Li-ion batteries: news, progress, history and background

RSC - J. Mater. Chem. latest articles Nicola Pinna Seung-Ho Yu, Andrea Pucci, Tobias Herntrich, Marc-Georg Willinger, Seung-Hwan Baek, Yung-Eun Sung, Nicola Pinna A one-pot template-free solvothermal synthesis of crystalline Li 4 Ti 5 O 12   nanostructures based on the “benzyl alcohol route” is introduced. The 1–2 µm sized nanostructured spherical particles are constituted of nanocrystallites in the size range of a few nm. This is the first report showing that crystalline Li 4 Ti 5 O 12   can be directly obtained by soft chemistry solution routes. The as-synthesized crystalline nanostructures show good lithium intercalation/deintercalation performances at high rates (up to 30 C) and good cycling stabilities. Annealing the nanostructures at 750 °C improves the performance, which approaches the theoretical capacity of Li 4 Ti 5 O 12   with no noticeable (less than 5%) capacity loss after 200 cycles. (Paper from J. Mater. Chem.) Seung-Ho Yu, J. Mater. Chem., 2011, ...

New high-power Si–graphene composite electrode for Li-ion batteries : Northwestern Univ. researchers report on a new high-power Si–graphene composite anode material for Li-ion batteries in the journal Advanced Energy Materials . With current technology, the capabilities of a lithium-ion battery are limited in two ways: energy capacity is limited by the charge density, and charge rate is limited by the speed at which the lithium ions can make their way from the electrolyte into the anode. The Northwestern research team combined two techniques to combat both these problems. First, to stabilize the silicon in order to maintain maximize charge capacity, they sandwiched clusters of silicon between the graphene sheets. This allowed for a greater number of lithium ions in the electrode while utilizing the flexibility of graphene sheets to accommodate the volume changes of silicon during use. Rendering of the composite electrode with sandwiched Si clusters and in-plane defects. Clic...

Image via Wikipedia Image via Wikipedia A breakthrough in components for next-generation batteries could come from special materials that transform their structure to perform better over time. A team of researchers at the U.S. Department of Energy 's Argonne National Laboratory , led by Argonne nanoscientist Tijana Rajh and battery expert Christopher Johnson, discovered that nanotubes composed of titanium dioxide can switch their phase as a battery is cycled, gradually boosting their operational capacity. Laboratory tests showed that new batteries produced with this material could be recharged up to half of their original capacity in less than 30 seconds. By switching out conventional graphite anodes for ones composed of the titanium nanotubes, Rajh and her colleagues witnessed a surprising phenomenon. As the battery cycled through several charges and discharges, its internal structure began to orient itself in a way that dramatically improved the battery's performance. …...

New hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications have been developed in Department of Chemistry and Laboratory for Advanced Materials and Department of Materials Science and Engineering, Stanford University. They selectively grow of Mn3O4 nanoparticles on RGO sheets, and in contrast to free particle growth in solution it allowed for the electrically insulating Mn3O4 nanoparticles to be wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to 900 mAh/g, near their theoretical capacity, with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn3O4 nanoparticles grown atop. The Mn3O4/RGO hybrid could be a promising candidate material for a high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Such approach may offer a ...

back to summer of 2006 A research team led by Carnegie Mellon University Materials Science and Biomedical Engineering Professor Prashant Kumta has discovered a nanocrystalline material that is cheaper, more stable and produces a higher quality energy storage capacity for use in a variety of industrial and portable consumer electronic products. Kumta said the discovery, published this summer in Advanced Materials Journal, has important implications for increasing the longevity of rechargeable car batteries, fuel cells and other battery-operated electronic devices. "We have found that synthesis of nanostructured vanadium nitride and controlled oxidation of the surface at the nanoscale is key to creating the next generation of supercapacitors commonly used in everything from cars, camcorders and lawn mowers to industrial backup power systems at hospitals and airports," Kumta said. Full story

Researchers at Delft University of Technology can predict how nanostructuring – the extreme reduction of structure – will affect the performance of Li-ion batteries. The nanostructuring of battery materials is likely to be common practice in the future, but it is not always performance-enhancing. The research findings have recently been published in the Journal of the American Chemical Society. A Li-ion battery is currently the smallest and lightest way to store as much rechargeable electrical energy as possible. However, the batteries are slow to charge and discharge, and this restricts their suitability for applications such as hybrid and electric vehicles. This sluggish performance is largely determined by the relatively long distance the lithium-ions have to travel through the electrode material in the battery. The speed at which the ions make their way through the electrode material is also slow compared to that in electrolyte (the fluid between the electrode material). The curren...