Recent Developments on Flexible Materials for Thermoelectrics

Abstract

In recent decades, thermoelectric materials have gained a significant attention due to their ability to directly convert waste heat into electricity. While extensive research has been focused on enhancing the thermoelectric properties of inorganic bulk materials, a new frontier has emerged in this area as flexible thermoelectric materials. These flexible thermoelectrics are driven by the limitations posed by the rigidity, less functional and toxicity of conventional inorganic thermoelectric materials. Despite notable achievements in the development of high-performance flexible thermoelectric materials, they still pose inferior figure of merit (zT) in comparison to their inorganic counterparts. This review encompasses various aspects of flexible thermoelectric materials including theoretical foundations which highlight the principles that explain the concepts and parameters of thermoelectricity to enhance the overall performance, serving as a foundation for understanding the subsequent developments. Further it is overviewed in detail the corresponding state of the art in development of conducting thermoelectric polymers, inorganic-polymer composites, carbon-based thermoelectric and inorganic thermoelectrics on flexible substrates to enhance their thermoelectric performances. Finally it includes the overlook to the future of flexible thermoelectric for wearable thermoelectrics.