Salt impregnated desiccant matrices for ‘open’ thermochemical energy storage—Selection, synthesis and characterisation of candidate materials

•A list of materials is provided for ‘open’ thermochemical energy storage (TES).•Characterisation of materials provided their hygrothermal and porous properties.•Characterisation enables future linking of material performance to its properties.•Vermiculite with CaCl2 or LiBr show the best potential for ‘open’ TES. A selection of hygroscopic salts and desiccant matrices (salt in matrix, SIM) were chosen from the literature as candidate materials for open thermal energy storage (TES) systems. The aim of the paper was to narrow this selection through the application of selective criteria to those that had a high affinity of each working pair to each other, were environmentally stable, had low raw material costs with high availability, a low regeneration temperature for charging (