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The present invention relates to a thermal energy storage material (TESM) system (and associated methods) that reproducibly stores and recovers latent heat. The Thermal energy storage material system comprises i) at least one first metal containing material including at least one first metal compoun

The present invention relates to a thermal energy storage material (TESM) system (and associated methods) that reproducibly stores and recovers latent heat. The Thermal energy storage material system comprises i) at least one first metal containing material including at least one first metal compound that includes a nitrate ion, a nitrite ion, or both; and ii) at least one second metal containing material including at least one second metal compound. The thermal energy storage material system may water. If any water is present in the thermal energy storage material system, the water concentration should be less than about 10 wt. %. The thermal energy storage material has a liquidus temperature, TL, from about 100° C. to about 250° C. and exhibits a heat storage density from 300° C. to 80° C. of at least about 1 MJ/l, so that upon being used in a system that generates heat, at least a portion of the heat is captured and stored by the thermal energy storage material and subsequently released for use. The thermal energy storage material system is generally resistant to corrosion at temperatures of about 300° C. Exemplary metal compounds include one or more cations selected from the group consisting of Li, Na, K, Be, Mg, Ca, Al, and Ga.

대표청구항 ▼

1. A thermal energy storage material system that reproducibly stores and recovers latent heat comprising: a. a container having a wall surface; andb. a thermal energy storage material in at least partial contact with the wall surface, and including: i) at least one first metal containing material in

1. A thermal energy storage material system that reproducibly stores and recovers latent heat comprising: a. a container having a wall surface; andb. a thermal energy storage material in at least partial contact with the wall surface, and including: i) at least one first metal containing material including at least one first metal compound that includes a nitrate ion, a nitrite ion, or both; andii) at least one second metal containing material including at least one second metal compound;wherein the thermal energy storage material is free of water or includes less than 10 wt. % of water;wherein the thermal energy storage material has a liquidus temperature, TL, from about 100° C. to about 250° C.; andwherein the thermal energy storage material exhibits a heat storage density from 300° C. to 80° C. of at least 1 MJ/l;so that upon being used in a system that generates heat, at least a portion of the heat is captured and stored by the thermal energy storage material and subsequently released for use;wherein the thermal energy storage material is encapsulated in a plurality of capsules each having a volume of less than 200 ml, the thermal energy storage material includes lithium cations, andwherein the absolute value of the change in mass of the wall surface in contact with the thermal energy storage material is less than about 1 g per m2 of the wall surface in contact with the thermal energy storage material after 45 days exposure to the thermal energy storage material at 300° C. in an inert atmosphere. 2. The thermal energy storage material system of claim 1 wherein the thermal energy storage material is enclosed in the container wherein the container has a cavity and the wall surface includes a metal oxide. 3. The thermal energy storage material system of claim 1 wherein the concentration of hydrogen atoms in the thermal energy storage material, if any is present is less than 5 mole %, based on the total concentration of atoms in the thermal energy storage material. 4. The thermal energy storage material system of claim 1 wherein the thermal energy storage material has a value of HC50/HC1 greater than 70%, where HC50 is defined as the quenched heat of crystallization measured by differential scanning calorimetry at a cooling rate of 50° C./min over a temperature range of TL+50° C. to TL−100° C. and HC1 is defined as the slow cooled heat of crystallization measured by differential scanning calorimetry at a cooling rate of 1° C./min. 5. The thermal energy storage material system of claim 1 wherein the thermal energy storage material includes lithium nitrate and sodium nitrate. 6. The thermal energy storage material system of claim 1 wherein the thermal energy storage material includes lithium nitrate at a concentration from 35 mole % to 65 mole % based on the total moles of thermal energy storage material. 7. The thermal energy storage material system claim 1 wherein the thermal energy storage material includes sodium nitrate at a concentration from 35 mole % to 65 mole % based on the total moles of thermal energy storage material. 8. The thermal energy storage material system of claim 1 wherein the thermal energy storage material includes a nitrate ion and a nitrite ion. 9. The thermal energy storage material system of claim 1 wherein the thermal energy storage material optionally includes water, wherein the water concentration if any is present is less than 2 wt. % based on the total weight of the thermal energy storage material. 10. The thermal energy storage material system of claim 1 wherein the thermal energy storage material includes a nucleator. 11. The thermal energy storage material system of claim 1 wherein the thermal energy storage material fills 70% or more of the cavity of the container. 12. The thermal energy storage material system of claim 1, wherein the thermal energy storage material includes an anti-corrosion agent. 13. The thermal energy storage material system of claim 1, wherein the thermal energy storage material contains lithium cations at a concentration from 40 mole % to 80 mole % based on the total concentration of cations in the thermal energy storage material. 14. The thermal energy storage material system of claim 1 wherein the thermal energy storage material has a water concentration, if any is present, less than 2 wt. %, based on the total concentration of the thermal energy storage material. 15. The thermal energy storage material system of claim 1 wherein the thermal energy storage material has a liquidus temperature which is less than Tmin−25° C., wherein Tmin is the lowest melting temperature of any binary salt which can be formed by any anion of the thermal energy storage material and any cation of the thermal energy storage material. 16. The thermal energy storage material system of claim 1 wherein the total concentration of lithium nitrate and sodium nitrate is greater than 95 wt. % based on the total weight of the thermal energy storage material. 17. The thermal energy storage material system claim 1, wherein the thermal energy storage material is a ternary material having a eutectic composition. 18. The thermal energy storage material system of claim 1, wherein the thermal energy storage material includes a eutectic composition of i) a lithium salt selected from the group consisting of lithium nitrate and lithium nitrite; andii) a sodium salt selected from the group consisting of sodium nitrate and sodium nitrite; andwherein the thermal energy storage material the water concentration in the thermal energy storage material, if any is present, is less than 2 wt. % based on the total weight of the thermal energy storage material. 19. A method of making a thermal energy storage material system wherein the thermal energy system includes a container having a wall surface and also including a thermal energy storage material in at least partial contact with the wall surface, the thermal energy storage material in turn including i) at least a first metal containing material including at least one first metal compound that includes a nitrate ion, a nitrite ion, or both, and ii) at least a second metal containing material including at least one second metal compound, the thermal energy storage material being free of water or including less than 10 wt. % of water, the thermal energy storage material having a liquidus temperature, TL, from about 100° C. to about 250° C., the thermal energy storage material exhibiting a heat storage density from about 300° C. to about 80° C. of at least 1 MJ/1, the thermal energy storage material being encapsulated in a plurality of capsules each having a volume of less than 200 ml, the thermal energy storage material including lithium cations, wherein the absolute value of the change in mass of the wall surface in contact with the thermal energy storage materials is less than about 1 g per m2 of the wall surface in contact with the thermal energy storage material after 45 days exposure to the thermal energy storage material at 300° C. in an inert atmosphere, the method comprising heating the thermal energy storage material to a temperature greater than 100° C.; andencapsulating the thermal energy storage material in a volume that is substantially free of water. 20. A method for storing and recovering latent heat comprising the steps of: a) transferring at least a portion of a source heat from a heat source or a heat collector to a thermal energy storage material system; wherein the thermal energy storage material system includes a thermal energy storage material;b) heating the thermal energy storage material using the source heat;c) increasing the amount of the liquid phase in the thermal energy storage material by converting at least a portion of the source heat into latent heat;d) maintaining the amount of the liquid phase in the thermal energy storage material to store the latent heat;e) converting at least a portion of the latent heat into released heat; andf) transferring the released heat to an object to be heated; wherein the thermal energy storage material system includes a container having a wall surface; the thermal energy storage material is in at least partial contact with the wall surface; the thermal energy storage material includes i) at least one first metal containing material including at least one first metal compound that includes a nitrate ion, a nitrite ion, or both; andii) at least one second metal containing material including at least one second metal compound; the thermal energy storage material is free of water or includes less than 10 wt. % of water; the thermal energy storage material has a liquidus temperature TL, from about 100° C. to about 250° C.; and the thermal energy storage material exhibits a heat storage density from 300° C. to 80° C. of at least 1 MJ/l; the thermal energy storage material is encapsulated in a plurality of capsules each having a volume of less than 200 ml, the thermal energy storage material includes lithium cations, and wherein the absolute value of the change in mass of the wall surface in contact with the thermal energy storage material is less than about 1 g per m2 of the wall surface in contact with the thermal energy storage material after 45 days exposure to the thermal energy storage material at 300° C. in an inert atmosphere.