Breaking the performance trade-offs of nano-metal fuels: ammonium perchlorate-mediated high-performance energetic microspheres

Simultaneously achieving high energy density, rapid reaction kinetics, and practical processability remains a fundamental challenge for metal fuels in next-generation solid propellants. Here, high-performance energetic microspheres (HPEMs) are established as a particle-level energetic composite by integrating nano-aluminum, nano-boron, and ammonium perchlorate into individual energetic microspheres, enabling intrinsic property complementarity to evolve into combustion synergy. The optimized HPEMs (Al:B = 7:3) simultaneously achieve high energy density, rapid reaction kinetics, and excellent processability. Specifically, the optimized HPEMs deliver a combustion heat of 24.0 kJ g −1 , 1.86 and 1.48 times higher than those of the Al@AP and B@AP counterparts, respectively. They exhibit the shortest ignition delay (577.2 ± 31.6 ms), accelerated flame propagation, and a balanced combustion duration (88.3 ± 5.0 ms), demonstrating efficient kinetic coupling between rapid Al oxidation and sustained boron combustion. The particle-level architecture suppresses nanoparticle aggregation, reducing slurry viscosity of propellant from 138.380 to 61.596 Pa·s while maintaining superior combustion performance in propellant formulations. Mechanistic investigations demonstrate that rapid Al/AP combustion establishes a self-sustained high-temperature oxidizing environment, which promotes the dynamic evolution of the molten B 2 O 3 layer, facilitates oxygen transport to the boron core, and continuously activates boron oxidation. Consequently, the rapid reaction kinetics of nano-aluminum are effectively transferred into sustained boron oxidation, establishing a synergistic combustion pathway that combines rapid reaction kinetics with continuous high-energy release. More importantly, this work establishes the coordinated integration of complementary energetic constituents as a general design strategy that shifts material optimization from overcoming the limitations of individual components toward synergistic optimization of multicomponent performance.