Researchers at Waterloo have created a battery with a silicon-based anode that has a significantly higher energy density than other lithium-ion batteries in the market. Their research has been published in the latest issue of <em>Nature Communications.</em></p>
Lithium-ion batteries are used to power rechargeable consumer electronics, such as smartphones and smartwatches. Currently, lithium-ion battery technology is limited in terms of the number of charge cycles for which they can last and the amount of energy that they can hold per charge cycle.
The researchers, consisting of Zhongwei Chen, a chemical engineering associate professor at Waterloo, and a few graduate students, have created a longer-lasting lithium-ion battery that has up to 60 per cent higher energy density compared to lithium-ion batteries that are currently on the market.
These significant gains in the battery’s performance were achieved through the use of a silicon-based anode, as opposed to graphite anodes that are normally used in the lithium-ion batteries. According to researchers, the silicon anode is a very promising alternative to graphite anodes; theoretically, silicon batteries can deliver up to 4,200 milliAmpere-hours (mAh) of charge per gram. In comparison, graphite anodes can, theoretically, only deliver up 370 mAh per gram.
The researchers encountered a major drawback to silicon anodes, however. Silicon-based anodes can undergo extreme changes in volume during periods of charge and discharge. As a result, batteries that use silicon-based anodes are susceptible to short-circuits and regular breakdown.
In order to tackle this problem, the researchers altered the silicon-electrode’s nanoarchitecture by creating nano-sized spaces within the electrode. This allows the electrode to accommodate the expansion and shrinking of the electrode during battery operation.
The researchers also employed a flash-heat treatment that improved the performance of the anode. This method, according to Chen, is very new and has not been used in the field of battery design.
Chen, who is also the Canada Research Chair in Advanced Materials for Clean Energy, believes that energy is currently one of the “hot topics” that must be addressed. He claims that the best way to address the issue of energy is to create usable technology that is energy efficient.
When asked about what motivated him to pursue research in this field, Chen pulled out his new Samsung smartphone and claimed that “[the phone] does not last for an entire day.” Chen is passionate about creating technology that is practical and has real-world applications. He believes that his batteries will benefit consumer-oriented electronic devices like smartphones. He also hopes that his batteries will have an impact outside of Canada. According to Chen, “Energy has become a global market” where energy efficiency and saving cost are of paramount importance, and he feels that his batteries can have an impact on the global market.
Chen is currently working on getting the batteries on the market for sometime in 2016.