Upcycling waste photovoltaic cells into silicon carbide via flash Joule heating

Abstract

With the increasing global demand for clean energy, the rapid development of photovoltaic (PV) power generation has led to a growing issue of waste PV module disposal. Traditional recycling methods face challenges such as low efficiency, high energy consumption, and environmental pollution. Flash Joule heating (FJH) technology offers a promising alternative for upcycling waste PV cells. Here, FJH was adopted to produce silicon carbide (SiC) from waste crystalline silicon (c-Si) PV cells that were pulverized and mixed with conductive carbon black (CB). Optimal reaction efficiency was achieved with an input voltage of 130 V and a peak temperature of ∼2200 °C during a single flash heating cycle of 0.5 s. Repeated FJH and regrinding steps resulted in high purity β-SiC (∼96–98%) after removal of excess carbon through calcination; most inorganic impurity elements were removed by evaporation during the heating process. FJH consumes significantly less energy and emits fewer greenhouse gases than alternative chemical or thermal technologies, resulting in a notable cost reduction.