Pub Date : 2024-01-08DOI: 10.1088/2515-7655/ad1c43
Yee Wei Foong, K. Bevan
The "holy grail" of energy storage is to achieve both high energy and high power densities (≧100 Wh/L and ~104 W/L, respectively) as characterized in a Ragone plot. However, across the macroscopic dimensions over which energy storage systems operate, power performance is fundamentally limited by both drift and diffusion processes. In this work a macroscopic variation on the Gerischer-Hopfield formalism is applied to explore how the motion of electrical charges, moving between redox species, and screening counter-ions might be engineered in a pseudocapacitive system employing quantized capacitance (in the form of a pseudocapacitive battery) to reach this long-sought metric. Our theoretical findings show that the electron diffusion timescale between redox species generally determines power performance trends when pseudocapacitive coatings are applied monolithically. This electron-diffusion--dominated timescale, in turn, is shown to scale with the square of the coating thickness. However, when conducting pathways (or shunts) are introduced to substantially reduce the mean distance for electron diffusion the Ragone performance becomes dominated by ion drift and diffusion --- even when the diffusion constants of all species are held equal. The resulting trends, for this shunting regime, show a power performance timescale that scales in a more linear fashion with increasing thickness of the redox-active region. By analyzing the Ragone performance metrics for realistic coating thicknesses between these two operational regimes, the resulting findings suggest that the diffusion constants needed to achieve the aforementioned high-performance metrics are plausibly achievable for both electronic and ionic charges in this proposed class of pseudocapacitive systems.
{"title":"Benchmarking the Ragone behaviour and power performance trends of pseudocapacitive batteries","authors":"Yee Wei Foong, K. Bevan","doi":"10.1088/2515-7655/ad1c43","DOIUrl":"https://doi.org/10.1088/2515-7655/ad1c43","url":null,"abstract":"\u0000 The \"holy grail\" of energy storage is to achieve both high energy and high power densities (≧100 Wh/L and ~104 W/L, respectively) as characterized in a Ragone plot. However, across the macroscopic dimensions over which energy storage systems operate, power performance is fundamentally limited by both drift and diffusion processes. In this work a macroscopic variation on the Gerischer-Hopfield formalism is applied to explore how the motion of electrical charges, moving between redox species, and screening counter-ions might be engineered in a pseudocapacitive system employing quantized capacitance (in the form of a pseudocapacitive battery) to reach this long-sought metric. Our theoretical findings show that the electron diffusion timescale between redox species generally determines power performance trends when pseudocapacitive coatings are applied monolithically. This electron-diffusion--dominated timescale, in turn, is shown to scale with the square of the coating thickness. However, when conducting pathways (or shunts) are introduced to substantially reduce the mean distance for electron diffusion the Ragone performance becomes dominated by ion drift and diffusion --- even when the diffusion constants of all species are held equal. The resulting trends, for this shunting regime, show a power performance timescale that scales in a more linear fashion with increasing thickness of the redox-active region. By analyzing the Ragone performance metrics for realistic coating thicknesses between these two operational regimes, the resulting findings suggest that the diffusion constants needed to achieve the aforementioned high-performance metrics are plausibly achievable for both electronic and ionic charges in this proposed class of pseudocapacitive systems.","PeriodicalId":509250,"journal":{"name":"Journal of Physics: Energy","volume":"42 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139446445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-21DOI: 10.1088/2515-7655/ad17e2
Tomás Lloret López, M. Morales-Vidal, Belén Nieto-Rodríguez, José Carlos García Vázquez, A. Beléndez, I. Pascual
Low-toxicity solar concentrator systems represent an important challenge for outstanding photovoltaic applications. Particularly, Multiplexed Holographic Lenses (MHL) as Holographic Solar Concentrators (HSC) provide insight into promising possibilities for Building-Integrated Concentrating Photovoltaics. This technology does not affect crucial ecosystems, and can convert buildings from energy consumers into energy suppliers. They can be used in windows, roofs, or walls, and a high diffraction efficiency and wide acceptance angle are desired. In this work, we presented several designs of multiplexed holographic lenses of low spatial frequency 525 lines/mm, based on a low-toxicity photopolymer and supported on a window glass. The average diffraction efficiency of these holographic solar concentrators was evaluated at 633 nm, whereas the acceptance angle was evaluated by measuring the short-circuit current under solar illumination at different incident angles. Versatile and high-efficiency holographic elements have been used to concentrate sunlight from different relative positions during the day, avoiding the need for expensive tracking systems. To the best of our knowledge, this is the best trade-off between high diffraction efficiency (85%) and wide acceptance angle (104◦) in a low-toxicity holographic solar concentrator.
{"title":"Building-Integrated Concentrating Photovoltaics based on a low-toxicity photopolymer","authors":"Tomás Lloret López, M. Morales-Vidal, Belén Nieto-Rodríguez, José Carlos García Vázquez, A. Beléndez, I. Pascual","doi":"10.1088/2515-7655/ad17e2","DOIUrl":"https://doi.org/10.1088/2515-7655/ad17e2","url":null,"abstract":"Low-toxicity solar concentrator systems represent an important challenge for outstanding photovoltaic applications. Particularly, Multiplexed Holographic Lenses (MHL) as Holographic Solar Concentrators (HSC) provide insight into promising possibilities for Building-Integrated Concentrating Photovoltaics. This technology does not affect crucial ecosystems, and can convert buildings from energy consumers into energy suppliers. They can be used in windows, roofs, or walls, and a high diffraction efficiency and wide acceptance angle are desired. In this work, we presented several designs of multiplexed holographic lenses of low spatial frequency 525 lines/mm, based on a low-toxicity photopolymer and supported on a window glass. The average diffraction efficiency of these holographic solar concentrators was evaluated at 633 nm, whereas the acceptance angle was evaluated by measuring the short-circuit current under solar illumination at different incident angles. Versatile and high-efficiency holographic elements have been used to concentrate sunlight from different relative positions during the day, avoiding the need for expensive tracking systems. To the best of our knowledge, this is the best trade-off between high diffraction efficiency (85%) and wide acceptance angle (104◦) in a low-toxicity holographic solar concentrator.","PeriodicalId":509250,"journal":{"name":"Journal of Physics: Energy","volume":"41 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139167484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-21DOI: 10.1088/2515-7655/ad17e3
Santiago Márquez González, S. Anelli, M. Nuñez Eroles, M. Lira, Antonio Maria Asensio, Marc Torrell Faro, A. Tarancón
Solid oxide cells are an efficient and cost-effective energy conversion technology able to operate reversibly in fuel cell and electrolysis mode. Electrolyte-supported solid oxide cells have been recently fabricated employing 3D printing to generate unique geometries with never-explored capabilities. However, the use of the state-of-the-art electrolyte based on yttria-stabilized zirconia limits the current performance of such printed devices due to a limited oxide-ion conductivity. In the last years, alternative electrolytes such as scandia-stabilized zirconia became more popular to increase the performance of electrolyte-supported cells. In this work, stereolithography 3D printing of scandia-stabilized zirconia co-doped with ytterbia was developed to fabricate solid oxide cells with planar and corrugated architectures. Symmetrical and full cells with about 250 μm-thick electrolytes were fabricated and electrochemically characterized using impedance spectroscopy and galvanostatic studies. Maximum power density of 500mW/cm2 in fuel cell mode and an injected current of 1A/cm2 at 1.3V in electrolysis mode, both measured at 900ºC, were obtained demonstrating the feasibility of 3D printing for the fabrication of high-performance electrolyte-supported solid oxide cells. This, together with excellent stability proved for more than 350h of operation, opens a new scenario for using complex-shaped solid oxide cells in real applications.
{"title":"3D printed electrolyte-supported solid oxide cells based on Ytterbium-doped scandia-stabilized zirconia","authors":"Santiago Márquez González, S. Anelli, M. Nuñez Eroles, M. Lira, Antonio Maria Asensio, Marc Torrell Faro, A. Tarancón","doi":"10.1088/2515-7655/ad17e3","DOIUrl":"https://doi.org/10.1088/2515-7655/ad17e3","url":null,"abstract":"Solid oxide cells are an efficient and cost-effective energy conversion technology able to operate reversibly in fuel cell and electrolysis mode. Electrolyte-supported solid oxide cells have been recently fabricated employing 3D printing to generate unique geometries with never-explored capabilities. However, the use of the state-of-the-art electrolyte based on yttria-stabilized zirconia limits the current performance of such printed devices due to a limited oxide-ion conductivity. In the last years, alternative electrolytes such as scandia-stabilized zirconia became more popular to increase the performance of electrolyte-supported cells. In this work, stereolithography 3D printing of scandia-stabilized zirconia co-doped with ytterbia was developed to fabricate solid oxide cells with planar and corrugated architectures. Symmetrical and full cells with about 250 μm-thick electrolytes were fabricated and electrochemically characterized using impedance spectroscopy and galvanostatic studies. Maximum power density of 500mW/cm2 in fuel cell mode and an injected current of 1A/cm2 at 1.3V in electrolysis mode, both measured at 900ºC, were obtained demonstrating the feasibility of 3D printing for the fabrication of high-performance electrolyte-supported solid oxide cells. This, together with excellent stability proved for more than 350h of operation, opens a new scenario for using complex-shaped solid oxide cells in real applications.","PeriodicalId":509250,"journal":{"name":"Journal of Physics: Energy","volume":"61 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139167944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-20DOI: 10.1088/2515-7655/ad1764
Krishna Seunarine, Zaid Haymoor, Michael Spence, Gregory Burwell, Austin M. Kay, P. Meredith, Ardalan Armin, M. Carnie
As the Internet of Things (IoT) expands, the need for energy-efficient, self-powered devices increases. This study examines light power resource availability for photovoltaics (PV) in various environments and its potential in self-powered IoT applications. We analyse light sources, considering spectral distribution, intensity, and temporal variations, and evaluate the impact of location, seasonal variation, and time of day on light power availability. Additionally, we discuss human and building design factors, such as occupancy, room aspect, sensor placement, and décor, which influence light energy availability and power for IoT electronics. Our data identifies best-case and non-ideal scenarios for light resources, estimating the energy yield from a commercially available organic photovoltaic cell, contributing to a deeper understanding of light power resource availability for self-powered IoT devices
{"title":"Light power resource availability for energy harvesting photovoltaics for self-powered IoT","authors":"Krishna Seunarine, Zaid Haymoor, Michael Spence, Gregory Burwell, Austin M. Kay, P. Meredith, Ardalan Armin, M. Carnie","doi":"10.1088/2515-7655/ad1764","DOIUrl":"https://doi.org/10.1088/2515-7655/ad1764","url":null,"abstract":"As the Internet of Things (IoT) expands, the need for energy-efficient, self-powered devices increases. This study examines light power resource availability for photovoltaics (PV) in various environments and its potential in self-powered IoT applications. We analyse light sources, considering spectral distribution, intensity, and temporal variations, and evaluate the impact of location, seasonal variation, and time of day on light power availability. Additionally, we discuss human and building design factors, such as occupancy, room aspect, sensor placement, and décor, which influence light energy availability and power for IoT electronics. Our data identifies best-case and non-ideal scenarios for light resources, estimating the energy yield from a commercially available organic photovoltaic cell, contributing to a deeper understanding of light power resource availability for self-powered IoT devices","PeriodicalId":509250,"journal":{"name":"Journal of Physics: Energy","volume":"12 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139169088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Direct electrocatalytic two-electro oxygen reduction (2e-ORR) on the cathode of a proton exchange membrane fuel cell (PEMFC) reactor for the co-generation of hydrogen peroxide (H2O2) and power is an economical, low-carbon, and green route for the on-site production of H2O2. However, in practice, the H2O2 that cannot be collected in a timely will accumulate and self-decompose in the catalyst layer (CL), reducing the H2O2 generation efficiency. Thus, accelerating the mass transport of H2O2 within the anodic CL is critical to efficient H2O2 generation in PEMFC. Herein, we investigated the effects of the membrane electrode assembly (MEA) fabrication process, cathode CL thickness, and cathode carrier water flow rate on H2O2 generation and cell performance in a PEMFC reactor. The results show that the catalyst-coated membrane (CCM)-type MEA exhibits high power output due to its lower proton transport resistance. However, the formed CL with a dense structure significantly limits H2O2 collection efficiency. The catalyst-coated gas diffusion electrode (GDE)-type MEA formed macroporous structures in the cathode CL, facilitating carrier water entry and H2O2 drainage. In particular, carbon cloth GDE with thin CL could construct rich macroscopic liquid channels, thus maximizing the generation of H2O2, but will impede fuel cell performance. These results suggest that the construction of a well-connected interface between CL and PEM in MEA and the establishment of a macroscopic pore structure of the CL are the keys to improve the cell performance and H2O2 collection efficiency.
{"title":"Optimal MEA structure and operating conditions for fuel cell reactors with hydrogen peroxide and power cogeneration","authors":"Jie Yang, Ruimin Ding, Chang Liu, Qinchao Xu, Shan-shan Liu, X. Yin","doi":"10.1088/2515-7655/ad15e7","DOIUrl":"https://doi.org/10.1088/2515-7655/ad15e7","url":null,"abstract":"Direct electrocatalytic two-electro oxygen reduction (2e-ORR) on the cathode of a proton exchange membrane fuel cell (PEMFC) reactor for the co-generation of hydrogen peroxide (H2O2) and power is an economical, low-carbon, and green route for the on-site production of H2O2. However, in practice, the H2O2 that cannot be collected in a timely will accumulate and self-decompose in the catalyst layer (CL), reducing the H2O2 generation efficiency. Thus, accelerating the mass transport of H2O2 within the anodic CL is critical to efficient H2O2 generation in PEMFC. Herein, we investigated the effects of the membrane electrode assembly (MEA) fabrication process, cathode CL thickness, and cathode carrier water flow rate on H2O2 generation and cell performance in a PEMFC reactor. The results show that the catalyst-coated membrane (CCM)-type MEA exhibits high power output due to its lower proton transport resistance. However, the formed CL with a dense structure significantly limits H2O2 collection efficiency. The catalyst-coated gas diffusion electrode (GDE)-type MEA formed macroporous structures in the cathode CL, facilitating carrier water entry and H2O2 drainage. In particular, carbon cloth GDE with thin CL could construct rich macroscopic liquid channels, thus maximizing the generation of H2O2, but will impede fuel cell performance. These results suggest that the construction of a well-connected interface between CL and PEM in MEA and the establishment of a macroscopic pore structure of the CL are the keys to improve the cell performance and H2O2 collection efficiency.","PeriodicalId":509250,"journal":{"name":"Journal of Physics: Energy","volume":"66 23","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139180308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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