Battery Component Materials, Chemical Instability and Safety

Ann Nguyen:
Hi. I'm Ann Nguyen, Senior Associate Conference Producer with Cambridge EnerTech. We’re here for a podcast for the Battery Safety conference, taking place this November 2-3 in Arlington, Virginia. Today I'm interviewing one of our speakers, Dr. Arumugam Manthiram, Director of the Texas Materials Institute and Professor of Mechanical Engineering at the University of Texas at Austin.

Hi, Arumugam, thank you for spending time with us today.

Arumugam Manthiram:
Thank you.

Ann Nguyen:
Your battery safety work is focused on rechargeable batteries and fuel cells. Why that focus and what research avenues and findings have shown the most promise?

Arumugam Manthiram:
As we try to increase the amount of energy stored in the battery, to realize longer user time between charges, generally the lithium-ion batteries tend to encounter chemical instability. And that leads to fire hazards and safety issues.

The chemical instability is largely controlled by three factors: the component materials used in the battery, the cell engineering involved in making the battery and the operating conditions. This means the positive and negative electrode materials, the separators and the electrolyte used in the battery, the way in which they are assembled in the battery, and the rate at which the batteries are charged or discharged; all of them will influence the safety.

The research in my group is focused on the development of component materials and their modifications to realize better safety with the batteries.

Ann Nguyen:
Your presentation on November 2 is called, “Battery Safety: A Materials Chemistry Perspective”. What's the main theme you'd like to convey to the R&D engineers, cell manufacturers and other peers in the audience?

Arumugam Manthiram:
As I indicated in my answer to my previous question, the component materials used in the battery and the interactions among them have a large role on the battery safety. My group is engaged currently in three topics. One, development of compatible electrode and the electrolyte materials with good interfacial stability and fast interfacial reaction kinetics for lithium-ion batteries, particularly based on high nickel content layered oxides as positive electrode and graphite as negative electrode to realize fast charge/discharge with good safety and high-energy density.

Number two, we are also focused on the development of batteries based on sulfur at the positive electrode instead of the metal oxides currently we use in lithium-ion batteries. Sulfur operates at a lower voltage and does not release any oxygen during overcharging, so the fire hazards are minimized.

Topic number three, we're also working on the development of water-based or aqueous batteries based on dense ceramic solid electrolytes, which do not allow the chemicals to cross over between the two electrodes and they offer high safety.

Ann Nguyen:
How do you see the field and the balance between increasing energy density in batteries, maintaining safety and lowering costs evolving in the next 10 years?

Arumugam Manthiram:
Maintaining a balance among energy density, safety and cost will need innovation in materials development, new process development, new cell configurations and robust cell engineering. In this regard both basic science research and engineering will play a role. I envision to see in the next 10 years a slow increase in energy density, and a decrease in cost through the innovations I mentioned in the above areas.

Ann Nguyen:
Well, thank you again Arumugam. That's all for now, but we'll look forward to digging deeper into your work and your insights this fall.

Arumugam Manthiram:
Thank you, it's a pleasure.

Ann Nguyen:
That was Arumugam Manthiram of the University of Texas at Austin. He'll be speaking during the Battery Safety conference happening this November 2-3 in Arlington, Virginia.

To learn more from him, visit CambridgeEnerTech.com/Battery-Safety for registration info and enter the keycode “Podcast”.

This is Ann Nguyen. Thanks for listening.