Upcycling spent alkaline batteries into rechargeable zinc metal batteries

Abstract

Recycling/upcycling alkaline batteries are significant for the sustainable development. Here, for the first time, we upcycle spent alkaline batteries into rechargeable Zn metal batteries through a simple thermal treatment of electrode waste. The regenerated Zn powder anode shows super-zincophilicity and low overpotentials even under fast rates (8 mA cm−2) and high depth-of-discharge (50 %), which can be ascribed to coating of hydroxyl-rich organic layer with abundant nucleation sites as well as high orientation of favorable (002) plane and induced horizontal plating behavior. The regenerated cathode composed of MnO2 and MnOOH manifests enhanced capacity in comparison to pristine ones. Under a low negative-to-positive capacity ratio of 3.8 and high loading of ~10 mg cm−2, the regenerated electrodes are paired to fabricate zinc metal batteries which demonstrate high energy and power densities (94 Wh kg−1, 1349 W kg−1), holding potential for practical applications. Given the sustainable, low-cost, environmental-friendly, and value-added features, the strategy proposed here will open a new pathway toward battery recycling/upcycling.