Dynamic tuning of optical absorbers for accelerated solar-thermal energy storage

Abstract

Currently, solar-thermal energy storage within phase-change materials relies on adding high thermal-conductivity fillers to improve the thermal-diffusion-based charging rate, which often leads to limited enhancement of charging speed and sacrificed energy storage capacity. Here we report the exploration of a magnetically enhanced photon-transport-based charging approach, which enables the dynamic tuning of the distribution of optical absorbers dispersed within phase-change materials, to simultaneously achieve fast charging rates, large phase-change enthalpy, and high solar-thermal energy conversion efficiency. Compared with conventional thermal charging, the optical charging strategy improves the charging rate by more than 270% and triples the amount of overall stored thermal energy. This superior performance results from the distinct step-by-step photon-transport charging mechanism and the increased latent heat storage through magnetic manipulation of the dynamic distribution of optical absorbers.

High‐Performance Thermally Conductive Phase Change Composites by Large‐Size Oriented Graphite Sheets for Scalable Thermal Energy Harvesting

“…Thermal energy harvesting using phase change materials (PCMs) can improve energy utilization efficiency and provide cost‐effective energy storage and thermal management by absorbing heat from the surrounding environment and solar irradiation, as well as waste heat produced by industrial processes and electronic devices . Organic solid–liquid PCMs have been extensively studied due to their appropriate physical and chemical properties and abundance in natural resources .…”

Ethylene glycol-based solar-thermal fluids dispersed with reduced graphene oxide

“…[3][4][5][6] To realize these applications, efficient collection of solar-thermal energy is a prerequisite. [7][8][9] Conventional solar-thermal collectors such as the at plate collector rely on a black solar-absorbing surface for solar-to-thermal conversion and the converted heat is transferred to the owing working uids underneath. 10 With such a design, the collector surface has a high temperature, and the thermal resistance between the absorber surface and working uids is large, which in turn lead to serious heat loss of the converted heat to the environment, especially under concentrated solar illumination.…”

The Design of Optical Circuit-Analog Absorbers through Electrically Small Nanoparticles

“…In the last few decades, there has been an increasing interest in extending similar effects to the visible spectrum [4][5][6][7][8][9][10][11][12][13][14][15]. Optical absorption, in fact, plays a key role in many relevant applications, including photovoltaics and thermophotovoltaics [16], photodetectors [17], color filters [18], and thermal light sources [19].…”