Dear Santosh,

I am not really sure Li-air provides higher power densities since the Li-air system is particularly slow in kinetics and depends on a catalytic effect. Li-air provides higher energy though, simply because its a light system, whether you calculate the energy based on the mass of carbon or electrode material or on the amount of reacted oxygen (this might prove a little more difficult).

I would not calculate the power densities since cycling of a Li-air system is extremely tricky and published articles clearly do not state every process involved in the electrochemical tests. This, as you might imagine, is quite important for future patents one wants to write. Moreover, it has been clarified that C components undergo corrosion at the charge potentials (4 to 4.6 V usually) and thus the very high energy values you can read on papers are often overestimated.

Concerning the problems:

-synthesis of a stable electrolyte at the reaction potentials

-synthesis of stable electrode materials at the reaction potential

-identification of suitable catalysts for the oxygen evolution reaction

-addressing the dendritic formation of Li anode or finding suitable anode materials

-starting the materials engineering: classical powders are not good electrodes so it would be wise to produce cages or otherwise engineered materials

-assuring high electron conductivity

-elimination/reduction of electrode additives (PVdF, PTFE etc.) which are demonstrated to be unstable during the charge step

hope this helps.

Dear Santosh,

I am not really sure Li-air provides higher power densities since the Li-air system is particularly slow in kinetics and depends on a catalytic effect. Li-air provides higher energy though, simply because its a light system, whether you calculate the energy based on the mass of carbon or electrode material or on the amount of reacted oxygen (this might prove a little more difficult).

I would not calculate the power densities since cycling of a Li-air system is extremely tricky and published articles clearly do not state every process involved in the electrochemical tests. This, as you might imagine, is quite important for future patents one wants to write. Moreover, it has been clarified that C components undergo corrosion at the charge potentials (4 to 4.6 V usually) and thus the very high energy values you can read on papers are often overestimated.

Concerning the problems:

-synthesis of a stable electrolyte at the reaction potentials

-synthesis of stable electrode materials at the reaction potential

-identification of suitable catalysts for the oxygen evolution reaction

-addressing the dendritic formation of Li anode or finding suitable anode materials

-starting the materials engineering: classical powders are not good electrodes so it would be wise to produce cages or otherwise engineered materials

-assuring high electron conductivity

-elimination/reduction of electrode additives (PVdF, PTFE etc.) which are demonstrated to be unstable during the charge step

hope this helps.

More details on your questions, in addition to the above mentioned comment, could be here:

Journal of The Electrochemical Society, 159 (2) R1-R30 (2012)

Adv. Energy Mater. 2011, 1, 34–50

I agree with Donato: Li-air (like Zn-air or fuel cells) can hardly provide high power density. Large energy density - YES. From my experience, supercapacitors can be a good choice if high power density is required, and a combination of battery and supercap can provide both energy and power (NOTE: due to unloading the battery in such a combined unit, the battery can provide even more energy and safety can be improved - no thermal runaway). See, e.g., www.yunasko.com for more detail.

Helpful additional informations may be found in here:

[1] P. Bruce et al., Nature Materials 11(1), pp 19-29, 2012

[2] J.G. Zhang et al., Journal of Power Sources 195(13), pp 4332-4337, 2010

[3] J.S. Lee et al., Advanced Energy Materials 1, pp 34-50, 2011

[2] cited best specific powers of Li-air batteries/cells(?) of 0.46mW/g which is only 1/100 compared to that of commercial lithium batteries (approximately 42mW/g). The basis of comparison is not quite clear to me (Power/mass electrode; Power/mass cell; Power/mass battery etc.)

On a technical level a complete battery has to be compared, hence including housing, electrolyte, seperator (if necessary), current collectors, additional components of the electrodes (binder etc.), excess lithium (in the case of lithium metal negative electrode) etc. etc.

In the lab and for scientific work it is meaningful to publish data based on electrode specific data such as mass or volume, but including all constituents of the electrode.

Yes. I agree with all the comments. Li-Air cell is like a fuel cell  and fuel cells are always shortchanged by the poor kinetics of oxygen reduction unless you use an expensive catalyst. A  Li -Air cell combined with a super cap may be a better proposition to get the energy and power at higher levels

Li-air batteries gain this advantage in specific energy since they use oxygen from the air instead of storing an oxidizer internally.

http://en.wikipedia.org/wiki/Lithium%E2%80%93air_battery

If you're interested in practical power densities then I suggest this article: Quantifying the promise of lithium–air batteries for electric vehicles, Kevin G. Gallagher,   Steven Goebel,  Thomas Greszler,   Mark Mathias,  Wolfgang Oelerich,   Damla Eroglu and   Venkat Srinivasan, Energy Environ. Sci., 2014,7, 1555-1563, DOI:10.1039/C3EE43870H 

i am going to make a membrane for li air battery, is there anybody who can help to make test cell assembly to test my membrane? if u know, plz let me know...thanks.