A stable and reversable zinc-ion microbattery from a printed gel-electrolyte and a carbon-zinc formulation

Aqueous zinc ion batteries (ZIBs) are attracting increasing attention due to their low cost, earth abundance and safety. So far, they have been regarded as a promising battery system for large scale grid applications, and here we demonstrate prospects of their use to power portable devices. We have fabricated fully 3D printed and rechargeable ZIB with interdigitated geometry capable to power a commercial sensor for days. A full battery was assembled using aqueous and scalable formulations with a printed anode based on zinc powder and carbon black, a printed colloidal electrolyte and a printed MnO2 cathode. The anode withstands more than 500h of galvanostatic plating/stripping with a low overpotential of ~32.2 mV and the ZIB displays a capacity of ~1.3 mAh/cm² and a capacity retention of ~66% after 100 cycles. Finally, we show how this battery can power a Bluetooth proximity sensor for more than 3 days of continuous operation