# US 11,306,238 B2 · Shape-stabilized phase change materials for energy storage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,238 B2 - Document ID: US11306238B2 - Status: Granted - Kind: B2 - Application number: 16/592,292 - Filed: 2019-10-03 - Published: 2021-04-08 - Granted: 2022-04-19 - Earliest claimed: 2019-10-03 - Assignees: King Fahd University of Petroleum and Minerals - Applicants: King Fahd University of Petroleum and Minerals - Inventors: Md. Hasan Zahir; Mohammed Mozahar Hossain; Mohammad Mizanur Rahman; Salhi Billel - Web page: https://patentgrep.com/patent/US11306238B2 ## CPC - C09K 5/063: {Materials absorbing or liberating heat during crystallisation; Heat storage materials} - F28D 20/023: {the latent heat storage material being enclosed in granular particles or dispersed in a porous, fibrous or cellular structure} - Y02E 60/14: Thermal energy storage - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A heat storage material comprising mesoporous Mg(OH)2 and having pores loaded with a phase change material is described. The heat storage material has a cooling latent heat of 130-140 J/g, and a solidification enthalpy of 120-135 J/g, and a thermal conductivity of 25-45 W·m−1·K−1. The phase change material may be polyethylene glycol, and the polyethylene glycol does not leak from the pores of the mesoporous Mg(OH)2 when heating or cooling over phase transitions. ## Claims ### Claim 1 A heat storage material, comprising: 10-50 wt % mesoporous Mg(OH)2, and 50-90 wt % phase change material, each relative to a total weight of the heat storage material, wherein the mesoporous Mg(OH)2 is in the form of particles with an average diameter in a range of 100 nm-1 μm, wherein the mesoporous Mg(OH)2 has pores with an average pore size in a range of 5-15 nm, wherein 10-100 wt % phase change material relative to a total weight of the phase change material is located within the pores, and wherein the phase change material is an organic compound. ### Claim 2 (depends on 1) The heat storage material of claim 1, wherein the mesoporous Mg(OH)2 is in the form of nanoplatelets, the nanoplatelets having an average diameter in a range of 400-700 nm and an average thickness in a range of 1-20 nm. ### Claim 3 (depends on 1) The heat storage material of claim 1, wherein the mesoporous Mg(OH)2 has a surface area in a range of 40-80 m2/g. ### Claim 4 (depends on 1) The heat storage material of claim 1, wherein the mesoporous Mg(OH)2 is crystalline with a lattice spacing in a range of 0.260-0.300 nm. ### Claim 5 (depends on 1) The heat storage material of claim 1, wherein the organic compound is at least one selected from the group consisting of polyethylene glycol, polyethylene, polypropylene, polyamide, polycarbonate, polyimide, poly(butadiene), poly(isoprene), poly(hydrogenated butadiene), polyetherester elastomer, ethylene/propylene/diene (EPDM) polystyrene, polyvinyl chloride, paraffin, and sugar alcohol. ### Claim 6 (depends on 5) The heat storage material of claim 5, wherein the organic compound is polyethylene glycol, and wherein the heat storage material consists essentially of Mg(OH)2 and polyethylene glycol. ### Claim 7 (depends on 5) The heat storage material of claim 5, wherein the phase change material consists essentially of polyethylene glycol having a weight average molecular weight in a range of 4,000-8,000 Da. ### Claim 8 (depends on 1) The heat storage material of claim 1, which is substantially free of aluminum. ### Claim 9 (depends on 1) The heat storage material of claim 1, further comprising mesoporous MgO in contact with the mesoporous Mg(OH)2. ### Claim 10 (depends on 1) The heat storage material of claim 1, wherein the phase change material has a melting point in a range of 50-65° C. ### Claim 11 (depends on 1) The heat storage material of claim 1, wherein the phase change material has a freezing point in a range of 30-40° C. ### Claim 12 (depends on 1) The heat storage material of claim 1, which has a cooling latent heat in a range of 130-140 J/g. ### Claim 13 (depends on 1) The heat storage material of claim 1, which has a solidification enthalpy in a range of 120-135 J/g. ### Claim 14 (depends on 1) The heat storage material of claim 1, which has a thermal conductivity in a range of 25-45 W·m−1·K−1. ### Claim 15 (depends on 1) The heat storage material of claim 1, wherein less than 10 wt % of the phase change material located in the pores, relative to a total weight of the phase change material located in the pores, exits the pores when the phase change material undergoes a melting or a solidifying transition. ### Claim 16 (depends on 1) The heat storage material of claim 1, wherein 80-100 vol % of a total pore volume is occupied by the phase change material. ### Claim 17 (depends on 1) A method for forming the heat storage material of claim 1, the method comprising: hydrothermally reacting Mg(NO3)2, pamoic acid, and NH3 in water in a closed vessel at a temperature in a range of 180-250° C. for 18-30 h to form a suspended precipitate, washing and drying the suspended precipitate to form mesoporous Mg(OH)2, mixing the mesoporous Mg(OH)2 with the phase change material in an organic solvent to form a mixture, and drying the mixture to form the heat storage material. ### Claim 18 (depends on 17) The method of claim 17, further comprising heating the mesoporous Mg(OH)2 for 1-6 h at a temperature in a range of 300-500° C. ### Claim 19 (depends on 17) The method of claim 17, wherein the mixture comprises the phase change material at a concentration in a range of 2-7 g/L. ### Claim 20 (depends on 1) A building material comprising the heat storage material of claim 1.