Researchers Develop Solid-State, Rechargeable Lithium-Air Battery; Potential to Exceed 1,000 Wh/kg
21 November 2009
|Sample UDRI solid-state, rechargeable lithium-air batteries, and Dr. Binod Kumar. Click to enlarge.|
Engineers at the University of Dayton Research Institute (UDRI) have developed a solid-state, rechargeable lithium-air battery. When fully developed, the battery could exceed specific energies of 1,000 Wh/kg in practical applications, the researchers wrote in a paper published online 13 November in the Journal of the Electrochemical Society.
The cell comprises a Li metal anode, a highly Li-ion conductive solid electrolyte membrane laminate fabricated from glass–ceramic (GC) and polymer–ceramic materials, and a solid-state composite air cathode prepared from high surface area carbon and ionically conducting GC powder.
The cell exhibited excellent thermal stability and rechargeability in the 30–105 °C temperature range. It was subjected to 40 charge–discharge cycles at current densities ranging from 0.05 to 0.25 mA/cm2.
Lithium-air batteries dispense with the intercalation cathode used in a lithium-ion rechargeable battery, instead using a catalytic air cathode in combination with an electrolyte and a lithium anode. Oxygen from the air is the active material for the cathode and is reduced at the cathode surface—the lithium reacts directly with the oxygen. Theoretically, with oxygen as essentially an unlimited cathode reactant source, the capacity of the battery is limited only by the lithium anode. The theoretical specific energy of the Li-air cell is 13,000 Wh/kg—the highest of any metal-air battery system. (Earlier post.)
There are numerous challenges for non-aqueous rechargeable Li-air systems, such as low rates of oxygen diffusion in the porous air cathode and the accumulation of solid reaction products on the electrode, which blocks the contact between electrolyte and air, reducing life and power. As with Li-ion batteries, there are many factors controlling the performance of a lithium-air battery, including cathode structure, anode morphology, electrolyte composition and cell assembly.
We have successfully fabricated and tested the first totally solid-state lithium-air battery, which represents a major advancement in the quest for a commercially viable, safe rechargeable battery with high energy and power densities and long cycle life.
—Binod Kumar, leader of UDRI’s electrochemical power group
In addition to increasing the battery’s energy density, the development is designed to mitigate the volatile nature of traditional lithium rechargeables, such as those used in cell phones and laptops, which can overheat and catch fire or rupture.
Kumar said that the team made and tested more than three dozen lithium-air batteries during the last year, with each exhibiting superior performance even at temperatures as high as 107 °C. As development of the technology continues, researchers will also focus on cycle life, with a goal of 4,000 cycles.
Research to develop the new lithium battery was funded in part by the Air Force Research Laboratory’s Propulsion Directorate at Wright-Patterson Air Force Base.
Binod Kumar, Jitendra Kumar, Robert Leese, Joseph P. Fellner, Stanley J. Rodrigues, and K. M. Abraham (2010) A Solid-State, Rechargeable, Long Cycle Life Lithium–Air Battery. J. Electrochem. Soc., Volume 157, Issue 1, pp. A50-A54; doi: 10.1149/1.3256129
Interesting news. This approach may bare fruits and make higher energy density (1000 Wh/Kg)rechargeable batteries a reality by 2015...
With 4000 usable cycles, it could become an acceptable unit for PHEVs and BEVs
The tolerance to high temperature is very positive. How will it perform in -30C?
Posted by: HarveyD | 21 November 2009 at 09:13 AM
Harvey, again you are taking your fantasies for reality, where do you get this 2015 date ? again you have no idea of what it takes to develop a new material for battery, not the slightest idea. The problems to solve in these metal/air battery are daunting. Try to oxidize a metal as reactive as lithium in a controlled way then you can talk, in practice it is next to impossible.
Posted by: Treehugger | 21 November 2009 at 11:33 AM
"Acceptable unit" is surely understatement. 1000Wh/kg would be nothing short of game changing.
Posted by: Scatter | 21 November 2009 at 11:35 AM
Yes but in practice in order to avoid the formation of dendrites that grow in an uncontrollable way (and kill the battery in a violent way) under high current densities, you have to work well below that value.
Posted by: Treehugger | 21 November 2009 at 11:58 AM
Scatter sorry I was talking about power density, so yes air/metal battery have huge power densities (but it is not new at all, it has been observed decades ago with Aluminum, Zinc, Sodium, Lithium, Calcium, Magnesium) the problem of air/metal batteries are their disastrous cycle-ability. They might be the holly grail of batteries (high energy density, low toxicity, long shelve life time) but the cycle-ability has plagued the development of these batteries for decades, so I don't expect that these batteries will become a game changer any time soon, unless some breakthrough is made to fix their basic problem. It might happen, but nobody knows when...instead I expected a tedious slow incremental process that can eventually make it though, eventually.
Asides it might make more sense to invest in high power highly Cycle-able technology suitable to PHEV as a trade off rather than in a high energy-density but pour cycle-ability and poor power-density technology for an ideal EV that will never come.
Posted by: Treehugger | 21 November 2009 at 12:23 PM
2015.... = 2015 ++++
Posted by: HarveyD | 21 November 2009 at 03:34 PM
Each (.) or (+) could mean one, five or ten years.
Posted by: HarveyD | 21 November 2009 at 03:43 PM
Things that appear technically impossible sometimes become commonplace quite quickly when enough R&D is poured into the problem.
When the EV market reaches a certain point, the money will pour into that R&D.
Posted by: danm | 21 November 2009 at 05:32 PM
yes and no, enough R&D is necessary anyway but not a guarantee of success. Keep in mind that Military, Space, Medical(pace maker), Computer, Portable tools, and many other applications always had huge incentives or interests to develop new batteries or simply to improve existing one. Still despite continuous investment in R&D batteries technologies have always progressed at a snail pace. Improving batteries is really a fight against material. Maybe we should look at mother nature who has invented some perfect infinitely reversible chemical reactions like the oxidization of ATP in the fibers of our muscles....
Posted by: Treehugger | 21 November 2009 at 07:21 PM
Using these li-air cells would allow a Tesla Roadster battery to weight just 50kg... 1/10th it's current weight. A theoretical maximum of 13 kWh/kg is mind blowing if achievable!
Posted by: Paul | 21 November 2009 at 10:44 PM
If I am not mistaken, light aircraft have already been flown on Li-air cells. A long-lived or easily refurbished Li-air cell would kill the bulk of the petroleum industry almost overnight.
Posted by: Engineer-Poet | 27 November 2009 at 05:12 PM