Thermal conductivity reduction in three dimensional graphene-based nanofoam

RSC Advances ◽  
2015 ◽  
Vol 5 (120) ◽  
pp. 99394-99397 ◽  
Author(s):  
Pradheep Thiyagarajan ◽  
Zhong Yan ◽  
Jong-Chul Yoon ◽  
Min-Wook Oh ◽  
Ji-Hyun Jang
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Three Dimensional ◽  
Layer Graphene ◽  
Few Layer Graphene

This work investigates the thermoelectric properties of a three dimensional nanofoam of few layer graphene (3D-NFG) decorated with holes having diameters of several tens of nanometers.

Structure and Thermoelectric Properties of New Quaternary Tin and Lead Bismuth Selenides, K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1+xSn5-xBi11+xSe22

2000 ◽  
Vol 626 ◽  
Author(s):  
Antje Mrotzek ◽  
Kyoung-Shin Choi ◽  
Duck-Young Chung ◽  
Melissa A. Lane ◽  
John R. Ireland ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Single Crystal ◽  
Thermoelectric Properties ◽  
Three Dimensional ◽  
Structure Type ◽  
Narrow Gap ◽  
Low Thermal Conductivity ◽  
Seebeck Coefficients ◽  
Metal Atoms ◽  
Anionic Framework

ABSTRACTWe present the structure and thermoelectric properties of the new quaternary selenides K1+xM4–2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22. The compounds K1+xM4-2xBi7+xSe15 (M= Sn, Pb) crystallize isostructural to A1+xPb4-2xSb7+xSe15 with A = K, Rb, while K1-xSn5-xBi11+xSe22 reveals a new structure type. In both structure types fragments of the Bi2Te3-type and the NaCl-type are connected to a three-dimensional anionic framework with K+ ions filled tunnels. The two structures vary by the size of the NaCl-type rods and are closely related to β-K2Bi8Se13 and K2.5Bi8.5Se14. The thermoelectric properties of K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22 were explored on single crystal and ingot samples. These compounds are narrow gap semiconductors and show n-type behavior with moderate Seebeck coefficients. They have very low thermal conductivity due to an extensive disorder of the metal atoms and possible “rattling” K+ ions.

Thermal Conductivity Reduction in Few-Layer Graphene

2011 ◽  
Author(s):  
Dhruv Singh ◽  
Jayathi Y. Murthy ◽  
Timothy S. Fisher
Keyword(s):  
Thermal Conductivity ◽  
Weak Coupling ◽  
Phonon Scattering ◽  
Single Layer ◽  
Acoustic Mode ◽  
Single Layer Graphene ◽  
Boltzmann Transport ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Few Layer Graphene

Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with weak coupling between layers, a significant reduction in the thermal conductivity of the out-of-plane acoustic modes is apparent. The main effect of this weak coupling is to open many new three-phonon scattering channels that are otherwise absent in graphene. The highly restrictive selection rule that leads to a high thermal conductivity of ZA phonons in single-layer graphene is only weakly broken with the addition of multiple layers, and ZA phonons still dominate thermal conductivity. We also find that the decrease in thermal conductivity is mainly caused by decreased contributions of the higher-order overtones of the fundamental out-of-plane acoustic mode. Moreover, the extent of reduction is largest when going from single to bilayer graphene and saturates for four layers. The results compare remarkably well over the entire temperature range with measurements of of graphene and graphite.

Three-dimensional nano-foam of few-layer graphene grown by CVD for DSSC

2012 ◽  
Vol 14 (22) ◽  
pp. 7938 ◽  
Author(s):  
Jung-Soo Lee ◽  
Hyo-Jin Ahn ◽  
Jong-Chul Yoon ◽  
Ji-Hyun Jang
Keyword(s):  
Three Dimensional ◽  
Layer Graphene ◽  
Few Layer Graphene

Thermal Transport Measurements of Bilayer and Few-Layer Graphene Supported on Silicon Dioxide

2011 ◽  
Author(s):  
Mir Mohammad Sadeghi ◽  
Li Shi
Keyword(s):  
Thermal Conductivity ◽  
Silicon Dioxide ◽  
Thermal Conductance ◽  
Layer Graphene ◽  
Scattering Effects ◽  
Before And After ◽  
Linear Rise ◽  
Opposite Behavior ◽  
Few Layer Graphene ◽  
Sio2 Support

The thermal conductivity of bilayer graphene (BLG) and few-layer graphene (FLG) samples supported on a silicon dioxide (SiO2) bridge has been measured in the temperature range between 80 K and 375 K. In the experiments, resistance heater and thermometer lines at the two ends of the bridge were used to implement steady-state thermal conductance measurements of the sample before and after the graphene on the bridge was etched away. The obtained thermal conductivity of the supported graphene increases and the temperature for the peak thermal conductivity decreases with increasing layer thickness. Compared to the reported thermal conductivity of suspended FLG samples, the opposite behavior observed here for the supported FLG reveals that interaction with the SiO2 support and also possibly polymer residue on top of the FLG sample suppresses the thermal conductivity of the supported FLG more than interlayer interaction within the FLG. The linear rise of thermal conductivity with layer number up to 8 layers suggests that the scattering effects due to substrate and polymer residue penetrates much more than 4 layers into a multilayer flake.

scholarly journals Binder free three-dimensional sulphur/few-layer graphene foam cathode with enhanced high-rate capability for rechargeable lithium sulphur batteries

Nanoscale ◽  
2014 ◽  
Vol 6 (11) ◽  
pp. 5746-5753 ◽  
Author(s):  
Kai Xi ◽  
Piran R. Kidambi ◽  
Renjie Chen ◽  
Chenlong Gao ◽  
Xiaoyu Peng ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Rate Capability ◽  
High Rate ◽  
High Rate Capability ◽  
Capacity Retention ◽  
Layer Graphene ◽  
Binder Free ◽  
Rate Discharge ◽  
Few Layer Graphene ◽  
High Rate Discharge

A novel ultra-lightweight 3-D Li-S battery cathode has been synthesised by loading sulphur on to an interconnected 3-D network of few-layered graphene. The battery shows high rate discharge capacity retention for up to 400 cycles.

Thermal conductivity of suspended few-layer graphene by a modified T-bridge method

2013 ◽  
Vol 103 (13) ◽  
pp. 133102 ◽  
Author(s):  
W. Jang ◽  
W. Bao ◽  
L. Jing ◽  
C. N. Lau ◽  
C. Dames
Keyword(s):  
Thermal Conductivity ◽  
Layer Graphene ◽  
Bridge Method ◽  
Few Layer Graphene
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