Nanotechnology has emerged as a revolutionary field with transformative potential across various sectors, particularly in energy applications. This abstract provides a concise yet comprehensive overview of the latest advancements in nanotechnology for energy harvesting and storage. In the realm of energy harvesting, nanostructured materials have paved the way for highly efficient solar cells, thermoelectric generators, and piezoelectric systems. Tailoring the properties of nanomaterials at the atomic and molecular scale has enabled enhanced light absorption, charge carrier mobility, and conversion efficiency, thereby revolutionizing renewable energy technologies. This paper also highlights the growing importance of sustainable and eco-friendly approaches in nanotechnology-enabled energy applications. Strategies for green synthesis, recycling, and resource utilization are integral to ensuring the scalability and environmental viability of nanotechnology-based energy technologies. This comprehensive review delves into applications of nanomaterials in energy devices and also their roles in energy devices like lithium-ion batteries.