A new path to self-powered infrastructure with thermoelectric cement

The innovative material is a cement-hydrogel composite constructed in a multilayered configuration. This structural design draws from nature to enhance functionality, enabling the composite to exhibit a Seebeck coefficient of -40.5 millivolts per Kelvin and a thermoelectric figure of merit (ZT) of 6.6+ 10^-2. These performance values exceed those of previously developed thermoelectric cement materials by factors of ten and six, respectively.

Central to the composite's performance is a method called interfacial selective ion immobilization. The hydrogel layers act as fast-conducting channels for hydroxide ions (OH-), while the interfaces between the cement and hydrogel layers selectively bond with calcium ions (Ca2+) and loosely interact with OH-. This selectivity intensifies the ion mobility imbalance, which is key to amplifying the thermoelectric output.

In addition to its energy harvesting capability, the composite also offers mechanical resilience and built-in energy storage. These dual functionalities position it as a promising solution for powering sensors, wireless devices, and other electronics embedded in smart infrastructure, including intelligent pavements and self-monitoring buildings.

Research Report:Bio-inspired thermoelectric cement with interfacial selective immobilization towards self-powered buildings