Energy storage technologies and their combinational usage in micro/mini unmanned aerial vehicles: a review

As the world population increases, energy consumption extensively increases in every field. Energy is a need in several applications, and depending on its importance, its production should be renewable and clean. In order to meet energy requirements sustainably nowadays various alternative energy resources and improvements are recommended in each sector. One of the environmental steps taken in the aviation industry is the improvement of the propulsion systems and the resources used. For this purpose, the use of electrical energy, a more sustainable option than the energy obtained from fossil fuels, is suggested. In order for electrical energy to be used efficiently, it must be stored. This article reviews energy storage technologies used in aviation, specifically for micro/mini Unmanned Aerial Vehicles (UAVs). Combinational energy storage technologies in hybrid propulsion system architectures and their individual usage in all-electric propulsion system architectures are examined. New-generation propulsion technologies are also evaluated and classified in detail.