Development of a Cascade Elastocaloric Regenerator

2019 ◽  
Author(s):  
Nehemiah Emaikwu ◽  
David Catalini ◽  
Jan Muehlbauer ◽  
Yunho Hwang ◽  
Ichiro Takeuchi ◽  
...  
Keyword(s):  
Solid State ◽  
Energy Use ◽  
Environmentally Friendly ◽  
High Energy ◽  
Heat Pumps ◽  
Vapor Compression ◽  
Regenerative Heat ◽  
Pump Design ◽  
Surface Areas ◽  
Elastocaloric Effect

Abstract Heat pumps based on the vapor compression cycle account for a significant portion of energy use around the world. However, growing demands for energy efficient and environmentally friendly technologies have created a need for new space conditioning approaches. Novel systems which use elastocaloric material have shown potential to replace traditional vapor compression due to high energy efficiency and use of environmentally friendly, solid-state refrigerants. The solid-state refrigerants exhibit the elastocaloric effect, a phenomenon that occurs when metal alloys experience stress-induced reversible phase transformations resulting in latent heat release or absorption. Prototypes built in the Center for Environmental Energy Engineering have utilized the active elastocaloric regeneration (AER) operating method to develop high temperature gradients between the ends of a regenerative heat exchanger made of tubular elastocaloric material. Though this schema significantly increases the temperature span developed by elastocaloric cooling devices, the current heat pump design leads to temperature degradation as a result of conduction along the length of the tubes in the regenerator. The novel regenerator concept presented in this work mitigates that issue by using short, thermally insulated tubes layers which also enables fluid flow over external surface areas of the material.

scholarly journals Materials research and development needs to enable efficient and electrified buildings

MRS Bulletin ◽  
2022 ◽  
Author(s):  
Shuang Cui ◽  
Adewale Odukomaiya ◽  
Judith Vidal
Keyword(s):  
Energy Use ◽  
Energy Intensity ◽  
Heat Pumps ◽  
Cold Climate ◽  
Vapor Compression ◽  
Current State ◽  
Material Component ◽  
Challenges And Opportunities ◽  
Materials Research ◽  
Building Components

Abstract Because of the complexity of modern buildings—with many interconnected materials, components, and systems—fully electrifying buildings will require targeted R&D and efficient coordination across those material, component, and system levels. Because buildings that consume the smallest amount of energy are easier to electrify, energy efficiency is a crucial step toward fully electrified buildings. Materials advances will play an important role in both reducing the energy intensity of buildings and electrifying their remaining energy use. Materials are currently being explored, discovered, synthesized, evaluated, optimized, and implemented across many building components, including solid-state lighting; dynamic windows and opaque envelopes; cold climate heat pumps; thermal energy storage; heating, ventilating, and air conditioning (HVAC); refrigeration; non-vapor compression HVAC; and more. In this article, we review the current state-of-the-art of materials for various buildings end uses and discuss R&D challenges and opportunities for both efficiency and electrification. Graphical abstract

scholarly journals Calculated and experimental evaluation heat pump distiller on pentane as working substance

2020 ◽  
Vol 324 ◽  
pp. 02007
Author(s):  
Gennady A. Ilyn ◽  
Ilya I. Malafeev ◽  
Vladimir B. Sapojnikov
Keyword(s):  
High Temperature ◽  
High Efficiency ◽  
Recovery Phase ◽  
High Energy ◽  
Heat Pumps ◽  
Working Fluid ◽  
Vapor Compression ◽  
The Cost ◽  
Reliable Methods ◽  
High Temperature Vapor

One of the most common and reliable methods of water treatment is the method of thermal distillation. Despite the reliability of the method, its application is constrained by high energy intensity. The most effective way to reduce the cost of production of distillate is the use of thermal transformers, providing regenerate and heat recovery phase transformations of the distillate. The use of working fluid with the most favorable thermodynamic properties is of paramount importance for the creation of high efficiency thermotransformers. The work is considered working fluid for high-temperature heat pumps and the results of the calculation-experimental study of high-temperature vapor compression heat-pumping distiller on natural working substance n-pentan.

TEM study of amorphization of Cu and Ti foils by cold-rolling

1990 ◽  
Vol 48 (4) ◽  
pp. 146-147
Author(s):  
W. A. Chiou ◽  
N. L. Jeon ◽  
Genbao Xu ◽  
M. Meshii
Keyword(s):  
Solid State ◽  
Cold Rolling ◽  
High Energy ◽  
Rapid Quenching ◽  
Vapor Condensation ◽  
Metallic Alloys ◽  
Solid State Reactions ◽  
High Energy Particle ◽  
Amorphous Metallic Alloys ◽  
Thin Foils

For many years amorphous metallic alloys have been prepared by rapid quenching techniques such as vapor condensation or melt quenching. Recently, solid-state reactions have shown to be an alternative for synthesizing amorphous metallic alloys. While solid-state amorphization by ball milling and high energy particle irradiation have been investigated extensively, the growth of amorphous phase by cold-rolling has been limited. This paper presents a morphological and structural study of amorphization of Cu and Ti foils by rolling.Samples of high purity Cu (99.999%) and Ti (99.99%) foils with a thickness of 0.025 mm were used as starting materials. These thin foils were cut to 5 cm (w) × 10 cm (1), and the surface was cleaned with acetone. A total of twenty alternatively stacked Cu and Ti foils were then rolled. Composite layers following each rolling pass were cleaned with acetone, cut into half and stacked together, and then rolled again.

Experimental Assessment of the Practical Oxidative Stability of Lithium Thiophosphate Solid Electrolytes

2019 ◽  
Author(s):  
Georg Dewald ◽  
Saneyuki Ohno ◽  
Marvin Kraft ◽  
Raimund Koerver ◽  
Paul Till ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Solid State ◽  
Oxidative Stability ◽  
Photoelectron Spectroscopy ◽  
Solid Electrolytes ◽  
Stability Limit ◽  
Lithium Ion ◽  
High Energy ◽  
Redox Activity ◽  
Solid State Batteries

<p>All-solid-state batteries are often expected to replace conventional lithium-ion batteries in the future. However, the practical electrochemical and cycling stability of the best-conducting solid electrolytes, i.e. lithium thiophosphates, are still critical issues that prevent long-term stable high-energy cells. In this study, we use <i>stepwise</i><i>cyclic voltammetry </i>to obtain information on the practical oxidative stability limit of Li<sub>10</sub>GeP<sub>2</sub>S<sub>12</sub>, a Li<sub>2</sub>S‑P<sub>2</sub>S<sub>5</sub>glass, as well as the argyrodite Li<sub>6</sub>PS<sub>5</sub>Cl solid electrolytes. We employ indium metal and carbon black as the counter and working electrode, respectively, the latter to increase the interfacial contact area to the electrolyte as compared to the commonly used planar steel electrodes. Using a stepwise increase in the reversal potentials, the onset potential at 25 °C of oxidative decomposition at the electrode-electrolyte interface is identified. X‑ray photoelectron spectroscopy is used to investigate the oxidation of sulfur(-II) in the thiophosphate polyanions to sulfur(0) as the dominant redox process in all electrolytes tested. Our results suggest that after the formation of these decomposition products, significant redox behavior is observed. This explains previously reported redox activity of thiophosphate solid electrolytes, which contributes to the overall cell performance in solid-state batteries. The <i>stepwise cyclic voltammetry</i>approach presented here shows that the practical oxidative stability at 25 °C of thiophosphate solid electrolytes against carbon is kinetically higher than predicted by thermodynamic calculations. The method serves as an efficient guideline for the determination of practical, kinetic stability limits of solid electrolytes. </p>

Experimental Assessment of the Practical Oxidative Stability of Lithium Thiophosphate Solid Electrolytes

2019 ◽  
Author(s):  
Georg Dewald ◽  
Saneyuki Ohno ◽  
Marvin Kraft ◽  
Raimund Koerver ◽  
Paul Till ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Solid State ◽  
Oxidative Stability ◽  
Photoelectron Spectroscopy ◽  
Solid Electrolytes ◽  
Stability Limit ◽  
Lithium Ion ◽  
High Energy ◽  
Redox Activity ◽  
Solid State Batteries

<p>All-solid-state batteries are often expected to replace conventional lithium-ion batteries in the future. However, the practical electrochemical and cycling stability of the best-conducting solid electrolytes, i.e. lithium thiophosphates, are still critical issues that prevent long-term stable high-energy cells. In this study, we use <i>stepwise</i><i>cyclic voltammetry </i>to obtain information on the practical oxidative stability limit of Li<sub>10</sub>GeP<sub>2</sub>S<sub>12</sub>, a Li<sub>2</sub>S‑P<sub>2</sub>S<sub>5</sub>glass, as well as the argyrodite Li<sub>6</sub>PS<sub>5</sub>Cl solid electrolytes. We employ indium metal and carbon black as the counter and working electrode, respectively, the latter to increase the interfacial contact area to the electrolyte as compared to the commonly used planar steel electrodes. Using a stepwise increase in the reversal potentials, the onset potential at 25 °C of oxidative decomposition at the electrode-electrolyte interface is identified. X‑ray photoelectron spectroscopy is used to investigate the oxidation of sulfur(-II) in the thiophosphate polyanions to sulfur(0) as the dominant redox process in all electrolytes tested. Our results suggest that after the formation of these decomposition products, significant redox behavior is observed. This explains previously reported redox activity of thiophosphate solid electrolytes, which contributes to the overall cell performance in solid-state batteries. The <i>stepwise cyclic voltammetry</i>approach presented here shows that the practical oxidative stability at 25 °C of thiophosphate solid electrolytes against carbon is kinetically higher than predicted by thermodynamic calculations. The method serves as an efficient guideline for the determination of practical, kinetic stability limits of solid electrolytes. </p>

scholarly journals Chitosan as a Protective Matrix for the Squaraine Dye

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1171
Author(s):  
Halina Kaczmarek ◽  
Patryk Rybczyński ◽  
Piotr Maćczak ◽  
Aleksander Smolarkiewicz-Wyczachowski ◽  
Marta Ziegler-Borowska
Keyword(s):  
Solid State ◽  
Uv Radiation ◽  
Dye Degradation ◽  
Protective Coatings ◽  
Protective Action ◽  
High Energy ◽  
Modified Chitosan ◽  
Dye Release ◽  
Squaraine Dye ◽  
Chitosan Films

Chitosan was used as a protective matrix for the photosensitive dye-squaraine (2,4-bis[4-(dimethylamino)phenyl]cyclobutane-1,3-diol). The physicochemical properties of the obtained systems, both in solution and in a solid-state, were investigated. However, it was found that diluted chitosan solutions with a few percent additions of dye show an intense fluorescence, which is suppressed in the solid-state. This is related to the morphology of the heterogeneous modified chitosan films. The important advantage of using a biopolymer matrix is the prevention of dye degradation under the influence of high energy ultraviolet (UV) radiation while the dye presence improves the chitosan heat resistance. It is caused by mutual interactions between macromolecules and dye. Owing to the protective action of chitosan, the dye release in liquid medium is limited. Chitosan solutions with a few percent additions of squaraine can be used in biomedical imaging thanks to the ability to emit light, while chitosan films can be protective coatings resistant to high temperatures and UV radiation.

scholarly journals A SnO2QDs/GO/PPY ternary composite film as positive and graphene oxide/charcoal as negative electrodes assembled solid state asymmetric supercapacitor for high energy storage applications

RSC Advances ◽  
2021 ◽  
Vol 11 (45) ◽  
pp. 27801-27811
Author(s):  
M. Vandana ◽  
Y. S. Nagaraju ◽  
H. Ganesh ◽  
S. Veeresh ◽  
H. Vijeth ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Energy Storage ◽  
Solid State ◽  
Composite Film ◽  
High Energy ◽  
Asymmetric Supercapacitor ◽  
Ternary Composite ◽  
Negative Electrodes ◽  
Energy Storage Applications ◽  
High Energy Storage

Representation of the synthesis steps of SnO2QDs/GO/PPY ternary composites and SnO2QDs/GO/PPY//GO/charcoal asymmetric supercapacitor device.

Graphite-Based Lithium-Free 3D Hybrid Anodes for High Energy Density All-Solid-State Batteries

2021 ◽  
pp. 1831-1838
Author(s):  
Xing Xing ◽  
Yejing Li ◽  
Shen Wang ◽  
Haodong Liu ◽  
Zhaohui Wu ◽  
...  
Keyword(s):  
Solid State ◽  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
Solid State Batteries ◽  
All Solid State Batteries
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