Mitochondrion-Inspired Magnesium-Oxygen Biobattery With High Energy Density in Vivo.

Implantable batteries are urgently needed as a power source to meet the demands of the next generation of biomedical electronic devices. However, existing implantable batteries suffer from unsatisfactory energy densities, hindering the miniaturization of these devices. Here, we report on a mitochondrion-inspired magnesium-oxygen biobattery that achieves both high energy density and biocompatibility in vivo. The resulting biobattery exhibits a recorded energy density of 2517 Wh·L -1 /1491 Wh·kg -1 based on the total volume/mass of the device in vivo, which is ∼2.5 times higher than the current state-of-the-art, and can adapt to different environments for stable discharges. The volume of the magnesium-oxygen biobattery can be as thin as 0.015 mm 3 and can be scaled up to 400 times larger without reducing the energy density. Additionally, it shows a stable biobattery/tissue interface, significantly reducing foreign body reactions. This work presents an effective strategy for the development of high-performance implantable batteries. This article is protected by copyright. All rights reserved.