Advancements in sustainable proton-conducting electrochemical cells: Direct recycling of sintered nickel oxide-doped barium zirconate half cells

•Over 92 % material recovery from PCEC manufacturing half cell scraps.•100 % recovery in performance in both fuel cell and electrolysis cell modes.•Close-loop solution for the recycling of complex functional ceramic composites.•Contributing to circular economy of PCEC by promoting resource efficiency. The ongoing evolution in energy production and conversion technologies has brought solid oxide electrochemical cells (SOCs) to the forefront, recognized for their high efficiency and environmental benefits. However, establishing sustainable and scalable manufacturing processes for SOCs presents formidable challenges, including sourcing large-scale raw materials and implementing effective recycling methods for spent cells and manufacturing scraps. In response, we demonstrate closed-loop direct recycling of proton-conducting solid oxide electrochemical half cells, incorporating active comminution and cell regeneration using the recycled materials. This innovative approach achieves over 92 % material recovery and an impressive 100 % recovery in full cell performance, addressing a significant gap in current sustainable manufacturing practices while setting a new standard for the industry. This technology not only addresses a significant gap in current sustainable manufacturing practices but also sets a precedent for future advancements in the sustainable SOC field, potentially influencing broader practices in the recycling of multi-functional ceramics.