Lead-free (Ag,K)NbO₃ materials for high-performance explosive energy conversion

Area of Science:

• Materials Science
• Solid State Physics
• Energy Storage

Background:

• Explosive energy conversion materials are crucial for rapid energy release applications.
• Current lead-based materials like Pb(Zr,Ti)O3 are environmentally hazardous and lack sufficient performance.
• Limited research exists on novel, high-performance, lead-free alternatives.

Purpose of the Study:

• To discover and characterize a new lead-free material for explosive energy conversion.
• To elucidate the underlying mechanism of its rapid energy release.
• To provide a high-performance, environmentally friendly alternative to existing technologies.

Main Methods:

• Synthesis and characterization of the lead-free (Ag0.935K0.065)NbO3 material.
• In situ experimental investigations (e.g., X-ray diffraction, electrical measurements).
• Theoretical calculations and simulations to understand phase transitions and mechanisms.

Main Results:

• Discovery of a novel lead-free (Ag0.935K0.065)NbO3 material.
• Achieved record energy storage density of 5.401 J/g.
• Demonstrated rapid pulse current delivery (~22 A in 1.8 µs) with excellent thermal stability up to 150°C.
• Identified pressure-induced octahedral tilt change and ferroelectric-antiferroelectric phase transition as the energy conversion mechanism.

Conclusions:

• The newly discovered (Ag0.935K0.065)NbO3 material is a high-performance, lead-free alternative for explosive energy conversion.
• The material's performance is attributed to a pressure-driven phase transition.
• This research offers guidance for developing next-generation energy conversion materials and devices.