April 24, 2014
Boost for electronic devices and vehicle batteries
An international team of researchers at the UOW’s Institute for Superconducting and Electronic Materials (ISEM) have developed a new way of constructing silicon-based lithium ion batteries that has important implications for the next generation of electric-powered vehicles and electronic devices.
The ISEM researchers have developed batteries that charge more quickly, hold their charge for longer and have a longer life – characteristics that make battery-powered vehicles and more appealing.
ISEM Director and leader of the Vehicle Electrification Program of the Australian Automotive Cooperative Research Centre (AutoCRC) said that this has a great contribution to the advance of lithium ion batteries for electric vehicles.
“The material design concepts involved in this work are general which may allow them to be extended to other materials with high energy densities and importantly the technique can be scaled up for mass production,” Professor Dou said.
“This means that we may be able to use the approach to assist in the development of the next generation of batteries such as lithium-air based batteries or sodium ion batteries.”
The ISEM team, led by , used electrospinning, a technique where an electrical charge is used to draw fine fibres from a liquid, to construct microscopic fibre consisting of a shell and core.
The dual-nozzle electrospinning technique allows for a protective layer of black titanium oxide to be spun into the battery anode that retards the thermal reaction between the silicon and the battery electrolytes without compromising the performance of the battery.
The result was a core-shell composite that did not lose capacity through multiple charge and discharge cycles, otherwise known as memory, and excellent rate-capability, a measure of its continuous power output. In addition the fibre showed improved retention of charge capacity during charge and discharge cycles with little expansion of the electrode.
Despite problems with overheating, silicon-based anode materials have been more attractive than graphite for battery construction due to a higher capacity and longer life cycles. Advances in capacity and life cycles without the drawbacks associated with overheating would allow for greater commercial applications of lithium ion batteries.
“The results of our research provide a new direction for lithium ion and potentially other energy storage materials as black titanium oxide may prove to be an exciting alternative to carbon,” Associate Professor Jung Ho Kim said.
“Globally, researchers have been working on battery materials that are safe, provide high energy densities and allow for longer battery lives and we believe that our findings can take battery research in a new and exciting direction.”
ISEM, located at UOW’s Australian Institute for Innovative Materials facility, ranks in the global top 10 research groups advancing the development of lithium ion batteries.
This work was recently and supported by the AutoCRC and the Australian Research Council.
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