Large electrocaloric response and energy storage study in environmentally friendly (1 − x)K0.5Na0.5NbO3–xLaNbO3 nanocrystalline ceramics

2018 ◽  
Vol 2 (12) ◽  
pp. 2698-2704 ◽  
Author(s):  
Raju Kumar ◽  
Ashish Kumar ◽  
Satyendra Singh

An electrocaloric material with a negative and positive electrocaloric effect (ECE) is identified to be a high potential candidate for solid-state refrigeration technology due to a changing dipolar entropy under a varying electric field.

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Chelladurai Karuppiah ◽  
Balamurugan Thirumalraj ◽  
Srinivasan Alagar ◽  
Shakkthivel Piraman ◽  
Ying-Jeng Jame Li ◽  
...  

Developing a highly stable and non-precious, low-cost, bifunctional electrocatalyst is essential for energy storage and energy conversion devices due to the increasing demand from the consumers. Therefore, the fabrication of a bifunctional electrocatalyst is an emerging focus for the promotion and dissemination of energy storage/conversion devices. Spinel and perovskite transition metal oxides have been widely explored as efficient bifunctional electrocatalysts to replace the noble metals in fuel cell and metal-air batteries. In this work, we developed a bifunctional catalyst for oxygen reduction and oxygen evolution reaction (ORR/OER) study using the mechanochemical route coupling of cobalt oxide nano/microspheres and carbon black particles incorporated lanthanum manganite perovskite (LaMnO3@C-Co3O4) composite. It was synthesized through a simple and less-time consuming solid-state ball-milling method. The synthesized LaMnO3@C-Co3O4 composite was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction spectroscopy, and micro-Raman spectroscopy techniques. The electrocatalysis results showed excellent electrochemical activity towards ORR/OER kinetics using LaMnO3@C-Co3O4 catalyst, as compared with Pt/C, bare LaMnO3@C, and LaMnO3@C-RuO2 catalysts. The observed results suggested that the newly developed LaMnO3@C-Co3O4 electrocatalyst can be used as a potential candidate for air-cathodes in fuel cell and metal-air batteries.


2019 ◽  
Vol 7 (23) ◽  
pp. 6836-6859 ◽  
Author(s):  
Ajeet Kumar ◽  
Atul Thakre ◽  
Dae-Yong Jeong ◽  
Jungho Ryu

The electrocaloric effect (ECE), which refers to changes in the temperature of a material when an electric field is applied to or removed from the material, is one of the key phenomena of future highly efficient solid-state refrigeration devices.


Electrochem ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 264-273
Author(s):  
João V. Paulin ◽  
Silvia L. Fernandes ◽  
Carlos F. O. Graeff

Biocompatible and biodegradable powering materials are appealing systems for biomedical and electronic devices. Melanin is a natural and multifunctional material with redox capability, which is of great interest in electrochemical energy storage functionalities. In our work, we explored the use of soluble melanin derivatives as active materials for symmetric solid-state supercapacitors operating in the dark and under illumination. We observed that our devices were photo-pseudocapacitive. Additionally, under illumination, our best device showed a specific capacitance of 57.7 mFg−1 at a scan rate of 0.01 Vs−1, with a decrease of 53% in resistance compared to that in the dark. Our outcome suggests that soluble melanin is a promising material for solid-state powering elements in wearable and environmentally friendly devices.


2021 ◽  
Author(s):  
Chittakorn Kornphom ◽  
Kamonporn Saenkam ◽  
Theerachai Bongkarn

Abstract Homogeneous 0.722(Bi0.5Na0.5TiO3)-0.228(SrTiO3)-0.05(AgNbO3) (BNT-ST-AN) ceramics with various amounts of potassium fluoride (KF) added were prepared by the solid-state combustion technique. The ceramics presented a single perovskite phase with coexisting rhombohedral (R), cubic (C) and orthorhombic (O) phases. The amount of the R phase decreased while the percentage of the C+O phase increased when KF addition increased from 0.0 to 3.0 mol%. The smallest grain size, the highest density and maximum dielectric constant (em) were achieved with a KF addition of 1.5 mol%. Following this design composition of the ceramics, the highest recoverable energy-storage density (Wrec ~1.60 J/cm3) and η above 85.8% at a low electric field (100 kV/cm) were obtained from BNT-ST-AN with KF addition at 1.5 mol% because this composition contained a morphotropic phase boundary (MPB) region and had the smallest grain size, which gave the lowest remnant polarization (Pr) and a large maximum polarization (Pm). Additionally, BNT-ST-AN with KF addition at 0.15 mol% exhibits stability over a wide range of temperatures (25–150°C) at a low electric field (100 kV/cm), which shows great potential in pulse-power system applications.


2018 ◽  
Vol 44 (17) ◽  
pp. 20845-20850 ◽  
Author(s):  
Raju Kumar ◽  
Divyansh Khurana ◽  
Ashish kumar ◽  
Satyendra Singh

2020 ◽  
Vol 13 (5) ◽  
pp. 1429-1461 ◽  
Author(s):  
Xiaona Li ◽  
Jianwen Liang ◽  
Xiaofei Yang ◽  
Keegan R. Adair ◽  
Changhong Wang ◽  
...  

This review focuses on fundamental understanding, various synthesis routes, chemical/electrochemical stability of halide-based lithium superionic conductors, and their potential applications in energy storage as well as related challenges.


RSC Advances ◽  
2021 ◽  
Vol 11 (45) ◽  
pp. 27801-27811
Author(s):  
M. Vandana ◽  
Y. S. Nagaraju ◽  
H. Ganesh ◽  
S. Veeresh ◽  
H. Vijeth ◽  
...  

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


1997 ◽  
Vol 481 ◽  
Author(s):  
Matthew T. Johnson ◽  
Shelley R. Gilliss ◽  
C. Barry Carter

ABSTRACTThin films of In2O3 and Fe2O3 have been deposited on (001) MgO using pulsed-laser deposition (PLD). These thin-film diffusion couples were then reacted in an applied electric field at elevated temperatures. In this type of solid-state reaction, both the reaction rate and the interfacial stability are affected by the transport properties of the reacting ions. The electric field provides a very large external driving force that influences the diffusion of the cations in the constitutive layers. This induced ionic current causes changes in the reaction rates, interfacial stability and distribution of the phases. Through the use of electron microscopy techniques the reaction kinetics and interface morphology have been investigated in these spinel-forming systems, to gain a better understanding of the influence of an electric field on solid-state reactions.


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