two-dimensional (2D) diamond has aroused remarkable interest in nanoelectronics and optoelectronics, owing to its superior properties and flexible characteristics compared to bulk diamond. Despite significant efforts, great challenges lie in the experimental synthesis and transformation conditions of 2D diamond. Herein, we have demonstrated the experimental preparation of high quality 2D diamond with controlled thickness and distinguished properties, realized by laser-heating few-layer graphene in a diamond anvil cell. The quenched 2D diamond exhibited a narrow T2g Raman peak (linewidth ~3.6 cm-1) and intense photoluminescence of SiV- (linewidth ~6.1 nm) and NV0 centers. In terms of transformation mechanism, atomic structures of hybrid phase interfaces suggested that the intermediate rhombohedral phase subtly mediate hexagonal graphite to cubic diamond transition. Furthermore, the tunable optical bandgap and thermal stability of 2D diamond sensitively depend on its sp3 concentration. We believe our results can shed light on the structural design and preparation of many carbon allotropes and further uncover the underlying transition mechanism.

The interaction between NH3 and NO plays a crucial role in controlling NOx formation during ammonia combustion. However, experimental data and mechanistic understanding under practical combustion temperatures and pressures remain limited. In this study, laminar burning velocities (LBVs) and ignition delay times (IDTs) of NH3/NO mixtures under oxygen-free conditions were systematically investigated. Experiments were conducted using a combustion vessel and a shock tube, covering a broad range of temperatures (1500–2800 K), pressures (1.5–10 atm), and equivalence ratios (ϕ = 1.0–2.0). Key findings reveal that LBVs peak at 31 cm/s (ϕ = 1.4, 373 K, 1 atm) but decrease significantly with pressure (24 cm/s at 5 atm). IDTs shorten abruptly above 1630 K at 10 atm (<100 μs). Kinetic analyses demonstrate that the reactions NH2 + NO → Products plays a dominant role in both flame propagation and ignition over the studied temperature range, due to their natures of chain branching and chain termination, with an even more pronounced influence during ignition. The pressure-dependent reaction NNH + M = N2 + H + M exhibits a significant pressure-dependent effect on flame propagation but has almost no influence on ignition. Through a careful evaluation of the branching ratio between NH2 + NO = NNH + OH and NH2 + NO = N2 + H2O, the kinetic mechanism was optimized using the rate constants recommended by Klippenstein [Proc. Combust. Inst. 36 (2017) 77–111], enabling the developed kinetic model to reasonably predict the newly obtained experimental data. These findings reveal the reaction mechanism governing the interactions between NH3 and NO, providing a solid theoretical foundation for achieving low-NOx ammonia combustion under practical operating conditions.Novelty and significance statement: Understanding the interaction between NH3 and NO is essential for advancing low-NOx ammonia combustion technologies, especially under fuel-rich conditions where NH3–NO reactions play a crucial role in NOx reduction. This work systematically investigates the interaction between NH3 and NO during ignition and flame propagation across a wide range of temperatures and pressures, achieving the first implementation of oxygen-free NH3/NO ignition experiments in a shock tube. The results demonstrate the dominant role of the two competing reactions NH2 + NO = NNH + OH and NH2 + NO = N2 + H2O in both ignition and flame propagation characteristics due to their roles as chain branching and chain termination reactions, respectively. These measurements establish highly sensitive validation targets for its kinetic chemistry. The updated kinetic model exhibits outstanding predictive performance across broad combustion regimes, offering critical insights into NOx-reducing ammonia combustion and providing foundational support for ammonia combustion applications.