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

Abstract

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.