From Composites to Modules: Process Engineering of Cement-Based Thermoelectric Materials and Prospects for Building Envelope Integration

Cement-based thermoelectric materials have progressed from laboratory composites toward devices, including structural thermoelectric generators and modules made from industrial by-products. Prior reviews surveyed filler chemistries, carrier-type mechanisms, and techno-economics, identifying manufacturability, scalability, and interfacial reliability as persistent barriers. None, however, follows fabrication from the composite to component scale or draws on conventional module manufacturing for transferable solutions. This systematic review does both across 34 studies, consolidating interfacial findings into a design principle organized around two carrier regimes, electronic and ionic/mixed, with opposing process requirements. At the material level, the one direct comparison of fabrication routes, in which forming and curing also differed, reported conductivity and Seebeck changes of more than 100-fold; at the device level, voltage fell up to 21-fold below predictions from composite properties. Durability evidence spans hours for devices and months for embedded fibers. Against envelope conditions, the evidence is direct but short-term for roofs, compatible in the operating range but untested in service for facades and walls, pavement-only for ground contact, and absent for openings. Output at envelope-like temperature differences was limited to voltage or sub-microwatt power, below the minimum converter input, pointing to sensing and micro-harvesting rather than bulk power. Reporting, scale-up, durability, and cost gaps remain.