High Energy Density High Thermal Conductivity Latent Heat Storage using Inorganic Nanocomposites

Project: Research project

Description

Form-stable materials are composites used for thermal energy storage and consist of a solid matrix with embedded phase change material. Typically these materials consist of a polymer matrix with embedded organic phase change materials (e.g. paraffins, fatty acids, and glycols). However, one major drawback of this matrix composition is that polymers have a very low thermal conductivity, which leads to slow thermal charging/discharging of the material. Polymers also suffer from low degradation temperatures, which eliminate the possibility of high temperature operation. This proposal explores a new type of form-stable thermal storage material that circumvents these problems and possesses additional benefits. I propose to use metallic nanocrystals embedded in inorganic matrices for latent heat storage. Bismuth, tin, and indium nanocrystals will be embedded into inorganic matrices using solution-phase chemistry. Two categories of matrices will be explored: metal-chalcogenide matrices and metal matrices. These form-stable materials will have many attractive qualities: 1. The high thermal conductivity of the inorganic matrices should lead to 100 1000x improvements in thermal energy charging/discharging. 2. The volumetric enthalpy of fusion for metals greatly exceeds that of the organics used in polymer form-stable materials. 3. Melting temperature can be tuned over a broad range by changing nanocrystal size (melting ~100C or more below bulk values is experimentally common). 4. Expanded operating temperature regime because the metallic inclusions melt at a higher temperature and the inorganic matrix has improved thermal stability over polymer matrices. To investigate these benefits, we will use an in-situ environmental transmission electron microscope to investigate the size-dependent melting temperature of the nanocrystals. Digital scanning calorimetry will be used to measure the composites enthalpy of fusion and corroborate melting temperatures acquired via transmission electron microscopy.
StatusFinished
Effective start/end date9/1/128/31/16

Funding

  • National Science Foundation (NSF): $292,579.00

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Heat storage
Latent heat
Thermal conductivity
Nanocomposites
Nanocrystals
Melting point
Phase change materials
Thermal energy
Polymer matrix
Enthalpy
Polymers
Fusion reactions
Metals
High temperature operations
Composite materials
Calorimetry
Glycols
Bismuth
Fatty acids
Paraffins