Original Article:
MgSO4-expanded graphite composites for mass and heat transfer enhancement of thermochemical energy storage
Qi Miao, et al.
Solar Energy, 2021, 220: 432-439.
10.1016/j.solener.2021.03.008
To address the environmental challenges posed by energy consumption, thermal energy storage (TES) offers a promising solution to address the mismatch between supply and demand. Among them, thermochemical energy storage has attracted much attention due to its characteristics of high energy density, low loss, low reaction temperature, low pressure, large choice, and cold and heat storage. Past studies have shown that salt hydrates serve as a commonly used thermochemical storage material (TCM), where heat storage and release processes occur through hydration and dehydration, respectively.
Among many salt hydrates, the theoretical heat storage density of magnesium sulfate (MgSO4) hydrate is as high as 2.8 GJ/m3, making it the most cost-effective. However, the swelling and agglomeration of MgSO4 during hydration limits the mass transfer, leading to performance degradation and material loss during thermal cycling.
In this study, the authors used MgSO4 as TCM to prepare composite materials for low- and medium-temperature thermal energy storage applications with expanded graphene (EG) as a porous material matrix (solving the mass transfer problem).
The specific preparation process of MgSO4-EG composite material is shown in the figure, including the following steps:1. EG was dried from ambient temperature to 800 °C in a muffle furnace at a heating rate of 10 K/min, followed by rapid cooling to remove moisture and volume expansion.
2. Prepare a salt solution by dissolving MgSO4 in distilled water.
3. During the impregnation process, slowly pour the MgSO4 salt solution into the beaker containing the EG powder and stir until the salt solution is just submerged in the EG and ensure that the salt enters the pores of the EG.
4. Dry the composites in an oven at 150 °C for 4 hours to obtain MgSO4-EG composites with different MgSO4 contents.
Chemicals Related in the Paper:
| Catalog Number | Product Name | Structure | CAS Number | Price |
|---|---|---|---|---|
| ACM139939756 | Magnesium Sulfate |  |
139939-75-6 | Price |
| ACM14168731 | Magnesium sulfate |  |
14168-73-1 | Price |
| ACM17830181 | Magnesium sulfate hexahydrate |  |
17830-18-1 | Price |
| ACM7487889 | Magnesium sulfate |  |
7487-88-9 | Price |
| ACM7782425-7 | Expanded graphite |  |
7782-42-5 | Price |
