Thermoelectric Building Cementitious Materials: A Review of Thermoelectric Mechanisms, Performance Modulation, and Engineering Applications

Abstract

Thermoelectric cementitious materials, capable of integrated building waste heat recovery and structural self-sensing, serve as core functional materials for intelligent low-carbon buildings. Existing research mainly focuses on two material systems, Portland cement-based and alkali-activated materials (AAMs). Based on fundamental thermoelectric theories, it reviews the transport mechanisms of three types of charge carriers, namely ions, holes, and electrons, sorts out modification strategies incorporating carbon-based fillers, semiconductor particles, and industrial solid wastes, and elaborates the coupling effects of pore solution, pore structure, temperature–humidity conditions, and curing regimes on the Seebeck coefficient, electrical conductivity, and thermoelectric figure of merit. The intrinsic thermoelectric performance of plain cement matrices is inferior, and performance enhancement relies on the construction of solid-state percolation networks via conductive fillers. By contrast, AAMs feature high ion concentrations in pore solutions and exhibit prominent intrinsic thermoelectric power; nevertheless, mixed ionic-electronic conduction readily forms within such systems, and the output stability is drastically disturbed by water allocation. Large-scale engineering applications are hindered by several bottlenecks, including filler agglomeration, strong environmental susceptibility, and challenges in scalable fabrication of p–n thermoelectric devices. This paper proposes future research perspectives: developing low-cost modification routes using solid wastes and biomass, fabricating self-healing stable material systems, establishing quantitative coupled ionic-electronic transport models, and advancing the practical deployment of thermoelectric components in waste heat harvesting and structural health monitoring. This work provides theoretical references for performance optimisation and industrial translation of thermoelectric cementitious materials.