scholarly journals Dielectric polymers for high-temperature capacitive energy storage

2021 ◽  
Author(s):  
He Li ◽  
Yao Zhou ◽  
Yang Liu ◽  
Li Li ◽  
Yi Liu ◽  
...  

The growing demand for advanced electronics requires dielectrics operating at high temperatures. The development of high-temperature dielectric polymers is reviewed from the perspective of structure design, dielectric and capacitive performance.

2018 ◽  
Vol 48 (1) ◽  
pp. 219-243 ◽  
Author(s):  
Qi Li ◽  
Fang-Zhou Yao ◽  
Yang Liu ◽  
Guangzu Zhang ◽  
Hong Wang ◽  
...  

The demand for high-temperature dielectric materials arises from numerous emerging applications such as electric vehicles, wind generators, solar converters, aerospace power conditioning, and downhole oil and gas explorations, in which the power systems and electronic devices have to operate at elevated temperatures. This article presents an overview of recent progress in the field of nanostructured dielectric materials targeted for high-temperature capacitive energy storage applications. Polymers, polymer nanocomposites, and bulk ceramics and thin films are the focus of the materials reviewed. Both commercial products and the latest research results are covered. While general design considerations are briefly discussed, emphasis is placed on material specifications oriented toward the intended high-temperature applications, such as dielectric properties, temperature stability, energy density, and charge-discharge efficiency. The advantages and shortcomings of the existing dielectric materials are identified. Challenges along with future research opportunities are highlighted at the end of this review.


2021 ◽  
pp. 2101976
Author(s):  
Zhizhan Dai ◽  
Zhiwei Bao ◽  
Song Ding ◽  
Chuanchuan Liu ◽  
Haoyang Sun ◽  
...  

RSC Advances ◽  
2019 ◽  
Vol 9 (35) ◽  
pp. 20107-20112 ◽  
Author(s):  
Hua Fang ◽  
Fanteng Meng ◽  
Ji Yan ◽  
Gao-yun Chen ◽  
Linsen Zhang ◽  
...  

A facile strategy was reported to synthesize highly wrinkled graphene film, exhibiting high packing density and excellent capacitive performance.


Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2098
Author(s):  
Hongying Guo ◽  
Jiang Chen ◽  
Zhumei Tian ◽  
Aizhen Wang

For the requirement of pressure detection in high temperature environments, this paper presents a fiber Bragg grating (FBG) based pressure sensor with a simple structure. The structural model of the sensor has been established with the consideration of a sensing principle and a small deflection effect of the circular membrane. The finite element analysis has been employed to validate the rationality of the sensor structure design and realize the digital simulation of the theoretical model. Through the analysis, the selection of packaging materials, the design of structural parameters and the pressure and temperature calibration of the developed sensor has been performed. The encapsulation of the sensor at high temperatures has been improved based on the theoretical analysis, simulation and testing, which proves the effectiveness of the sensor for pressure measurement at high temperatures of 100 °C~250 °C. The study provides a feasible sensing device for high-temperature pressure detection.


2018 ◽  
Author(s):  
Nasser Vahedi ◽  
Qasim A. Ranjha ◽  
Alparslan Oztekin

Large-scale solar power generation becomes feasible using concentrated solar power plants, as the received heat is collected at high temperatures compatible with power cycle operations. The main drawback of solar power generation is the intermittent nature of available solar irradiation, which results in a mismatch between collected heat and electrical demand. Thermal energy storage (TES) systems are the options to resolve this problem by storing excess heat during high solar irradiance and releasing at off-sun conditions. Thermochemical energy storage (TCES) systems have the potential to store the solar energy at high temperatures suitable for CSP plants’ operations because of the higher energy density of the TCES materials than those used for sensible and latent heat storage options. In TCES, the heat is stored in the form of thermo-chemical energy using an endothermic reaction and is released by carrying out the reverse exothermic reaction. TCES using cobalt oxide redox (reduction/oxidation) reaction is selected for this study because of its unique features suitable for high temperature thermal energy storage. A reactor with the cylindrical fixed bed is considered, in which air flows through the bed during charging and discharging modes. Air is used as heat transfer fluid (HTF) and as the reactant gas supplying oxygen. Transient mass and energy transport equations are solved along with reaction kinetics equations using finite element method. Charging and discharging processes are investigated. The effect of geometrical and operational parameters including the material properties on overall storage and retrieval process has been studied. It was shown that the bed porosity plays a dominant role in the reactor performance. The increase in the bed porosity improves the reactor performance for both charging and discharging mode.


2016 ◽  
Author(s):  
Qasim A. Ranjha ◽  
Nasser Vahedi ◽  
Alparslan Oztekin

Thermal energy storage units are vital for development of the efficient solar power generation systems due to fluctuating nature of daily and seasonal solar radiations. Two available efficient and practical options to store and release solar energy at high temperatures are latent heat storage and thermochemical storage. Latent heat storage can operate only at single phase change temperature. This problem can be avoided by some of the thermochemical storage systems in which solar energy can be stored and released over a range of high temperature by endothermic and exothermic reactions. One such reaction system is reversible reaction involving dehydration of Ca(OH)2 and hydration of CaO. This system is considered in the present study to model a circular fixed bed reactor for storage and release of heat at high temperatures. Air is used as heat transfer fluid (HTF) flowing in an annular shell outside the bed for charging and discharging the bed. The bed is filled with CaO/Ca(OH)2 powders with particles diameter of the order 5μm. Three dimensional transient model has been developed and simulations are performed using finite elements based COMSOL Multiphysics. Conservation of mass and energy equations, coupled with reaction kinetics equations, are solved in the three dimensional porous bed and the heat transfer fluid channel. Parametric study is performed by varying HTF parameters, bed dimensions and process conditions. The results are verified through a qualitative comparison with experimental and simulation results in the literature for similar geometric configurations.


2020 ◽  
Vol 10 (16) ◽  
pp. 1903881 ◽  
Author(s):  
Ding Ai ◽  
He Li ◽  
Yao Zhou ◽  
Lulu Ren ◽  
Zhubing Han ◽  
...  

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