EES Blog

A new recombination layer for use in tandem polymer solar cells has been developed by scientists in the US. Tandem polymer solar cells are two single-junction solar cells connected in series by a conducting layer (the recombination layer). The new layer – made of the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) modified at one interface with ethoxylated polyethylenimine – results in the highest fill factor value (0.72) ever reported for a tandem polymer solar cell. The fill factor is the ratio of maximum obtainable power to the product of the open-circuit voltage and short-circuit current.

Read the full details of this exciting Energy & Environmental Science article today:

High performance polymeric charge recombination layer for organic tandem solar cells
Yinhua Zhou, Canek Fuentes-Hernandez, Jae Won Shim, Talha Mansur Khan and Bernard Kippelen
DOI: 10.1039/C2EE23294D

Scientists in China, Singapore and Australia have made a supercapacitor electrode from a single-walled carbon nanotube (SWCNT) skeleton surrounded by a polyaniline (PANI) skin. This hybrid film was made by in situ electrochemical polymerisation in which a directly grown SWCNT film with continuous reticulate architecture acts as a skeleton and PANI is electrodeposited as a ‘skin’.

The unique reticulate structure of the SWCNT film has an advantage in transporting electrons over a larger area, and the continuous SWCNT/PANI structure avoids the PANI/PANI overlaps seen in other composites, which reduce power density. Previous SWCNT/PANI composite electrodes have been brittle, which hinders their practical application; the films produced here display good mechanical properties, thinness and porosity, making them more applicable in flexible energy storage devices. In addition to this, high energy and power densities were achieved (131 Wh/kg and 62.5 kW/kg, respectively) – this is compared to other CNT/PANI-based supercapacitors (<2.5 kW/kg).

Read this exciting Energy & Environmental Science article today:

A “skeleton/skin” strategy for preparing ultrathin free-standing single-walled carbon nanotube/polyaniline films for high performance supercapacitor electrodes
Zhiqiang Niu, Pingshan Luan, Qi Shao, Haibo Dong, Jinzhu Li, Jun Chen, Duan Zhao, Le Cai, Weiya Zhou, Xiaodong Chen and Sishen Xie
Energy Environ. Sci., 2012, 5, 8726-8733
DOI: 10.1039/C2EE22042C

Scientists working at Oregon State University have made scaled up microbial fuel cells, which use microorganisms to generate electricity from wastewater, that show enhanced performance over those previously studied. The double cloth electrode assembly-based cells were over 10 times larger than those previously reported and showed good performance even after 9 weeks of continuous operation. The group’s results have been highlighted on the ScienceDaily website.

Read the full details of this exciting article today:

Improved performance of CEA microbial fuel cells with increased reactor size
Yanzhen Fan, Sun-Kee Han and Hong Liu
Energy Environ. Sci., 2012, 5, 8273-8280
DOI: 10.1039/C2EE21964F

Researchers working in the US and China have reported a composite zinc oxide–poly(vinylidene fluoride) nanogenerator (NG) which can convert energy from an air flow into electricity with no need for additional battery power. The system shows improved power density and sensitivity compared to previously reported NGs, with a lower limit of flow detection of 0.6m s^-1 and is environmentally friendly. The system has potential applications in gas pipeline monitoring.

Nanogenerator as an active sensor for vortex capture and ambient wind-velocity detection
Rui Zhang, Long Lin, Qingshen Jing, Wenzhuo Wu, Yan Zhang, Zongxia Jiao, Liang Yan, Ray P. S. Han and Zhong Lin Wang
DOI: 10.1039/C2EE22354F

The Fukushima Daiichi Nuclear Power Station was badly damaged in the magnitude 9.0 earthquake and tsunami which occurred off the east coast of Japan in March last year. The resulting meltdown of nuclear fuel rods and explosions at the plant caused the leakage of nuclear material.

In this fascinating Energy & Environmental Science article John E. Ten Hoeve and Mark Z. Jacobson working at Stanford University report a detailed analysis of the effects of this accident on the health of the population worldwide. They estimate that the accident resulted in 130 cancer-related mortalities (with a lower confidence limit of 15 and upper limit of 1100) and 180 (24–1800) cancer-related morbidities worldwide.

The authors also modelled a hypothetical accident at the Diablo Canyon Power Plant in California, USA, predicting that such an event could result in a ~25% higher morality level due to the meteorological conditions found there.

In his Opinion article commenting on the results, Nobel Prize-winning physicist Burton Richter comments that “My rough analysis finds that health effects, including mortality, would have been much worse with fossil fuel used to generate the same amount of electricity as was nuclear generated.” A surprising conclusion perhaps and something policy makers will no doubt be thinking hard about in the months and years to come.

Read this Energy & Environmental Science article in full today along with the accompanying Opinion and response:

Worldwide health effects of the Fukushima Daiichi nuclear accident
John E. Ten Hoeve and Mark Z. Jacobson
DOI: 10.1039/C2EE22019A

Opinion on “Worldwide health effects of the Fukushima Daiichi nuclear accident” by J. E. Ten Hoeve and M. Z. Jacobson, Energy Environ. Sci., 2012, 5, DOI: 10.1039/c2ee22019a
Burton Richter
DOI: 10.1039/C2EE22658H

Reply to the ‘Opinion on “Worldwide health effects of the Fukushima Daiichi nuclear accident”’ by B. Richter, Energy Environ. Sci., 2012, 5, DOI:10.1039/c2ee22658h
John E. Ten Hoeve and Mark Z. Jacobson
DOI: 10.1039/C2EE22659F