Intrinsically lighting absorptive PANI/MXene aerogel encapsulated PEG to construct PCMs with efficient photothermal energy storage and stable reusability

Nowadays, green energy conversion and storage materials are the research attention. Reusable stability is an important indicator in the application. In this work, the framework material formed by polyaniline (PANI) and MXene shows strong intrinsic light absorption performance and outstanding cycling stability for the solar-light to thermal energy conversion. With composition of polyethylene glycol (PEG) and PANI/MXene, a series of composite phase change materials were prepared, exhibiting great reusable capacity for solar light response and thermal energy storage. In this system, PM24 (n(PANI): n(MXene) = 100:24) shows the best comprehensive performance. During melting and freezing process, its latent heat values are as high as 150.93 J/g and 146.6 J/g, respectively, and the corresponding enthalpy efficiency are 90.1% and 89.6%, respectively. After ultra-long 1000 heating-cooling cycles, only 2.91% and 2.87% enthalpy rate loss of melting and freezing, indicating its superior cycling stability. Furthermore, with excellent solar light absorption capacity, the solar-to-thermal conversion efficiency of PM24 exceed 95.29%, and it also keeps stable reusability. Hence, PM24 exhibits a huge potential in terms of heat storage and photothermal conversion for long-term use.