Highly thermally conductive graphene-based electrodes for supercapacitors with excellent heat dissipation ability

2017 ◽  
Vol 1 (10) ◽  
pp. 2145-2154 ◽  
Author(s):  
Bo Zhao ◽  
Xian-Zhu Fu ◽  
Rong Sun ◽  
Ching-Ping Wong
Keyword(s):  
Heat Dissipation ◽  
Cycling Performance ◽  
Thermally Conductive ◽  
Rate Capacity ◽  
Electrodes For Supercapacitors

The highly thermally conductive graphene-based electrodes for supercapacitors exhibit great heat dissipation ability as well as excellent cycling performance and rate capacity.

scholarly journals Waterborne polyurethane as a carbon coating for micrometre-sized silicon-based lithium-ion battery anode material

2018 ◽  
Vol 5 (8) ◽  
pp. 180311 ◽  
Author(s):  
Chunfeng Yan ◽  
Tao Huang ◽  
Xiangzhen Zheng ◽  
Cuiran Gong ◽  
Maoxiang Wu
Keyword(s):  
Carbon Coating ◽  
Lithium Ion ◽  
Waterborne Polyurethane ◽  
Cycling Performance ◽  
Capacity Retention ◽  
Lithium Ions ◽  
Rate Capacity ◽  
Silicon Based ◽  
Carbon Network ◽  
A Current

Waterborne polyurethane (WPU) is first used as a carbon-coating source for micrometre-sized silicon. The remaining nitrogen (N) and oxygen (O) heteroatoms during pyrolysis of the WPU interact with the surface oxide on the silicon (Si) particles via hydrogen bonding (Si–OH⋯N and Si–OH⋯O). The N and O atoms involved in the carbon network can interact with the lithium ions, which is conducive to lithium-ion insertion. A satisfactory performance of the Si@N, O-doped carbon (Si@CNO) anode is gained at 25 and 55°C. The Si@CNO anode shows stable cycling performance (capacity retention of 70.0% over 100 cycles at 25°C and 60.3% over 90 cycles at 55°C with a current density of 500 mA g −1 ) and a superior rate capacity of 864.1 mA h g −1 at 1000 mA g −1 (25°C). The improved electrochemical performance of the Si@CNO electrode is attributed to the enhanced electrical conductivity and structural stability.

scholarly journals Development of Thermally Conductive Polyurethane Composite by Low Filler Loading of Spherical BN/PMMA Composite Powder

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kai-Han Su ◽  
Cherng-Yuh Su ◽  
Cheng-Ta Cho ◽  
Chung-Hsuan Lin ◽  
Guan-Fu Jhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Three Dimensional ◽  
Filler Loading ◽  
High Thermal Conductivity ◽  
Heat Diffusion ◽  
Composite Powders ◽  
Polyurethane Composite ◽  
Uniform Dispersion ◽  
Thermally Conductive

Abstract The issue of electronic heat dissipation has received much attention in recent times and has become one of the key factors in electronic components such as circuit boards. Therefore, designing of materials with good thermal conductivity is vital. In this work, a thermally conductive SBP/PU composite was prepared wherein the spherical h-BN@PMMA (SBP) composite powders were dispersed in the polyurethane (PU) matrix. The thermal conductivity of SBP was found to be significantly higher than that of the pure h-BN/PU composite at the same h-BN filler loading. The SBP/PU composite can reach a high thermal conductivity of 7.3 Wm−1 K−1 which is twice as high as that of pure h-BN/PU composite without surface treatment in the same condition. This enhancement in the property can be attributed to the uniform dispersion of SBP in the PU polymer matrix that leads to a three-dimensional continuous heat conduction thereby improving the heat diffusion of the entire composite. Hence, we provide a valuable method for preparing a 3-dimensional heat flow path in polyurethane composite, leading to a high thermal conductivity with a small amount of filler.

Multifunctional Liquid Crystal Polymeric Composites Embedded With Graphene Nano Platelets

2011 ◽  
Author(s):  
Muhammad Omer Khan ◽  
Ellen Chan ◽  
Siu N. Leung ◽  
Hani Naguib ◽  
Francis Dawson ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Crystal ◽  
Heat Dissipation ◽  
Three Dimensional ◽  
Cost Effective ◽  
Polymeric Composites ◽  
Potential Cost ◽  
Conductive Composites ◽  
The Matrix ◽  
Thermally Conductive

This paper studies the development of new multifunctional liquid crystal polymeric composites filled with graphene nano platelets (GNPs) for electronic packaging applications. A series of parametric studies were conducted to study the effect of GNP content on the thermal conductivity of LCP-based nanocomposites. Graphene, ranging from 10 wt. % to 50 wt. %, were melt-compounded with LCP using a twin-screw compounder. The extrudates were ground and compression molded into small disc-shaped specimens. The thermal conductivity of LCP matrix was observed to have increased by more than 1000% where as the electrical conductivity increased by 13 orders of magnitude with the presence of 50 wt% GNP fillers. The morphology of the composites was analyzed using SEM micrographs to observe the dispersion of filler within the matrix. These thermally conductive composites represent potential cost-effective materials to injection mold three-dimensional, net-shape microelectronic enclosures with superior heat dissipation performance.

A Systematic Approach for Designing Multifunctional Thermally Conducting Polymer Structures With Embedded Actuators

2009 ◽  
Vol 131 (11) ◽  
Author(s):  
Wojciech Bejgerowski ◽  
Satyandra K. Gupta ◽  
Hugh A. Bruck
Keyword(s):  
Heat Dissipation ◽  
Systematic Approach ◽  
Assembly Process ◽  
Processing Conditions ◽  
Molding Process ◽  
Filled Polymers ◽  
Thermally Conductive ◽  
Thermally Conducting ◽  
Process Constraints

Thermally conductive filled polymers enable the creation of multifunctional structures that offer both anchoring points for the embedded actuators, as well as heat-dissipation functions, in order to facilitate the miniaturization of devices. However, there are two important challenges in creating these structures: (1) sufficient thermal management to prevent failure of the actuator and (2) the ability of the actuator to survive the manufacturing process. This paper describes a systematic approach for design of multifunctional structures with embedded heat-generating components using an in-mold assembly process to address these challenges. For the first challenge, the development of appropriate thermal models is presented along with incorporation of in-mold assembly process constraints in the optimization process. For the second challenge, a simulation of the molding process is presented and demonstrated to enable the determination of processing conditions ensuring survival of the in-mold assembly process for the embedded actuator. Thus, the design methodology described in this paper was utilized to concurrently optimize the choice of material, size of the structure, and processing conditions in order to demonstrate the feasibility of creating multifunctional structures from thermally conductive polymers by embedding actuators through an in-mold assembly process.

scholarly journals Enhanced thermal conductivity of graphene nanoplatelets epoxy composites

2017 ◽  
Vol 35 (2) ◽  
pp. 382-389 ◽  
Author(s):  
Lukasz Jarosinski ◽  
Andrzej Rybak ◽  
Karolina Gaska ◽  
Grzegorz Kmita ◽  
Renata Porebska ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Electronic Devices ◽  
Graphene Nanoplatelets ◽  
Electrical Insulation ◽  
Graphene Nanocomposites ◽  
Thermally Conductive ◽  
Conductive Particles ◽  
Proper Performance ◽  
Enhanced Thermal Conductivity

Abstract Efficient heat dissipation from modern electronic devices is a key issue for their proper performance. An important role in the assembly of electronic devices is played by polymers, due to their simple application and easiness of processing. The thermal conductivity of pure polymers is relatively low and addition of thermally conductive particles into polymer matrix is the method to enhance the overall thermal conductivity of the composite. The aim of the presented work is to examine a possibility of increasing the thermal conductivity of the filled epoxy resin systems, applicable for electrical insulation, by the use of composites filled with graphene nanoplatelets. It is remarkable that the addition of only 4 wt.% of graphene could lead to 132 % increase in thermal conductivity. In this study, several new aspects of graphene composites such as sedimentation effects or temperature dependence of thermal conductivity have been presented. The thermal conductivity results were also compared with the newest model. The obtained results show potential for application of the graphene nanocomposites for electrical insulation with enhanced thermal conductivity. This paper also presents and discusses the unique temperature dependencies of thermal conductivity in a wide temperature range, significant for full understanding thermal transport mechanisms.

scholarly journals High thermal conductivity in soft elastomers with elongated liquid metal inclusions

2017 ◽  
Vol 114 (9) ◽  
pp. 2143-2148 ◽  
Author(s):  
Michael D. Bartlett ◽  
Navid Kazem ◽  
Matthew J. Powell-Palm ◽  
Xiaonan Huang ◽  
Wenhuan Sun ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Metal ◽  
Heat Dissipation ◽  
Dielectric Materials ◽  
Phonon Transport ◽  
High Thermal Conductivity ◽  
Stretchable Electronics ◽  
Mechanical Stiffness ◽  
Mechanical Coupling ◽  
Thermally Conductive

Soft dielectric materials typically exhibit poor heat transfer properties due to the dynamics of phonon transport, which constrain thermal conductivity (k) to decrease monotonically with decreasing elastic modulus (E). This thermal−mechanical trade-off is limiting for wearable computing, soft robotics, and other emerging applications that require materials with both high thermal conductivity and low mechanical stiffness. Here, we overcome this constraint with an electrically insulating composite that exhibits an unprecedented combination of metal-like thermal conductivity, an elastic compliance similar to soft biological tissue (Young’s modulus < 100 kPa), and the capability to undergo extreme deformations (>600% strain). By incorporating liquid metal (LM) microdroplets into a soft elastomer, we achieve a ∼25× increase in thermal conductivity (4.7 ± 0.2 W⋅m−1⋅K−1) over the base polymer (0.20 ± 0.01 W⋅m−1·K−1) under stress-free conditions and a ∼50× increase (9.8 ± 0.8 W⋅m−1·K−1) when strained. This exceptional combination of thermal and mechanical properties is enabled by a unique thermal−mechanical coupling that exploits the deformability of the LM inclusions to create thermally conductive pathways in situ. Moreover, these materials offer possibilities for passive heat exchange in stretchable electronics and bioinspired robotics, which we demonstrate through the rapid heat dissipation of an elastomer-mounted extreme high-power LED lamp and a swimming soft robot.

Study on the ALN Thin Film for Improving the Performance of Heat Dissipation on High Power LED Substrate

2013 ◽  
Vol 834-836 ◽  
pp. 613-616 ◽  
Author(s):  
Yang Li ◽  
Chen Kui ◽  
Hui Ren Peng ◽  
Ming Jia Zhu ◽  
Ya Wen Pan ◽  
...  
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Direct Current ◽  
High Power ◽  
Heat Dissipation ◽  
Aluminum Substrate ◽  
Back Side ◽  
Dc Magnetron Sputtering ◽  
High Power Led ◽  
Thermally Conductive

This dissertation employs the method of direct current (DC) magnetron sputtering on the reverse side of the high power LED aluminum substrate to deposit the AlN thin film. And then, we paste the high power LED beads to the front of the substrate, testing and studying the heat dissipation influences of the AlN thin film on the high-power LED beads. In order to compare easily, some parts of the reverse of aluminum substrate should be overlaid thermally conductive silicone. The result indicates that depositing the AIN thin film or the overlay thermally conductive silicone on the back side of the aluminum substrate can improve the heat dissipation capability of high power LED, the AIN thin film especially.

Sign in / Sign up

Export Citation Format

Share Document