Metal Nanoparticle–Carbon Matrix Composites with Tunable Melting Temperature as Phase-Change Materials for Thermal Energy Storage

Abstract

Phase-change materials with tunable melting temperature provide a new design for thermal energy storage applications. Here, we demonstrate a general one-pot synthesis of composites containing ligand-free metal nanoparticles (Bi or Pb) distributed in a mesoporous carbon matrix as form-stable phase change materials. The melting temperature of the encapsulated metal nanoparticles (NPs) can be tuned as a function of particle size, which depends on the metal loading in the composite material. Melting and resolidification temperatures are stable through multiple melt− freeze cycles. The carbon matrix encapsulating the metal NPs prevents aggregation of the NPs, accommodates volume change, and prevents leakage during phase change process. The melting temperature of the Bi NPs decreases by 33 °C compared to the melting point of bulk Bi with a Bi loading of 48 wt % in the composite materials, and that of Pb NPs decreases by 18 °C compared to bulk Pb with a Pb loading of 47 wt %. Using transmission electron microscopy, we also demonstrate that the porous channels of the carbon matrix serve as containers for the melted Pb NPs.

Liquid Processing of Bismuth–Silica Nanoparticle/Aluminum Matrix Nanocomposites for Heat Storage Applications

“…Bi@SiO 2 particles exhibit an endothermic peak at ∼242 °C, which is in agreement with the depression of the melting point (271 °C for bulk Bi) with particle size decrease . The melting point measured herein for 25 nm silica-coated Bi nanoparticles is in accordance with the results obtained for Bi-carbon nanocomposites . Bi@SiO 2 nanoparticles exhibit reversible thermal properties over four cycles (Figure a).…”

Micro- and nano-encapsulated metal and alloy-based phase-change materials for thermal energy storage

“…11 ). 95 The embedded metal nanoparticles helped in controlling the melting temperature of these composites (this was achieved by changing the size of the metal nanoparticles by tuning the amount of metal loaded inside the composites). A decrease in the melting temperature of both Bi and Pb nanoparticles in the composite materials compared to their bulk counterparts was observed.…”

Dual Phase Change Thermal Diodes with High Rectification for Thermal Management near Room Temperature

“…[24][25][26] PCMs are a great choice for use in thermal diodes because phase changes are often accompanied by changes in thermal conductivity, and they provide a few additional advantages. The variety of available PCMs offers a wide range of transition temperatures and thermal conductivities, [27] and these can be further tuned through eutectic mixing or addition of nanoparticles, [27][28][29] and the transitions are generally reversible and reliable. Furthermore, PCMs are amenable to both small-scale and large-scale applications.…”