Sustainable Power Sources for Portable Applications

Abstract Sustainable power sources are essential for the realization of portable applications, especially in wearable and mobile electronics. This review systematically summarizes recent advances in environmentally friendly energy storage systems, including flexible lithium‐ion batteries, zinc‐based batteries, and high‐performance supercapacitors, emphasizing the material innovations and design strategies that enhance flexibility, energy density, and sustainability. In addition, the integration of energy harvesting modules, such as flexible photovoltaics, piezoelectric and triboelectric nanogenerators, thermoelectric generators, and biofuel cells, is highlighted, enabling fully self‐powered and autonomous systems. The review identifies key challenges, including limited energy conversion efficiency, mechanical durability under dynamic conditions, and scalable manufacturing, and discusses potential strategies such as hybrid energy architectures, multifunctional integration, and novel material engineering. These findings provide comprehensive insights into current progress, technological bottlenecks, and future opportunities, offering guidance for the design of sustainable and high‐performance power solutions for next‐generation portable electronics.