Hur, Sunghoon Kim, Sangtae Kim, Hyun-Soo Kumar, Ajeet Kwon, Choah Shin, Joonchul Kang, Heemin Sung, Tae Hyun Ryu, Jungho Baik, Jeong Min Song, Hyun-Ceol 2024-01-19T09:00:20Z 2024-01-19T09:00:20Z 2023-08-17 2023-09 2211-2855 https://pubs.kist.re.kr/handle/201004/113341 Identifying reliable and sustainable sources of electricity is a significant challenge of the present time. However, most energy-generation mechanisms produce unavoidable low-grade waste heat as a byproduct while harvesting (or converting) electrical energy from conventional or renewable energy sources. Each year, over 60% of the primary energy is wasted as heat. Accordingly, considerable efforts are being made to convert this waste heat into usable electrical energy using diverse energy conversion materials. In this review, three actively investigated energy conversion mechanisms beyond thermoelectrics, i.e., (1) pyroelectric, (2) thermomagnetic, and (3) thermogalvanic generators, are reviewed and compared from the viewpoint of fundamental theories, critical parameters for high energy conversion efficiency, and current status of materials and devices. The challenges and opportunities in low-grade waste-heat recovery are discussed in terms of material science and structural design. This review provides an overview of the current progress in thermal-energy-harvesting research, future challenges, and opportunities. English Elsevier BV Low-grade waste heat recovery scenarios: Pyroelectric, thermomagnetic, and thermogalvanic thermal energy harvesting Article 10.1016/j.nanoen.2023.108596 1 Nano Energy, v.114 Nano Energy 114 Y scie scopus 001038712400001 2-s2.0-85163509135 Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Chemistry Science & Technology - Other Topics Materials Science Physics Article POWER-GENERATION CONVERSION FIGURE MERIT TECHNOLOGIES CERAMICS DEVICES CYCLE CELL SR Thermal energy harvesting Pyroelectric Thermomagnetic Thermogalvanic Low grade waste heat