Nanoarchitecture tailoring of biomass-derived bowl-shaped carbon superstructures-based LiOH-LiCl composite for low-grade solar heat harvesting

Abstract

The fussy and toxic building process of 3D carbon superstructures with expensive precursors has critically encumbered their topological versatility and application territory broadening. Herein, an innovative bowl-shaped carbon superstructure was fabricated via a straightforward and eco-friendly double-template methodology in the aqueous environments using naturally available and cost-effective biomass. And its carbonaceous derivative (BBAC) served as the skeleton matrix for thermochemical adsorption heat storage (TAHS) material for the first time. At low ambient humidity, LiOC3/BBAC2 composites present prospective hydratability and heat storage capacity (HSC) up to 1379.6 kJ kg⁻¹ empowered by the collaborative effort between BBAC2 features exquisite 3D bowl-shaped architecture, delicately engineered hierarchical porosity stretching cross-scale pores, exceptionally approachable surface area and hygroscopic salt hybrids of LiOH-LiCl. Meanwhile, the LiOC3/BBAC2-60 could hold 96.1 % of the initial HSC after 20 thermal storage cycles while showing impressive solar-heat conversion properties arising from the fine thermal conductivity of BBAC2, manifesting its superb cycling consistency. And the numerical simulation findings endorse its great heat transfer properties. This work not only delivers concise and green inspirational approaches to the exploration of anisotropic 3D carbon superstructures with well-orchestrated morphologies and desirable functionalities but may also provide a favorable option for the productive transformation and storage of low-grade energy.