No abstract

Sorption-based thermal storage has drawn considerable attention for sustainable and cost-effective thermal management and energy storage. However, the low sorption capacity of sorbents is a long-standing challenge for achieving high-energy-density sorption-based thermal storage. Herein, we demonstrate an ultrahigh-energy/power-density sorption thermal battery (STB) enabled by graphene aerogel (GA)-based composite sorbents for efficient thermal harvesting and storage with record performance. Scalable GA-based composite sorbents with high salt loading are synthesized by confined calcium chloride inside a GA matrix (CaCl 2 @GA), showing fast sorption kinetics and a large sorption capacity up to 2.89 g•g −1 contributed by the GA matrix and chemisorption−deliquescence−absorption of CaCl 2 . The STB realizes thermal charging−discharging via the multistep water desorption−sorption of CaCl 2 @GA sorbent with the humidity from air. Importantly, the lab-scale STB exhibits record energy density of 1580 Wh•kg −1 and power density of 815 W•kg −1 for space heating. Our work offers a promising low-carbon route for efficient thermal energy harvesting, storage, and utilization.

No abstract

Metal–organic frameworks (MOFs) possess unique flexibility of structure and properties, which drives them toward applications as water adsorbents in many emerging technologies, such as adsorptive heat transformation, water harvesting from the air, dehumidification, and desalination. A deep understanding of the surface phenomena is a prerequisite for the target-oriented design of MOFs with the required adsorption properties. In this work, we comprehensively study the effect of functional groups on water adsorption on a series CAU-10- X substituted with both hydrophilic ( X = NH 2 ) and hydrophobic ( X = NO 2 ) groups in the linker. The adsorption equilibrium is measured at P = 7.6–42 mbar and T = 5–100 °C. The study of water adsorption by a set of mutually complementary physicochemical methods (TG, XRD in situ, FTIR, and 1 H NMR relaxometry) elucidates the nature of primary adsorption sites and water adsorption mechanisms.