Polymer-derived silicon nitride aerogels as shape stabilizers for low and high-temperature thermal energy storage. Issue 11 (September 2021)

• Record Type: Journal Article
• Authors: Zambotti, Andrea; Caldesi, Edoardo; Pellizzari, Massimo; Valentini, Francesco; Pegoretti, Alessandro; Dorigato, Andrea; Speranza, Giorgio; Chen, Kan; Bortolotti, Mauro; Sorarù, Gian D.; Biesuz, Mattia
• Is Part Of: Journal of the European Ceramic Society. Volume 41:Issue 11(2021)
• Page Start: 5484
• Page End: 5494
• Publication Date: 2021-09
• Subjects: Thermal energy storage -- Phase change material -- Sodium nitrate -- Paraffin -- Aerogel; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2021.04.056
• Languages: English
• ISSNs: 0955-2219

Abstract

Graphical abstract: Highlights: Si3 N4 aerogel can be easily synthesized from preceramic precursors with no catalyst. Infiltration of phase change material is spontaneous and immediate. Thermal performances can be optimized tailoring shape-stabilizer pore distribution. Si3 N4 aerogel withstand oxidation over 1000 °C in air. Abstract: This work presents a new skeleton material for thermal energy storage (TES), a silicon nitride aerogel obtained through the pyrolysis of a pre-ceramic polymer. Silicon nitride offers a good combination of thermal conductivity, high-temperature resistance, and chemical inertness. The aerogel porosity can be spontaneously infiltrated with molten NaNO3, which is a typical phase change material (PCM) in high-temperature TES. The Si3 N4 /NaNO3 composite exhibits excellent thermal properties with a thermal energy storage efficiency of 82 %, a limited molten salt leakage, and good stability to thermal cycling. The aerogel withstands oxidation up to high temperature and is chemically inert even in contact with salts. This novel aerogel shows also a notable paraffin absorption ability (used in room temperature TES) with negligible leakage even when in contact with absorbent paper. The so-obtained composite reached ≈ 82.4 vol % of organic PCM and a thermal energy storage efficiency of ≈ 62 % compared to neat paraffin.