By Rud Istvan,
EV Batteries—and A New Hope
This is the second of two loosely related guest posts that ctm and I recently discussed, drawing on my subject matter expertise (SME) in energy storage materials and related matters. My SME status was hard won over several intense research years in support of my now globally issued energy storage materials patents for supercapacitors. This post is written for laymen (in the spirit of expert Andy May concerning his recent superb petroleum shale geophysics posts). It omits non-essential technical details (of which there are many) and focuses on electric vehicles (EV), because that is most relevant to global warming concerns and WUWT skeptics. It intentionally contains a lot of ‘terminology’ that enables those interested to follow up with independent internet based research. There are also some related ‘obiter dicta’ making separate points leading to an important ancillary WUWT conclusion. It is written in two parts: Current lithium ion improvements, and A New Hope (an intentional nod to Star Wars Episode IV, because that is what it is).
Current LiIon improvements
All true batteries store electric charge in some form of an electrochemical reaction, either primary or secondary (aka reversible/rechargeable). All are descended from Alessandro Volta’s 1800 invention of his primary ‘pile’ using copper, zinc, paper separators, and brine as electrolyte. (You can make a Volta pile in your kitchen by taking a US penny (outer surface is now plated copper), a sanded US penny (interior is now zinc) and sticking both about ¾ the way into close together but not touching (~2mm separation) slits into a lemon (lemon juice is the electrolyte, lemon pulp is the separator). Good enough for lighting a small Christmas tree bulb for a while (until the undefaced penny’s copper plating is consumed) for your child’s middle school science fair project. Just touch the two bulb wires to the protruding penny edges. Either way works, since this is a DC pile and little Xmas bulbs only care about amp*volt since they heat by resistance ohms. (For the historically inclined, Alessandro’s invention of the battery pile got the volt (electrical ‘force’)–one of three fundamental DC electricity parameters–named after him. [The other two are the ohm (resistance, named after Georg Ohm for his 1827 paper, and the amp named after Andre Ampère for his 1823 current [{charge ‘volume”} speculation—although that was not established rigorously in physics until Maxwell in 1861 in his famous four tensor equation system fully describing all of electromagnetism]. But I digress.) So history suggests Volta’s frog leg twitching battery pile discovery was important. And our modern life, with or without global warming, but definitely with electrics and electronics, confirms history’s judgment.
In the most familiar reversible (rechargeable) commercial battery type, vehicular lead acid (PbA) invented in 1859, the electrochemical reaction is simply lead to lead sulfate and back, using sulfuric acid in water as electrolyte providing sulfate ions plus the disassociated hydrogen ions as electrical charge carriers.
Lithium ion batteries (LIB) are the most energy dense rechargeable electrochemistry presently known, essentially because lithium ions transfer twice the electrical charge of aqueous hydrogen ions (PbA, NiMH). (Since lithium, like sodium, really doesn’t like water, the LIB electrolyte solvent must be a water free organic [aprotic] solvent, hence their infamous flammability.) LIBs were initially developed in the 1980s. The conventional rechargeable LIB used in portable electronics and EVs is an electrochemical ‘rocking chair’ subtype, where on charging the lithium ions resident in the metallic cathode intercalate into the carbon (graphite) anode via an aprotic (organic, usually propylene carbonate [PC] or acetyl nitrile [AN] electrolyte) containing a dissolved lithium salt such as LiPF6. This intercalation process electrochemically reverses on discharge, just like like PbA.
There are several metallic LIB cathode materials, the two most common being Lithium iron phosphate (LiFePF4) and Lithium cobalt oxide (LiCoO2, ‘LCO’)—often with other added metals like nickel and manganese (LiNiMnCoO2, ‘NMC’). The cobalt cathode types have the best energy density so are the most common—hence legitimate media concerns about future cobalt supply. The alternative “Peak lithium” concern is mostly fake news, as lithium is the 20th most abundant element on earth. The peak lithium question is cost not abundance, as the inexpensive present supplies come from lithium rich brines or spodumene rich pegmatites. Most cobalt is a minor byproduct of copper ore production, a vastly greater mining proposition already much more depleted in global ore grade.
The individual LIB cells packaged into the battery come in two common form factors:
Cylindrical has the anode/separator/cathode assembly spiral wound and stuffed in a tube (like an AA battery). Tesla uses this form factor, as do Apple’s new iAirPods.
Pouch has the assembly stacked flat like pancakes and sealed with electrolyte in an impermeable ‘bag’. Chevy Volt uses this form factor, as do iPhones and iPads.
These permutations lead to many tradeoffs among cost, energy density (both volumetric and gravimetric), power density, and cycle life as a function of heat dissipation and solid electrolyte interface (SEI) buildup on the carbon anode. Virtually all LIB improvement initiatives focus on reducing cost, enhancing energy/power density, or extending cycle life. Despite much press hype (usually as part of some fund raising scheme), none of these labs/startups are anywhere near volume commercialization, and none solve the fundamental energy density related range anxiety issues for EV’s.
The inescapable LIB range anxiety problem is basic electrochemistry. Although the figures vary some with precise cathode composition, the theoretical limit for LIB LCO or NMC is ~280Wh/kg. The Tesla cell is already 254Wh/kg in 2018! Elon Musk cannot overcome approaching that theoretical limit with his Tesla GigaFactories. Nor can any LIB startup, no matter how innovative they claim to be.
Tesla says its Supercharger stations are an alternative range anxiety solution (20 minutes to 50% charge, 40 minutes to 80%—versus 5 minutes to gas up). BUT what they don’t say is that such rapid charging kills battery life due to rapid charging heat buildup thanks to the inescapable Nernst electrochemistry equation, which is derivable in two separate ways (fundamental thermodynamics and Boltzmann statistical mechanics) insuring Nernst is ‘real’–like the Pythagorean theorem.
Two fascinating related sidebars:
(1) The Pythagorean theorem (in a right triangle, a2+b2=c2 where c is the hypotenuse) has been derived thousands of ways both geometric and algebraic. It is thought the original Greek ‘proof’ was geometric despite Diophantus, since algebra was ‘invented’ much later by the Arab al-Kwarizmi.
(2) Walther Nernst derived his famous equation in 1887, for which he received the Nobel Prize in 1920. Tesla hype is NOT ignoring some minor annoying detail.
A New Hope
The other basic form of direct electrical charge storage is capacitance where no chemical reaction is involved, only basic Maxwell physics. The most familiar is the simple ceramic ‘chipcap’ where charge is stored electrostatically on metallized plates separated by a ceramic dielectric. These capacitors are the modern descendants of the Leyden jar invented in 1745, and are ubiquitous—trillions of tiny chipcaps worth $billions per year, used in all electrical and electronic devices. In the following image all those little variously sized, both ends white tipped, brownish things are chipcaps.
Passive filtering components for the A11 on an iPhone 8 Plus PCB
The most energy dense capacitor is a supercapacitor (aka ultracapacitor aka ELDC), where the charge storage mechanism is the interface between two phases of matter and the storage is in the Helmholtz’ ‘electrolytic’ double layer capacitance (DLC), first explained by him in 1888. This is the electrostatic physics mechanism that produces lightning in thunderstorms. (As an aside, the motto of my NanoCarbons LLC company holding my materials patents is “Lightning in a Bottle”, for good reason.) Most supercaps use special expensive high purity activated carbons for both the anode and cathode, and a standard aprotic solvent with a lithium salt (or cheaper salt equivalents such as TEMA or TEA) as the electrolyte. Supercaps have between 10 and 100 times the power density of the best power dense LIB, but only about 1/10th the energy density. Their main advantage is where power density and cycle life are paramount. Supercaps have tested cycle lives >106 compared to LIB with at best low single digit 103 when babied. A $billion plus market today, and about a $250 million plus carbon materials market (which suffices for NanoCarbons LLC).
It turns out that it is possible to create a hybrid cell that is half LIB and half DLC. The details are complicated, but the basics are simple. Lithiate the carbon anode rather than the (also carbon) cathode of what would otherwise be a supercap, with LiPF6 as the electrolyte salt. This hybrid is called a Lithium Ion Capacitor (LIC).
In 2007 and 2008, Subaru head of R&D Dr. Hatozaki presented prototype data (at the 17th-18th annual International Seminars on DLC and Hybrid Energy Storage Devices) for LIC cells with very attractive measured properties.
Subaru was looking for a replacement to standard automotive lead acid batteries (PbA) that would have a significantly enhanced cycle life with more energy/power density in a PbA size without excessive cost. Subaru’s motivation was an under hood battery replacement for mild hybridization like the Valeo system, that did not kill cycle life via the Nernst equation. They used a standard activated carbon for the cathode, lithiated graphite for the anode (with a very clever first charge lithiation scheme using a wrapped lithium metal foil mesh), and standard LIB LiPF6 as the electrolyte salt in PC solvent. The result was a 3.8 volt device (better than ~3.6V LIB and much better than supercaps at 2.7V for basic electrochemical potential breakdown reasons beyond the scope of this post) with a demonstrated 20,000 cycles (95%SoC to 45%SoC [Δ2.2V] at a 40C rate at 80°C (Holy Nernst equation!!) for simple under the engine hood replacement where an ordinary PbA otherwise sits but even beefed up fails early and often in mild hybrid applications.
But, Subaru decided LIC enabled mild hybridization did not make commercial sense (see companion post ‘Electrification Common Sense). So they licensed their LIC technology to JM Energy. It is sold as the Ultimo and used in specialty applications like industrial UPS (backup/reactive power/peak support). A Subaru commercial near miss, despite Dr. Hatozaki’s brilliant R&D success.
The supercapacitor energy density limitation that LIC seeks to overcome is directly related to the effective (carbon) surface (per gram or cc) upon which the Helmholtz double layer can form, and to the voltage at which it can operate for adequate cycle life. Activated carbons have high total surface areas, but surprisingly low effective surfaces. (Full disclosure: My NanoCarbons inventions cost effectively increase effective surface about 50% using patented tricks, lowering cell costs by 20-30%.)
Growth of vertically aligned closely spaced multiwall carbon nanotubes on a metal current collector via a chemical vapor deposition (CVD) process provides very high effective surface (an MIT Ph.D thesis). But CVD is difficult to scale and quite expensive.
The 2009 MIT spinout company that attempted to commercialize this technology for EV’s has received tens of $millions in DARPA and DOE grants, but has struggled to get beyond very high priced very small niche specialty markets. It survived, barely, mostly on continued government R&D support rather than product sales.
When Geims got the 2010 Nobel Prize for discovering graphene, it was surmised by many that graphene based structures could solve the effective surface problem more easily and cheaply than vertically aligned carbon nanotubes. Graphenes are essentially single atom sheets of carbon (like an ‘unrolled’ single wall nanotube, only with greater XY area). They are extremely strong, highly conductive, and fairly easy to make. Graphene Energy (spun out of Ruoff’s nanotech materials group at U. Texas Austin) investigated this energy storage possibility. Ruoff converted graphite oxide (GO) to graphene in an aqueous solution using acid. Their problem was that the resulting graphenes clump thanks to Van der Waals forces, and the effective clump surface was no better than NanoCarbons LLC but much more expensive. Graphene Energy failed and folded.
What this failed company’s research suggested was that some inexpensive way to make a robust unclumped graphene structure might be a path forward.
Given that background, imagine my SME shock reading in 2016 that Henrick Fisker has just founded a new electric vehicle company plus a new ‘battery’ subsidiary, Fisker Nanotech, claiming >400 mile battery range plus very rapid charge time in a lithium/graphene device. The HOLY GRAIL according to MSM PR! For those who do not know about him, Henrick Fisker is a famous Danish supercar designer (Aston Martin DB8 of James Bond movie fame, amongst others). He started a US electric supercar company before Musk’s Tesla. Alas, the sourced batteries exploded over 100 times in his Karma cars (really bad karma). Then his LIB supplier A123 Systems (a nanotech spun out of MIT) imploded into bankruptcy losing $250 million of US subsidies and grants plus $100 million for investors, after being sold to China for ~$200 million. Fisker Automotive quickly followed, whose investors promptly lost an additional $1.4 billion.
Can there be any credence to Fisker’s 2016 announced phoenix like rise from his EV Karma ashes? He has funding, so somebody believes. But then, many somebodies also believe Elon Musk and his LIB GigaFactory. The credibility question requires untangling a fascinating technology development web that leads to a new LIC technology. The patent applications for Fisker’s PR’d New Hope have now published. The most important of several are US20170149107 (Hybrid electrochemical cell) and US20170369323 (Production on a large scale). Interested readers can go examine the technical invention details for free using the simple application number search function at the USPTO website.
In what follows we explain simply what Fisker is up to, and how the New Hope invention came about. There are several subparts, producing a combined plausible commercial breakthrough. Each is yet another self-contained energy storage R&D mini-saga teaching lesson.
Thread one is the invention of laser scribed graphene (LSG) in 2012. Then UCLA Ph.D student El-Kady in Prof. Kaner’s nanotech lab made the LSG breakthrough. He took ordinary graphite oxide, coated it onto an ordinary DVD disk using water, then ran the dried DVD disk through an ordinary commercial HP DVD Lightscribe. (Lightscribe used a 780nm [infrared] 5 mW LED laser to inscribe a DVD label/illustration onto a DVD surface coated with heat sensitive dye, each scribe track about 20 microns wide, total full disk pass for a ‘label’ about 20 minutes.)
HP has since stopped selling LightScribe technology because it is monochromatic and not durable. Another commercial near miss.
The LSG lab process produced about 8μ thick 3D graphene structures in DVD sized sheets via simple laser heat reduction of graphite oxide to graphene. These graphene films are extremely mechanically robust because of 3D edge interlinking.
He further showed that six passes of the Lightscribe laser (each ~20 minutes per dvd) improved conductivity many fold. He made a high effective surface, mechanically robust, highly conductive graphene structure for supercaps. Ph.D granted along with a major Nature paper. This was reported and intensively discussed at the ISDLC conference in 2012. We global ‘experts’ discounted it, because the Nature paper showed the electrode thickness was only ~8 microns and the reported supercap energy density was nothing exceptional in aqueous phosphoric acid electrolyte at maximum 1 V, practically useless since energy stored is a function of voltage squared and supercaps were at that time already at 2.7V. We were probably right about the Nature paper, but (mea culpa) probably wrong on its subsequent New Hope implications.
Thread two is the subsequent 2015 El Kady and Kaner development of an asymmetric hybrid device based on LSG. Their new hybrid combined LSG graphene carbon supercapacitance with (subsequently electrodeposited nanoparticle) MnO2 pseudocapacitance. Total voltage was now 2 V, up from 1 V. Still not a lot of stored energy, but perhaps interesting for specialized niche applications like transdermal drug delivery via electroporation according to hyped UCLA PR. Yawn.
Thread three is from recent LIB research. Lithium titanate has been an object of intense study for several years as a safer, energy denser alternative to traditional intercalating graphite for LIB anodes. There is a big problem. The material’s conductivity is very poor, so its power density is grossly inadequate, and its charging time excessive even for cell phones and laptops. Graphene is extremely conductive. So this nanotech research focused on somehow incorporating conductive graphene into the bulk of lithium titanate at a nano-level in order to improve anode conductivity.
There have been two ‘recent’ seminal lab research ‘breakthroughs’. Both use nanotechnology and the idea of graphite oxide plus chemical precursors to lithium titanate, with the final material mix formed in a single heat treatment synthesis. One paper used an aerosol process. The other paper used a sol gel process. [Guo et. al., Electrochemica Acta 109: 33-38 (2013), available outside paywall via google as an MIT.edu posting.] These newish papers present two different lithium titanate precursor chemistries together with graphite oxide deposited using two different methods for a subsequent single nanocomposite heat synthesis.
Fisker Nanotech did not said anything specific in their massive 2016 fundraising PR about their ‘battery’ other than it uses graphene and lithium (their patent applications published more than a year AFTER their big PR funding push). My SME supposition in 2016 was that they had a new manufacturing method LIC. A mechanically robust LSG graphene cathode plus a mechanically robust hybrid graphene/lithium titanate anode, anodes synthesized in one step from triple precursors using an LSG analog rather than the literature’s sol gel or aerosol. Much easier and cheaper than Subaru’s 2008 anode lithiation. And likely still ~20000 LIC cycle life at a 40C charge rate for much faster EV charging while still meeting 20000 cycle vehicle device life (20000/365 is 27 years at two charges per day). The now published applications show that my initial SME 2016 suppositions were correct.
Fisker also said they had a patent pending machine to make 1000 Kg (/day?) of graphene electrode at $0.10/Kg. That may be a bit hyped, but was not implausible even in 2016 by simply ‘thought experiment’ reengineering of LSG in light of the two LIB lithium titanate anode papers already cited above, before reading now published US20170369323. Following is the written (posted 2016 on Judith Curry’s Climate Etc), thought experiment at the time.
The commercial Lightscribe 780nm 5mW laser has a track width of 20 microns. It took 6 20 minute DVD spins to reach optimal LSG conductivity. Fine for simple lab proof of principle for a Ph.D thesis. Not fine for volume production. But there are cheap commercial solid-state diode 780nm lasers with up to 2 watts (2000 mW) power each. Rather than a lens concentrating the laser power as in the Lightscribe, it could be a lens dispersing 2000mW over a larger area with enough power for 1 pass heat treatment as in the sol gel and aerosol papers. Lightscribe hit 20 microns track width with 5mW 6 times for perhaps a millisecond each for an optimal graphene electrode; that is a total of ~30mW on 20 microns for ~6 milliseconds. A 2000mW 780nm laser could hit a 1.3 millimeter stripe with the same total power at the same scan speed. Or an even wider track with a slower scan rate (more likely for a bulk production machine).
Imagine a paper machine like system. The anode furnish box equivalent is continuously spreading a water based graphite oxide (GO) plus 2 lithium titanate chemical precursors slurry onto a rapidly moving continuous support substrate equivalent to the Lightscribe DVD. First step beyond the furnish box, evaporate the furnish water with radiant heat and fans. Second step, IR heat nanosynthesize using powerful 2W spread focus 780nm lasers, converting GO to graphene and the lithium titanate precursors to interspersed lithium titanate nanocrystals. This finished anode material is still supported by the rapidly moving continuous support belt. Third step, peel off and spool up a finished continuous electrode sheet as wide and long as wished as the support belt turns under at the end of the machine for its return trip.
Imagine a second identical machine making the complementary 3D graphene only cathode by simply leaving out the lithium titanate precursors from the furnish box mix. Big rolls, made very fast and cheap. Spooling up very thin but very strong electrodes, made continuously in bulk very cheaply. No expensive aerosol or sol gel or CVD small batches as in the previous lab papers and commercial attempts.
Imagine assembly of Chevy Volt like prismatic pouch ‘battery’ cells. Cut the electrode materials to size before or after stacking as many layers (with separators) as wanted from the spooled rolls; they are very conductive so simple contact likely suffices. No backing metal current collector is needed like for LIB anodes and supercap anodes and cathodes (a cost and weight saving). Attach a current collector to one end (the hybrid MnO2 patent application describes simple silver soldering at the external case connection point of the stacked layers). Encapsulate in pouch, fill with electrolyte, seal—just like Chevy Volt cells.
Form a battery pack similar to Chevy Volt/Bolt, with fewer interleaved thin aluminum heat extraction plates needed. Done except for the control electronics.
The basic cell and battery production steps have already been developed by GM. Continuous sheet nanoelectrode production is analogous to conventional papermaking, substituting purpose build evaporation/ LSG for the draining mesh belt/heat calendaring of paper machines. Every other needed technology element has been shown in the lab. Thanks to optics and LED infrared lasers, scale up appears to be a matter of straightforward engineering rather than invention.
Concluding comments
First, the various asides in this guest post were intended to make a fundamental science/technology point indirectly. Battery electrochemistry is NOT a ‘new’ invention like semiconductors in 1949. Nor does it follow Moore’s law as warmunists might wish. (This is also true for PV, but proving that is way beyond the technical scope of this post. See guest post Grid Solar Parity at Judith Curry’s Climate Etc for a factual take on that subject.) Battery technology is now a very tough slow slog, nothing like what global warming activists fantasize.
Second, in 2017 Fisker announced his coming EV supercar will NOT initially use the Fiskers Nanotech revolutionary LIC that he (fundraising) PR’d in 2016 as discussed in this post. Fisker will instead use conventional LIB pouch cells from Korea’s LG Chem, the supplier to the Chevy Volt (to newly be discontinued in 2019 by GM for apparent reasons predicted in loosely companion post Vehicle Electrification Common Sense). The path from lab to commercial scale production is long, fraught, and uncertain. Fisker just proved that truism again.
Nanotechnology enabled LIC is the only plausible EV option on the present technical horizon. It is truly the only New Hope. But like the rest of the Star Wars saga, it presently exists in another galaxy far far away.
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“Lithium ion batteries (LIB) are the most energy dense rechargeable electrochemistry presently known, essentially because lithium ions transfer twice the electrical charge of aqueous hydrogen ions (PbA, NiMH).”
Not sure about the assertion that the lithium ion transfers twice as much charge as a proton. Both ions have a charge of +1.
Yes, it is far more complex than that because of the energy changes associated with the hydration (solvation) of the charge on any ion.
In proper graduate Chemisty classes you will get your wrist smacked with metal ruler for thinking there is ever ever any such thing as an unsolvated H+ ion. But it is just so much more convenient to draw and write it as such.
Heh. Back when I earned mine, some 40 years ago; that the proton is never “free’ was well known to us at the freshman level. What generated loud conversations was how many water molecules were associated to each proton. Was it 6? More? Whole bulk? 🙂
People seem so nonchalant about hydrogen. That may be because they’ve never worked with the stuff. I have worked with a lot of nasty chemicals; yet hydrogen scares me the most, when present in amounts more than a gram or two. (2g of pure hydrogen is about 6.023 x 10^23 molecules)
Rud, do you have a graph of where your materials come on energy density vs mass (& volume) and power density vs mass (& volume). The usual graphs, I’m sure know what I’m referring to.
I haven’t seen them on either of these posts, but haven’t read them all in depth or clicked on all links. WUWT unfortunately seems to be less friendly towards posting images after recent changes/hiccups.
Sure. There are several in my various ISDLC conference papers. You are referring to a standard Nyquist plot (usually energy density on the y, power density on the x, both axis logarithmic). Google will bring up any number of them , maybe even some of mine.
Take a standard supercap (say Maxwell 3000 Farad). My materials (standard low cost from 12dtex rayon, notbthe more expensive finer fibers, provide 1.4x the energy density and ~2x the power density, while reducing cell cost 20-30% depending on cell capacitance (higher=>more).
So appreciably up and to the right (both good) on any Nyquist plot.
And you are quite correct that Nyquist plots for volumetric and gravimetric e/p density look different. And there are even more tricks to the trade. For example, to maximize power density you thin electrodes, resulting in more seperator and current collector, so poorer volumetric and gravimetric energy density. That is how the power dense LIB for the experimental F1 ‘hybrids’ for race year 2010 were created. Did not end well, as that year’s Mercedes F1 caught fire due to overheated LIB battery at the last practice run for the first F1 race in Singapore. One of my faborite Nyquist plot illustrations is the driver jumping out as the LIB located under his seat exploded. No wonder F1 is an exciting sport.
Thanks. I’ll take a further look. I’ve often wondered about the F1 energy storage materials, with some thoughts of my own. Living in Northamptonshire, the Mercedes Team is actually a ‘local business’. Not many things where Northamptonshire gets to claim the title of World Champions. Not since the death of the shoe industry of the British Empire!
Interesting. The discussion of the HP Lightscribe was interesting. I still have one of them (it was functioning as a paperweight until the DVD slot in my Mac decided to spit out all DVDs I tried to insert…..now I use the thing to read DVDs but can’t write to it). I was somewhat disappointed with the device as the labels were not all that striking. However, putting paper labels on DVDs was a no-no and I needed a more professional label than just writing on the disk. This was what was available at the time.
I bought a Think City EV in 2012 when the company was going bankrupt. Think was Ford’s EV division, and spun out in the early ’00s. The company didn’t have a sugar daddy, corporate or financial, so I was able to snag one for a 70% discount just as the doors were closing. It was entirely a curiosity purchase, as I had been interested in EVs for a long time.
I have kept close track of the performance and fuel economy, and generally used my ownership as the focal point for my ongoing personal study of EVs, electricity generation, and renewables in general. My car resembles the offspring of a drunken three-way among a Chunk candy bar, a Mercedes Smart car, and an escaped rodeo bull. I outfitted it with a set of steer horns and named it “Thumper the Baby Bull,” but the horns tragically blew off on the Interstate last spring as I drove at 70 mph into a 35 mph headwind.
Thumper has 13,400 miles on the odometer. He’s got a 24 kW battery, with average summer range of 75 miles and an average winter range of 50 miles on 80% of the battery. We live in the countryside above the Columbia Gorge, a 12-mile round trip from town. Thumper is a fun little grocery-getter, and at 2-1/2 to 3 cents/mile for fuel (vs 24 cents a mile in the other vehicle here, a Ram 3500 diesel pickup truck), the price is right for the jaunts into town.
I have seen three reasons for EVs.
1. Fuel efficiency
2. Performance
3. Ecology
I can dispense with the third argument right away. Even if we were to care about CO2 (which I don’t), replacing every sedan in America with a fully electric vehicle would reduce CO2 output by 3%. I’ve compiled that number from a detailed study of the actual statistics, mapped to the average U.S. generation sources. We are seeing an ongoing shift from coal to natural gas, and an increase in wind and solar, but the effects on that 3% number will be mild. In a few decades, maybe it would expand to 4%? Trivial at best.
The second argument is a pretty good one, and would be much better if driving ranges were longer and recharging was a lot quicker. EVs, by the nature of electric motors vs internal combustion engines, are much simpler and therefore much cheaper to maintain. Driving dynamics are superior given the torque characteristics of electric motors.
The first argument is potentially the strongest. At the U.S. generation mix, the thermal efficiency of an EV is in the low 40% range. A standard gas car’s efficiency is about 19%, incorporating the losses of making gasoline. But new engines from Toyota and Mazda (“SkyActiv’) show great promise in radically increasing the thermal efficiency of gasoline-powered cars to EV levels.
I have personally wavered on the subsidy issue. I have long supported the U.S. subsidies on the grounds of energy efficiency, but have questioned my view in light of the new SkyActiv high-compression technology. The best long-term argument for ongoing subsidy would be geopolitical; much of our oil is sourced from politically dicey places, while the fuel for generating electricity is present in abundant quantities much closer to home.
People really get worked up about EVs — both positive and negative.
My take:
EVs have evolved to the point where they are a practical choice for some people. Battery technology is just the first of several major barriers to wider adoption. I looked at EVs several years back and concluded that for me, even with all the tax credits and other subsidies there was not one that met my needs at a price I could justify.
If you concentrate on just the practicality and Total Cost of Ownership (TCOE) of EVs (i.e., ignore any consideration of saving the planet), there are some clear benefits:
* Lifetime maintenance expenses per mile should be significantly less with an EV. No transmission, no exhaust system, no cooling system, no fuel or air filters, no ignition system. In general a whole lot fewer moving parts that wear and require lubrication, which account for most of the scheduled maintenance cost. Less wear on brake pads and rotors saves on another standard maintenance item. All of this should more than make up for the eventual cost of battery replacement or refurbishing.
* Unless you live somewhere that has gone howl-at-the-moon crazy with renewable energy mandates, you will spend less on electricity than you would for fuel to go the same distance in an ICV (Internal Combustion Vehicle). Making this work for all your neighbors too will likely require electrical distribution upgrades, which will eventually raise your electric bill, but you will still save.
But some things which appear to be benefits are either temporary or somewhat deceptive:
* Tax credits will expire eventually and they only apply to new vehicles, so you trade a savings up front for an instant depreciation by the same amount.
* Lack of fuel taxes will also go away at some point. Georgia already has a way to tax EVs for road use; every other state will get there sooner or later.
EVs also have significant shortcomings:
* They are not suitable for extremely cold conditions — battery output and life both suffer and range is sharply reduced.
* They are marginal for extremely hot conditions — continuous AC use also reduces range.
* You simply cannot drive an EV as many miles per year as an ICV — charging waits will kill you. I knew people in sales who routinely put 100K miles/year on their cars. Refueling plus bathroom break takes 10 minutes at most. With an EV you will spend 5-10 times longer waiting to get back on the road.
* Even with the subsidies, an EV with a reliable 300-mile range is going to cost more than a comparable ICV. The breakeven point is most likely well beyond the term of the new car loan you take out to buy one.
* Depreciation on Nissan Leaf models is much higher than their ICV cars, even taking into account the tax-credit discounted price. If your situation changes and the EV no longer works for you, you will likely take more of a loss in selling it than you managed to save driving it. There isn’t enough resale data on Tesla to compare.
When I looked into them in my situation the only way I could possibly justify an EV would be if I could completely replace one of our existing ICVs. We are a two car family with a two car garage and two reasonably economical and fully paid for vehicles already. At the time there was no charging station at my place of employment and the range of the Nissan Leaf was already marginal for my regular commute; let alone any side trips. Even with all the tax breaks and other subsidies available at the time the economics of buying a Leaf simply didn’t work, especially if it would have to be a third car. A Tesla with much better range was completely out of the question.
The situation today is different: there is a charging station at work and used 2013 Leafs with 30K miles and under are available in this market for less than $10,000. I could probably live with a used Leaf knowing my wife’s SUV was available for long trips and any other needs the Leaf couldn’t handle. From my garage back wall to the main electrical panel is ~20 feet through a raised ceiling, so the electrical work to put in a 240V charger is about as cheap as it could be. I still can’t possibly justify a Tesla.
Commenter Greg above clearly has the right idea: buy a heavily depreciated EV and use it where the much more expensive to operate Suburban is not needed.
You also have to consider that you are not just betting on the technology, but on the company as well. The TCOE savings only work if the company will be around for the next 10 years to take care of you. As a company, Toyota is an extremely safe bet; Tesla is a risky one. Tesla has very much a DeLorean reboot vibe — a lot of hype and dazzle, but so far lacking demonstrated performance for staying power. I wouldn’t make a $60K bet on the Tesla company at this point. GM is much more likely survive but the Volt is discontinued.
So last year I turned in my old 2005 Toyota Corolla with 191K miles on it and bought a 2013 Toyota Avalon Hybrid. I haven’t bought a new car since 1990; my general rule of thumb is buy a car when it’s 50% depreciated but still has 75% of its reliable service left, and pay cash for it. With modern quality cars this works out to be roughly 36-48 months old and 36-48K miles. The low fuel price at the time depressed resale values on hybrids; I figure I paid about a $1,000 premium for the hybrid over the V6 Avalon with the same options. So far I’ve put 17K miles on it and have a cumulative 38.6 MPG, with an average fuel price of $2.43 / gal. Almost all that fuel was E10. If I consider just the tanks of no-ethanol I’ve used in that time, I’m right at the EPA 40 MPG estimate. And with a 17-gallon tank, I’m good for 620+ miles before any risk of running out. In practice, it has worked out to a refill every 10-12 days, and only then because the instrument panel really starts to bug me about needing fuel. I’ve never put in more than 14 gallons, so the dire warnings are probably based on IPCC models.
There are compromises: I give up cargo space and at least in theory I’ve got all the same maintenance liabilities as a straight ICV plus the added risks of the hybrid battery. Was it a smart choice? I don’t know yet; ask me in 10 years. In the meantime I’m happy: I have an extremely nice ride, better economy and much better range than the car I traded in, and the regular winner of CU’s most reliable used car, large sedan category. My brother recently bought a Tesla — he claims he will save TCOE over the next 20 years; we’ll see.
I’d like to thank Rud Istvan; reading his original article at Judith Curry’s site made me realize I had dismissed hybrids unfairly, which definitely had an impact on my Avalon purchase.
Most of wouldn’t care in the slightest regarding EV’s if it weren’t for the fact that we are being forced to help pay for them.
Electrics have both a transmission and a cooling system for the battery.
EVs have a differential and CV joints of course, but they don’t have the planetary reduction gears, clutches, torque converter or the control systems to manage gear shifting that ICVs require.
I believe the battery cooling is only required if you use a super charger.
‘I believe the battery cooling is only required if you use a super charger.’
No you need to understand how the battery modules are made up to make a car battery pack and Tesla are at the cutting edge of some sophisticated technology-
https://www.youtube.com/watch?time_continue=3&v=TdUqQZC2dcE
Those cylindrical cells are efficient building block storages but then you have to string them all together with lots more considerations and hence the price.
I wish my car still had an electric heater that use to be a common option.
Summertime mileage with my 1.4 liter engine is 34-35 mpg. Currently at about 18F its 26-27 and will be about 24 in January-February. It just barely hits normally operating temperature on my nine mile commute with the transmission lagging the engine in reaching an optimum temperature. About 1 kw-hr of electricity each day would likely boost my winter time mileage by about 2-3 mpg. Twice that if it could be plugged in at work.
Wow. What a very interesting informative post
Thank you Rud.
What an informative and well written article that was. Thanks, my knowledge of batteries has been greatly enhanced.
Notwithstanding all that was credibly (and in some cases, incredibly) written above, there does lie outside the ‘normal’ box that 99.99999% of ppl find themselves confined to (by choice, by failure to look outside said ‘box’ and observe for game-changing tech on the horizon) OTHER solutions to motive (as well as stationary) ‘power’ or energy production/generation.
Progress continues on the development of one particular “energy source” with the immediate goal being a field-deployable (meaning, beyond the simple laboratory-curiosity and “tech-demo” stage) unit designed to showcase both the underlying technology and demonstrate an actual, practical application.
But, don’t take my word for it, nor anyone else’s word for it as expressed by Huub Bakker in this informative, whirl-wind tour of this tech:
Note: lecture begins at timestamp 04:30
http://webcast.massey.ac.nz/Mediasite/Play/8ef7e03e26fc458b8eb7f351738f26811d
Why not instead of recharging batteries just replace each time empty battery with a charged one. It lowwers the “charging” time to minimum if properly constructed.
It would just require to have more backup batteries or a system of battery replacement maybe with battery being a borrowed or leased part.
Then you can stop worrying with the time of charching and prolong batteries life massively while cost substantially (also building additional market demand).
Leaving a stack of batteries costing 5,000.00 to 7500.00 each piled up in the recharge racks awaiting re-charging, so the technicians can forklift them over to the parking lot and exchange them underneath car one at a time? People do not even now wait 15 minutes-20 minutes for a lube oil change every 3000 miles!
The battery stores will be able to keep that stack of batteries for how many nights before they are stolen?
Before the one bad battery in that rack of a 100 batteries overheats and burns up while recharging each night?
The electric car batteries require replacement, not recharging? They need a replacement every other day, would they not?