Reported widely late last year as a “Junkyard Wars” contraption, University of Toronto researcher Illan Kramer’s spray rig for coating just about anything with a thin film of colloidal quantum dots (QCDs) offers the potential for making Kramer’s hopes come true. “My dream is that one day you’ll have two technicians with Ghostbusters backpacks come to your house and spray your roof.” Kramer is a post-doctoral fellow with The Edward S. Rogers Sr. Department of Electrical & Computer Engineering at the University of Toronto and IBM Canada’s Research and Development Centre. His spray equipment, composed of a “spray nozzle used in steel mills to cool steel with a fine mist of water, and a few regular air brushes from an art store,” manages to spread colloidal quantum dots with the precision usually found in atomic layer deposition managed in laboratory or carefully-controlled manufacturing conditions. He admits to the unaesthetic look of the setup, but notes that the $1,000 sprayLD system …
Doubling Down on Sulfur
Lithium-sulfur batteries have been off-stage hopefuls, waiting for their chance to strut their stuff – and that time may have arrived, at least in trial performances. Researchers at the Department of WCU Energy Engineering, Hanyang University in South Korea and the Department of Chemistry at the University of Rome, Italy have “demonstrated a highly reliable lithium–sulfur battery showing cycle performance comparable to that of commercially available lithium-ion batteries while offering more than double the energy density.” The team, led by a group from Hanyang University, designed a lithium-sulfur cell using “a highly reversible dual-type sulfur cathode (solid sulfur electrode and polysulfide catholyte) and a lithiated Si/SiOx nanosphere anode.” Their paper in the ACS journal Nano Letters reported that their cell showed “superior battery performance in terms of high specific capacity, excellent charge–discharge efficiency, and remarkable cycle life,” The cell delivered ∼750 mAh g–1 over 500 cycles (85-percent of the initial capacity). Researchers suggested these “behaviors” may result from “a synergistic effect of the …
Dr. Yi Cui’s Latest, a Solid-state Electrolyte
Green Car Congress reports that, “Stanford researchers led by Professor Yi Cui have used ceramic nanowire fillers to enhance the ionic conductivity of polymer-based solid electrolyte by three orders of magnitude. The ceramic-nanowire filled composite polymer electrolyte also shows an enlarged electrochemical stability window.” With solid-state batteries coming to the fore through efforts by Ann Marie Sastry at Sakti 3 and Qichao Hu at Solid Energy Systems, an improved solid electrolyte would seem to offer greater battery safety and stability “when compared with conventional liquid electrolytes. The abstract for the Stanford researchers’ paper in the journal ACS Nano Letters explains that “Currently, the low mobility of lithium ions in solid electrolytes limits their practical application. The ongoing research over the past few decades on dispersing of ceramic nanoparticles into polymer matrix has been proved effective to enhance ionic conductivity although it is challenging to form the efficiency networks of ionic conduction with nanoparticles. In this work, we first report that ceramic nanowire …
Lithium Gets a Good Wrap
Shadi Dayeh, professor in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering, has been designing new electrode architectures that could solve one of lithium batteries’ biggest problems. When lithium diffuses across the surface of a lithium-ion battery electrode, it causes the electrode to expand and contract depending on its charging or discharging. This eventually leads to cracking and ultimate disintegration of the anode or cathode – weakening and finally disabling the battery. Dayeh, working with colleagues at the University and Sandia and Los Alamos National Laboratories, came up with nanowires that, “Block diffusion of lithium (Li) across their silicon surface and promote layer-by-layer axial lithiation of the nanowire’s germanium core.” Seeing possibilities beyond his current research, Dayeh says the work could lead to, “An effective way to tailor volume expansion of lithium ion battery electrodes which could potentially minimize their cracking, improve their durability, and perhaps influence how one could think about …
Wollongong Cites Battery Breakthrough
Professor Zaiping Guo at the University of Wollongong’s Institute for Superconducting & Electronic Materials is working on improving lithium-ion batteries for use in electric vehicles, as well as portable devices like mobile phones, and her school proclaims a breakthrough. Her team has developed a novel nanostructured Germanium (Ge)-based anode material for high-powered rechargeable lithium batteries. Professor Guo, an Australian Research Council (ARC) QEII Fellow, said the development of this inexpensive manufacturing technique is a breakthrough that will provide a significant improvement in battery technology, which can be used to power the next generation of clean-tech electric cars. “The novel anode materials are very simple to synthesize and cost-effective,” she said. “They can be fabricated in large-scale by industry, therefore have great commercial potential.” In tests, Ge-based cells have five times more energy storage and the potential to go at least twice as far on a charge as batteries used in current electric vehicles, according to the University. “This equates to …