Stability and reversibility are important properties for batteries which can be determined by CV tests. Since NHPI has not been investigated in solid state as a cathode material, we first use CV measurement to characterize the reversibility and stability of the NHPI in different electrolyte for the Zn-NHPI battery development. Based on previous experience, NHPI has better reversibility in particular acidic electrolyte. Thus, different acidity gradients electrolyte is used to figure out the most suitable acidity of electrolyte in NHPI-Zn battery. However, considering Zn anode is easy to generate H 2 in acidic environment, only small amount of H 2 SO 4 is used to adjust the pH value of the electrolyte. Figure shows the electrolyte in different acidity used in the experiment. (a), it can be obviously seen that from the second to the sixth cycle, there is a small oxidation peak exists before the main oxidation peak of the NHPI cathode in the 1MZnSO 4 electrolyte (pH=4.70). This may be some sort of irreversible side reaction between the battery components that only occurs in the charging process. This side reaction is believed to be related to the Zn 2+ in the electrolyte solution. As shown in Fig. , in order to eliminate the effect of Zn 2+ , a new electrolyte consisting of saturated Na 2 SO 4 solution and H 2 SO 4 was prepared to match the pH as well as the ionic strength of the 1MZnSO 4 solution. But in this electrolyte under the same testing parameters, no peak in 0.7-0.9 V region can be observed, suggesting that no side reactions occurred at this potential range in the absence of Zn 2+ . Each of the reduction peak in Fig. (a) is much shorter than the corresponding oxidation peak, which means the NHPI suffered a poor reversibility. And after the sixth cycle, the oxidation peak of the battery vanishes gradually, which means that the current NHPI is almost impossible to charge at this time. This phenomenon indicates that the stability of the battery material in this electrolyte is also unsatisfied. This may be due to the combination of the decomposition of the nonpersistence of NHPI and the side reactions mentioned above. In short, a battery use NHPI as cathode is inferior in performance without adjusting the pH of the electrolyte.