scholarly journals From natural to artificial photosynthesis

2013 ◽  
Vol 10 (81) ◽  
pp. 20120984 ◽  
Author(s):  
James Barber ◽  
Phong D. Tran
Keyword(s):  
Solar Energy ◽  
Large Scale ◽  
Nuclear Fusion ◽  
Fusion Energy ◽  
High Energy ◽  
Primary Energy ◽  
Energy Resources ◽  
High Energy Density ◽  
Chemical Bonds ◽  
Natural Photosynthesis

Demand for energy is projected to increase at least twofold by mid-century relative to the present global consumption because of predicted population and economic growth. This demand could be met, in principle, from fossil energy resources, particularly coal. However, the cumulative nature of carbon dioxide (CO 2 ) emissions demands that stabilizing the atmospheric CO 2 levels to just twice their pre-anthropogenic values by mid-century will be extremely challenging, requiring invention, development and deployment of schemes for carbon-neutral energy production on a scale commensurate with, or larger than, the entire present-day energy supply from all sources combined. Among renewable and exploitable energy resources, nuclear fusion energy or solar energy are by far the largest. However, in both cases, technological breakthroughs are required with nuclear fusion being very difficult, if not impossible on the scale required. On the other hand, 1 h of sunlight falling on our planet is equivalent to all the energy consumed by humans in an entire year. If solar energy is to be a major primary energy source, then it must be stored and despatched on demand to the end user. An especially attractive approach is to store solar energy in the form of chemical bonds as occurs in natural photosynthesis. However, a technology is needed which has a year-round average conversion efficiency significantly higher than currently available by natural photosynthesis so as to reduce land-area requirements and to be independent of food production. Therefore, the scientific challenge is to construct an ‘artificial leaf’ able to efficiently capture and convert solar energy and then store it in the form of chemical bonds of a high-energy density fuel such as hydrogen while at the same time producing oxygen from water. Realistically, the efficiency target for such a technology must be 10 per cent or better. Here, we review the molecular details of the energy capturing reactions of natural photosynthesis, particularly the water-splitting reaction of photosystem II and the hydrogen-generating reaction of hydrogenases. We then follow on to describe how these two reactions are being mimicked in physico-chemical-based catalytic or electrocatalytic systems with the challenge of creating a large-scale robust and efficient artificial leaf technology.

scholarly journals Building high accuracy emulators for scientific simulations with deep neural architecture search

2021 ◽  
Author(s):  
Muhammad Firmansyah Kasim ◽  
D. Watson-Parris ◽  
L. Deaconu ◽  
S. Oliver ◽  
P. Hatfield ◽  
...  
Keyword(s):  
Large Scale ◽  
Scientific Discovery ◽  
Fusion Energy ◽  
High Energy ◽  
Training Data ◽  
High Energy Density ◽  
Neural Architecture ◽  
Large Scale Data ◽  
Scientific Simulations ◽  
Computational Discovery

Abstract Computer simulations are invaluable tools for scientific discovery. However, accurate simulations are often slow to execute, which limits their applicability to extensive parameter exploration, large-scale data analysis, and uncertainty quantification. A promising route to accelerate simulations by building fast emulators with machine learning requires large training datasets, which can be prohibitively expensive to obtain with slow simulations. Here we present a method based on neural architecture search to build accurate emulators even with a limited number of training data. The method successfully emulates simulations in 10 scientific cases including astrophysics, climate sci-ence, biogeochemistry, high energy density physics, fusion energy, and seismology, using the same super-architecture, algorithm, and hyperparameters. Our approach also inherently provides emulator uncertainty estimation, adding further confidence in their use. We anticipate this work will accelerate research involving expensive simulations, allow more extensive parameters exploration, and enable new, previously unfeasible computational discovery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Organic solvent-assisted free-standing Li2MnO3·LiNi1/3Co1/3Mn1/3O2 on 3D graphene as a high energy density cathode

2015 ◽  
Vol 51 (91) ◽  
pp. 16381-16384 ◽  
Author(s):  
Yuelong Xin ◽  
Liya Qi ◽  
Yiwei Zhang ◽  
Zicheng Zuo ◽  
Henghui Zhou ◽  
...  
Keyword(s):  
Energy Density ◽  
Organic Solvent ◽  
Freeze Drying ◽  
Large Scale ◽  
High Energy ◽  
High Energy Density ◽  
Free Standing ◽  
3D Graphene ◽  
Active Particles

A novel organic solvent-assisted freeze-drying pathway, which can effectively protect and uniformly distribute active particles, is developed to fabricate a free-standing Li2MnO3·LiNi1/3Co1/3Mn1/3O2 (LR)/rGO electrode on a large scale.

High energy density aqueous zinc–benzoquinone batteries enabled by carbon cloth with multiple anchoring effects

2021 ◽  
Author(s):  
Zhiqiang Luo ◽  
Silin Zheng ◽  
Shuo Zhao ◽  
Xin Jiao ◽  
Zongshuai Gong ◽  
...  
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Porous Carbon ◽  
Large Scale ◽  
High Energy ◽  
High Energy Density ◽  
Carbon Cloth ◽  
Anchoring Effects ◽  
High Theoretical Capacity ◽  
Energy Storage Applications

Benzoquinone with high theoretical capacity is anchored on N-plasma engraved porous carbon as a desirable cathode for rechargeable aqueous Zn-ion batteries. Such batteries display tremendous potential in large-scale energy storage applications.

scholarly journals Nitrogen-enriched graphene framework from a large-scale magnesiothermic conversion of CO2 with synergistic kinetics for high-power lithium-ion capacitors

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Chen Li ◽  
Xiong Zhang ◽  
Kai Wang ◽  
Xianzhong Sun ◽  
Yanan Xu ◽  
...  
Keyword(s):  
Energy Density ◽  
High Power ◽  
Power Output ◽  
Large Scale ◽  
Electrode Materials ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Chemical Doping ◽  
Lithium Ion Capacitor

AbstractLithium-ion capacitors are envisaged as promising energy-storage devices to simultaneously achieve a large energy density and high-power output at quick charge and discharge rates. However, the mismatched kinetics between capacitive cathodes and faradaic anodes still hinder their practical application for high-power purposes. To tackle this problem, the electron and ion transport of both electrodes should be substantially improved by targeted structural design and controllable chemical doping. Herein, nitrogen-enriched graphene frameworks are prepared via a large-scale and ultrafast magnesiothermic combustion synthesis using CO2 and melamine as precursors, which exhibit a crosslinked porous structure, abundant functional groups and high electrical conductivity (10524 S m−1). The material essentially delivers upgraded kinetics due to enhanced ion diffusion and electron transport. Excellent capacities of 1361 mA h g−1 and 827 mA h g−1 can be achieved at current densities of 0.1 A g−1 and 3 A g−1, respectively, demonstrating its outstanding lithium storage performance at both low and high rates. Moreover, the lithium-ion capacitor based on these nitrogen-enriched graphene frameworks displays a high energy density of 151 Wh kg−1, and still retains 86 Wh kg−1 even at an ultrahigh power output of 49 kW kg−1. This study reveals an effective pathway to achieve synergistic kinetics in carbon electrode materials for achieving high-power lithium-ion capacitors.

scholarly journals LQR control of interleaved double dual boost converter for electrical vehicles and renewable energy conversion

2019 ◽  
Vol 16 (3) ◽  
pp. 1240
Author(s):  
J. S. V. Siva Kumar ◽  
P. Mallikarjunarao
Keyword(s):  
Fuel Cell ◽  
Automobile Industry ◽  
Large Scale ◽  
Petroleum Products ◽  
High Energy ◽  
High Energy Density ◽  
Control Technique ◽  
Boost Converters ◽  
Lqr Control ◽  
Electrical Vehicles

<p>The automobile industry is one of the major industries that are having its new innovations at a great pace according to the requirements of the day-to-day life. Due to the usage of conventional vehicles on a large scale which usually use petroleum products as fuel, is leading to a vast environmental effect, mainly due to the emission of greenhouse gases. So in order to reduce the ill effects of the greenhouse gas emissions great efforts are being put in   manufacturing of electrical vehicles. Among the currently available greenhouse technologies the fuel cell provides high energy density in spite of its expenses. So, in this aspect a required mechanism has to be adopted to make it energy efficient and affordable. In order to overcome the drawback of fuel cell i.e. low output voltage, the boost converters are to be used and to be more precise Non-isolated Interleaved Double Dual Boost (IDDB) converters are recommended which makes it efficient and also the reduction of overall vehicle weight can be achieved. The LQR control technique is applied in this work to make the transient response of the fuel cell powered IDDB converter for various load conditions effective. The verification of results is done with simulation techniques using MATLAB/Simulink.</p>

Manganese phosphoxide/Ni5P4 hybrids as an anode material for high energy density and rate potassium-ion storage

2021 ◽  
Author(s):  
Sen Yang ◽  
Ting Li ◽  
Yiwei Tan
Keyword(s):  
Energy Density ◽  
Lithium Ion Batteries ◽  
Large Scale ◽  
Low Cost ◽  
Lithium Ion ◽  
High Energy ◽  
Potassium Ion ◽  
High Energy Density ◽  
Active Materials ◽  
Ion Storage

Potassium-ion batteries (PIBs) that serve as low-cost and large-scale secondary batteries are regarded as promising alternatives and supplement to lithium-ion batteries. Hybrid active materials can be featured with the synergistic...

Interfacial electron modulation of MoS2/black phosphorus heterostructure toward high-rate and high-energy density half/full sodium-ion batteries

2021 ◽  
Author(s):  
Chenrui Zhang ◽  
Tingting Liang ◽  
Huilong Dong ◽  
Junjun Li ◽  
Junyu Shen ◽  
...  
Keyword(s):  
Energy Density ◽  
Volume Expansion ◽  
Anode Materials ◽  
Large Scale ◽  
Electrochemical Reaction ◽  
High Energy ◽  
Sodium Ion ◽  
High Rate ◽  
High Energy Density ◽  
Sodium Ion Batteries

Sodium-ion batteries (SIBs) have been considered as promising candidates for large-scale energy storage. However, viable anode materials still suffer from sluggish electrochemical reaction kinetics and huge volume expansion during cycling,...

Ionic liquid electrolytes supporting high energy density in sodium-ion batteries based on sodium vanadium phosphate composites

2018 ◽  
Vol 54 (28) ◽  
pp. 3500-3503 ◽  
Author(s):  
C. V. Manohar ◽  
Tiago Correia Mendes ◽  
Mega Kar ◽  
Dabin wang ◽  
Changlong Xiao ◽  
...  
Keyword(s):  
Energy Storage ◽  
Large Scale ◽  
Cost Effective ◽  
High Energy ◽  
Sodium Ion ◽  
High Energy Density ◽  
Sodium Ion Batteries ◽  
Vanadium Phosphate ◽  
Energy Storage Devices ◽  
Storage Devices

Sodium ion batteries (SIBs) are widely considered as alternative, sustainable, and cost-effective energy storage devices for large-scale energy storage applications.

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