Researchers develop new silicon-sulfur-graphene electrode material

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Researchers from the University of Waterloo and GM’s Global Research and Development Center have developed a new silicon-based anode material that they say could enable batteries with almost 10 times more energy density than today’s state of the art.

In “Evidence of covalent synergy in silicon–sulfur–graphene yielding highly efficient and long-life lithium-ion batteries,” published in Nature Communications, the team reports that the new electrode material shows superior reversible capacity, high coulombic efficiency, and high aerial capacity.

“Graphite has long been used to build the negative electrodes in lithium-ion batteries,” said Professor Zhongwei Chen, leader of the Waterloo team. “But as batteries improve, graphite is slowly becoming a performance bottleneck because of the limited amount of energy that it can store.”

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Silicon is a strong candidate to replace graphite, but it tends to undergo significant expansion and contraction with each charge cycle, which causes the material to crack. To overcome this problem, Professor Chen’s team developed a flash heat treatment for fabricated silicon-based lithium-ion electrodes that minimizes volume expansion.

“The economical flash heat treatment creates uniquely structured silicon anode materials that deliver extended cycle life to more than 2,000 cycles with increased energy capacity of the battery,” said Professor Chen.

Chen plans to commercialize this technology, and expects to see new batteries on the market within the next year.

 

Source: University of Waterloo via Green Car Congress
Images: Hassan et al (CC BY 4.0)