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Wang G, Lu Z, Li Y, Li L, Ji H, Feteira A, Zhou D, Wang D, Zhang S, Reaney IM. Electroceramics for High-Energy Density Capacitors: Current Status and Future Perspectives. Chem Rev 2021; 121:6124-6172. [PMID: 33909415 PMCID: PMC8277101 DOI: 10.1021/acs.chemrev.0c01264] [Citation(s) in RCA: 123] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Materials exhibiting high energy/power density are currently needed to meet the growing demand of portable electronics, electric vehicles and large-scale energy storage devices. The highest energy densities are achieved for fuel cells, batteries, and supercapacitors, but conventional dielectric capacitors are receiving increased attention for pulsed power applications due to their high power density and their fast charge-discharge speed. The key to high energy density in dielectric capacitors is a large maximum but small remanent (zero in the case of linear dielectrics) polarization and a high electric breakdown strength. Polymer dielectric capacitors offer high power/energy density for applications at room temperature, but above 100 °C they are unreliable and suffer from dielectric breakdown. For high-temperature applications, therefore, dielectric ceramics are the only feasible alternative. Lead-based ceramics such as La-doped lead zirconate titanate exhibit good energy storage properties, but their toxicity raises concern over their use in consumer applications, where capacitors are exclusively lead free. Lead-free compositions with superior power density are thus required. In this paper, we introduce the fundamental principles of energy storage in dielectrics. We discuss key factors to improve energy storage properties such as the control of local structure, phase assemblage, dielectric layer thickness, microstructure, conductivity, and electrical homogeneity through the choice of base systems, dopants, and alloying additions, followed by a comprehensive review of the state-of-the-art. Finally, we comment on the future requirements for new materials in high power/energy density capacitor applications.
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Affiliation(s)
- Ge Wang
- Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, U.K
| | - Zhilun Lu
- Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, U.K.,The Henry Royce Institute, Sir Robert Hadfield Building, Sheffield S1 3JD, U.K
| | - Yong Li
- Inner Mongolia Key Laboratory of Ferroelectric-related New Energy Materials and Devices, School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, China
| | - Linhao Li
- Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, U.K
| | - Hongfen Ji
- Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, U.K.,Laboratory of Thin Film Techniques and Optical Test, Xi'an Technological University, Xi'an 710032, China
| | - Antonio Feteira
- Christian Doppler Laboratory for Advanced Ferroic Oxides, Sheffield Hallam University, Sheffield S1 1WB, U.K
| | - Di Zhou
- Electronic Materials Research Lab, Key Lab of Education Ministry/International Center for Dielectric Research, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Dawei Wang
- Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, U.K.,Shenzhen Institute of Advanced Electronic Materials, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Shujun Zhang
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, NSW 2500, Australia
| | - Ian M Reaney
- Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, U.K
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Tuning the Electrical and Thermoelectric Properties of N Ion Implanted SrTiO 3 Thin Films and Their Conduction Mechanisms. Sci Rep 2019; 9:14486. [PMID: 31597931 PMCID: PMC6785559 DOI: 10.1038/s41598-019-51079-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 09/11/2019] [Indexed: 11/30/2022] Open
Abstract
The SrTiO3 thin films were fabricated by pulsed laser deposition. Subsequently ion implantation with 60 keV N ions at two different fluences 1 × 1016 and 5 × 1016 ions/cm2 and followed by annealing was carried out. Thin films were then characterized for electronic structure, morphology and transport properties. X-ray absorption spectroscopy reveals the local distortion of TiO6 octahedra and introduction of oxygen vacancies due to N implantation. The electrical and thermoelectric properties of these films were measured as a function of temperature to understand the conduction and scattering mechanisms. It is observed that the electrical conductivity and Seebeck coefficient (S) of these films are significantly enhanced for higher N ion fluence. The temperature dependent electrical resistivity has been analysed in the temperature range of 80–400 K, using various conduction mechanisms and fitted with band conduction, near neighbour hopping (NNH) and variable range hopping (VRH) models. It is revealed that the band conduction mechanism dominates at high temperature regime and in low temperature regime, there is a crossover between NNH and VRH. The S has been analysed using the relaxation time approximation model and dispersive transport mechanism in the temperature range of 300–400 K. Due to improvement in electrical conductivity and thermopower, the power factor is enhanced to 15 µWm−1 K−2 at 400 K at the higher ion fluence which is in the order of ten times higher as compared to the pristine films. This study suggests that ion beam can be used as an effective technique to selectively alter the electrical transport properties of oxide thermoelectric materials.
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