Self-sustaining microbattery fueled by pectin via enzymatic catalysis

Bio-derived self-sustaining microbatteries are promising power sources for implantable and wearable electronics due to their excellent biocompatibility and biodegradability. However, their practical deployment is hindered by limited operational lifetime and low energy density, primarily stemming from the rapid depletion of conventional monosaccharide fuels such as glucose. Herein, we report an enzymatic microbattery fueled by pectin, a naturally abundant polysaccharide, with methylene blue (MB) immobilized on a pectinase-modified anode as a redox mediator. Unlike conventional enzymatic biofuel cells (EBFCs) that rely solely on continuous fuel supply, our hybrid EBFCs can be electrochemically “recharged” by reducing oxidized MB to its leuco form under an applied potential, enabling repeated discharge cycles without immediate fuel replenishment. As a results, the hybrid EBFCs deliver a high maximum power density of 1.57 mWcm −2 , substantially exceeding that of recently reported EBFCs. Moreover, it retains 96.03% of its initial capacity after 100 charge-discharge cycles at a current density of 2.25 mA cm −2 , demonstrating exceptional cycling stability. This pseudo-rechargeable behavior bridges the gap between enzymatic energy conversion and secondary battery functionality.