Thermal Management Using Graphene And Carbon Nanotubes

This dissertation investigates the application of graphene and carbon nanotubes (CNTs) for thermal management of high-power batteries and interconnects. The research is focused on three applications: (i) thermal phase change materials (PCMs) with graphene fillers for thermal management of battery packs; (ii) CNTs incorporated in the battery electrodes; (iii) graphene coatings for copper (Cu) interconnects. In this study, lithium-ion (Li-ion) batteries were used for testing the proposed approaches. The graphene solutions for synthesis of graphene PCMs were obtained by the liquid-phase exfoliation. The graphene coatings on Cu films were grown by the chemical vapor deposition (CVD). In the first part of the dissertation, it is demonstrated that thermal management of Li-ion batteries can be drastically improved using PCM with graphene fillers. Incorporation of graphene to the hydrocarbon-based PCM allowed one to increase its thermal conductivity by more than two orders of magnitude while preserving its latent heat storage ability. A combination of the sensible and latent heat storage together with the improved heat conduction outside of the battery pack leads to a significant decrease in the temperature rise inside the Li-ion battery pack. I the second part of the dissertation, it is shown that thermal properties of Li-ion battery electrodes can be improved by incorporation of CNTs. The electrodes were synthesized via an inexpensive scalable filtration method , which can be extended to commercial electrode-active materials. The measurements reveal that the in-plane (cross-plane) thermal conductivity of the cathodes with the highest battery capacity was ~50 W/mK (3 W/mK) at room temperature. These values are up to two-orders-of-magnitude higher than those for conventional electrodes based on carbon black. The highest in-plane thermal conductivity achieved in the carbon-nanotube-enhanced electrodes was ~141 W/mK. In third part of the dissertation, it is demonstrated that graphene coating can strongly increase the thermal conductivity of Cu films as compared to the reference Cu and annealed Cu films. The observed improvement of thermal properties of graphene coated Cu films results primarily from the changes in Cu morphology during graphene CVD rather than from graphene's action as an additional heat conducting channel. The obtained results are important for thermal management of advanced batteries and downscaled computer chips.

In part two of this dissertation, I report the results of investigation of thermal conductivity of thin films made of a novel nanostructured graphene material, which consists of graphene nanoribbons encapsulated in single walled carbon nanotubes. The temperature dependent Raman spectrum of this material was measured in order to obtain the temperature coefficients of G + peak and 2D peaks. Using the Raman optothermal technique, I determine the local temperature rise due to laser heating from the shifts in Raman peak positions. A finite element analysis method was conducted to simulated heat dissipation in the samples and to determine their effective thermal conductivity. The obtained results suggest that this hybrid graphene-carbon nanotube material can be used as fillers in thermal interface materials.

Thermal Transport in Carbon-Based Nanomaterials describes the thermal properties of various carbon nanomaterials and then examines their applications in thermal management and renewable energy. Carbon nanomaterials include: one-dimensional (1D) structures, like nanotubes; two-dimensional (2D) crystal lattice with only one-atom-thick planar sheets, like graphenes; composites based on carbon nanotube or graphene, and diamond nanowires and thin films. In the past two decades, rapid developments in the synthesis and processing of carbon-based nanomaterials have created a great desire among scientists to gain a greater understanding of thermal transport in these materials. Thermal properties in nanomaterials differ significantly from those in bulk materials because the characteristic length scales associated with the heat carriers, phonons, are comparable to the characteristic length. Carbon nanomaterials with high thermal conductivity can be applied in heat dissipation. This looks set to make a significant impact on human life and, with numerous commercial developments emerging, will become a major academic topic over the coming years. This authoritative and comprehensive book will be of great use to both the existing scientific community in this field, as well as for those who wish to enter it. Includes coverage of the most important and commonly adopted computational and experimental methods to analyze thermal properties in carbon nanomaterials Contains information about the growth of carbon nanomaterials, their thermal properties, and strategies to control thermal properties and applications, allowing readers to assess how to use each material most efficiently Offers a comprehensive overview of the theoretical background behind thermal transport in carbon nanomaterials

This book comprehensively reviews recent and emerging applications of carbon nanotubes and graphene materials in a wide range of sectors. Detailed applications include structural materials, ballistic materials, energy storage and conversion, batteries, supercapacitors, smart sensors, environmental protection, nanoelectronics, optoelectronic and photovoltaics, thermoelectric, and conducting wires. It further covers human and structural health monitoring, and thermal management applications. Key selling features: Exclusively takes an application-oriented approach to cover emerging areas in carbon nanotubes and graphene Covers fundamental and applied knowledge related to carbon nanomaterials Includes advanced applications like human and structural health monitoring, smart sensors, ballistic protection and so forth Discusses novel applications such as thermoelectrics along with environmental protection related application Explores aspects of energy storage, generation and conversion including batteries, supercapacitors, and photovoltaics This book is aimed at graduate students and researchers in electrical, nanomaterials, chemistry, and other related areas.

This book comprehensively reviews recent and emerging applications of carbon nanotubes and graphene materials in a wide range of sectors. Detailed applications include structural materials, ballistic materials, energy storage and conversion, batteries, supercapacitors, smart sensors, environmental protection, nanoelectronics, optoelectronic and photovoltaics, thermoelectric, and conducting wires. It further covers human and structural health monitoring, and thermal management applications. Key selling features: Exclusively takes an application-oriented approach to cover emerging areas in carbon nanotubes and graphene Covers fundamental and applied knowledge related to carbon nanomaterials Includes advanced applications like human and structural health monitoring, smart sensors, ballistic protection and so forth Discusses novel applications such as thermoelectrics along with environmental protection related application Explores aspects of energy storage, generation and conversion including batteries, supercapacitors, and photovoltaics This book is aimed at graduate students and researchers in electrical, nanomaterials, chemistry, and other related areas.

This is an advanced modern textbook on thermal stresses. It serves a wide range of readers, in particular, graduate and postgraduate students, scientists, researchers in various industrial and government institutes, and engineers working in mechanical, civil, and aerospace engineering. This volume covers diverse areas of applied mathematics, continuum mechanics, stress analysis, and mechanical design. This work treats a number of topics not presented in other books on thermal stresses, for example: theory of coupled and generalized thermoelasticity, finite and boundary element method in generalized thermoelasticity, thermal stresses in functionally graded structures, and thermal expansions of piping systems. The book starts from basic concepts and principles, and these are developed to more advanced levels as the text progresses. Nevertheless, some basic knowledge on the part of the reader is expected in classical mechanics, stress analysis, and mathematics, including vector and cartesian tensor analysis. This 2nd enhanced edition includes a new chapter on Thermally Induced Vibrations. The method of stiffness is added to Chapter 7. The variational principle for the Green-Lindsay and Green-Naghdi models have been added to Chapter 2 and equations of motion and compatibility equations in spherical coordinates to Chapter 3. Additional problems at the end of chapters were added.

Thermal Management for Opto-electronics Packaging and Applications A systematic guide to the theory, applications, and design of thermal management for LED packaging In Thermal Management for Opto-electronics Packaging and Applications, a team of distinguished engineers and researchers deliver an authoritative discussion of the fundamental theory and practical design required for LED product development. Readers will get a solid grounding in thermal management strategies and find up-to-date coverage of heat transfer fundamentals, thermal modeling, and thermal simulation and design. The authors explain cooling technologies and testing techniques that will help the reader evaluate device performance and accelerate the design and manufacturing cycle. In this all-inclusive guide to LED package thermal management, the book provides the latest advances in thermal engineering design and opto-electronic devices and systems. The book also includes: A thorough introduction to thermal conduction and solutions, including discussions of thermal resistance and high thermal conductivity materials Comprehensive explorations of thermal radiation and solutions, including angular- and spectra-regulation radiative cooling Practical discussions of thermally enhanced thermal interfacial materials (TIMs) Complete treatments of hybrid thermal management in downhole devices Perfect for engineers, researchers, and industry professionals in the fields of LED packaging and heat transfer, Thermal Management for Opto-electronics Packaging and Applications will also benefit advanced students focusing on the design of LED product design.

This Special Issue includes recent research articles and extensive reviews on graphene-based next-generation electronics, bringing together perspectives from different branches of science and engineering. The papers presented in this volume cover experimental, computational and theoretical aspects of the electrical and thermal properties of graphene and its applications in batteries, electrodes, sensors and ferromagnetism. In addition, this Special Issue covers many important state-of-the-art technologies and methodologies regarding the synthesis, fabrication, characterization and applications of graphene-based nanocomposites.

Thedemandfore?cientthermalmanagementhasincreasedsubstantiallyover the last decade in every imaginable area, be it a formula 1 racing car suddenly braking to decelerate from 200 to 50 mph going around a sharp corner, a space shuttle entering the earth’s atmosphere, or an advanced microproc- sor operating at a very high speed. The temperatures at the hot junctions are extremely high and the thermal ?ux can reach values higher than a few 2 hundred to a thousand watts/cm in these applications. To take a speci?c example of the microelectronics area, the chip heat ?ux for CMOS microp- cessors, though moderate compared to the numbers mentioned above have 2 already reached values close to 100 W/cm , and are projected to increase 2 above 200 W/cm over the next few years. Although the thermal mana- ment strategies for microprocessors do involve power optimization through improved design, it is extremely di?cult to eliminate “hot spots” completely. This is where high thermal conductivity materials ?nd most of their appli- tions, as “heat spreaders”. The high thermal conductivity of these materials allows the heat to be carried away from the “hot spots” very quickly in all directions thereby “spreading” the heat. Heat spreading reduces the heat ?ux density, and thus makes it possible to cool systems using standard cooling solutions like ?nned heat sinks with forced air cooling.