Advances in integrated self-charging capacitors and batteries

• Systematically and comprehensively evaluates the recent advancements in integrated self-charging capacitors and batteries. • Highlighting some of the problems in existing self-charging designs and proposing solutions to address these challenges. • Prospecting the future research directions of self-charging energy storage devices, especially in the biological field. Energy storage technologies have enabled a wide range of applications, from portable power supplies to tiny sensors. However, the advancement of certain applications is hindered by environmental factors and reliance on external power sources. Developing integrated self-charging energy storage systems is therefore of paramount importance. This refined review summarizes recent advancements in integrated self-charging capacitors and batteries, focusing on three key mechanisms: physical piezoelectricity, chemical oxidation, and biological enzyme catalysis. We analyze the material systems selection and design exhibiting self-charging behavior, elucidate the underlying reaction mechanisms, and highlight the challenges and potential solutions in existing designs. Furthermore, we envision future applications of self-charging energy storage devices, which are expected to attract significant attention in physics, chemistry, and biological energy storage.