GRA
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Re: All "Future" battery technology thread

Mon May 15, 2017 6:10 pm

JRP3 wrote:Battery University isn't always an up to date resource, but even they show NCA as lower cost than LiFePO4, and though their graph shows LiTiO as least expensive, further down in their summary table they say the following:

Long life, fast charge, wide temperature range but low specific energy and expensive.

Looking at the graphs I think we may both be making the same mistake in interpretation, but in different cases. I was reading the graphs as if the radial distance indicates worst to best as you go outwards, but if it instead means lowest to highest the contradictions disappear. It only matters which it is in terms of cost, and BU doesn't say which it is .

Another, more detailed source I have at home, probably dating from 2012 as it mentions the Roadster, LEAF and Volt as being available (Unfortunately while I usually write the name, date and author(s) on a xerox when I make it if it isn't already present, I didn't in this case), does say LTO is more expensive, which agrees with you and BU and also with my thought that titanium is expensive.

I suspect, as BU says, that much of the switch from LMO towards NMC is driven as much by longevity as it is by higher capacity. The same source I mentioned above lists the various Li-ion types, and after giving their voltages and specific capacities (in mAh/g rather than Wh/kg.), leaving out Li-Co-O2 here's what it says of each in the comments section:

[Cathodes]
LiMN2O4: Most commonly used in automobile, low cost, acceptable rate capability, poor cycle and calendar life.

LiFEPO4: Low cost, improved abuse tolerance, good cycle life, and power capability, but low capacity and calendar life.

NMC: Lowest cost, high capacity, life is less than NCA.

NCA: Highest capacity, low cost, but safety concerns.

[Anodes]
Graphite: Most commonly used in all applications, low cost.

LTO: Highest cycle and calendar life, but costly and low in energy density.

Silicon: Still in research stage, high energy [3,700 mAh/g!, versus 372 for graphite and 168 for LTO], but large volume expansion during charging [elsewhere stated as up to 270%] need[s] to be solved.

Another academic source, which I believe was in the same collection of articles I copied the first one from contradicts some of the above. It rates each type (not including NMC) by energy and power density, maturity, life expectancy, cost, safety, operating temp characteristics, usable charge range, and application. As it quotes a battery manufacturing cost study from 2010 it must post-date that. Anyway, here's what it has to say, for each at that time (there've undoubtedly been changes in the interim, especially with NCA and LMO). My comments are in [ ]:

Energy density: NCA 170; LMO 150; LMO/LTO 150; LFP 140.

Power density: NCA Highest; LMO Good; LMO/LTO Good; LFP fair.

Maturity: NCA Most proven[?]; LMO Safety and durability needs proving; LMO/LTO safety and durability need proving; LFP electric monitoring needs proving.

Life expectancy: NCA Good, demonstrated 15 years and 350,000 cycles; LMO OK, capacity fading concerns; LMO/LTO Very good; LF Very good.

Cost: NCA High (cobalt and nickel); LMO High; LMO/LTO Highest; LFP lowest.

Safety: NCA Least thermal stability, high charge thermal runaway; LMO better than NCA, some thermal instability expected; LMO/LTO better than LMO and NCA; LFP Best, least risk of overcharge.

Op. Temp characteristics: NCA [blank]; LMO Capacity fades above 40 deg. C, poor charging at low temp; LMO/LTO Capacity fades above 40 deg. C; LFP Poor cold temperature performance.

Usable charge range: NCA Degrade at high charge, approximately 30-70%; LMO Capacity fades with cycling, approximately 30-70%; LMO/LTO 100% charge; LFP 10-100% charge.

Application: NCA Power-assisted HEVs, because of high power density and cycle life; LMO HEV; LMO/LTO HEVs, because of long life, low energy but high power; LFP PHEV and BEV.

What's of additional interest in this last source is that it includes the most comprehensive cost breakdown for Li-ion battery manufacturing I've ever seen, with three bar graphs which divide costs into 'Materials', 'Manufacturing', and 'Other' [Profit, Warranty, Transportation, Marketing, R&D, Corporate O/H], and the total at that time seems to be about $1,100/kWh if I'm reading it right. Each larger category is further divided into cell, module and pack sub-levels, and each sub-level even more specifically in each stage - for instance, the materials cost graph lists costs for cathodes as Active materials, Binder (PVFD), Additives (Carbon), Aluminum foil (if I've got the divider in the right place) then the anode; Graphite, Binder (PVFD), copper foil here or in the next category; Lithium salt, Polyethylene, Tabs/terminals, Container, Yield adjustment, Enclosure (I think this is at the module level), Terminals, Enclosure (pack level?), Connections, Control/Safety circuitry. Similar divisions are present in the other two graphs.

The imprecision is due to the fact that the original source from which the graphs were taken was probably in color but was printed in this book in black & white, making many of the divisions difficult or impossible to determine, even if I weren't trying to read them from a Xerox.

This kind of data is undoubtedly considered a proprietary trade secret by the companies, so it's not surprising that precise cost data is scarce. One of the most surprising statements to me, and what may well be the largest source of cost reduction since then, even more than economies of scale, is that the article states:

"What stands out immediately from Fig. 4.7 [the bar graphs] is the enormous scrap rate, which is estimated to contribute about 25% of total pack cost [ Note, I believe that this refers to the portions of the graphs labeled 'yield adjustment', as they represent the largest single category that are under the control of the manufacturer]. To help put this measure of wasted material in context, while automotive industry standards require scrap rates below 0.1%, battery manufacturers have been found to operate with scrap rates of up to 60%!"
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

JRP3
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Re: All "Future" battery technology thread

Mon May 15, 2017 7:04 pm

NMC: Lowest cost, high capacity, life is less than NCA.


More incorrect information. NMC has higher cycle life than NCA, hence why Tesla uses it in their daily cycling grid storage products instead of NCA. Much of the other data you listed is also inaccurate, I just don't have the time to pick it all apart I'd suggest you toss away any old sources you may have and look for more recent information.

GRA
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Re: All "Future" battery technology thread

Wed May 17, 2017 3:57 pm

JRP3 wrote:
NMC: Lowest cost, high capacity, life is less than NCA.

More incorrect information. NMC has higher cycle life than NCA, hence why Tesla uses it in their daily cycling grid storage products instead of NCA. Much of the other data you listed is also inaccurate, I just don't have the time to pick it all apart I'd suggest you toss away any old sources you may have and look for more recent information.

That's always the problem with immature technology, as it's a moving target and the relative advantages and disadvantages of different approaches can change over relatively short periods of time. Then there's the problem of definitions - e.g. are they talking about initial or life-cycle costs in a particular case, or are we comparing the same kind of operating service/cycles (DoD etc.), or is it apples and oranges? and finally, there's the difficulty of finding an independent source, as most of the academic researchers, including people like Jeff Dahn, Yet-Ming Chiang , Stan Whittingham or John Goodenough, are all or have been involved in for-profit spin-offs from their university work, so their claims are likely to be less than objective.

Oh, I believe I've identified the source for the two articles that provided conflicting data in my previous post. From my EV Bibliography page, I'm pretty sure they were from

"Electric Vehicle Integration into Modern Power Networks"; Garcia-Valle, Rodrigo, and Pecas Lopes, Joao, ed.; 2013. This is a collection of articles by various, mostly European authors on different aspects of the subject. Articles range from the fairly non-technical to ones filled with formulas. The fact that English is a second language for many of the authors means some of the articles have awkward syntax, a minor irritation. Beyond the needs of the average owner, but there's some good descriptions of the differences between current Li-ion battery chemistries, what kinds of communications will be necessary for Smart charging, different types of infrastructure needs, forecast demand curves for 5 different EU countries with various levels of EV penetration as of 2030, etc., if you're curious about this sort of thing.

ISTR a couple of the articles were filled with SEM photographs of dendrite formation and discussion of causes of same, i.e. way over my head technically.

A possible source for one of the articles, also listed in the EV Bibliography, is "Electric Vehicles: Technology, Policy and Commercial Development"; Serra, Joao Vitor Fernandez; 2012. Written by an EV enthusiast so less objective than it could be, but provides a good overview of the various issues involved in EVs.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

GRA
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Joined: Mon Sep 19, 2011 1:49 pm
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Re: All "Future" battery technology thread

Sun May 21, 2017 4:41 pm

Via IEVS:
With Cost Of Cobalt Rising, EV Prices May Increase…Or They Might Not
http://insideevs.com/with-cost-of-cobal ... -increase/
Nikkei reports a high increase in lithium-ion battery making materials such as lithium (go figure) and also cobalt over the past few years, which now could apparently affect battery cell pricing, and in turn, the pricing of EVs themselves.

Cobalt has surged a couple times over the past ~twelve months. . . .

    “The international price of cobalt, a material used in rechargeable lithium ion batteries, rose to an eight-year high of around $27.50 per pound in mid-April, a 90% increase since the beginning of the year and 2.5 times greater than a year ago. Cobalt is “being bought on the anticipation of increasing demand for use in electric vehicles,” according to an official at a major trading house.”

    “Cobalt is a byproduct of nickel and copper, but supply is falling as mining companies roll back production due to a sluggish copper market and stronger environmental regulations. Some are also worried about instability in the Democratic Republic of the Congo, which is a major producer of cobalt.”
    .

Separately lithium also is becoming more expensive. Prices are three times higher than two years ago in China (“international benchmark for the metal”). . . .

Chemistries which don't make use of Cobalt (LMO, LFP) might be looked on more favorably at least for shorter-ranged cars, despite their disadvantages of lower Es and (in the case of LMO) poorer longevity/heat tolerance. Or not, as commodity prices always fluctuate due to changes in supply/demand.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

GRA
Posts: 7359
Joined: Mon Sep 19, 2011 1:49 pm
Location: East side of San Francisco Bay

Re: All "Future" battery technology thread

Fri Jul 21, 2017 2:29 pm

Via GCC:
First crop of DOE Battery500 seedlings awarded nearly $6M; high-risk, high-reward toward 500 Wh/kg
http://www.greencarcongress.com/2017/07 ... 1-doe.html

Announced in 2016, the Battery500 consortium, led by the US Department of Energy (DOE) Pacific Northwest National Laboratory (PNNL), intends to build a battery pack with a specific energy of 500 Wh/kg, compared to the 170-200 Wh/kg per kilogram in today’s typical EV battery. (Earlier post.) Achieving this goal would result in a smaller, lighter and less expensive battery, and electric vehicles with significantly extended range.

As part of its efforts, the Battery500 consortium announced the “Seedling” program—new, potentially risky battery technology research projects complementing the core Battery500 research effort (earlier post)—and said it was setting aside a projected 20% of its 5-year, $50-million funding for that purpose, or about $2 million per year. Now, DOE has selected the first crop of seedlings: 15 Phase 1 projects, receiving almost $5.7 million in funding. (Earlier post.) Promising phase 1 awardees will be competitively down-selected at the end of 18 months for a second phase of research. . . .

The Battery500 project is focused on three keystone projects:

    A high nickel content cathode with a Li-metal anode;

    Sulfur cathode and Li-metal anode; and

    Innovative electrode and cell design.

The Seedling projects are intended to enhance one of the three keystone projects, or to provide new concepts. . . .

Howell said the Battery500 keystone projects themselves are well underway, with full participation in the annual Merit Review planned for next year.

    Nickel-rich cathodes today (NMC) have somewhere around 30-40% nickel in the cathode itself. To achieve higher energy density goals, Howell said, you need more nickel. However, that can blowback on cycle life. Howell said that some of the researchers are seeing a 30-40% increase in capacity through using a different binder technology in conjunction with a Li-metal system. He expects a first baseline cell by the end of the first fiscal year and a test by the end of the calendar year.

    Sulfur coupled with Li metal has the highest energy density outside of Li air systems, Howell said. While there are still huge gains to be made even falling short of the theoretical capacity of the system, there are also significant problems, he noted. Dendrite growth with a Li metal anode can short out the cell within 10-30 cycles. There are a lot of good ideas on how to mitigate those issues, Howell said—but it will take time.

    We have made a lot of progress in the past in Li-ion technology. We are taking the expertise and refocusing it on the longer term issues. If we can achieve our targets, that would result in a significant boost in the performance of batteries and a significant reduction in cost.

    —David Howell. . . .
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

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