Germans clash over fuel cells or batteries for EVs

Audi is aiming to stretch the range of its future battery-electric cars out to as much as 700km by as early as 2020, but don’t expect Germany’s other two perennial premium contenders to race it to the mark.

While BMW and Mercedes-Benz have both delivered battery-electric electric vehicles (BEVs) to market, they are both putting their big bets on hydrogen fuel-cells (FCEVs) as the long-range automotive power source of the future, rather than big batteries.

All three German car-makers are committed to both FCEVs and BEVs, it seems, but where Audi is prioritising battery-electric cars for the immediate future, its rivals aren’t completely convinced and their development priorities are significantly different.

“The capacity of the lithium-ion cells are constantly rising and the prices are constantly degrading,” Audi’s head of electronics development, Ricky Hudi, said last week.

“By around 2020, 2021 or 2022, you will drive 600 to 700km with the battery alone, with a reasonable price.

“It will be economically logical — that will be a big influence – and there are still dramatic improvements with lithium-ion, and Samsung and LG are the best at it today.

“We don’t see it slowing down soon,” he said.

The claim comes on the back of the Volkswagen Group insisting it is on the cusp of a major breakthrough in battery-electric range.

Audi has plans for a pure-electric version of its all-new Q7 SUV and hopes to spread that technology to the rest of its MLB Evo platform buddies, including the next A6 and A7, the replacement for the Q5 and the next A4.

While Audi is developing hydrogen fuel-cell electric cars (like its A7 h-tron) in parallel to its battery-electric program, it will point to its immediate future with a stand-alone battery-electric concept car at September’s Frankfurt motor show.

But its rivals aren’t completely convinced that lithium-ion batteries hold the key to the future, even as European emissions laws tighten so much in 2020 that they virtually mandate at least some electrically powered cars in every model range.

“We stay committed to fuel cells,” Mercedes-Benz board member in charge of development, Dr Thomas Weber, explained.

“Nobody knows if the hype on the battery-electric vehicle side will pay off. It’s not clear. The range isn’t clear. The future isn’t clear.
    
“The cars are quite good. The weak point is where can I charge my car?”

In most countries, a similar argument could be mounted against hydrogen refueling, though Dr Weber insists demand will force fuel suppliers to upgrade their infrastructure.

Germany has around 50 hydrogen filling stations today and plans to have 400 by 2023, ostensibly to help its carmakers meet EU emissions targets.

In other parts of the world, there are 40 in California, which has plans for 100 by 2020, and Japan has 100 today, but plans 800 by 2025. So, lots of planned improvements, but still nowhere near the convenience of a traditional petrol station, even in a decade.

Dr Weber is also listening intently to his own electronics engineering boffin, Professor Herbert Kohler, who used an interview with Engine Technology International magazine to hose down battery-electric optimism.

“Lithium-ion batteries are indeed getting better and better, because that’s what everybody is pushing and so that’s what you keep hearing. But I would not confirm that unconditionally,” he insisted.

“A ‘boom in range’ suggests double the charging capacity, something like Moore’s Law, but that will not happen with the lithium-ion technology. We’re not looking at a 100 per cent improvement, it’s going to be 20 or 30 percent better than three or five years ago, but that’s all.

“That is no surprise to me; we predicted exactly that years ago. At the same time we said charging capacity would be the limiting factor.

“The situation is that we will have a restricted capacity of the cell by the lithium-ion cell-technology itself.”

Some senior engineers and marketers are suggesting that current battery ranges are sufficient today, with the biggest issue related to charging. Handling dirty, wet or heavy power cables up to four times a day isn’t appealing, particularly for premium and luxury car owners, and inductive charging is not yet a commercial reality, though it’s coming.

“There is really a lot of progress there with charging, but that just mainly depends on the power of the charger” Prof Kohler said. “Compared to the 3kW or 4kW charging with eight to 10 hours, we achieved a big reduction in charging time with our 22kW on-board charger.

“The question is how many kiloWatts you can pump in (to the battery) in a short period of time? There is a kind of natural boundary; otherwise you will destroy the lithium-ion cells themselves.

“We can’t ignore the laws of physics, but of course we like to challenge them.”

While Tesla draws media kudos for delivering continual increases in range and speed, the company has never made an annual profit and, essentially, delivers a big battery and fits a car around it. Mainstream car-makers, with a broader spread of shareholders to answer to, can’t deliver loss-making products, even if they are technically advanced machines.

“With the current B-Class Electric Drive, we already have our fifth generation of battery-electric vehicles in customer hands,” Prof Kohler said.

“Don’t forget, our electrified-powertrain portfolio is much more differentiated and if I may add, much more profitable -- with highly efficient combustion engines and plug-in hybrids.”

The battery-electric B-Class might run on a powertrain pulled directly from Tesla (which it once owned 20 per cent of), but BMW has an entire new model series dedicated to electric drive, with the price leader being the battery-electric i3 city-car.

BMW, though, is coy on revealing i3 sales numbers, having backed down from its initial target of 30,000 a year to instead focus its communications on markets where the car sells strongly via government incentives (Norway, The Netherlands) and avoid mention of countries where it struggles (particularly, embarrassingly, Germany).

But, according to BMW’s board member in charge of development, Klaus Fröhlich, its struggle to gain an electric beachhead in some markets is no surprise internally.

“I knew for electrification that it would take five generations (at three years per generation) before we would get to where we need to be, so we have to do it anyway.

“We could learn because we are doing it anyway so why not give us some cars to sell, too?

“The technical systems are clear. Cell development in the batteries is very rapid. Energy density is what they talk about but the Amperes flowing in and out is the key,” Fröhlich said.

BMW isn’t betting the farm on battery electrics, though, and its strategy to close in on 2021 emissions targets is to use battery-electric power for smaller cars and hydrogen fuel cells for larger cars, with plug-in hybrids filling any gaps.

“In the past we were asked in interviews what we were doing and were we late in our development. But you don’t always put your development into production and we have been working with fuel cells for 30 years,” Fröhlich said.

His Vice President of Powertrain Research, Matthias Klietz, explained that while battery-electric cars would remain part of the BMW line-up, they had been internally re-categorised to suit the work they did best.

“A hydrogen fuel-cell vehicle is going to be used for long driving. It can save a lot of power,” Klietz said.

“We have categorised it as for a large vehicle, because it will work best if it’s doing long distances – more than 18,000km a year.

“A battery-electric vehicle will be a small vehicle with low to medium range and vehicles with plug-in hybrid or range-extender internal-combustion engines will stretch range more. They will be medium- to long-range cars.”

But Benz’s Dr Weber sounded another note of caution, warning that anybody who focuses too much on the issue could fall behind anyway.

“I believe the next big thing will not happen around powertrain – it will be around autonomous and connectivity – but everything we can do on the conventional side will help to reduce the cost of electrified vehicles.

“It’s wise not to focus on everything around CO2 reduction in internal-combustion engines.

“I believe that it’s dangerous to focus too long on too much with these conventional things. In the moment we are all focusing too much on one thing; one of the newcomers could focus on completely different things and could get ahead.

“The prioritisation of investment is the question and the key is to use what we know and to do it fast – as fast as we can,” he insisted.