Oak Ridge National Laboratory Designs and Tests All Solid Lithium-Sulfur Battery with 4 Times the Energy Density of Lithium-Ion


Researchers at Oak Ridge National Laboratory (ORNL) have successfully demonstrated that lithium-sulfur battery technology can indeed outdo lithium-ion on several fronts.

Lithium Sulfur Potential

Lithium Sulfur Potential

At ORNL, researchers “designed and tested an all-solid lithium-sulfur battery with approximately four times the energy density of conventional lithium-ion technologies,” says Green Car Congress, who further adds that “The ORNL battery design also addresses flammability concerns experienced by other chemistries.

We all know that, in theory, lithium-sulfur is an energy-dense beast.  Theoretically, lithium-sulfur has the potential to be four times as energy dense as today’s lithium-ion batteries, but that’s all in theory and, until a working example is demonstrated, we’re all left dreaming.

However, the steps made by ORNL show true promise.  Remember, there have been some breakthroughs related to extended the longevity of lithium-sulfur, but the problem with the liquid electrolyte breaking down the battery over time still remains with this chemistry.

Not anymore, says ORNL.

ORNL’s lithium-sulfur battery does away with the conventional liquid electrolyte in favor of solid electrolyte material.  As Green Car Congress says:

“The ORNL team overcame these barriers by first synthesizing a new class of sulfur-rich materials—lithium polysulfidophosphates (LPSPs)—that conduct ions as well as the lithium metal oxides conventionally used in the battery’s cathode.”

“LPSPs have ionic conductivities of 3.0×10−5 S cm−1 at 25 °C, which is 8 orders of magnitude higher than that of Li2S (lithium sulfide). The high lithium ion conductivity imparts excellent cycling performance, the researchers noted.”

“The researchers then combined the new sulfur-rich cathode and a lithium anode with a solid electrolyte material, also developed at ORNL, to create an energy-dense, all-solid battery.”

And here’s an excerpt from ORNL’s research paper, which was published in Angewandte Chemie International Edition:

“Our approach is a complete change from the current battery concept of two electrodes joined by a liquid electrolyte, which has been used over the last 150 to 200 years. This game-changing shift from liquid to solid electrolytes eliminates the problem of sulfur dissolution and enables us to deliver on the promise of lithium-sulfur batteries. Our battery design has real potential to reduce cost, increase energy density and improve safety compared with existing lithium-ion technologies.”

Now for some of the gritty technical details, presented by Green Car Congress:

“The new ionically-conductive cathode enabled the ORNL battery to maintain a capacity of 1,200 mAh/ g after 300 charge-discharge cycles at 60 °C. By comparison, a conventional lithium-ion battery cathode has an average capacity between 140-170 mAh/g. Because lithium-sulfur batteries deliver about half the voltage of lithium-ion versions, this eight-fold increase in capacity demonstrated in the ORNL battery cathode translates into four times the gravimetric energy density of lithium-ion technologies.”

Most importantly, though, is that the inclusive of solid electrolyte materials makes the battery inherently safer than ones that use a liquid.

ORNL’s potential breakthrough lithium-sulfur battery is still in the demonstration/development phase.  Commercialization is tentatively set for…quickly.   Actually, there’s no set timeline for commercialization, but a patent is at least pending for ORNL’s design.

Source: Green Car Congress

Categories: Battery Tech

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10 Comments on "Oak Ridge National Laboratory Designs and Tests All Solid Lithium-Sulfur Battery with 4 Times the Energy Density of Lithium-Ion"

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What is the Y axis on first chart?

The Y axis is the gravimetric energy density, althout it appears to me to be inaccurate since Envia has already demonstrated 400Wh/kg for nano structured lithium-ion.

For most of the article…I need an interpreter.

Someone give Oak Ridge Labratories Elon Musk’s number!

I bet if one of these did catch on fire for whatever reason, it would be extraordinarily stinky due to the sulfur.

Volumetric capacity matters no less than kg/kwh. I do not see Li-S advantage over Lithium ion.

The mAh/g of the cathode and voltage aren’t enough to compare batteries. There is also the anode capacity, the electrolyte weight, and the casing. This is obviously pretty good, but there is not enough information to tell just how good it is.

Article says that there is a metallic lithium anode, so it should have 3860 mah/g.

Another key piece of information is the specific power (W/kg). Having high energy density is going to be less useful in an electric car if you can’t pull a high enough current to give the car acceptable performance. Typically, as you go up in energy density you decrease in specific power.

400Wh/kg is very good but without cycle life it is worthless.
power density is also important

Any news on this topic? Are Li-S commercially available now?