sounds new to me

A laminated battery subcutaneously implanted in rats delivers a power density of 2.6 μW/cm2 at 1.3 V (vs. Na/Na+) and demonstrates excellent bio-compatibility in vivo. Capillaries regenerate well around the cathode, providing a continuous source of O2 for the battery. Our Na-O2 battery revolutionizes the concept of implantable batteries, the consumption of O2 during discharging results in a deoxygenation function, which also offers a new way to combine bio-electronic implants and biotherapy toward the diseases associated with anaerobic environments.

However, to utilize these energy sources in vivo, the battery must be designed with an open architecture that ensures the adsorption of active components from body fluids and the battery components should demonstrate good bio-compatibility. Moreover, the intermediate product should be easily metabolized during battery cycling. To date, there have been few reports of this open type of batteries. Although there are significant advantages for implantable metal-O2 batteries, there are still several challenges should be addressed.

The O2 can be continuously supplied from body fluids and is reduced through the catalysis of NPG during discharging. The excellent bio-compatibility of NPG enables long-term battery operation within organisms, while the capillaries regenerate around the cathode and continuously supply O2.

https://www.sciencedirect.com/science/article/pii/S2451929424000743