Qualifying the cathode aging process for storage life prediction for primary AgO-Zn batteries

AgO-Zn batteries are widely recognized for their high energy density, specific capacity, and safety features. Especially the AgO-Zn reserve battery, which possesses good storage stability to better adapt to the application requirements of long-term storage, is considered an ideal candidate for applications in military, aerospace, and other fields. However, since there are only a few studies on the decomposition kinetic of the cathode for the AgO-Zn reserve battery, further in-depth research is needed on the aging mechanism. Herein, we conduct a comprehensive investigation of the aging behavior of the cathode in commercial AgO-Zn reserve batteries. The physicochemical properties of the cathodes with different storage years are characterized by multiple methods, including phase composition, surface morphology, and thermal behaviors. The evolution of structure and performance for the cathodes with storage time and their impact on the electrical performance of AgO-Zn batteries are studied. In addition, a multiple heating rate method is performed to determine the thermal decomposition kinetics of the cathode. Based on the obtained kinetic parameters, a model for the decomposition of the AgO in the cathode is developed, enabling the estimation of theoretical storage time for achieving the cathode with the same retention rate as actual storage in a shortened time by accelerated aging. Validation studies comparing accelerated aging results with real-time aging under natural conditions are further performed to assess the reliability of the accelerated aging model. This research provides insights into the aging mechanisms of cathode for AgO-Zn batteries and offers a systematic approach for the accelerated aging test, paving the way for the development of the prediction of battery performance and lifespan.