Lead-free KNN-based ceramics incorporated with Bi(Zn2/3Nb1/3)O3 possessing excellent optical transmittance and superior energy storage density

The application of lead-free dielectric ceramics for energy storage has received extensive attention because of their remarkable potential as pulse capacitors in power electronic devices. The current study developed a strategy for improving the energy storage performance of (K 0.5 Na 0.5 )NbO 3 (KNN)-based ceramics by incorporating Bi(Zn 2/3 Nb 1/3 )O 3 to reduce grain size, increase dielectric breakdown strength, and enhance ferroelectric relaxation degree. The resulting 0.87KNN–0.13BZN ceramics exhibited a high energy density (7.4 J/cm 3 ) and moderate energy efficiency (74%) at an ultrahigh electric field (750 kV/cm) as well as excellent optical properties. Therefore, the 0.87KNN–0.13BZN ceramic is a promising candidate for pulse capacitors, providing a feasible approach for the development of new lead-free energy storage materials.