<p>The integration of energy harvesting and energy storage in a single device signifies notable progress in the creation of intelligent energy systems for portable electronics. This concept can address issues associated with the limited battery life of electronic gadgets and contribute to the advancement of sustainable and self-sufficient technology. Nanotechnology plays a crucial role in facilitating this significant development by offering unique materials and structures at the nanoscale. It enables the fusion of energy harvesting and storage by utilizing nanomaterials, hybrid nanomaterials, and nanoscale devices. The incorporation of nanoscale components into the device’s architecture ensures a compact and efficient energy system. Nanosensors and control system components can monitor energy levels, environmental conditions, and device usage, enabling intelligent energy management and optimization. This article reviews the integration of nanotechnology that enables the combination of energy harvesting and energy storage into a single system, introducing innovative smart energy solutions for portable electronics. The integration of both functionalities in one device, made possible by nanotechnology, creates new opportunities for developing self-sustaining and environmentally friendly smart energy systems. This not only enhances the convenience of electronic gadgets but also contributes to the broader objective of advancing more eco-friendly and energy-efficient technologies.</p>