Transforming waste cigarette filters into 3D carbon scaffolds for form-stable and energy conversion phase change materials

Energy conversion phase-change materials (PCMs) have recently attracted increasing attention in thermal energy storage applications. In particular, integrating PCMs with carbon scaffolds can effectively enable the stimulus-responsive latent heat storage and improve the shape stability of PCMs. In this work, we fabricated a conductive 3D reduced graphene/carbon scaffold (GPC) via the carbonization of graphene oxide (GO) doped cellulose acetate fiber scaffolds derived from waste cigarette filters. The GO coating preserved the structural integrity and enhanced the conductivity of the carbonized scaffold. The mesoporous characteristics of the GPC scaffold provided a good encapsulation efficiency of paraffin wax (PW) with leakage-proof performance during the phase-change process. The GPC, with a high conductivity of approximately 294.9 S m−1, offered excellent electrothermal conversion and storage efficiency of about 88% for the GPC–PW composite. The PCM composite was also an energy-efficient electrothermal storage material that releases heat more steadily and improves the thermal management function compared with its counter-part GPC scaffold. Thus, GPC fabrication paves a new path toward the sustainable and eco-friendly production of energy conversion supports for practical applications of PCM based thermal energy storage and thermal management devices.