Inspired by the recycling approach of electronic waste, within this research paper, we extracted exhausted materials from spent primary zinc batteries and then annealed them in a modified condition, forming a ZnMn2O4/ C composite with a uniform nanoparticles’ porous morphology. The produced material has been examined as a supercapacitor active one, which showed promising electrochemical properties for supercapacitor application. At a current density of 3 A g− 1, it exerted a comparatively significant capacitance of 1696.88 F g− 1 along with a capacity of 807 C g− 1. Furthermore, the fabrication of a flexible all-solid-state symmetric supercapacitor prototype has been accomplished. It exhibited promising initial results that carried a specific energy of 76.75 Wh kg− 1 at a specific power of 333.86 W kg− 1. After 3000 cycles, it maintained an acceptable capacity. Thus, this eco-friendly approach can successfully convert the spent battery material to new value-added materials for supercapacitors in the clean energy area.

Spent zinc batteries: a pathway to Sustainable ZnMn2O4C supercapacitors electrode
    Abstract
    1 Introduction
    2 Experimental section
        2.1 Synthesis of ZnMn2O4
    3 Results and discussion
        3.1 Material characterizations
        3.2 Electrochemical performance
    4 Conclusions
    Acknowledgements 
    References

• Aya Mohamed Abuelftooh(Chemistry Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Cairo, Egypt)
• S. S. Mahmoud(Chemistry Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Cairo, Egypt)
• S. Y. Ahmed(Chemistry Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Cairo, Egypt)
• Sayed Y. Attia(Mining and Metallurgy Engineering Department, Tabbin Institute for Metallurgical Studies (TIMS), Tabbin, Helwan 109, Cairo 11421, Egypt)
• Saad G. Mohamed(Mining and Metallurgy Engineering Department, Tabbin Institute for Metallurgical Studies (TIMS), Tabbin, Helwan 109, Cairo 11421, Egypt) Corresponding author