Electric Cars: Are we nearly there yet?

We are led to believe that electric cars are an invention of modern times, a testament to Moore’s law – which posits that the processing power of computers will double every two years.

But in fact electric vehicles have very little to do with computers, and we haven’t progressed very far in their development during the past 100 years.

Before the internal combustion engine took hold, electric-powered vehicles were the ‘sports cars’ of their day – holding numerous speed and distance records – but then fuel became cheaper and more plentiful, while oil companies grew richer and more influential. The industry stopped investing in their development and oil companies invested in EV-startups so they could control the industrialisation of new technologies.

The energy crises of the 1970s and 80s brought about renewed interest in electric cars, with California leading the way in the 1990s, but they did little to change the market’s perception that electric vehicles were slow, lacked range and looked boring.

Earlier this month, BMW sent out a press release entitled “40 years of electric mobility at the BMW Group”, as they prepare for the new BMW i3 in late 2013. They describe the i3 as the culmination of 40 years of development work, but look closely and you’ll notice that most of this development has been in battery technology and companies like BMW spent most of those years investing in hydrogen vehicles (such as the Hydrogen 7).

The Hydrogen 7, produced from BMW’s CleanEnergy programme, is based on a 6.0 litre V12 760Li.

Back in 1972 a converted BMW 1602 needed 350kg of lead-acid starter batteries to achieve a range of 37 miles. Fifteen years later and a modified BMW 325iX was fitted with 265 kg of sodium-sulphur batteries, delivering 42% higher (continuous) power and 75% more capacity. Range was now up to 93 miles (in city traffic), but still woefully short of a combustion engine and considerably heavier.

Four years later and the purpose-built BMW E1 introduced sodium-nickel chloride batteries, weighed just 200kg and offered 88% more power. Not exactly Moore’s Law, but a noticeable improvement nonetheless.

Development then ground to a halt, before being re-ignited in 2008 with the Lithium-ion powered MINI E. This was the precursor for the soon-to-be-launched i3 Megacity car, with a range of 155 miles and enough power to lap the Nürburgring in 9 minutes 51.45 seconds. The batteries still weighed a not inconsiderable 260 kg, but were compact enough to fit into a small(ish) car like the MINI and propel it from 0-62mph in 8.5 seconds.

The i3 has reduced the powerplant’s size by a further 40 per cent, will crack 62mph from zero in less than 8 seconds, but still relies on rechargeable lithium-ion cells for its batteries.

Is this the kind of progress we’ve become accustomed to with computers and other consumer tech?

Well, perhaps the first thing to understand is this is about chemistry more than physics. EVs depend on batteries for the storage and release of energy, and the energy density of this medium is dictated by the choice of materials used.

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In recent years, the hype has focused on lithium-ion batteries, but old-school lead-acid batteries (as used to start our cars) haven’t disappeared and are regaining prominence with the latest fast charging lead-acid batteries. These lead-carbon based cells with their split-electrodes act more like super-capacitors and offer considerably longer cycle lives (the number of times a battery can be charged and discharged) than the latest lithium-ion batteries, but they are heavier and not really suited for use in passenger cars.

On the other hand, lithium-ion batteries are only four or five times more energy dense than the batteries made a century ago, and have failed to deliver the performance levels expected by consumers. Earlier this year, South Korean scientists claimed a hundred-fold increase in the charging time of lithium-ion batteries after their cathodes were carbonised, but this is an industry where hype arises on a daily basis and still needs to be proven in consumer trials.

Even so, you’d think now would be a great time to be in the battery business, but with the recent collapse of A123 Systems (OEM supplier to Fisker, BMW, McLaren and General Motors) and Sony looking to offload its lithium-ion battery business, it is clearly not a market which favours new entrants.

Samsung, Sony and Panasonic/Sanyo account for around 60% of global lithium-ion battery production, while battery makers in China and Korea are taking advantage of the incentives available in their domestic markets to eat into this share. And yet many of the leading battery manufacturers have overbuilt capacity (in expectation of huge EV demand) and are now ‘closing down’ production plants.

Most of the recent progress in automotive battery technology has arisen in the area of micro-hybrids and regenerative braking (the technology behind those stop-start systems that seem to be fitted to every new car these days). These are forecasted to represent more than 30 per cent of the market by 2015 and have encouraged battery makers to improve the Dynamic Charge Acceptance (ability of the battery to recover during an engine off interval) performance of their products.

This is a long-way from delivering a pure-EV future, and given that micro-hybrid tech favours lead-acid batteries, it also goes in the opposite direction to that which the current EV movement would prefer us to take.

Most car makers are relying on a substantial reduction in the cost of batteries, but in such a mature industry (producing millions of lithium-ion batteries per year), there are few economies of scale available from bulk buying raw materials or improving production processes.

Above: The toy-like Renault Twizy. Below: Renault presents the first ZOE to French Minister Arnaud Montebourg.

With material costs accounting for roughly 50 per cent of battery production, the irony is that increasing demand may lead to a scarcity of raw materials – and an increase in prices. Exactly the opposite of what the car makers need to increase consumer adoption.

So where does that leave the consumer?

There remains considerable doubt over the future of pure-EV cars, with KPMG’s recent Global Automotive Exec Forecast predicting hybrids as the better mid-term solution. Indeed, with the rate of innovation for lead-acid batteries exceeding that of lithium-ion and consumer’s proven appetite for enhanced petrol or diesel hybrids, the future seems more evolution than revolution – delivering more of what we know, with lower cost and less consequences to the environment.

It’s a complex issue, with no ‘silver bullet’ solutions and a whole load of hype.

Are we nearly there yet?

I very much doubt we’ll ever achieve the vision touted by today’s politicians and environmental activists, but I suspect car makers will be resourceful enough to invent something even better. One thing that’s for certain though, the technology needed at the right price is not yet a reality, nor will it be, unless we see a breakthrough in some good old fashioned chemistry.

Further Reading

• Battery technology charges ahead (July 2012 – McKinsey Quarterly)
• Understanding Economies Of Scale In Battery And EV Manufacturing (17/12/2012 – John Petersen)
• KPMG’s Global Automotive Executive Survey 2012 (January 2012 – KPMG LLP)
• Carbon-Coated Single-Crystal LiMn2O4 Nanoparticle Clusters as Cathode Material for High-Energy and High-Power Lithium-Ion Batteries (2/08/2012 – Wiley)

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