Thursday, April 23, 2009

EEStor Bloggertivity Announcement

The EEStor blogger has observed that a new announcement from EEStor Inc. has hit the wire. Curious question about this latest announcement: what does it really mean? Does it bode well for EEStor believers or does it play into the claws of EEStor skeptics? The EEStor blogger knows.


But what's the rush? There's so many other bloggers and reporters out there working diligently to figure out the puzzle. Surely, there's no need for the EEStor blogger to enlighten anyone. It's all so transparent and easy to decipher. Why, just look at the market movement of the Zenn Motor Company. Surely the market has it right, RIGHT? Right?



thubten said...

Blogger come out of the closet. YOu think it is a scam don't you.

How about this missive.

Below is a detailed discussion clearly demonstrating the invalidity of EEstor’s claims and targets.

EEstor does not report either a new material, or any data that indicates the ability to store more energy than known titanate dielectrics. EEstor calculates the amount of energy they expect their capacitor to store. A fundamental oversight results in an invalid calculation that is inaccurate by more than a factor of 100! The error is uncomplicated. Simply, energy does not equal ½ CV2 for a capacitor made from a nonlinear dielectric. For all high permittivity ceramics, the dielectric permittivity (K’) decreases markedly with increasing electric field E (dielectric saturation). Energy increases roughly linearly with voltage for these materials, as opposed to with the square of the voltage (ref 2).

Importantly, this is not a case wherein EEstor claims to have made some specific breakthrough regarding this issue. No such breakthrough is reported. There are no energy storage measurements, no permittivity versus field data, and no mention of eliminating or reducing dielectric saturation. Their patent and presentations indicate a complete lack of awareness (or lack of acknowledgment) of this issue. EEstor simply purports to make (or aspires to make) high K barium titanate based material, with a K of 18,000, and ultimately with an incredibly high breakdown strength of up to 300V/um. They then calculate the energy stored as ½ CV2 without comment on the use of this equation.

How large of an error does this cause? Calculated energy density is ½K’E2 when calculated total energy is ½CV2. For K = 18,000, and a field 100 V/um, this invalid calculation gives 800 J/cc. (½K’E2 = (0.5)(8.85×10-12 F/m)(18,000)(1×108 V/m) = 8×108 J/m3 = 800 J/cc). Eight references describing actual studies of energy storage in high permittivity ceramic dielectrics (including barium titanate and BST) are noted below. All of these studies indicate a maximum energy density ranging from about 2 to 12 J/cc, depending on the exact material and the maximum breakdown voltage (which is on the order of 100V/um in most cases). Notably, for the studies involving very high K materials, if the authors had simply calculated energy storage using ½ CV2, as EEstor does, it would have similarly resulted in reported values on the order of 100 times greater than the actual measured values!

Hence there is no basis for concluding EEstor has made any advance in the field, and clear evidence that the sole basis for their claim of unbelievably high energy storage is the simple, invalid calculation. Their aspiration (with no reported results) to triple the breakdown field to 300 V/um in combination with the invalid calculation adds an additional factor of 9, giving an absurd 7200 J/cc (along with all of the corresponding hype and speculation about a new miracle material).

Below are notes regarding the references noted above that clearly substantiate the analysis above (one report of personal measurements, the other seven directly from a Google search on energy storge in ceramic dielectrics). .

1. (My work, unpublished), 1987 – Report to Maxwell Corporation on energy storage potential in high permittivity ceramics. Measurements were made on thin films up to 100V / um on barium titanate and PLZT based dielectrics. K varied as ~ 1/E over much of the voltage range, resulting in an approximately linear increase in energy density with field. Maximum energy storage was 4 – 8 J/cc.

2. Love, Journal of the American Ceramic Society 1990 – Also observed a linear increase in energy with voltage for several classes of high permittivity (up to 12,000) thick film ceramics (barium titanate, PLZT, PMN). Reported up to 5 J/cc at 80 V/um.

3. Triani,, (ANSTO and CSIRO – Australia, 2001 – J. Materials Science and Engineering. They reported 8 – 10 J/cc for PbSr titanate, and noted that the energy densities were similar to those of the best BaSr titanate materials for a given field, but the maximum fields of up to 100V/um (100KV/mm) were superior for the PST.

4. Kaufmann, et.,al, Penn State and Argonne, 1999. DOE Contract Report. They report sputtered BaSr titanate thin films with a K of 500 and a breakdown field of 100 V / um. K decreases to 120, and the energy storage is 11 J/cc. Also reported are data for hot pressed AFE/FE lead zirconate. These had a maximum K of 12,000, and a breakdown strength of 12 V/um, resulting in an energy storage of 3.2 J/cc.

5. Fletcher,, 1996 Journal of Applied Physics D. They report a theoretical analysis based on Devonshire theory of ferroelectrics. Optimal energy density is predicted for materials with Curie Temperatures well below the operating temperatures. Applied to BaSr titanate, the model predicts an energy density of 8 J/cc at 100 V/um. The model was verified in actual materials.

6. Randolf, et. al, (Austria, 1996) – IEEE Annual Report - Studied dielectric energy storage for powders embedded in polymer matrices. They reported using a PbTitanate-PbZnNiobate material with K = 5000, and reported energy densities of 1 – 10 J/cc.

7. Lawless, et. al., Ceramphysics Inc. 1992 report a high permittivity ceramic (K = 8000) for which a maxium energy density of 6 J/cc was observed for samples with optimum breakdown strength.

8. Freim, Nanomaterials Research Corp NASA SBIR Proposal 1998, reports reduced dielectric saturation for nanocrystalline microstructures, and states that “Commercial coarse grain dielectric based ceramic capacitors are ineffective for use in high energy storage and delivery applications since the dielectric’s permittivity decreases sharply when the applied voltage is increased.” They target 5 – 10 J/cc for the proposed new improved materials.

If you aren’t familiar with dielectric saturation, or even if you are and you don’t think back to where ½ CV2 comes from – you miss it. And until you collect information and compare with the calculation, you have no clue it makes a factor of 100 difference in this case. People don’t even realize what EEstor is asserting. If they said, “we are going to use barium titanate based materials, which up until now how only been able to store 8 J/cc, but our barium titanate will store over 1000 J/cc – people would ask themselves how is that possible and what is the basis for that claim.

Then you would find out it’s not just a case of them not providing data or proof of their claims. They don’t even claim to have observed or measured a property indicating their barium titanate would be different. There is nothing left but the calculation. The sole origin for their high numbers is that they simply start with the K of high permittivity modified barium titanate (eg., K = 18,000 not a new achievement), and simply calculate energy = 1/2CV2. Anyone could have done that at any time for any high K material and gotten the same outrageous numbers.

So at that point, one should ask why people get a factor of 100 less when they actually measure it. The answer is well documented and obvious – dielectric saturation. So the only justification for using 1/2CV2 which gives a factor of 100 higher than known and understood measured values, would be if you made a measured observation that you have a fantastic new material that doesn’t saturate at all and stores 100 times the energy.

EEstor has never made any such claim or reported to have made any such obvservation. They just did the calculation. It’s just a mistake.


b said...

fred, i think it's a world changing technology.

b said...

or i mean thubten or fred or

aaron said...

No thubten, Science does not matter to weir, he has no interest in PHD's or any other publications with all that boring dialectric breakdown nonsense. Its all just so ancillary. Regardless if the whole shabang can be accurately traced back to a math error.

Friendly advise from my brother Zawy. Dont talk about falling rocks with someone when they assume there is something wrong with gravity. You always loose. They can fill in the blanks with anything.

B cant admit its a scam an more. It would really make him look silly. The best thing he can do is play along and appear to be imbicillic.

Bretspot said...

Hillarious thubten, you've been saying the same stuff for as long as I can Google it back. You just copy-pasted this info again. Do you have a special folder on your computer that says "EEStor is impossible". Do us all a favor and rename that folder "EEStor is impossible because I don't know how they prevent dielectric saturation and they don't tell me how to in my patent" :)

David said...

EEStor was expected to have had their EESU technology certified as achieving its stated functionality at working voltage, though were not required to publicly release these findings.