Over the past few decades, concerns over the development of alternative energy sources have been increasing due to problems such as depletion of fossil fuels and environmental pollution. Among various types of environmentally friendly energy sources, mechanical energy can be easily obtained from anywhere in our common life. Therefore, various kinds of energy harvesting devices for efficiently converting such mechanical energy into electric energy are being studied. Among them, a piezoelectric energy harvesting device is the device which has the simplest working principle in which electricity is obtained by momentary change of internal polarization when pressure is applied to the material. The output performances of the devices highly depend on the piezoelectric coefficient of the materials and the orientation (alignment) of the materials relative to the direction of the external pressure. In this study, we have developed a piezoelectric energy harvesting device with improved output characteristics by synthesizing lead-free piezoelectric materials with high piezoelectric coefficients.