Upcycling spent alkaline batteries into rechargeable zinc metal batteries

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 high orientation of favorable (002) plane and induced horizontal plating behavior. The regenerated cathode composed of MnO 2 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. • A “two-birds-one-stone strategy” is developed for recycling alkaline battery electrodes and reshape them for rechargeable zinc-ion batteries; • Upcycled zinc-ion batteries deliver excellent performance at high loadings, high DOD, and low N/P ratios; • Mechanisms are investigated on recycled electrode materials; • Such simple strategy and practice paves a new avenue and holds great potential for practical application.