Battery-powered cars offer many environmental benefits, but a car with a full tank of gasoline can travel further. By improving the energy capacity of lithium-ion batteries, a new electrode made from iron oxide nanoparticles could help electric vehicles to cover greater distances.
Electric vehicles could travel further when powered by a higher-capacity lithium-ion battery made with inexpensive iron oxide nanoparticles.
Developed by Zhaolin Liu of the A*STAR Institute of Materials Research and Engineering, Singapore, and Aishui Yu of Fudan University, China, and co-workers, the electrode material is inexpensive, suitable for large-scale manufacturing and can store higher charge densities than the conventional electrodes used in lithium-ion batteries1.
These batteries store and release energy by shuttling lithium ions between two electrodes connected in a circuit. During charging, lithium ions escape from the cathode, which is made from materials such as lithium cobalt oxide. The ions migrate through a liquid electrolyte and into the anode, which is usually made of graphite riddled with tiny pores. When the battery discharges, the process runs in reverse, generating an electrical current between the electrodes.
Iron oxides have a much higher charging capacity than graphite, but the process is slow. Forcing lithium ions into the material also changes its volume, destroying the anode after just a few charging cycles.
Liu, Yu and team reasoned that an anode made from iron oxide nanoparticles would charge more quickly, because its pores would give ready access to lithium ions. The pores may also allow the material’s structure to change as the ions pack inside.
The researchers made 5-nanometer-wide particles of an iron oxide known as á-Fe2O3, simply by heating iron nitrate in water. They mixed the particles with a dust called carbon black, bound them together with polyvinylidene fluoride and coated the mixture onto copper foil to make their anodes.
During the first round of charging and discharging, the anodes showed an efficiency of 75–78%, depending on the current density used. After ten more cycles, however, the efficiency improved to 98%, almost as high as commercial lithium-ion batteries. Research by other teams suggests that during the first few cycles, the iron oxide nanoparticles are broken down until they reach an optimum size.
After 230 cycles the anode’s efficiency remained at 97%, with a capacity of 1,009 milliamp hours per gram (mA h g−1 ) — almost three times greater than commercial graphite anodes. The material experienced none of the degradation problems that have plagued other iron oxide anodes.
The team is now working to optimize the nanoparticle synthesis and increase the efficiency of the anode’s initial charging cycles.
The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and EngineeringAssociated links
Organic-inorganic heterostructures with programmable electronic properties
30.03.2017 | Technische Universität Dresden
Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering