Toward Efficient Thermoelectric Materials and Devices: Advances, Challenges, and Opportunities

Thermoelectric technology enables the direct conversion between heat and electricity, offering distinct advantages for applications such as waste heat recovery, solid-state cooling, wearable electronics, and thermal management. Enhancing the energy conversion efficiency of thermoelectric devices (TEDs) requires both the advancement of material composition and structure, as well as innovation in device design. This review begins with an overview of the fundamental principles of thermoelectric conversion and then summarizes key developments over the past five years in thermoelectric materials and TED architectures. It covers recent progress in thermoelectric mechanisms, high-performance materials, and strategies for optimizing plastic bulk, thin-film, and fiber-based materials. The review also examines methods for evaluating TED performance, explores new design paradigms enabled by computer-aided manufacturing, and highlights advances in solid-state, miniaturized, and flexible TEDs (F-TEDs). Representative design strategies and application scenarios are presented. Finally, current challenges and future directions in thermoelectric materials and devices are discussed to guide ongoing innovation in the field.