Take a look at this week’s selection! This article is available free for a limited time:
Constructing ionic highway in alkaline polymer electrolytes
Jing Pan, Chen Chen, Yao Li, Lei Wang, Lisheng Tan, Guangwei Li, Xun Tang, Li Xiao, Juntao Lu and Lin Zhuang
DOI: 10.1039/C3EE43275K, Paper
After years of using platinum, scientists suggest they could one day use extracts from marine plants to replace it in solar cells.
Dye-sensitized solar cells (DSCs) are quickly becoming a widespread and affordable alternative to photovoltaic solar cells. With this change of direction, it is pertinent that DSCs are made to be as efficient and inexpensive as possible for the mass market.
Platinum is traditionally used as the electrode material in DSCs, which, although it shows impressive performance, is not environmentally friendly and has high production costs.
Now, Tingli Ma and co-workers based in China, Japan and Switzerland have expanded their research on natural dyes and biomass manipulation to see if sea tangle, a common marine plant, is a suitable source of raw materials for DSCs. And their results look promising. The naturally sourced materials improve on the power conversion efficiency of previously tested natural dyes to the point where they are comparable to those of synthetic, more expensive materials.
Interested to know more? Read the full news article by Jessica Brand in Chemistry World here…
Read the article by Liang Wang et al. in EES:
From Marine Plant to Photovoltaic Devices
Liang Wang, Yantao Shi, Xiaogong Bai, Yujin Xing, Hong Zhang, lin Wang, Wei Guo, Ning Wang, Ting Li Ma and Michael Gratzel
Energy Environ. Sci., 2013, Accepted Manuscript
DOI: 10.1039/C3EE42767F, Communication
The latest issue of EES is now online. You can read the full issue here.
The outside front cover features the paper Simulations of the irradiation and temperature dependence of the efficiency of tandem photoelectrochemical water-splitting systems by Sophia Haussener, Shu Hu, Chengxiang Xiang, Adam Z. Weber and Nathan S. Lewis.
Facile synthesis of mesoporous Ni 0.3Co 2.7O 4 hierarchical structures for high-performance supercapacitors is the paper highlighted on the inside front cover by Hao Bin Wu, Huan Pang and Xiong Wen (David) Lou.
Issue 11 contains a number of excellent Opinion, Analysis, Review and Perspective articles:
Survival of the fattest
Peter R. Mooij, Gerben R. Stouten, Jelmer Tamis, Mark C. M. van Loosdrecht and Robbert Kleerebezem
Towards 15% energy conversion efficiency: a systematic study of the solution-processed organic tandem solar cells based on commercially available materials
Ning Li, Derya Baran, Karen Forberich, Florian Machui, Tayebeh Ameri, Mathieu Turbiez, Miguel Carrasco-Orozco, Martin Drees, Antonio Facchetti, Frederik C. Krebs and Christoph J. Brabec
The identification, characterization and mitigation of defect states in organic photovoltaic devices: a review and outlook
John A. Carr and Sumit Chaudhary
Metal free sensitizer and catalyst for dye sensitized solar cells
Shahzada Ahmad, Elena Guillén, Ladislav Kavan, Michael Grätzel and Mohammad K. Nazeeruddin
Retrieving and converting energy from polymers: deployable technologies and emerging concepts
Bilge Baytekin, H. Tarik Baytekin and Bartosz A. Grzybowski
Graphene-based nanocomposites: preparation, functionalization, and energy and environmental applications
Haixin Chang and Hongkai Wu
Exceeding the Shockley–Queisser limit in solar energy conversion
Cory A. Nelson, Nicholas R. Monahan and X.-Y. Zhu
Stimulus-responsive graphene systems towards actuator applications
Yang Zhao, Long Song, Zhipan Zhang and Liangti Qu
Take a look at this week’s selection! These articles are available free for a limited time:
N-doped graphene film-confined nickel nanoparticles as a highly efficient three-dimensional oxygen evolution electrocatalyst
Sheng Chen, Jingjing Duan, Jingrun Ran, Mietek Jaroniec and Shi Zhang Qiao
DOI: 10.1039/C3EE42383B, Paper
Structure–property relationships of oligothiophene–isoindigo polymers for efficient bulk-heterojunction solar cells
Zaifei Ma, Wenjun Sun, Scott Himmelberger, Koen Vandewal, Zheng Tang, Jonas Bergqvist, Alberto Salleo, Jens Wenzel Andreasen, Olle Inganäs, Mats R. Andersson, Christian Müller, Fengling Zhang and Ergang Wang
DOI: 10.1039/C3EE42989J, Paper
Vertically aligned BaTiO3 nanowire arrays for energy harvesting
Aneesh Koka, Zhi Zhou and Henry A. Sodano
DOI: 10.1039/C3EE42540A, Communication
Piezoelectric and ferroelectric materials and structures for energy harvesting applications
C. R. Bowen, H. A. Kim, P. M. Weaver and S. Dunn
DOI: 10.1039/C3EE42454E, Review Article
We are delighted to announce that Professor Thomas Jaramillo been selected by the EES Editorial Board as the winner of the 2014 “Energy & Environmental Science Readers’ Choice Award and Lectureship” for his article “New insights into the electrochemical reduction of carbon dioxide on metallic copper surfaces“.
Based at Stanford University in the USA, Prof. Jaramillo’s research focuses on chemical transformations in energy. Specifically, his group studies the chemistry and physics of materials as they relate to catalyzing chemical reactions of interest, namely those that convert water and CO2 into fuels and chemicals utilizing renewable energy (e.g. solar or wind), and those that convert those fuels back into usable energy in the form of electricity.
Prof. Jaramillio will give his award lecture at the upcoming 2nd International Conference on Clean Energy Science (ICCES2) taking place in Qingdao, China from 13-16 April 2014. Please do consider joining us for this exciting event.
Read Prof. Jaramillo’s award winning research today:
New insights into the electrochemical reduction of carbon dioxide on metallic copper surfaces
Kendra P. Kuhl, Etosha R. Cave, David N. Abramc and Thomas F. Jaramillo
Energy Environ. Sci., 2012, 5, 7050-7059
DOI: 10.1039/C2EE21234J
After 150 million theoretical calculations, scientists at Harvard University in the US reveal results that could cut down the time and cost of experimental tests to find better organic electronic materials for solar cells.
Most solar cells are made from expensive inorganic materials. Solar cells from organic materials are a cheaper alternative and scientists have been working to find designs that are as efficient as their inorganic counterparts. However, new organic solar cell materials must be built and tested before scientists can decide whether the idea is an improvement.
The Harvard Clean Energy Project (CEP) team led by Alán Aspuru-Guzik is using the predictive power of computers to speed up this process. Analogous to the modern drug discovery process, where large numbers of molecules can be virtually screened taking only the most biologically active ones forward into development and trials, Aspuru-Guzik’s group screened 2.3 million molecular structures to find ones that had the best properties for solar cells.
Interested to know more? Read the full news article by Rowan Frame in Chemistry World here…
Read the article by J Hachmann et al. in EES:
Lead candidates for high-performance organic photovoltaics from high-throughput quantum chemistry – the Harvard Clean Energy Project
Stuart Licht, Baochen Cui, Jessica Stuart, Baohui Wang and Jason Lau
Energy Environ. Sci., 2013, Advance Article
DOI: 10.1039/C3EE42654H, Paper
The researchers describe a new optical architecture for CZTSSe photovoltaic devices that improves the record power-conversion efficiency for this technology from 11.1 per cent to 12.0 per cent. CZTSSe absorbers are appealing for terawatt-scale thin-film solar deployment because they are composed of earth-abundant, non-toxic metals.
Using analytical modelling, verified by experiments, the team identified the optimal optical design for increasing the amount of light absorbed in the CZTSSe layer. The new design uses thinner CdS and transparent-conducting layers that lie atop the CZTSSe absorber.
The researchers also showed that that the approach typically used for solar-cell photon management – that is minimising the number of photons reflected from the solar cell surface – does not maximise current for this type of device.
Read the full details of this article in Energy & Environmental Science:
Optical designs that improve the efficiency of Cu2ZnSn(S,Se)4 solar cells
Mark T. Winkler, Wei Wang, Oki Gunawan, Harold J. Hovel, Teodor K. Todorov and David B. Mitzi
DOI: 10.1039/C3EE42541J
Efforts towards a less energy and environmentally intensive method for CO2 capture has resulted in a novel porous polymer with noteworthy performance.
Current industrial standards for carbon dioxide scrubbing in coal-fired power plants utilize an energy intensive liqu
id amine process to reduce CO2 gas emissions. Ultimately, a technology that can reduce the energy input required to release captured CO2 while maintaining substantial adsorption selectivity and capacity would be ideal. Investigations performed at Texas A&M have demonstrated high adsorption capacities of 1.7 mmol CO2 /g polymer with a gas flow comprised of 15% CO2 / 85% N2 under ambient conditions.
This work is the fruit of grafting NH4 groups to the sulfonate sites on a porous polymer network that was previously published, which leads to a higher selectivity to CO2 over N2 and CH4 gases also present in the exhaust streams of coal-fired power plants. Further improvements in adsorption capacity, while reducing the temperature required to remove the captured gas, can eventually yield a cheaper, more environmentally friendly alternative for greenhouse gas sequestration.
Interested? Read the full communication in Energy and Environmental Science here:
Building multiple adsorption sites in porous polymer networks for carbon capture applications
Weigang Lu, Wolfgang M. Verdegaal, Jiamei Yu, Perla B. Balbuena, Hae-Kwon Jeong and Hong-Cai Zhou
DOI: 10.1039/C3EE42226G
Researchers compare the energy return on energy investment (EROI) ratios of electricity storage versus curtailing electricity production for renewable, but variable, resources.
Wind and solar power are current leaders in renewable energy resources, but pose a challenge to more widespread use because of their variable, weather dependent nature. Currently, wind and solar energy harvesting is curtailed during times of oversupply, resulting in a forfeiture of energy. A clear solution to keep from losing all of this energy would be to store it for later use; however, storage can come at its own energetic cost that is often greater than the gain of the energy stored.
In a recent EES paper, Barnhart et al. examined the EROI ratios for methods of energy storage and compared the ratios with those during curtailment of electricity production for solar and wind power generation. Specifically, they explored electrical energy storage through both battery and geologic storage technologies, and compared the electrical cost of those storage methods to curtailment energy losses.
Barnhart et al. found that, depending on the type of energy resource, usage patterns, and storage type, there are cases in which it is more energetically favorable to store excess electricity, and cases in which it is more favorable to curtail the resources. Conventional battery technologies did not perform well in terms of energy cost compared to geologic storage technologies. Based on these findings, the authors recommend focusing on ways to improve battery EROI ratios, such as improving cycle life, as the next step toward developing electricity storage in which the energy cost is less than loss incurred from curtailment of electricity generation.
This paper recognizes that wind and solar energy are becoming more widely used and are proving to be excellent resources, which is great news from the perspective of reducing carbon usage in electricity production. But it is clear from the findings, as well as from a practical standpoint, that energy storage needs to be the next step for an increase in usability of these resources. These power generation technologies continue to grow, but due to variability, production does not always match with consumer usage patterns. Wouldn’t it be great, from the perspectives of both affordability and sustainably, to be able to run your appliances with solar power at night, or with wind power on a still day? Energy storage that is cost-effective from an energy expenditure standpoint is clearly the next step in paving the way for more widespread use of these sustainable, low-carbon energy resources.
Learn more about this analysis in the full EES article here:
The energetic implications of curtailing versus storing solar- and wind-generated electricity
Charles J. Barnhart, Michael Dale, Adam R. Brandt and Sally M. Benson
Energy Environ. Sci., 2012, 5, 8430
DOI: 10.1039/c2ee21581k
A) Microcell design B) Microcell fabrication scheme C)SEM of fabricated microcells D) optical image of microcell array
While silicon solar panels corner a large part of the current solar energy market, they are still too expensive to compete directly with fossil fuels. However, new advances in silicon solar microcells bring increases in process reliability, efficiency and cost, making solar energy more scalable and affordable.
In their recent paper, Yao et. al demonstrate a redesigned silicon solar µ-cell which incorporates a thermal oxide as a robust etching and diffusion mask, which also serves as an anti-reflection and surface passivation coating. They also put forth design criteria optimizing the spatial distribution of µ-cells to maximize light-trapping and for the integration of backside reflectors and polymer waveguides into devices for optimal performance.
The figures of merit for the champion device are an open-circuit voltage of 0.534 V, a short-circuit current density of 28.7 mA cm-2, a fill-factor of 0.762 and an overall efficiency of 11.7%. Interestingly, they demonstrate the efficacy of the thermal oxide as a passivation layer by testing a device before and after the oxide is etched off, showing that removing the oxide causes a significant decrease in performance. They also show that the incorporation of backside reflectors and planarization layers significantly enhances device performance.
An important consideration for any emerging solar energy technology is scalability. These redesigned silicon solar µ-cells have a peak-power-generation referenced silicon consumption of only 0.4 g Wp-1, substantially lower than the 10 g Wp-1 of commercially available silicon solar cells. Combined with the scalability of the processing steps used in the µ-cell fabrication, the low amount of silicon required could be a huge step forward in reducing the cost of solar energy.
Excited about new advances in renewable energy? Read this full article and many more in EES today!
Fabrication and assembly of ultrathin high-efficiencysilicon solar microcells integrating electrical passivation and anti-reflection coatings
Yuan Yao, Eric Brueckner, Lanfang Lib and Ralph Nuzzo
DOI:10.1039/C3EE42230E
