The twenty-first century has introduced major environmental challenges, rising energy demands, and a greater focus on sustainable architectural practices, all of which are crucial for the long-term preservation of resources and the improvement of overall quality of life. Smart materials are at the forefront of these advancements, offering innovative solutions for energy storage and environmental sustainability. In this chapter, we explore the environmental impact of smart materials used in energy storage devices, particularly batteries and supercapacitors. Key materials discussed include metal–organic frameworks (MOFs) for ion transport and adsorption, graphene-based materials for high-performance electrodes, phase change materials (PCMs) for thermal energy storage, and shape-memory alloys for adaptive energy systems. Furthermore, we examine critical environmental aspects such as the physicochemical nature of these materials, potential toxicity, carcinogenic organic solvents, recyclability, lifespan, and waste management. Additionally, challenges related to nuclear contamination, lack of established reliability, market fluctuations, and inconsistencies in environmental regulations are addressed. By evaluating both the benefits and potential risks of smart materials, this chapter aims to provide a comprehensive understanding of their role in advancing sustainable energy solutions.