The growing demand of consumer printed electronics such as smart cards, smart packaging, automotive displays, electronic paper and others led to the increased interest in fully printed electrochemical devices. These components are expected to be developed based on films derived from cheap and widely accessible compounds. This book presents the long stretch of technical research that was performed to realize printed energy efficient concepts such as electrochromic displays and smart-windows. Within this broad theme, the presented study had a number of specific objectives, however, the overall aim was to develop low-cost material systems at a lab-scale, which would be compatible with large-scale roll-to-roll processing. Presented results concern three main topics: (i) dual-phase inorganic electrochromic material processed at low temperature, (ii) enhancement in electrochromic performance via metal-oxide nanoparticles engineering, and (iii) highly conductive and mechanically stable solid-state electrolyte. Coupling of statistical methods with formulation of electrochemically active materials shows the potential to maximize the capabilities of these systems.