Compositions suitable for reversibly storing heat in thermal energy systems (TES) include a salt hydrate represented by the formula: MX.sub.q.nH.sub.2O. M is a cation selected from Groups 1 to 14 of the IUPAC Periodic Table, X is a halide of Group 17, q ranges from 1 to 4, and n ranges from 1 to 12. The cation (M) may have an electronegativity of ≤ about 1.8 and a molar mass ≤ about 28 g/mol. The anion (X) may have an electronegativity of ≥ about 2.9 to ≤ about 3.2. A distance between a cation (M) and coordinating water molecules (H.sub.2O) is ≤ about 2.1 Å. Thermal energy systems (TES) incorporating such compositions are also provided that are configured to reversibly store heat in the thermal energy system (TES) via an endothermic dehydration reaction and to release heat in in the thermal energy system (TES) via an exothermic hydration reaction.

The invention describes a composite material for heat storage comprising a thermochemical material (TCM) encapsulated in a water vapour permeable polymeric material. The thermochemical material preferably comprises at least one salt, at least one salt hydrate or a mixture of these, wherein the salt is preferably capable of binding water in an exothermic reaction, such as calcium chloride. Encapsulation in a water vapour permeable polymeric material results in an improved stability, cyclability of the thermochemical material, a reduced regeneration temperature and reduced corrosion of the environment. The composite according to the invention is particularly suitable for energy storage, preferably in the field of building and construction, and more preferably in the seasonal storage of solar energy.

The invention describes a composite material for heat storage comprising a thermochemical material (TCM) encapsulated in a water vapour permeable polymeric material. The thermochemical material preferably comprises at least one salt, at least one salt hydrate or a mixture of these, wherein the salt is preferably capable of binding water in an exothermic reaction, such as calcium chloride. Encapsulation in a water vapour permeable polymeric material results in an improved stability, cyclability of the thermochemical material, a reduced regeneration temperature and reduced corrosion of the environment. The composite according to the invention is particularly suitable for energy storage, preferably in the field of building and construction, and more preferably in the seasonal storage of solar energy.

A plate-shaped chemical heat storage comprising a substrate composed of a net made of metal and a heat storage material composition supported on the substrate, wherein the heat storage material composition comprises at least one selected from the group consisting of magnesium hydroxide or oxide, strontium hydroxide or oxide, barium hydroxide or oxide, calcium hydroxide or oxide, and calcium sulfate, and optionally at least one selected from the group consisting of titanium dioxide, silicon dioxide, alumina silicate fiber, E-glass fiber and cellulose.

A plate-shaped chemical heat storage comprising a substrate composed of a net made of metal and a heat storage material composition supported on the substrate, wherein the heat storage material composition comprises at least one selected from the group consisting of magnesium hydroxide or oxide, strontium hydroxide or oxide, barium hydroxide or oxide, calcium hydroxide or oxide, and calcium sulfate, and optionally at least one selected from the group consisting of titanium dioxide, silicon dioxide, alumina silicate fiber, E-glass fiber and cellulose.

An electrochemical heat transfer device for a hot water tank utilizes an electrochemical hydrogen compressor to pump hydrogen into and out of a tank having a metal hydride forming alloy therein. The absorption of hydrogen by the metal hydride forming alloy is exothermic, produces heat, and the desorption of the hydrogen from the metal hydride forming alloy is endothermic and draws heat in. An electrochemical hydrogen compressor may be configured between to tanks and pump hydrogen back and forth to form a heat transfer device, such as a hot water heater. A heat transfer device may be coupled with the tank or may comprise the outer surface of the tank to transfer heat to an object or to the surroundings. A closed loop may be configured having two tanks and one or two electrochemical hydrogen compressors to pump the hydrogen in a loop around the system.

An electrochemical heat transfer device for a hot water tank utilizes an electrochemical hydrogen compressor to pump hydrogen into and out of a tank having a metal hydride forming alloy therein. The absorption of hydrogen by the metal hydride forming alloy is exothermic, produces heat, and the desorption of the hydrogen from the metal hydride forming alloy is endothermic and draws heat in. An electrochemical hydrogen compressor may be configured between to tanks and pump hydrogen back and forth to form a heat transfer device, such as a hot water heater. A heat transfer device may be coupled with the tank or may comprise the outer surface of the tank to transfer heat to an object or to the surroundings. A closed loop may be configured having two tanks and one or two electrochemical hydrogen compressors to pump the hydrogen in a loop around the system.

High-temperature thermochemical energy storage materials using doped magnesium-transition metal spinel oxides are provided. —transition metal spinel oxides, such as magnesium manganese oxide (MgMn).sub.3O.sub.4, are promising candidates for high-temperature thermochemical energy storage applications. However, the use of these materials has been constrained by the limited extent of their endothermic reaction. Embodiments described herein provide for doping magnesium-transition metal spinel oxides to produce a material of low material costs and with high energy densities, creating an avenue for plausibly sized modules with high energy storing capacities.

High-temperature thermochemical energy storage materials using doped magnesium-transition metal spinel oxides are provided. —transition metal spinel oxides, such as magnesium manganese oxide (MgMn).sub.3O.sub.4, are promising candidates for high-temperature thermochemical energy storage applications. However, the use of these materials has been constrained by the limited extent of their endothermic reaction. Embodiments described herein provide for doping magnesium-transition metal spinel oxides to produce a material of low material costs and with high energy densities, creating an avenue for plausibly sized modules with high energy storing capacities.

A thermal management system includes a slurry generator, an injector pump coupled to the slurry generator, a heat exchanger reactor coupled to the injector pump, wherein the heat exchanger reactor is adapted to subject a thermally expendable heat absorption material to a temperature above 60° C. and a pressure below 3 kPa, and wherein the expendable heat absorption material endothermically decomposes into a gaseous by-product. A vapor cycle system is coupled to the heat exchanger reactor and is operatively connected to a thermal load. A thermal energy storage system may be coupled to the vapor cycle system and the thermal load. The thermal energy storage system may isolate the heat exchanger reactor from thermal load transients of the thermal load.