Experimental investigation on properties of composite sorbents for three-phase sorption-water working pairs

Abstract LiCl/H 2 O and CaCl 2 /H 2 O show a great potential for sorption air-to-water and thermal energy storage (TES) with their large water sorption capacity. A concept of three-phase composite solid-liquid/gas sorption is proposed by using activated carbon fiber (ACF) felt as a porous host matrix to combine with LiCl and CaCl 2 . Samples with different proportions of salts and varied mass ratios between LiCl and CaCl 2 are developed, and thermal conductivity, sorption kinetics and simultaneous thermal analysis (STA) are experimentally investigated. Results reveal that ACF is a better choice of matrix because water uptake and energy storage density of aforementioned samples are greatly increased. It appears that the composite sorbent of ALiCa30(3:1) is a promising material for sorption air-to-water and TES, with water uptake of 2.98 g g −1 at 25 °C and 90% relative humidity, mass energy storage density of 0.41 kWh kg −1 and volume energy storage density of 223 kWh m −3 .