Recycling spent zinc ion primary batteries for use in superior rechargeable lithium-ion energy storage

Recovering electroactive materials from spent primary batteries and converting them into useful products is a crucial and interesting topic for solving many environmental issues. Therefore, in this present work, we recovered useful electroactive materials from spent zinc-carbon (Zn-C) primary cells and utilized them to develop lithium-ion supercapacitor electrodes. In this typical recycling process, the electroactive composite was recovered using a two-step process combining electrochemical exfoliation and sonochemical technique. The structure, morphology and composition of the electroactive composite were studied in detail to explore its feasible electrode properties. Furthermore, a supercapacitor was designed using the composite; it operated at a wide voltage window of 2.5 V in 1 M LiClO₄/acetonitrile electrolyte and showed a maximum specific capacitance of 84 F g⁻¹. Moreover, the supercapacitor exhibited a high specific energy of ∼18.22 W h kg⁻¹ with a maximum specific power of ∼6387 W kg⁻¹ and a stability of ∼73% over 10 000 charge/discharge cycles at 1 A g⁻¹. Besides, the fabricated supercapacitor demonstrated practical application potential and showed that the composite recycled from spent primary cells is viable for developing rechargeable energy storage devices.