Electrocaloric heat transfer system

Abstract

A cooling system includes an electrocaloric element having a nanoparticulate ion scavenger and a co-continuous polymer network of a first polymer phase and a second polymer phase wherein the first polymer includes a liquid crystal polymer. A pair of electrodes is disposed on opposite surfaces of the electrocaloric element. A first thermal flow path is disposed between the electrocaloric element and a heat sink. A second thermal flow path is disposed between the electrocaloric element and a heat source. The system also includes a controller configured to control electrical current to the electrodes and to selectively direct transfer of heat energy from the electrocaloric element to the heat sink along the first thermal flow path or from the heat source to the electrocaloric element along the second thermal flow path.

What is claimed: 
     
         1 . A heat transfer system, comprising
 an electrocaloric element comprising a nanoparticulate ion scavenger and a co-continuous polymer network of a first polymer phase and a second polymer phase wherein the first polymer phase comprises a liquid crystal polymer;   a pair of electrodes disposed on opposite surfaces of the electrocaloric element;   a first thermal flow path between the electrocaloric element and a heat sink;   a second thermal flow path between the electrocaloric element and a heat source; and   a controller configured to control electrical current to the electrodes and to selectively direct transfer of heat energy from the electrocaloric element to the heat sink along the first thermal flow path or from the heat source to the electrocaloric element along the second thermal flow path.   
     
     
         2 . The system of  claim 1 , wherein the heat source is a conditioned dielectric fluid. 
     
     
         3 . The system of  claim 2 , wherein the conditioned fluid is air. 
     
     
         4 . The system of  claim 1 , wherein the nanoparticulate ion scavenger comprises freestanding cerium (Ce), platinum (Pt), palladium (Pd), silver (Ag), and gold (Au) nanoparticles. 
     
     
         5 . The system of  claim 1 , wherein the nanoparticulate ion scavenger comprises silica-supported cerium (Ce), platinum (Pt), palladium (Pd), silver (Ag), and gold (Au) nanoparticles. 
     
     
         6 . The system of  claim 1 , wherein the second polymer phase comprises a liquid crystalline mesogenic group. 
     
     
         7 . The system of  claim 1 , wherein the second polymer phase is coated. 
     
     
         8 . The system of  claim 1 , wherein the second polymer phase is a sol-gel. 
     
     
         9 . The system of  claim 1 , wherein the first polymer phase is crosslinked. 
     
     
         10 . The system of  claim 1 , further comprising an ion barrier layer between the electrocaloric element and the electrodes. 
     
     
         11 . The system of  claim 10 , wherein the ion barrier layer has a thickness of 10 nanometers to 10 micrometers. 
     
     
         12 . The system of  claim 1 , wherein first polymer phase comprises a main-chain liquid crystal polymer. 
     
     
         13 . The system of  claim 1 , wherein first polymer phase comprises a side-chain liquid crystal polymer. 
     
     
         14 . A method of using the system of  claim 1 , comprising
 applying an electric field as a voltage differential across the electrocaloric element, thereby causing a decrease in entropy and a release of heat energy by the electrocaloric element;   transferring at least a portion of the released heat energy to the heat sink;   removing the electric field, thereby causing an increase in entropy and a decrease in heat energy and absorption of heat energy by the electrocaloric element; and   transferring heat energy from the heat source to be absorbed by the electrocaloric element.   
     
     
         15 . The method of  claim 14 , wherein at least a portion of the released heat energy to the heat sink is transferred to the heat sink simultaneously with applying the electric field. 
     
     
         16 . The method of  claim 14 , comprising
 applying the electric field to the electrocaloric element to increase the temperature of the electrocaloric element until the temperature of the electrocaloric element reaches a first threshold;   transferring heat energy from the electrocaloric element to the heat sink to reduce the temperature of the electrocaloric element until the temperature of the electrocaloric element reaches a second threshold;   removing the electric field to reduce the temperature of the electrocaloric element until the temperature of the electrocaloric element reaches a third threshold;   transferring the heat energy from the heat source to cool the heat source and increase the temperature of the electrocaloric element until the temperature of the electrocaloric element reaches a fourth threshold; and optionally   repeating the above steps until a target temperature is reached for the heat source or heat sink.   
     
     
         17 . The method of  claim 14 , wherein the nanoparticulate ion scavenger comprises freestanding cerium (Ce), platinum (Pt), palladium (Pd), silver (Ag), and gold (Au) nanoparticles. 
     
     
         18 . The method of  claim 14 , wherein the nanoparticulate ion scavenger comprises silica supported cerium (Ce), platinum (Pt), palladium (Pd), silver (Ag), and gold (Au) nanoparticles. 
     
     
         19 . The method of  claim 14 , further comprising an ion barrier layer between the electrocaloric element and the electrodes. 
     
     
         20 . The method of  claim 14 , wherein the second polymer phase comprises
 a liquid crystalline mesogenic group.