Upcycling waste photovoltaic cells into silicon carbide via flash Joule heating

Abstract

As global demand for clean energy increases, 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 SiC (>98%) after removal of excess carbon through calcination; most inorganic impurities elements were removed by evaporated during the heating process. Flash-heated product is a promising anode material, and FJH consumes significantly less energy and emits fewer greenhouse gases than alternative chemical or thermal technologies, resulting in a notable cost reduction.