Energy storage properties, transmittance and hardness of Er doped K0.5Na0.5NbO3-based ceramics

Transparent energy storage ceramics can balance energy storage characteristic and optical characteristic, and are expected to be used in areas such as transparent pulse capacitors. However, excellent energy storage performance and dramatic light transmittance are difficult to achieve simultaneously, limiting their subsequent development in the actual applications. The paper proposes a way to improve the transparent energy storage properties of KNN-based samples by regulating domain and grain size. By introducing an appropriate amount of Er2O3, fine cube grains and nanodomains are constructed. When doping 0.20 mol% Er2O3, the ceramics exhibited excellent recoverable energy storage density W rec 6.2 J/cm3, superior energy-storage efficiency 71.3 %, large dielectric breakdown strength E b 670 kV/cm, ultrahigh hardness value of 6.9 GPa, and a maximum transmittance T 72 % at 880 nm. Dense microstructure, nanoscale grains, symmetrical lattice structure and relaxor behavior are the main reasons for obtaining high energy storage and transparency properties.