Cleaner, greener, safer batteries
Dr Dawei Wang and his research team are working to solve the global energy crisis by creating innovative ways to store the energy generated from renewable energy sources. Using water and abundant elements like sulphur, sodium and magnesium, his team are well on the way to creating cleaner, greener and safer batteries.
Human beings are facing a global energy crisis. Across the world there is a growing realisation that current energy systems are negatively impacting both human health and the environment, and there is a strong recognition that things need to change.
Increasing our reliance on renewable energy generation is one obvious way to mitigate against the crisis; but the major problem preventing the wholesale uptake of renewables like solar and wind, is that they don’t work to order like fossil fuels, which we can burn on demand. In order for renewables to finally supersede fossil fuels, we must be able to store the renewable energy when it is generated, for use when it is needed.
So, how can this be achieved? For Dr Wang and his research team from the School of Chemical Engineering at UNSW, the answer to this storage problem is really quite simple: batteries.
“I’ve been devoted to developing better technologies for efficient energy storage since first exploring the topic in my PhD,” says Dr Wang, who gained his doctorate in 2009 and now leads a team of eight researchers working to create clean, green and safe batteries.
“Our focus is typically on residential storage, for example batteries which can be connected to the solar panels on the rooftops of homes; but the technologies we’re developing could also have applications in mobile phones and electric vehicles etc.”
Batteries, of course, are not a new concept and the type available on the market today include lithium-ion batteries, nickel-metal hydride batteries and lead acid batteries. But these all have significant shortcomings: some are toxic and some are too expensive.
…we are on the right track to making aqueous batteries more powerful by combining new chemicals with the right elements from the lithium-ion battery. The key advantage of the aqueous system is that it will maintain a similar energy performance but will be cheaper, safer and greener.
Dr Dawei Wang
Dr Wang and his team are hoping to resolve these issues by collaborating on a series of projects with industry to guide the invention of new technologies; as well as undertaking fundamental research in chemistry and physics to better understand what is happening with the different materials and chemicals in batteries.
One type of battery under serious scrutiny by the team is the aqueous battery which uses water as the battery’s solvent. “Aqueous batteries are not currently in widespread use because their energy storage capacity is not very high compared to the lithium-ion battery,” says Dr Wang. “However, we are on the right track to making aqueous batteries more powerful by combining new chemicals with the right elements from the lithium-ion battery. The key advantage of the aqueous system is that it will maintain a similar energy performance but will be cheaper, safer and greener.”
Wang’s team are also collaborating with researchers from China and the US with a view to creating batteries from abundant, and therefore highly affordable, sodium and magnesium elements. According to Dr Wang, the problem with using sodium and magnesium at present is that the chemistry of these two elements in the battery is quite complex. His team are modifying the interface between the sodium and magnesium materials with the electrolyte so they can make the interface more efficient for the charge transfer.
“We’ve recently investigated the interface between a sodium material anode and an electrolyte, and we’ve found that when we reduce the thickness of the interface film, the performance and efficiency of the battery can be improved,” Dr Wang explains.
“Energy storage is really important for the future of human society and it’s great to be part of finding a sustainable solution,” he continues. “Experiment is never predictable, so I’m always expecting surprises from the lab and from the students. That’s the most enjoyable part of this research for me.”