Here again is the table shown by MKTY at the same conference:
Note that in moving from a 140 cc prototype to the current 90 cc prototype, the maximum power the MKTY device can generate has dropped from 2000mW (2 watts) to 600mW (0.6 watts).
A reader asked this week how current direct alcohol fuel cell performance compares with lithium-ion batteries. The chart below from Motorola shows energy density for the main battery types by both volume and weight:
 
click chart to view Motorola page that it came from
In a presentation at the Knowledge Foundation's Conference on Small Fuel Cells, April 2002, Kurt Kelty, Director of Business Development, Battery R&D Center, Panasonic Technologies Co. (Panasonic is part of Matsushita, which holds a top three market share in Li-Ion, Ni-MH and Ni-Cd batteries) stated the following (all data from the published proceedings of the conference):
- From table titled "Current Li-ion Prismatic Pack Performance":
- 400 W/l
- 320 W/kg
- 200-220 Wh/l
- cycle life: 300-500 cycles
- Temp range: -20 C. to 40 C
- Assumptions: 6 cells of 16850 Li-ion; 2 Ah capacity @ 2C discharge; 3.7V; 220cc pack volume; 275g pack weight.
- (from a chart titled "Li-ion Cylindrical Development Trend")
- Limit for current Li-ion materials: ~500 Wh/l
- 2005 target for "next generation" Li-ion materials: ~550 Wh/l
- Another chart indicates a theoretical limit for Li-ion of ~580 Wh/l
The table below, prepared by Motorola fuel cell scientist Christopher Dwyer and published in the July 1999 issue of Scientific American, shows the the theoretical performance limits for FCs running on various fuels:
 Several observations can be made based on all of this information:
- The current energy density of Li-ion batteries (200-220 Wh/l) is already more than a third of the way to its absolute theoretical limit (~580 Wh/l), and only a 10% improvement is expected by 2005.
- DMFCs are only about than 1% along on the way to their theoretical energy density limit (based on Dwyer's limit of 4,900 Wh/l and MKTY's current claim of 55.5 Wh/l).
- A small fuel cell running on any fuel practical for small fuel cell applications (liquid H2 isn't practicle) has a theoretical volumetric energy density limit at least 5 times that of Li-Ion.
- Of the fuels that can be delivered with existing technology and can be easily stored at room temperature, alcohol offers the most potential by far. (Medis is now focused on ethanol, at least in part because ethanol is less toxic and less regulated than methanol. H2FC doesn't know how ethanol compares with methanol with respect to energy content. They should be similar. H2FC will try to find out.)
- The volumetric energy density (watt-hours per liter) of Medis fuel cells is already about 50% higher than Li-Ion, but the Medis chemistry has still only gone about 6% of the way to its theoretical limit (based on the theoretical electrochemical energy potential for methanol stated in Dwyer's table).
- The volumetric energy density of the current Medis prototype is about 6 times that of of the best reported current PEM-DMFC prototype (MKTY's).
- H2FC needs to try again to get gravimetric energy density (Wh/kg) data from Medis and MTI.
It seems to be a fact of life that the closer you get to any theoretical limit, the harder (and more expensive) it becomes to get any closer to that limit. This is good news for developers of direct alcohol fuel cells (DAFCs). Lithium-ion battery technology, according to the leader of the Panasonic/Matsushita R&D effort, is already within about 80% of its limit, and this is after many millions have been spent on R&D over many years, with a large number of talented brains being applied to the problem. Li-ion is at the point where it will take ever increasing amounts of resources to realize ever smaller improvements in performance.
DAFCs on the other hand are really at the beginning of their R&D curve. If, as expected, electronic device manufacturers apply substantial resources to the problem (both money and brains), it seems reasonable to expect that progress will be rapid and that it will move in large steps. This is especially true for the Medis technology, which has really been developed on a shoestring so far, and on which so far only a very small number of people (only Medis people) have worked so far. It is less true for PEM-DMFCs, which have already been worked on by many more people and with many more R&D dollars. Medis has said repeatedly that it will sign a major manufacturing partner or partners by the end of this year. When that happens many more dollars and brains will start being applied to the Medis R&D effort. H2FC continues to be confident that Medis will deliver a major partner or partners as promised, and that improvement in the Medis technology will become even more rapid once the resources of those partners are applied to the problem.
Manufacturers of hand held electronic devices will need new types of power supplies and will need them soon if they want to keep offering customers more functionality and maintain or increase usage times between rechargings/refuelings. The manufacturers have already done about all they can with Li-Ion without R&D and final product costs becoming prohibitive. They will have to look elsewhere if they want to deliver the products that will resuscitate their businesses. Medis clearly seems to have the best alternative to LI-Ion. This is why H2FC views Medis technology as so promising and MDTL stock such a good (albeit risky) investment
11:45:35 AM 
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