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UT Austin team achieves best reported full-cell hybrid Li-air battery cycling with new ordered catalyst

Master.img-003
Cycling performance of the hybrid Li− air batteries with (top) ordered Pd3Fe/C air electrode and (bottom) conventional Pt/C air electrode. Credit: ACS, Cui et al. Click to enlarge.

A team from the University of Texas at Austin led by Professor John Goodenough has achieved significantly enhanced activity and durability for the oxygen reduction reaction under alkaline conditions in a hybrid Li-Air battery using a new ordered Pd3Fe/C catalyst. The new catalyst exhibits much higher activity and durability than disordered Pd3Fe/C, Pd/C, and Pt/C.

As reported in a paper in the Journal of the American Chemical Society, the new ordered Pd3Fe/C catalyst enables long-term cycling performance of hybrid Li−air batteries over 880 hours (220 cycles) with only a 0.08 V increase in round-trip overpotential. The extraordinarily high performance of ordered Pd3Fe/C catalyst provides a very promising alternative to the conventional Pt/C catalyst for an air cathode in alkaline electrolyte, they concluded.

… the practical energy density of aprotic Li−air batteries is limited by the deposition of the insoluble discharge products (Li2O2) clogging the air electrodes, the decomposition of organic electrolytes, and the need for excess packaging to keep the battery in a dry oxygen environment. To overcome these problems, a hybrid system has been developed, composed of a nonaqueous electrolyte in the anode side (oxidation of Li to Li+) and an aqueous electrolyte in the cathode side (reduction of oxygen in the presence of Li+), separated by a solid lithium-ion-conducting electrolyte. However, the cycle life of such hybrid systems is limited. The problem lies mainly in the sluggish kinetics of the oxygen reduction reaction (ORR) and poor durability of the cathode catalyst, which actually is also the major limiting factor for other energy conversion and storage technologies, such as fuel cells and metal−air batteries. Therefore, it is desirable to develop highly active and stable electrocatalysts for the ORR in aqueous media.

Pt and Pt-based alloys remain the most efficient ORR catalysts, but their high cost and scarcity have made them increasingly unattractive for such applications.… Recent studies have shown that supported Pd and Pd-based alloys exhibit ORR activity comparable to that of Pt/C in alkaline media. However, most reports have focused mainly on the disordered Pd-based alloy catalysts, which have varying surface composition and thus randomly distributed active sites. … Herein we report an ordered Pd3Fe intermetallic catalyst that exhibits significantly enhanced activity and durability for the ORR relative to disordered Pd3Fe/C, Pd/C, and Pt/C.

—Cui et al.

In contrast to disordered materials, in an ordered intermetallic phase, every crystallographic site is occupied by only one type of atom. An ordered phase can provide predictable control over structural, geometric, and electronic effects. Further, the researchers noted, as the order in intermetallic phases arises from the high enthalpy of mixing, a high chemical and structural stability can be expected. Ordered intermetallic catalysts also appear to possess different catalytic properties in comparison to their disordered alloys. The discovery of ordered Pt-based catalysts inspired the UT team to investigate Pd-based intermetallic catalysts.

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Left. Crystal structure of ordered Pd3Fe. Right. Crystal structure of disordered Pd3Fe. Credit: ACS, Cui et al. Click to enlarge.

The UT team compared the catalytic performances of ordered Pd3Fe/C and conventional Pt/C in a rechargeable hybrid Li−air battery. The polarization curve for ordered Pd3Fe/C almost overlapped that for Pt/C, indicating that these two catalysts have similar activities for the ORR in hybrid Li−air cells.

The team calculated the maximum power densities to be 11.7 mW cm−2 for ordered Pd3Fe/C and 12.3 mW cm−2 for Pt/C. For the battery with ordered Pd3Fe/C as the ORR catalyst, the round-trip overpotential increased from 0.9 V at the first cycle to 0.92 V at the 55th cycle and to 0.98 V at the 220th cycle. In the case of the cell with Pt/C as ORR catalyst, the round-trip overpotential is 0.9 V initially, and it increases to 1.31 V at the 55th cycle.

The small (2.2%) increase relative to the initial round-tip overpotential in the the battery with ordered Pd3Fe/C compared to the much larger increase (45.5%) for the battery with Pt/C indicated that the ordered Pd3Fe/C catalyst significantly enhances the cycling stability of hybrid Li−air batteries.

Resources

  • Zhiming Cui, Longjun Li, Arumugam Manthiram, and John B. Goodenough (2015) “Enhanced Cycling Stability of Hybrid Li–Air Batteries Enabled by Ordered Pd3Fe Intermetallic Electrocatalyst” Journal of the American Chemical Society doi: 10.1021/jacs.5b03865

Comments

sd

This will be known as the Goodenough battery?

Seriously, why they did not say was anything about energy or power density but maybe that will come after the basic research.

Sublime

You realize this is the inventor of the lithium ion battery?
I'm kind of amazed he's looking into Li-Air when so many others have written it off.

TheOne

Lithium-air is not being abandoned everywhere. At Argonne, Michael Thackeray is directing work on a novel hybrid battery combining lithium-ion and lithium-air. The result is the potential for a battery with specific density of 500 watt hours per kilogram, two-and-a-half times greater than today’s best commercial lithium-ion cell.

IBM is working on both lithium-air and sodium-air types. Yes, early last year, IBM’s Winfried Wilcke, director of the Battery 500 Project, did say that he now believes that the economics of an EV using a sodium-air battery stands a better chance of competing with a conventional car.

Peter Bruce, a leading at the University of St. Andrews, said battery scientists should work both on technologies with a high certainty of success—such as better lithium-ion and riskier ideas like lithium-air. It wasn't that long ago when Peter said that so far he hasn’t seen any show stoppers for lithium-air.

Just remember that the specific charged-state energy density is close to 12,000 Wh kg−1, which is not far from the energy density of gasoline (13,000 Wh kg−1). The energy density per unit mass and per unit volume of non-aqueous lithium–air batteries is about 10 times and 6 times higher than those of lithium-ion batteries, respectively, with a carbon anode and LiCoO2 cathode.

Thus, I am not surprised that Goodenough is pursuing Li-Air. If anyone on the planet can succeed technically with it, Goodenough can. He has had a long standing vision for Li batteries and must enjoy the challenge. I am still blown away by A123 M1A/M1B cells in terms of their cycle life, safety and 0-leakage seemingly infinite shelf life which makes all NiMH cells look like junk.

electric-car-insider.com

TO> energy density is close to 12,000 Wh kg−1, which is not far from the energy density of gasoline (13,000 Wh kg−1).

Not to mention that electric drivetrains are ~ 2.5 times more efficient than ICE, and because you don't have the inconvenience of driving to a gas station, starting each day with full fuel, 200 mile range gives you a 100% effortless solution within your metro area.

Add superchargers and another hundred miles range, and you have a car that will take you anywhere in the country with a 30-45 min rest stop after each 4 hours of travel.

Add a few rooftop solar panels to your whole-house installation and your fuel cost is ~$2,000 for the rest of your life.

Tell a friend.

gorr

I said many time that these batteries will never took off because the difficulty is to recharge and these batteries do not have sufficient range. Both of these difficulties can't be overcome and also a third difficulty that cannot be overcome is that it cost MORE, so wake-up everybody.

This green market is just fraud organized by international banks to lend more money to goverments all over the world , acquire patents to push price up for all kind of products.

This website is useless.

SJC

then leave

ejj

gor said "This green market is just fraud organized by international banks to lend more money to goverments all over the world , acquire patents to push price up for all kind of products."

It's more like "This green market is just fraud organized by democratic party interests as payoffs for political contributions and to advance the power of the hammer & sickle"

Brent Jatko

@ejj:

Ah, the old contemptible saw. "Democrats = communists."

Never seen that before. Troll elsewhere, please.

Brent Jatko

He's full of crap like that.
Read his other "gems" on his profile.
A true "legend in his own mind!"

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