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2012-03-27_accelerating_innovation

By Raymond Murphy,2014-12-03 15:42
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2012-03-27_accelerating_innovation

Accelerating Innovation (text version)

    Below is the text version of the Webinar titled “Accelerating Innovation,” originally

    presented on March 27, 2012. In addition to this text version of the audio, you can

    access a PDF of the slides, a resource document, and a recording of the webinar.

    Operator:

The broadcast is now starting. All attendees are in listen-only mode.

Rebecca McEwen:

    Good afternoon, everyone. I'm Rebecca McEwen with the National Renewable Energy Laboratory. Welcome to today's webinar sponsored by the U.S. Department of Energy's Office of Energy Efficiency and Renewable energy. Our presentation today will feature information on accelerating innovation. I'd like to begin by thanking all of you on the phone for joining us this afternoon. I'm here with Matt Ringer and Meghan Bader of NREL and a number of esteemed presenters who I'll introduce in a moment. We're broadcasting from the National Renewable Energy Laboratory in Golden, Colorado.

[Next Slide]

    We're gonna give people a few more minutes to call in and log on, so while we wait I'll go over some logistics. After that, Matt will provide a little bit of background about the Energy Innovation Portal and then we'll delve into today's topic.

[Next Slide]

    First of all, I would like to let our listener's know that today's presentation will be posted online. You have two options for how you can hear today's webinar. In the upper right corner of your screen, there's a box that says "Audio Mode." This will allow you to choose whether or not you wanna listen to the webinar through your computer speakers or a telephone. As a rule, if you can listen to music on your computer, you should be able to hear the webinar. Number two, select either "use telephone" or "use mic and speakers." If you select "use telephone" the box will display the telephone number and specific audio PIN that you need to use to dial in. If you select "use mic and speakers" you might wanna click on audio set up to test your audio. Please mute either your telephone or your computer before the presentation starts. If you have questions during the presentation please go to the questions panel in the box showing on your screen. There you can type in any question you have during the course of the webinar. We'll start to present your questions during the question and answer segment of today's presentation if we have time, and if we do run out of time we'll post the questions and answers to the webinar archive. Also, there may be a survey that you can take after one of our webinars. Sometimes we send these surveys with the follow-up email that you'll get. Just keep your eye out for it. If you see one, we'd love to hear back from you. And last but not least, we will post the slide deck and a recording of this webinar to our website archives in the next few days. We'll send you the URL to access this in the follow-up email that will go out to you tomorrow. And with that, I would like to introduce our speakers today. First, we will be hearing Kandler Smith from NREL. He's a senior engineer who specializes in vehicle energy storage. Kandler works in the Lab Center for Transportation Technologies and Systems. Next, Chad Riggs from Oak Ridge National Laboratories Commercialization

    and Tech Transfer Office will present. We'll then here from Arrelaine Dameron who's a senior scientist from NREL. Arrelaine is an expert in surface chemistry and she works at the National Center for Photovoltaics. And wrapping up our presentation, we'll hear from Hannah Farquar from Lawrence L

    Livermore National Laboratory. Presenters, I wanna thank you all for being here today.

[Next Slide]

    And now I'm gonna turn you over to Matt Ringer.

[Next Slide]

    Matt Ringer:

    Good afternoon, everybody. My name is Matt Ringer. I work here at the National Renewable Energy Laboratory in the Commercialization and Tech Transfer Office. This is the first in the series of webinars that we're trying to do that will help highlight the technologies available on the Energy Innovation Portal. The portal as we call it, the address shown in the lower left portion of this slide is a web-based application that allows viewers to see and then generate leads for DOE-created innovation. We right now have more than 600 marketing summaries, actually, of DOE-funded innovation with $15,000.00 DOE-funded U.S. patents and published U.S. patent applications since 1992. At this point I'd like to turn it over to our first presenter, Kandler Smith from NREL. Kandler, we'll be transitioning over to you now.

Kandler Smith:

    Okay.

[Next Slide]

    All right, Matt. Can you see my screen now?

[Next Slide]

    Matt Ringer:

    We're good.

Kandler Smith:

    Well, great. Thanks for the opportunity. Thanks for joining this webinar. Today, this talk is about a fail-safe design concept which we have filed for visual patents on for a large capacity of lithium-ion batteries. As you know, lithium-ion batteries are reaching into new applications such as electric vehicles and also stationary power storage. These particular applications in some cases have hundreds or tens of thousands of cells such as that large trailer that you see in the top of this slide produced by A123.

[Next Slide]

    So what are some of the challenges, specifically safety challenges for large lithium-ion batteries? Lithium-ion batteries, all the chemistries, especially the electrolyte are flammable. They can undergo exothermic reactions if they reach a hot enough trigger temperature which then sustains further heat generation and if there's a spark present to catch the battery on fire. There's a lot of extra-expensive manufacturing quality processes

    that is required just to make sure that there's no foreign objects inside the cell and there's no defects. There's a lot of screening that also has to go on for cells. In general, for consumer electronics, there have been a variety of different protection devices which have been developed such as positive temperature coefficient, current interrupt device, shut-down separators which do not necessarily work or function the same way when you scale up these small cells into very large systems that have hundreds or thousands of cells. It's also very difficult to detect fault in large cells before catastrophe might occur. Some of the colorful images which I have here in the top right corner you can see the outer cell temperature during a simulated short where the inner portion of the cell close to the short has reached 800 degrees Celsius. The outside of the cell is still around 25 degrees Celsius, so temperature sensing is really not a practical manner to detect failures. Similarly if you tried to detect failures from voltage sensing, you can see some of the issues between small cells and large cells here so we have this dotted blue line is a healthy cell for reference undergoing discharge and charge pulses periodically, and we've simulated a short here at this one period in time. The large cell has sufficient capacity that the capacity itself can actually sustain that short for some time without seeing a measurable difference in the normal voltage response.

[Next Slide]

    So this is a list of some barriers which we feel are necessary to overcome for safe large lithium-ion batteries. So we believe that faults that lead to field accidents such as fires of large battery packs are believed to grow from some latent defect which evolves over time.

[Next Slide]

    So it's really necessary to detect as early as possible that some fault might be present in the battery system and also isolate if possible to a particular cell.

[Next Slide]

    You would like to separate any faulty cell from the pack to limit the electric current that feeds through the fault.

[Next Slide]

    And some of the typical methods which are used, both fuses and circuit breakers, neither is directly applicable, but with some smart combination you might be able to have some luck in isolating the fault.

[Next Slide]

    And then suppressing the fault, really the pack-fault response depends on many different pack integration characteristics such as how quickly you can dissipate heat from a faulted cell as well as individual cell safety characteristics.

[Next Slide]

    But you're not guaranteed if you take a safe cell design from a manufacturer if you scale it up to a large system putting mini cells and parallel and series that that cell will be safe

    it if undergoes some volt condition.

[Next Slide]

    So our concept differentiates the two different electrical current pathways in lithium-ion batteries. The first is the charge/discharge path and so that charge/discharge path is really what's important for electric power delivery so you want that path to be as conductive as possible. For cell balancing, uniformly using material inside the batteries, mini cells and parallel for example, you'd like to put electric current pathways such that those cells are all utilized uniformly.

[Next Slide]

    So the key area of our concept is that this fail-safe design concept is that it differentiates the power lines to be as conductive as possible and the balancing lines to be relatively resistive, and so what we'll see is that this limits the amount of energy that can be fed into the faults from surrounding cells.

[Next Slide]

    And furthermore, this proposed architecture really facilitates some unique capability for early fault detection and isolation.

[Next Slide]

    So looking at this concept, you can think of this as a module of five unit cells in series, and you can think of the two unit cells within each individual yellow box as being two separate battery cells that are contained in their own container or this could be internal connections inside of one battery container. So what we have here are relatively conductive branches which deliver the power to the system and then relatively resistive branches which are used for cell balancing and active material balancing.

[Next Slide]

    So during a normal discharge of a healthy module here, you see equal power flow between the left and right parallel branches of this unit.

[Next Slide]

    However, if you have some sort of fault, such as an internal short which occurs in one of the cells here, now you have an imbalanced flow of power or current throughout the system, and so it sets up this loop where the healthy cell is wanting to feed some of its current into the damaged cell, and at the top here, where we've placed two current centers, you see an imbalance between the two measured currents. And so one of the really nice features of this design concept is that rather than comparing what you think a healthy cell should be doing, comparing any cell in the pack to some sort of reference model or computer simulation which has inherent uncertainties in it, now you're comparing the faulted cell to other similar cells in the pack, and so just by taking the difference of these current measurements at the top of the module is what we propose to use as fault signal.

[Next Slide]

    So the advantage here is that your signal measurement is much greater than your noise, you have a known reference which is just zero at all times irregardless of whether the battery pack is under operation or not, and you have a single measurement per module.

[Next Slide]

    So, so far we have investigated the viability of this proposed concept against different design parameters primarily through simulation models and also some initial testing.

[Next Slide]

    So I'll show you some of the simulation model results, and here we have this same configuration with a faulted cell, Cell No. 2 we assume has a short at some period in time. We have chosen this to represent a 40-amp hour unit which consists of two 20-amp hour cells in parallel and chosen one particular value for the balancing resisters here, and so you can see depending upon whether you take your measurements from the top of the module or the bottom of the module, you get two different signals. In this case they look very similar, and so at 5 seconds when we've induced this simulated short into one of the cells, you get all the sudden a step change in this fault signal.

[Next Slide]

    And then depending on how large the magnitude of the short is, whether it's a very hard short or soft short, you get different magnitudes in signals. And while I won't share results today, there's very unique patterns in the signal which we feel we can actually isolate which cell in the module has gone bad.

[Next Slide]

    Looking briefly at some of the experiments which we've done, we have mocked up a similar system from the simulation results here.

[Next Slide]

    And in this situation, once again, you get very clear signals as soon as the short is induced.

[Next Slide]

    And for a range of hard and soft shorts you still get fairly clear signals here.

[Next Slide]

    So now moving on to isolating the fault since once we've detected a fault, what we propose here we feel can help some of the mitigation technologies which have been developed around small capacity batteries, help scale those up to a large configuration. So once this fault occurs and the fault is detected, you can open up a contactor at either end of the module which if it was a faulted cell at the bottom or top of the module it would be completely isolated at that moment. For this particular cell it would be isolated once a fused resister here from one of the balancing circuits either at the bottom or the top, whichever one sees the successive circuit as the neighboring healthy cell feeding the damaged cell,

[Next Slide]

    that fuse would completely isolate the cell.

[Next Slide]

    So once that faulted electrode or individual unit cell is electrically isolated, the subsequent behavior of the faulted electrode depends on the characteristics of that individual unit, so whether that unit's gonna go into thermal runaway or not depends on whatever safety characteristics you designed into that unit, and so the really nice thing about this concept is that we feel that designing safe packs can possibly be reduced to designing safe unit cells which is something that industry is familiar with.

[Next Slide]

    So the next steps, we feel we have a really good concept for overcoming some of the barriers of early fault detection, electrical isolation and fault suppression. We've developed simulation models to demonstrate the viability of the proposed concept.

[Next Slide]

    And as a next step we are starting some collaborations

[Next Slide]

    with others for further evaluation and development embodiment of the design in the technologies that were proposed.

[Next Slide]

    And finally, I'd like to just acknowledge our funding from Dave Howell and Brian Cunningham, our program managers at the Department of Energy as well as my NREL colleagues, so thank you.

Matt Ringer:

    Kandler, thank you very much. I'll just wait for a minute or two before we move on to our next presenter, Chad Riggs, to see if there's any questions that anybody has, and if not, I just wanna point out that all the technologies that you'll be hearing about today are available for some type of a license agreement here at the National Labs that are presenting them. There are summaries that describe the various technologies available on the Energy Innovation Portal. Again, the address for that is techportal.edre.energy.gov. At this point in time I'd like to move over to Chad Riggs.

[Next Slide]

    Chad works at the Oak Ridge National Laboratory just outside of Knoxville, Tennessee. Chad, you're on.

[Next Slide]

    Chad Riggs:

    Thanks, Matt. I am here with the inventor, John Simpson, who is one of the chief driving forces behind our superhydrophobic portfolio.

[Next Slide]

    And what he is going to do is step us through some of the recent technology breakthroughs that we've had and talk about some of the good things that are going on with this technology.

John Simpson:

    This is John Simpson. I've been working with the superhydrophobic coatings and surface treatments and what I wanted to do with this presentation is just talk about one aspect of it and what you can potentially do with our superhydrophobic coating surface treatments in the area of desalinization. Here we're showing what the problem with large-scale desalinization. Well, really, it's not commercially viable that's why you don't see desalinization plants all over the world now. Significance is pretty obvious. Abundant fresh water is limited and crucial for survival on the planet. The facts are, earth water supply is roughly 95 percent salt water, 2 ? percent locked up in ice, and the rest, half a percent or so is the only thing available for humans to, in most cases, fight over. Water disputes increasingly lead to conflicts. Unlike fuel crisis, there's no substitute for water. Oceans contain plenty of water, but unfortunately you would need to get the salt out to be able to use them, so that's what we'd really like to use desalinization. Current seawater desalinization is really limited by the economically, not being able to remove the salt buildup. Evaporated desalinization is easily the cheapest and the original way of doing

    desalinization, but in fact, the problem was you'd have to shut down the plant fairly often because of the salt tends to creep and go everywhere, clogs up everything, and so they shut down the plants and try to remove the salt buildups. Well, how do you do that? Well, the way is they would steam clean the fresh water, so not only do you shut down the plant, but you also are throwing away the thing you're trying to produce, and so commercially viable evaporative desalinization is basically in the United States has pretty much been abandoned. Well, with superhydrophobic coatings and surface treatments, we can change that game. We in fact can manage the salt buildup and manage the salt creep such that now desalinization with evaporative measures now becomes economically viable.

[Next slide]

    Technical solution: Our superhydrophobic coatings and treatments really have two unique features that make them commercially viable. One is that our coatings and surface treatments really pin a layer of air on the surface, and this pin layer of air really prevents salt from attaching to the surface and also prevents the salt creep that eliminates salt-induced corrosion on any surface that was coated. Plus it also stops the salt from adhering to the surface strongly too. In addition, we have various coatings, but the ones that we're really most excited about use diatomaceous earth as the main ingredient with these coatings. Diatomaceous earth is plentiful throughout the world, it's very inexpensive. We say it's dirt cheap, and the reason we say that is because it's actually a form of dirt, and it actually is. The price typically ranges from 30 to 50 cents a pound, and with a pound you can coat a very large surface with it. Of course we have to modify the diatomaceous earth from a chemistry standpoint, but once we do that and then put it into a solution with a binder and a surfactant so we can spray it on, then we have a coating that water in general, but salt water specifically, really stays away from and doesn't bond to. Now, I have some movies here. Up in top right-hand side, we show a stick that's been coated with the

    superhydrophobic diatomaceous earth and light hitting it, and you can see this, basically, the whole thing just lights up, what's happening there is we're seeing this pin layer of air. The light goes through the beaker of water, and instead of the light hitting the stick, it actually goes through the water and hits a layer of air first, and the layer of air causes ____ reflection. You see this mirror effect. So that's basically showing that the entire stick has a pinned layer of air on it. Now, I don't know if you can see it, but it would be nice to

Chad Riggs:

    We're gonna try to play these videos at the end of this, during the question part, but if not we have them posted on YouTube and we can forward that on to people, but we'll just stick with the presentation.

John Simpson:

    Well, I'll just describe them a little bit. The picture to the far left is an aluminum plate that's been half coated with the superhydrophobic diatomaceous earth. The other half's been uncoated, and we have a time lapse of sequence here showing that a pan of salt water, once it evaporates, the salt just climbs right up the surface of the uncoated surface, but it doesn't climb up the coated part at all, so basically that's showing that the sale water's repelled to the point where it doesn't creep up the surface at all if it's coated with our superhydrophobic ___. The next picture in the center there, and it shows a pan that had some ocean seawater in it, and left over the weekend to evaporate. You see the salt climbed up the top and over this aluminum pan. It even covered the table that this thing was sitting on. So salt creep was pretty dramatic. The next picture to the right shows another aluminum pan that was coated with our superhydrophobic diatomaceous earth and again left over the weekend for salt water to evaporate. In this case, not only did the salt not climb up on the pans, but the entire salt turned into a giant crystal that we just picked up and took out of the pan and put into a bag basically showing that not only do you eliminate salt creep with these coatings, but you eliminate the salt sticking to any surface, and it just forms a solid crystal that you can take out. From a desalinization standpoint, not only do you prevent salt from creeping up all over the place and corroding everything, but you could actually harvest the salt, and as far as that goes, other minerals too with this process. Now the picture to the far right in the center, is a little demonstration where I've got a powder coating which is a blend of our superhydrophobic diatomaceous earth with a black powder coating resin where we've sprayed this on, cured it so it's a nice well-bonded surface, but it's very superhydrophobic and we've covered this completely with water in the movie it hopefully will show you and then take

    some water out and then add some air to the layer and the entire surface just opens up indicating that the surface was completely dry the whole time even though it was covered with water so to speak because of the layer of air that was pinned on the surface.

[Next Slide]

    So advantages of these is it really makes evaporative desalinization commercially viable by preventing salt creep and keeping the salt buildup and localizing and making the whole thing manageable and the fact that this base material is very inexpensive, but the cost of coating the stuff now becomes pennies per square yard which is actually quite

    remarkable especially when you look at other superhydrophobic coatings they tend to be quite expensive and/or very low quality superhydrophobic behavior. Easy spray-on applications, it's non-toxic stuff, basically diatomaceous earth is a morpha silicon oxide.

    It's used as a food additive in food filler, it's probably a main ingredient in your toothpaste that you used this morning. It's very non-toxic. Once we change the chemistry, it will inhibit corrosion, inhibits bio-fouling we've shown, salt deposits are easily removed, and hopefully we'll show you a movie of some of that __ showing you the pictures. And again, we can also use this to harvest materials and salts from seawaters, but the fact that the evaporating seawater does not stick to the pan means that it's gonna start crystalizing next to itself and different materials crystalize at different rates and so you can just pull off the stuff that's crystalized and harvest various minerals and salts based on at what point in time they solidify. So it offers electrical, icing and corrosion protection for circuits in the grid also.

[Next Slide]

    So the superhydrophobic can do that. Thank you. This is me. I'm a senior researcher at Oak Ridge National Lab and I'll let Chad kind of take over from here.

Chad Riggs:

    Yes, we have a variety of materials. This is sort of an update to the ongoing work which we have in this portfolio which covers the superhydrophobics which are excellent for waterproofing, anti-fouling, anti-corrosion and energy efficiency applications, and anyone interested in licensing, I have my contact information there.

[Next Slide]

    With that, I think that Matt may be able to link this webinar material to some of the videos that we had available.

[Next Slide]

    I was gonna show the shortest one. We can just sort of scrub through the salt creep which shows the salt going up and I know it may be jumping on your computer but it's

    interesting, the beige side is coated, and as the water is reduced in the pan, the salt even creeps up the uncoated edge, and it's a time-lapsed film so you can just see how the salt creeps. With that, I think that we'll take this time now to ask if there are any questions and we'll turn things over to Matt and the next presenter if not.

Matt Ringer:

    Thanks a lot Chad and John. I appreciate your time both of you spending and describing this technology. I do encourage those of you who are listening in to the webinar to go and visit some of the other videos that are associated with this particular technology on the Energy Innovation Portal. I'm looking right now and I'm not seeing any questions, so I wanna move to our next presenter, Arrelaine Dameron.

[Next Slide]

    She works here at NREL

[Next Slide]

    in our National Center for ___, and is gonna talk to us about a new methodology for determining water permeation. Arrelaine.

Arrelaine Dameron:

    This is Arrelaine Dameron. I'm a scientist at NREL and I'm speaking to you from the Solar Energy Research Facility.

[Next Slide]

    Just to get everyone sort of on the same page, myself, two other scientists, Matt Reese and Michael Kempe, sort of devised the means to measure water permeating through ____ barriers. Our interest is primarily in helping out _, you know, creating barrier films for water-sensitive components in ___ PV and OPV which is definitely applicable to a broader field of flexible electronics, ___, PV, etc. So just to get everyone on the same page, what we're talking about is creating a barrier layer that keeps out the ambient environment, mostly water, humidity from the ambient environment protecting sensitive components on the other side. The way that works is in real general terms the vapor absorbs onto the barrier film and then dissolves through the barrier and the desorbs on the other side or outgasses and then ___ whatever your sensitive components might be such as contacts or transparent conducting oxide ___ layers, organic __, etc. Pretty much anything that's sensitive to water. So barrier components are typically your front sheet or your back sheet. They can also be encapsulant in the realm of electronics, it might be

    your touch screen, the aspects like that. The problem is that barrier manufacturers, people developing these materials, needs some means to characterize how much and how fast water's moving through these barriers. To give you an idea what that looks like, down here in the lower right-hand corner I'm showing EVA which is a typical back side encapsulant for PD. I'm showing the water vapor transport through the film as a function of time. And you can see at the beginning when you just stick the humid environment barrier you have no transmission and then as time progresses, the water first transports through the film and then reaches a steady state ___ through the film. So what we're looking for is a reproducible, sensitive scalable method for measuring characterization.

[Next Slide]

    So just to give you an idea for these different applications what tolerable water permeation levels are, you know how your standard bag of chips that you find in the vending machine down the hall would be somewhere in the range of 1 gram per meter squared per day. Your favorite TV screen at your house, you know, a couple orders of magnitude lower. A thin-film PV falls in the range of 3 to 5 grams per meter squared per day. OPV and OLEDs, they're tolerable components need water vapor transport rate barrier that can provide less than 1 times 7 minus 6 grams per meter squared per day. And to give you an idea of what that means relative to the lifetime of say your standard PV module, on the left I've given you an estimate of the total volume of 1 meter squared area of film might be after 20 years of accumulation, so at 1 gram per meter squared you're talking about collecting 7 meters of water over the course of 20 years and at 1 times 7 minus 6, you're talking about 7 microliters. So we're talking about really small amounts of water permeating through these films and somehow characterizing that. So the reason

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