Emerging Design Strategies Toward Developing Next-Generation Implantable Batteries and Supercapacitors

In recent years, the development of implantable bioelectronics has garnered significant attention. With the continuous advancement of IoT and information technology, implantable bioelectronics can be utilized more effectively for health monitoring to enhance treatment outcomes, reduce healthcare costs, and improve quality of life. Implantable energy storage devices have been widely studied as critical components for energy supply. Conventional power sources are bulky, inflexible, and potentially contain materials that are dangerous to the body. Meanwhile, human tissues are soft, flexible, dynamic, and closed, which puts new requirements on energy storage devices to improve the safety, stability, and matching of implantable batteries or supercapacitors. Herein, recent advances in state-of-the-art nonconventional power options for implantable electronics, specifically biocompatible, miniaturized, stretchable/deformable, biodegradable/bioresorbable, edible, and injectable energy storage devices, are reviewed in this paper. The material strategy and architectural design of the next-generation implantable energy storage device are discussed, including the selection principle of electrolytes, the all-in-one structure design strategy, and the way to realize self-charging. Finally, the challenges and prospects of emerging design strategies toward developing next-generation implantable batteries and supercapacitors for the future are put forward.