Pumping up energy storage with metal oxides

March 21, 2016
This schematic illustration shows metal oxides tented inside graphene. Many metal oxide/graphene composites offer unexpected capacity synergy that helps to increase storage capacity. Credit: Ryan Chen/LLNL.

Material scientists at Lawrence Livermore National Laboratory have found certain metal oxides increase capacity and improve cycling performance in lithium-ion batteries.

The team synthesized and compared the electrochemical performance of three graphene metal oxide nanocomposites and found that two of them greatly improved reversible lithium storage capacity.

The research appears on the cover of the March 21 edition of the Journal of Materials Chemistry A.

Graphene-metal oxide (GMO) nanocomposites have become renowned for their potential in energy storage and conversion, including capacitors, , catalysis (for fuel cells, water splitting and air cleaning) and sensors.

For applications in lithium-ion batteries, nanosized metal oxide (MO) particles and highly conductive graphene are considered beneficial for shortening lithium diffusion pathways and reducing polarization in the electrode, leading to enhanced performance.

In the experiments, the team dipped prefabricated graphene aerogel electrodes in metal ion solutions where all appear to be anchored on the surface of graphene and are fully accessible to the electrolyte (i.e., open pore space).

"In essence, our approach helps to optimize the system-level performance by ensuring that most oxides are active," said LLNL material scientist Morris Wang and corresponding author of the paper.

The method can deposit most types of MOs onto the same prefabricated 3D graphene structure, allowing for direct comparison of electrochemical performance of a wide range of GMOs.

"We found that the experiments showed large reversible lithium storage capacities of graphene sheets, enabled by the unheralded roles of ," Wang said. "Surprisingly we saw the magnitude of capacity contributions from graphene is mainly determined by active materials and the type of MO bound onto the graphene surface."

Specifically, the lithium storage mechanisms of MOs and their loading ratio versus graphene play key roles in determining graphene capacity contributions.

Explore further: Safe lithium-metal batteries with graphene

Related Stories

Safe lithium-metal batteries with graphene

March 21, 2016

Recently, researchers at Tsinghua University, China have proposed a graphene-based nanostructured lithium metal anode for lithium metal batteries to inhibit dendrite growth and improve electrochemistry performance. They report ...

From graphene hydrogels to high-performance anodes

March 18, 2015

How can the electrodes of batteries be made more efficient? In the journal Angewandte Chemie, American scientists describe a powerful approach that uses solvated graphene frameworks as the anode material. Assembled in a lithium ...

Could bread mold build a better rechargeable battery?

March 17, 2016

You probably don't think much of fungi, and especially those that turn bread moldy, but researchers reporting in the Cell Press journal Current Biology on March 17, 2016 have evidence that might just change your mind. Their ...

Future batteries: Lithium-sulfur with a graphene wrapper

December 16, 2014

What do you get when you wrap a thin sheet of the "wonder material" graphene around a novel multifunctional sulfur electrode that combines an energy storage unit and electron/ion transfer networks? An extremely promising ...

Recommended for you

New aspect of atom mimicry for nanotechnology applications

December 2, 2016

In nanotechnology control is key. Control over the arrangements and distances between nanoparticles can allow tailored interaction strengths so that properties can be harnessed in devices such as plasmonic sensors. Now researchers ...

Engineers create prototype chip just three atoms thick

November 29, 2016

For more than 50 years, silicon chipmakers have devised inventive ways to switch electricity on and off, generating the digital ones and zeroes that encode words, pictures, movies and other forms of data.

Nanotechnology a 'green' approach to treating liver cancer

November 29, 2016

According to the American Cancer Society, more than 700,000 new cases of liver cancer are diagnosed worldwide each year. Currently, the only cure for the disease is to surgically remove the cancerous part of the liver or ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.