Biogenic architectures for green, cheap, and efficient thermal energy storage and management

A key challenge for efficient thermal management of civil buildings is the development of shape-stabilized phase change materials (PCM) for thermal energy storage and release. Nevertheless, some issues related to the disposal of such devices are arising as they are generally not biodegradable and recyclable. In this work, we developed two new renewable and biodegradable thermal energy storage composites obtained from renewable resources. These are based on the use of bio-derived alcohol as PCM and on porous biogenic structures, namely cuttlebone and pomelo peel, as shape stabilizers, which are currently waste materials. The results point out that both cuttlebone and pomelo peel can spontaneously absorb huge amounts of the considered PCM and retain it in the liquid state. The thermal energy storage capacity of the composites is about 70% that of neat PCM, whereas the volumetric efficiency (i.e., the ratio between the thermal energy storage capacity of the composite and the neat PCM in J cm−3) approaches 90% and 70% in cuttlebone and pomelo peel composites, respectively. The properties appear stable over at least 100 melting/solidification cycles. © 2021 Elsevier Ltd. All rights reserved.