Oak Ridge Today

Rubber meets the road with new ORNL carbon, battery technologies

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Recycled Tire Battery Schematics

ORNL researchers’ goal is to scale up the recovery process and demonstrate applications as anodes for lithium-ion batteries in large-format pouch cells. (Image courtesy ORNL)

 

Recycled tires could see new life in lithium-ion batteries that provide power to plug-in electric vehicles and store energy produced by wind and solar, say researchers at Oak Ridge National Laboratory.

By modifying the microstructural characteristics of carbon black, a substance recovered from discarded tires, a team led by Parans Paranthaman and Amit Naskar is developing a better anode for lithium-ion batteries. An anode is a negatively charged electrode used as a host for storing lithium during charging.

The method, outlined in a paper published in the journal RSC Advances, has numerous advantages over conventional approaches to making anodes for lithium-ion batteries.

“Using waste tires for products such as energy storage is very attractive not only from the carbon materials recovery perspective but also for controlling environmental hazards caused by waste tire stock piles,” Paranthaman said.

The ORNL technique uses a proprietary pretreatment to recover pyrolytic carbon black material, which is similar to graphite but man-made. When used in anodes of lithium-ion batteries, researchers produced a small, laboratory-scale battery with a reversible capacity that is higher than what is possible with commercial graphite materials. [Read more…]

ORNL microscopy system delivers real-time view of battery electrochemistry

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ORNL Battery Electrochemistry

A new in situ transmission electron microscopy technique enabled ORNL researchers to image the snowflake-like growth of the solid electrolyte interphase from a working battery electrode. (Photo courtesy ORNL)

Using a new microscopy method, researchers at Oak Ridge National Laboratory can image and measure electrochemical processes in batteries in real time and at nanoscale resolution.

Scientists at ORNL used a miniature electrochemical liquid cell that is placed in a transmission electron microscope to study an enigmatic phenomenon in lithium-ion batteries called the solid electrolyte interphase, or SEI, as described in a study published in Chemical Communications.

The SEI is a nanometer-scale film that forms on a battery’s negative electrode due to electrolyte decomposition. Scientists agree that the SEI’s formation and stability play key roles in controlling battery functionality. But after three decades of research in the battery field, details of the SEI’s dynamics, structure, and chemistry during electrochemical cycling are still debated, stemming from inherent difficulties in studying battery electrode materials in their native liquid environment.

“We’ve used this novel in situ method to understand the dynamics of how this layer forms and evolves during battery operation,” said Raymond Unocic, ORNL research and development staff scientist. [Read more…]

ORNL leading study focused on afterlife of electric vehicle batteries

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Once they’ve finished powering electric vehicles for hundreds of thousands of miles, it may not be the end of the road for automotive batteries, which researchers believe can provide continued benefits for consumers, automakers, and the environment.

Five used Chevrolet Volt batteries are at the heart of the Oak Ridge National Laboratory’s effort to determine the feasibility of a community energy storage system that would put electricity onto the grid. During the next year, researchers from ORNL, General Motors, and the ABB Group will conduct studies and compile data using a first-of-its-kind test platform officially commissioned Tuesday. [Read more…]

ORNL research paves way for larger, safer lithium ion batteries

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Solid Electrolyte for Lithium Ion Batteries

Oak Ridge National Laboratory researchers developed a nanoporous solid electrolyte (bottom left and in detail on right) from a solvated precursor (top left). The material conducts ions 1,000 times faster than its natural bulk form and enables more energy-dense lithium ion batteries. (Submitted photo)

Looking toward improved batteries for charging electric cars and storing energy from renewable but intermittent solar and wind, scientists at Oak Ridge National Laboratory have developed the first high-performance, nanostructured solid electrolyte for more energy-dense lithium ion batteries.

Today’s lithium-ion batteries rely on a liquid electrolyte, the material that conducts ions between the negatively charged anode and positive cathode. But liquid electrolytes often entail safety issues because of their flammability, especially as researchers try to pack more energy in a smaller battery volume. Building batteries with a solid electrolyte, as ORNL researchers have demonstrated, could overcome these safety concerns and size constraints.

[Read more…]