High-performance lead free piezoceramics have drawn much attention because of their excellent piezoelectricity, strong ferroelectricity, and wide application potentials in many electronic devices (e.g., sensors, actuators, ultrasound transducers, etc.)[1-5].Among all the lead-free piezoelectric ceramics, (K0.5Na0.5)NbO3 (denoted hereafter as KNN) has become one of the most extensively studied piezoelectric systems due to its large d33 and high Tc[6-8]. However, it is very difficult to obtain high-density KNN ceramics by ordinary sinitering method because of their poor sinterability and high volatility[9]. Furthermore, very narrow sintering temperature range is also a big challenge for its industrial production[10, 11].Over the past few decades, numerous efforts have been made on KNN-based ceramics to improve the sinterability of KNN based ceramics.[12-15]