Conversion reaction that is beyond the intercalation in specific structures has the great potential to higher energy density with a variety of low cost materials. Nevertheless, several critical fundamental issues, such as poor reversibility and stability due to the ever-changing reaction interface, is far from being understood compared with the widely investigated intercalation reactions. How to understand and predict a stable conversion reaction that relays on the reaction interface is extremely important to the material physics and chemistry science and energy storage. In this poster, we will present a new concept of dynamic-equilibrium to stabilize the conversion reactions in rechargeable aqueous Zn battery systems. Our systematical studies in Zn-MnO2 and Zn-I2 electrochemical systems indicate that a well combination of appropriate active material and reaction media is important to enable a stable conversion reactions with a dynamic equilibrium of active species at the interface. (Nature Energy, 1, 16039, 2016; ACS Energy Lett, 2, 2674, 2017) In such conversion systems, active species can exchange between the electrode and the reaction media with manageable equilibrium. We believe that the principles for stabilizing the conversion Zn battery system could provide new insight into other conversion systems such as the widely investigated Li-S systems.