A Comprehensive Review of Battery‐Integrated Energy Harvesting Systems

Abstract At the forefront of technological advancement, the proliferation of portable and wearable electronics has necessitated the development of innovative power solutions. As these devices become increasingly indispensable in daily life, the demand for sustainable and adaptable power sources has intensified. This review focuses on integrated self‐charging power systems (SCPSs), which synergize energy storage systems, particularly through rechargeable batteries like lithium‐ion batteries, with energy harvesting from solar, mechanical, thermal, and chemical energy. These SCPSs extend operational times, reduce recharging frequency, and have the potential to develop self‐sufficient power systems. The study explores various approaches to optimize both individual components and the integrated power system for wearable and flexible electronics, covering SCPSs that combine multiple energy‐harvesting strategies. Special attention is given to design considerations, material advancements, and engineering challenges, alongside the latest research breakthroughs in energy harvesting and storage technology. The review concludes with an assessment of the prospects and challenges in the field of battery‐integrated energy harvesting systems, highlighting the need for advancements in energy density, power output, and safety to meet the demands of modern electronics.