Upcycling electrode materials from spent single-use zinc-carbon/alkaline batteries into rechargeable lithium-ion battery application

Battery recycling/upcycling is a key component of modern e-waste reduction by transforming discarded electrode powder to value-added materials and chemical feedstocks for the proposed applications. In this study, electrode powder from spent zinc-carbon/alkaline batteries was upcycled into LiMn2O4 cathode and carbon anode for rechargeable lithium-ion battery. The main metallic contents (zinc and manganese) in electrode powder were quantitatively leached using diluted H2SO4 with the presence of H2O2 as a reducing agent. By applying sequential precipitation, ZnS nanospheres and MnCO3 nanocubes were obtained as determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The recovered MnCO3 was heated with a stoichiometric amount of Li2CO3 to produce high crystalline and pure LiMn2O4. For the electrochemical performance, the results show that upcycled LiMn2O4 exhibits initial discharge capacity of 99.0 mAh g-1 for zc-LiMn2O4 and 111.0 mAh g-1 for al-LiMn2O4, compared to 90.4 mAh g-1 for pristine LiMn2O4. Moreover, recovered carbon materials obtained as an insoluble powder after acid leaching possess unique morphology and crystallinity. The zc-carbon shows superior cycling performance with reversible charge capacity of 552 mAh g-1 at 1C rate after 100 cycles. This study provides the great potential for upcycling waste battery electrodes to high-value LiMn2O4 cathode and carbon anode for lithium-ion battery application.