Toyota developing LPG hybrid taxi for Japan market
Volkswagen Group brings in new Head of Group Strategy from GM

Technical review outlines challenges for both batteries and fuel cells as basis for electric vehicles

In an open-access invited review for the Journal of the Electrochemical Society, Oliver Gröger (earlier post), Volkswagen AG; Dr. Hubert A. Gasteiger, Chair of Technical Electrochemistry, Technische Universität München; and Dr. Jens-Peter Suchsland, SolviCore GmbH, delve into the technological barriers for all-electric vehicles—battery-electric or PEM fuel cell vehicles.

They begin by observing that the EU’s goal of 95 gCO2/km fleet average emissions by 2020 can only be met by means of extended range electric vehicles or all-electric vehicles in combination with the integration of renewable energy (e.g., wind and solar). Based on other studies, they note that without an increasing percentage of renewables in the European electricity generation mix, the only vehicle concept which could meet the 95 gCO2/km target is the pure battery electric vehicles. (Hydrogen produced via electrolysis using the EU mix or by natural gas reforming would exceed the target.)

Theoretically, with renewable electricity, the 95 gCO2/km target could also be met by extended range electric vehicles with 40 miles all-electric range if 50% of driving is powered by the battery, or by fuel cell electric vehicles (FECVs), with hydrogen produced by water electrolysis.

While these propulsion concepts look promising, their contribution to CO2 emission savings in the transportation sector would only be meaningful if their market penetration were substantial. In the absence of government regulations, the latter largely hinges on consumer acceptance, which in turn strongly depends on cost. In addition, in the case of BEVs, recent studies clearly showed that BEV driving range (closely followed by cost) are the predominant variables determining consumer acceptance.

Since vehicle cost and range largely control market penetration, we will first provide a rough estimate of the cost/range projected for BEVs and FCEVs. Next, we will briefly review the current status and the expected future progress in lithium ion battery (LiB) technology, which is currently used to power BEVs. This will be followed by an assessment of the perceived technological barriers and the potential energy density gains for so-called post-LiBs, namely lithium-oxygen and lithium-sulfur batteries. Last, we will discuss the materials development challenges for FCEVs, focusing on approaches to reduce platinum catalyst loadings and to improve fuel cell durability.

—Gröger et al.

(Volkswagen’s Gröger, who holds a number of battery patents, was responsible for the Li-sulfur section of the paper.)

Factors influencing the needed/perceived range of all-electric vehicles: i) amount of storable energy (in units of Wh) either in (post-)lithium ion batteries or in hydrogen to power H2-fuel cells; ii) vehicle energy consumption (in units of Wh/mile); iii) the customer’s perceived range, strongly affected by the recharge rate; and, iv) novel integrated mobility concepts. Source: Gröger et al. Click to enlarge.

As others, including automakers such as Toyota, have done, Gröger and his colleagues suggest that that BEVs will be the preferred option for short-range vehicles, while FCEVs are more suitable for large driving distances. In explaining this, they note that:

Since the societal value of electromobility requires substantial market penetration, it hinges on consumer acceptance of all-electric vehicles. … the main obstacles to BEV consumer acceptance are driving range and cost. The observed paradox with regards to driving range is the difference between actually needed and preferred driving range, which is related to several factors: i) inaccurate understanding of needed driving range; ii) habitually large driving range of conventional vehicles; iii) so-called “range anxiety”, i.e., the fear of getting stranded; and, iv) lack of experience with limited-range vehicles.

… Since driving range is a critical factor determining market penetration, it is useful to briefly examine the options to increase the actual or the perceived range of all-electric vehicles… Quite clearly, increasing the gravimetric and volumetric energy density by means of advanced LiBs and so-called post-LiBs would be the most straightforward way toward long-range BEVs; alternatively, H2-powered FECVs would be another path toward long-range all-electric vehicles. Driving range could also be increased by reducing energy consumption per mile … which can be accomplished by the use of light-weight materials (e.g., carbon composite chassis explored by BMW), by improvements in electric-drive efficiency, and by advanced vehicle climatization concepts (e.g., for the UDDS (urban dynamometer drive schedule) drive cycle, BEV driving range reductions by ≈17 and ≈50% have been reported for cooling and heating, respectively).

In some studies it has been noted that the adequate BEV range perceived by the customer could be lower if the recharging time would be sufficiently short. Therefore, companies have been establishing fast-charging stations (ranging, e.g., from 24 kW by BMW to 120 kW by Tesla). For a 100 mile-range BEV requiring ≈21 kWhnet, complete recharge could be accomplished within ≈60 min. using a 24 kW charging station and within ≈12 min. using a 120 kW charging station (assuming 90% charging efficiency). … On the other hand, FCEVs requiring ≈5 kg H2 for 300 miles range can be refilled within conventional filling times (≈8 min. acc. to the 0.6 kgH2 /min. filling rate reported by DoE, and only 3.5 min. from 20 to 95% fill-level for Toyota’s Mirai vehicle), so that they would have similar range and refilling attributes as conventional vehicles.

—Gröger et al.

In either case, however, cost and durability challenges still remain and at least evolutionary technology advances are still required, the authors go on to explain. Some of their main points, backed up by references to the literature, with respect to major technology options include:

  • Despite the enormous amount of research and development efforts put into Li-ion batteries, specific energies significantly larger than 0.25 kWhname-plate/kgbattery-system are not yet on the horizon. As a result, lithium-ion battery-based BEVs with 200 miles range or more will probably be out of scope for mid-size car market/pricing that would be attractive for mass adoption.

  • With respect to one of the targeted post-LiB systems, the Li-air or Li-O2 battery, no stable electrode components and electrolytes which would result in a demonstrated/reproducible 100% O2-recovery over a Li-O2 battery charge/discharge cycle have yet been confirmed. Therefore, the authors note, further fundamental research and materials development is required to determine the viability of Li-O2 batteries.

    If successful, the expected gains in specific energy of a practical battery-system would likely be not better than ≈1.5–fold compared to advanced lithium-ion batteries (Si/C-composite anodes with HE-NMC, NMC811, or NCA cathodes), they suggest.

  • On the Li-sulfur side, it is difficult to achieve the expected gravimetric energy density from a lithium sulfur battery-system. Along with that, the requirements of the automotive industry have also changed over the years, with increased focus on volumetric energy density rather than only gravimetric energy density. The achievable volumetric energy densities for lithium—sulfur batteries, independent of the anode, will always be substantially lower than that of lithium ion batteries, the authors observe.

    To deliver cell-level gravimetric energy densities competitive with advanced LiBs (Si-anode and HE-NMC, nickel-rich NMC811, or NCA), lithium-sulfur batteries would require relatively large areal capacities (≥4 mAh/cm2) and high cathode sulfur content (≥60 %wt). Such Li-S batteries with silicon anodes could reach 350–400 Wh/kgcell—at best ≈1.3-fold larger than the values projected for advanced LiBs.

    450– 500 Wh/kgcell could be obtained using a Li-metal anode—assuming the issues of safety and durability were dealt with successfully. This is ≈1.3-fold larger than the gravimetric energy densities for advanced LiB cathode materials coupled with lithium anodes.

    In terms of volumetric energy density, lithium-sulfur battery cells are definitively inferior to LiBs. However, with regards to cost, lithium-sulfur batteries might be superior, if the additional components which might be needed to improve cycle-life and safety (diffusion barriers, etc.) can be realized at low cost, the authors suggest.

    Further using silicon anodes instead of metallic lithium might enable higher power densities and longer cycle-life, if SEI-stabilizing electrolytes/additives can be developed which prevent the continuous consumption of electrolyte during cycling. One open issue with silicon anodes in lithium-sulfur batteries is the incorporation of lithium by either industrially feasible pre-lithiation procedures or by the use of LiS- rather than S-cathodes.

  • For hydrogen fuel cells, they note that much progress has been made over the last 10 years. Concepts for platinum-based cathode catalysts with high mass activity catalysts are putting the targeted Pt loading reduction to the 10 g/FCEV in reach. The new class of Pt-alloy catalysts formed by dealloying also shows improved voltage-cycling stability, reaching the targets set by the DOE.

    The challenge is now to combine these catalyst concepts with support materials with higher durability in order to ensure fuel cell performance over FCEV service life. In addition, the origin of the yet unassigned mass transport losses at low Pt loadings must be understood and mitigated, they write.

    The main challenge in fuel cell membrane research seems to be to identify materials suited for higher operating temperatures and at low relative humidity in order to simplify system design, improve heat rejection, and reduce energy losses by the air compressor.

An analysis of the system-level energy density of lithium ion batteries (LiBs) suggests that the gravimetric energy density of advanced LiBs is unlikely to exceed 0.25 kWhname-plate/kgbattery-system, which would limit the range of BEVs for the compact car market/pricing to ca. 200 miles, with recharging times substantially larger than that of conventional vehicles. Whether this will suffice for a large market penetration will depend not only on the needed but also on the perceived range requirement by customers. Higher energy densities would only be possible, if one were able to develop durable and safe metallic lithium anodes. While the so-called post-LiBs, viz., lithium-air and lithium-sulfur batteries have been assumed to revolutionize battery energy storage, cell- and system-level gravimetric energy densities are not expected to substantially exceed that of advanced LiBs; volumetric energy densities will most definitely be lower.

In contrast to BEVs, H2-powered FCEVs are capable of large driving ranges (>300 miles) and can be refilled within several minutes. Besides the need for a hydrogen infrastructure based on hydrogen produced from renewable energy, a reduction of the platinum requirement per vehicle (currently ≈20–40 gPt/FCEV) still requires further development. Nevertheless, current data suggest that advanced catalysts (dealloyed Pt-alloys) are able to meet the long-term DOE activity and durability targets, but their integration into MEAs which can operate at high current densities and low Pt loadings still needs to be demonstrated.

—Gröger et al.


  • Oliver Gröger, Hubert A. Gasteiger, and Jens-Peter Suchsland (2015) “Review—Electromobility: Batteries or Fuel Cells?”, J. Electrochem. Soc. volume 162, issue 14, A2605-A2622 doi: 10.1149/2.0211514jes



It depends on whether you decide to focus on CO2 or local pollutants (NOX, HC, particulates, etc.)

The Eu is going to miss its 95 gms/km goal by a mile (1.6km) once they start testing using real world conditions. 2020 is only 5 years away and this is not enough time to switch from diesel to BEV or FCEV.
Also, the idiocy of the Germans shutting down their nuclear reactors means that the electricity supply is higher CO2 than necessary.
They point out that there is no post LiIon battery visible (say within 5 years).
So what can we do ?
a: Design and implement new real world tests to find out where we actually are in terms of CO2 and Nox, etc.

b: Have an amnesty on emissions cheats. The companies need all their money to fix diesel and move beyond it. Maybe put 1 or 2 from VW in jail, but leave it at that.

c: Have a crash program to get cars hitting their current NOX and HC emissions targets, and freeze the targets for a few years till reality can catch up with the test figures.

d: Ban the worst emitting vehicles from cities. You might have to give compensation to owners, or move them to less densely populated places.

e: Make it easier to swap cars for a few days (change taxation and insurance laws if required). Make it cheaper to own a second car if you have an EV.
The silliest problem with EVs is that people won't buy them because the MIGHT do the odd long run, even though their typical daily use is easily covered. The engineering approach is to build a supercharger network and add larger batteries to cars. The administrative approach is to make it easier for people to use ICEs occasionally. The administrative approach is much faster and cheaper [IMO].

f: Put in a dense network of high speed chargers.

g: Develop a decent 30Kw range booster pack that can drive a car 300 miles on petrol or diesel. It does not have to be particularly efficient, it just has to be small, light and have low NOX etc emissions and reasonably smooth in operation. It could well be petrol rather than diesel.

I would push the electromobility for larger cities as a cure for local pollution, rather than long range use in the countryside. Buses could go electric, taxis could go petrol hybrid. Long and medium range trucks can remain diesel.

IMO the problem is that the EU has become fixated on CO2 levels to the exclusion of local pollution and real testing.
This has led to far too many diesels being used in cities.
They need to get over that ASAP.

Account Deleted

Fuel cell vehicles are utter nonsense for multiple obvious reasons. Don't believe they will have better range than BEVs. They won't. However, it is a waste of time to even discuss them so I won't.

Autonomous BEVs is the future of the auto industry with autonomous taxi BEV services taking over the market for private ownership of 15,000 to 35,000 USD gassers. Autonomous BEV taxis will cost only 0.15 to 0.2 USD per mile and still be highly profitable for the fleet owners. This is less than the 0.30 to 0.45 USD per mile that it cost to drive and own a 15,000 to 35,000 USD gasser. For autos costing 35,000 USD and above private ownership of autonomous long-range BEVs will eventually be possible. The Norwegian EV union had a story on Model S with a picture of a leaked design and a blogger reporting from a Tesla presentation a few days ago in China said that Tesla revealed the following specks for model 3. If they are true I have no idea. However, they do not seem completely off line although the battery pack seems too small in my mind. I would guess 60kwh for the smallest version. The 205 miles range on 50kwh is going to be very difficult. I totally believe the acceleration figure though. Model 3 will start at 0-60 in 6.1 sec and go all the way down to 0-60 in 3 sec for the ludicrous version that will probably cost twice the starter model.

217 hp
205 miles range
0-60 in 6.1 sec
50 kWh battery
38125 dollars


FCs for electric vehicles is a targeted scheme of big business to keep the cash cows in their pasture.
Consumer acceptance of electric vehicles is certainly not as implied in the article. There are three main reasons for apparent reluctant acceptance; these are exorbitant prices, short range and in most cases, extreme ugly design. E. g. just look at the tail end of a Leaf.
If manufacturers keep production quantities so low just to qualify for compliance, not much is bound to change for the price aspect.
Short range and design are intended to divert the consumer from BEVs and keep on drawing his attention conventional gas guzzlers.
With the exception of TESLA and BMW, I am not familiar of any manufacturer with a honest intent on BEVs.


Why can't someone work with Elio and make an electric version. The aerodynamics, size and weight make it a very attractive platform to electrify. So if you add 7000 to electrify the vehicle to the current price and get 200 miles per charge you would have a VERY attractive affordable electric. WAY under 20K and with tax incentives around $7000..
Please tell me SOMEONE is going to do this?

Rip the gas engine out reinforce the suspension and put in batteries etc.
CMON folks I need update a car next year..


With the exception of TESLA and BMW, I am not familiar of any manufacturer with a honest intent on BEVs.
I am still trying to make sens of the VOLT by GM. cost is HIGH car quality is like a Chevy Cobalt and the effective range on the highway is awful.
Maybe you are right, maybe others are not serious..

Excellent summary of the Electromobility Review paper, Mike.

The authors make the following point in their introduction:

"However, for electricity produced entirely by renewable energy sources, the 95 gCO2/km target could also be met by extended range electric vehicles with 40 miles all-electric range (E-REV40 in Fig. 1), if 50% of driving is powered by the battery (i.e., the average driving range would have to be below 80 miles)"

And then go on to make two curious omissions;

Consideration of PHEVs with 50-80 miles range, which are already demonstrated.
Consideration of the lack of, and cost of creating, an adequate H2 fueling infrastructure, estimated by the DOE at $500 billion to $1 trillion in the US alone.

The issue of high speed charging is addressed briefly, and the authors point out that if Tesla-speed 120kW charging was employed, a 12 minute charge would suffice to double current 80 mile BEV range. 7 extra minutes to refuel is a pretty small consumer accommodation to make, especially if those charging sessions take place in a shopping center parking lot rather than a gas station style queue. Considering that most charging would take place at home or work, that extra time charge would only occur a few times a month, if even that often.

The authors spent a lot of time discussing manufacturing price points, but none on total cost of ownership especially refueling costs.

Consumer experience with 150-200 mile range BEVs, and the low fuel price point (<$1gge) will decisively tip consumer favor to BEVs and PHEVs.

Somehow most automakers seem to be missing the realization that a consumer can buy a lot more car when their fuel costs drop by $200 month. Tesla seems to get it.


Excellent review.

One easy short term, lower cost way to meet lower pollution standards may be with 80 Km to 100 KM PHEVs and the use of public transport (e-trains etc) for longer distances.

FCEVs will also meet the chalenge, but at a higher initial and operation cost, specially for the first 5 to 10 years.

Extended range BEVs (500+ Km) will eventually also meet the challenge but need a breakthrough in batteries development, i.e to reach 600+ Wh/Kg and under $100/KW. That may not happen much before 2025 or so.


Henrik said:

'Don't believe they will have better range than BEVs. They won't. However, it is a waste of time to even discuss them so I won't.'

'Moreover, the all-new FCV features a cruising range of more than 700 km*2'

Re cruising range of 2016 Honda.

When conclusions are drawn on the basis of obviously erroneous notions and not modified as new information comes in, they are not going to be of much value.


According to BMW, a single H2 dispenser can support 80,000 Km/day of FCEV operation while a single quick charge e-station can only support 6,000 Km/day of extended range BEV operation.

In other words, H2 stations are 13.3 times more effective than quick charge e-stations but cost ONLY 4 times more.

Based on effective energy dispensing efficiency, H2 dispensers cost about 3 times less than quick charge e-stations?

That much about comparative H2 relative false high station cost?


You refuse to acknowledge that Tesla owners will have to pay $20000-30,000 to replace the battery packs, so that is part of the cost of operation.

If you want to reduce CO2 emissions, start with replacing coal fired power plants with natural gas combined cycle. No mountains of coal ash either.

Patrick Free

The Germans are clearly in front of a mountain. Only way to do what is needed is to move to all electric drive trains, scrapping hundreds factories and patents and know-how ... through which they used to control the High End cars market for years. Will they do it ? I don't believe it, ... and I now plan for a Tesla Model X for next year, after 20 years of BMW.
They screwed up the PHEV alternative to BEV, loosing precious years that are gone now, just because all PHEVs they provided so far were ICE cars pulling nothing and adding an Electric system on top of every things. Which makes far too expensive and too heavy and too complex cars that nobody is buying, and to limit the cost they used that meaningless "Electric Turbo" sizing for the Electric part, with meaningless 10KWH batteries and 100KW engines, that prevents a decent all electric mode, making these cars # useless for CO2 and Petrol savings.
Now they agree they need BEVs too, but still don't plan for competitive SuperCharger networks, and find excuses to try get a delay from the regulators.
Just forget them !

SJC, I'm all for replacing coal with a more benign substitute and it does appear that gas will supplant coal in the mid term.

Tesla offers 10 year, unlimited mile warranty on Model S 85kWh packs. Is it your belief that these will all fall over dead at age 3651 days?

All available evidence indicates that they will gracefully degrade, perhaps lose 20-30 miles range at 100k miles. No big deal, they will still be perfectly serviceable with 235 mile range, especially as Supercharger network gets more dense, never need to stretch your glide.

Even when they do get replaced, their trade-in value on the aftermarket will probably be pretty high (relative to market), and in 10 years, I don't expect a Tesla "repack" to cost anything remotely similar to the cost of a brand new pack does today. GM is already confidently predicting $100kWh at the cell level in only 5 years. Tesla seems well positioned to beat that (volume, vertical integration). The electronics and battery chasis will presumably be reused.

Tesla is on record as saying their entire Model 3 will cost $35k for 200 mile range. GM has made a similar claim for the Bolt.

So there's really no rational justification for quoting $20-30k as the replacement cost of a Model S battery in 15-20 years.

btw, thank you for setting me straight in the H2 aero discussion with Roger. I appreciate your speaking up.


Patrick Free
After the consumer report on Tesla I would not be in a hurry to buy that problem car. It seems they are really prone to need constant repair.

Anthony F

Interesting the report pours cold water on Li-S batteries. There has been a lot of research, and I believe they may be preferable for aviation due to their light weight and relative availability.

Also, it mentions the change in focus of the EV battery markets - away from how much the batteries weigh to how much volume they use. The smaller the physical pack, who really cares how much it weighs now that most battery manufacturers have managed to get close to or exceed the 200Wh/kg metric (cell level). Further gains to 500+ Wh/kg aren't needed more than increasing cell density up above 750Wh/l to fit in appropriate sized cars.


Anthony said:

'There has been a lot of research, and I believe they may be preferable for aviation due to their light weight and relative availability.'

Fuel cells and hydrogen are further along the route to powering small commuter aircraft, due to the higher energy density of the hydrogen system than any battery we can do at the moment:

Account Deleted

The Tesla battery will last the life of the car. Tesla offers 8 year, infinite mile battery and drive unit warranty on all of their models. You are right that a short-range BEV like a Leaf may need a battery replacement before the end of the cars life. However, not a Tesla.

Indeed, Tesla's official goal is to make their cars last a million miles before mayor repair or scrapping. I would say the Model S70 currently is good for 300k miles and the Model S90 is good for 450k miles. Try and do that in a gasser.

Totally agree that coal power should be replaced asap with natural gas combined cycle and then add a lot of wind and solar to save the natural gas for emergencies.

Davemart last time I checked there were no official EPA range for any FCV because they do not exist yet as anything but a test fleet. You have no good range numbers and when they come they will disappoint and not be able to beat Tesla's best.


The new Toyota FCEV is rated at 67 empg.
That is about 3X the equivalent ICEV.

Considering that H2 dispenser stations are 3X times more efficient than quick charge e-stations, the comparative price of H2 per Km driven will soon be cheaper than liquid fuels and probably cheaper than electricity (for extended range BEVs) from new NPPs.

Account Deleted

That consumer report used old data from the first Model S made. They did have issues that all was fixed under warranty. These issues are not present in the latest versions of Model S. The acid test is the percentage of Tesla owners that say their next car is also going to be a Tesla. That pct is over 95% for Tesla. No other car owners are that happy for their brand.

Tesla is a new company doing lots of firsts. So you should expect issues for every new car introduced in the first year or two. All of which will be fixed under warranty. It is not a big deal and nothing to worry about.



'Mirai’s driving range is estimated at 312 miles, making it the only zero emission vehicle to surpass the 300-mile range mark. Additionally, the vehicle was certified by the US Environmental Protection Agency (EPA) for 67 miles per gallon equivalent (MPGe), last month.'

Post July 2015.


EPA range also given on the Mirai factsheet from the Toyota USA website:

Account Deleted

Problem is the Mirai is still a test fleet car and will be for a few more years. This is why EPA has still not put it on When it does start real sales Tesla will have something to trump it like a Model S100. The Mirai is impossible to sell commercially has no truck, has lame 0 to 60 whereas Model S 90D does 0 to 60 in 4.1sec. with two large trunks etc etc. The Mirai is incredible wasteful compared to the Model s that has 100mpge. Also hydrogen takes twice as much energy to make as electricity for BEVs so fuel cells are four times as inefficient as BEVs. Their fuel cost over ten times more per mile driven compared to BEVs etc etc. How stupid can people be to believe in that crap.



That is all changing the subject.

Clearly there are in fact EPA ratings for fuel cell cars, and the Honda will do better than the Toyota, probably mainly because fuel cells and their ancillaries are continuing to shrink and being a later design than the Mirai they have got everything except the fuel tanks under the bonnet, although efficiencies are also improving.

So your:
'Don't believe they will have better range than BEVs. They won't.'

Is unfounded.


Heh, the only GCC threads that can do 22 comments in a day are FC/BEV.

This has led to far too many diesels being used in cities.

Oil imports were a major issue for Europe long before there was an EU; diesels were the remedy.  The problems having been re-defined, the solutions must also be accordingly.

Don't believe they [FCEVs] will have better range than BEVs.

This.  There are ways to "refuel" a BEV while it is in motion.  If one could squeeze as little as 10 kW through the road, a Tesla Model S could run all day at 60 MPH and a Leaf could run well beyond human endurance at that speed.  At 380 Wh/mi and 70 MPH, a Model S would consume 26.6 kW; at 16.6 kW net, the 85 kWh battery is good for a whopping 5 hours.  If charging is available at all stops, that is effectively no limit at all.

a single quick charge e-station can only support 6,000 Km/day of extended range BEV operation.

A single port of a Tesla Supercharger can support roughly 250 MPH of extended range, or 6000 miles/10000 km/day.  4 ports is 40,000 km/station/day; practically, 20,000.  But it's far cheaper than H2.

with meaningless 10KWH batteries and 100KW engines, that prevents a decent all electric mode

Funny, I'm driving a car with a 7.5 kWh and 70 kW electric system and I find the all-electric mode eminently satisfactory save for the limited range.  Oh, and I'm averaging about 126 MPG (US); if my electricity was carbon-free and gasoline was 9 kg(CO2)/gallon, that would be 71 g(CO2)/mi or 44 g(CO2)/km.


I see no evidence that the Tesla battery packs will "last the life of the car", if you have that evidence please post it. After 10 years if the owner of a Tesla has to pay $20,000 for a new battery pack, that is part of the Cost of Operations.


This article seems to make a good case for FVEVs, an electric with a fuel cell range extender. More batteries and smaller fuel cell give it range and versatility.

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