Quantifying Silver Dissolution in Primary and Secondary AgO-Zn Batteries

Printable AgO-Zn batteries are highly attractive for wearable devices for their safe chemistry, high energy density, and rechargeability. However, silver dissolution from AgO cathodes limits the shelf life and cycle life of primary and secondary AgO-Zn cells. In this study, factors including electrolyte, cell configuration, and cycling rate on silver dissolution were investigated systematically via precise identification and quantification of dissolved silver species in AgO-Zn cells. The mechanism of silver dissolution is studied by characterizing both dissolved silver species and cathode surfaces with chemical analysis including Raman spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy. We found that reducing the complexation step within the two-step reaction of AgO to [Ag(OH)2+x]−x is key to mitigating the silver dissolution, which can be controlled by selecting the proper electrolytic species as well as cycling rate and creating rough surfaces of cathodes.