Story tips from the Department of Energy's Oak Ridge National Laboratory, November 2014

SOLAR – Made to order ...

With the addition of a dash of a common solvent, researchers realized an efficiency gain of about 36 percent for organic solar cells. A team led by Oak Ridge National Laboratory's Kai Xiao added diiodooctane -- 3 percent of the weight of the entire solution -- to a blend of polymers and fullerene derivatives and saw the cell's power conversion efficiency jump from 4.5 percent to 7.1 percent. An added benefit is that the technique requires no additional processing, which means lower costs and higher production efficiency. While similar efficiency gains have been documented, this work provides a glimpse into the phase-segregated domains of electron donors and acceptors as they approach the theoretical optimum size of 20 nanometers. These findings were presented in a recent paper published in Advanced Functional Materials. [Contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]

COMPUTING – Smarter oil exploration ...

An innovative computational tool developed at Oak Ridge National Laboratory could reduce uncertainties and the time required to decide where to drill for gas and oil. Compared to previous approaches, this multilevel Monte Carlo method, which involves computational algorithms that rely on repeated random sampling, provides a better understanding of the subsurface's influence on oil and gas production. "The heterogeneous nature of the Earth's surface causes a large number of model parameters, making this approach especially effective," said Clayton Webster, who led the team from the lab's Computational and Applied Mathematics group. Ultimately, this new approach could reduce computational costs and help industry make better decisions. [Contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]

VEHICLES – ORNL inverter licensed ...

Oak Ridge start-up New Hybrid Technologies has licensed a power conversion technology developed by Gui-Jia Su of Oak Ridge National Laboratory's Power Electronics and Electric Machinery group. The patented current source inverter takes direct current and converts it into alternating current, boosting the voltage by up to three times and enabling electric vehicle motors to operate at higher speeds. The technology offers improved durability and power range in a smaller package, which enables reductions in battery size, saves costs and weight, and increases fuel economy. [Contact: Kim Askey, (865) 946-1861; askeyka@ornl.gov]

BATTERIES – 10,000 charges ...

With the demonstration of a 5-volt thin-film battery that can be charged and discharged 10,000 times, Oak Ridge National Laboratory's Juchuan Li and Nancy Dudney are entering new territory. Consumers could be the big beneficiaries because these batteries boast higher energy for the same weight, lower cost and longer life. In addition, compared to thin-film batteries on the market, this new battery is less sensitive to overcharging, according to Li. "With additional good performance tests, this thin-film battery could be readily adopted by the thin-film battery market and used in cell phones, laptops and other consumer electronics," Li said. [Contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]

Source: DOE/Oak Ridge National Laboratory