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
Stretchable biofuel cells extract energy from sweat to power wearable devices
22.08.2017 | University of California - San Diego
Laser sensor LAH-G1 - optical distance sensors with measurement value display
15.08.2017 | WayCon Positionsmesstechnik GmbH
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
23.08.2017 | Life Sciences
23.08.2017 | Life Sciences
23.08.2017 | Physics and Astronomy