Materials, performances and applications of electric heating films

With the intensification of global climate problems, the worldwide call for reducing CO2 emissions is getting louder and louder. Low-carbon development has become the consensus of all countries. The electric heating film systems (EHFS) have recently attracted much attention as a clean and low-carbon building heating way due to the global target of carbon neutrality. This paper aims to provide a comprehensive review of the materials, performances and applications of the electric heating film (EHF). The conductive materials for the EHF mainly include graphene and carbon nanotubes (CNTs). Moreover, the main preparation methods are redox method, chemical vapor deposition (CVD), vacuum filtration method and screen printing. It was found that the EHF doped with the graphene or the carbon nanotubes (CNTs) has better performance on flexibility and thermal stability. The EHF prepared by chemical vapor deposition (CVD) has the best performance on uniformity and structure. However, this method is costly and difficult to implement for large-scale industrial production. Therefore, the screen printing technology remains the most widely used method. The composite EHF with two or more conductive materials (graphene and multi-walled carbon nanotubes (MWCNT)) has excellent mechanical properties, superb damage resistance and flexibility. In addition, the numerical simulation based on computational fluid dynamics (CFD) will be an important research method to investigate the indoor thermal environment of building heating by EHFS, which needs to be conducted in the future. The high performance EHF will be widely used in international applications such as artificial intelligence, wearable devices, aerospace, solar energy and medical protection.