New Nanosheets Show Promise for Lithium-Ion Battery Anodes

IBN’s nanosheets, shown here, are said to be 50,000 times thinner than a sheet of paper. Image courtesy of A*STAR.

Researchers at the Institute of Bioengineering and Nanotechnology (IBN) of Singapore’s government-led Agency for Science, Technology and Research (A*STAR) have developed a new way of producing more durable lithium-ion batteries that last for a longer amount of time.

Led by Jackie Y. Ying, an executive director professor for the IBN program, the researchers invented a generalized method of producing anode materials for lithium-ion batteries. The anodes are made from metal oxide nanosheets, which are ultrathin, two-dimensional (2D) materials with strong electrochemical and mechanical properties.

These nanosheets are 50,000 times thinner than a sheet of paper, allowing for faster charging of power compared to current battery technologies, the researchers say. The wide surface area of the nanosheets makes better contact with the electrolyte, thus increasing the storage capacity.

The material is also highly durable and does not break easily, which improves the battery shelf life. Existing methods of making metal oxide nanosheets are time-consuming and difficult to scale up, the researchers explain.

As part of their work, the IBN team came up with a simpler and faster way to synthesize the metal oxide nanosheets using graphene oxide. Graphene oxide is a 2D carbon material with chemical reactivity that facilities the growth of metal oxides on its surface.

Graphene oxide was used as the template to grow metal oxides into nanosheet structures via a simple mixing process, followed by heat treatment. The researchers were then able to synthesize a wide variety of metal oxides as nanosheets, with control over the composition and properties.

The new technique takes one day to produce the nanosheets, compared to one week for previously reported methods. It does not require the use of a pressure chamber and has just two steps in the synthesis process, making the nanosheets easy to manufacture on a large scale.

Tests showed that the nanosheets produced using this approach have strong lithium-ion battery anode performance, with some materials lasting three times longer than graphite anodes used in current batteries.

“Our nanosheets have shown great promise for use as lithium-ion anodes,” Ying says. “This new method could be the next step toward the development of metal oxide nanosheets for high performance lithium-ion batteries. It can also be used to advance other applications in energy storage, catalysis, and sensors.”

Source: A*STAR,