Science – Cars of the future

Reviewing the exceptional characteristics of the most advanced autonomous electric vehicles (such as the Volvo 360c), it becomes apparent that we are observing a transformation in the nature and functions of the automobile itself.

The transformation has only recently started in earnest. Within the next few years, 55 new electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV), manufactured by 18 major companies, are expected to become available. These vehicles have a range of between 55km and 640km.

Electric vehicles usually cost twice as much as comparable vehicles with conventional internal combustion engines, largely because of the high cost of research and development to produce improved batteries to power the electric drivetrain. The International Council on Clean Transportation expects that purchase price parity with conventional short-range vehicles will occur around 2024. By this point, the research and development costs of new improved batteries will have been recovered.

Further improvement in EV performance requires continuing global research into the development of improved battery technologies. Current EVs mainly use various types of lithium-ion batteries. Lithium is a relatively rare element and so future supplies of the element for battery manufacture will become increasingly problematic.

Alternative batteries such as sodium-ion batteries have the advantage that sodium is a common element. However, sodium-ion batteries have limitations of their own. The intrinsic weakness of all conventional batteries is that the rate of their charging and discharging depends on a specific chemical reaction associated with each battery type.

For this reason, leading-edge research at present is mainly focused on the development of super-capacitors, rather than conventional batteries. The super-capacitors have the advantage that they are not limited by the rate of a chemical reaction as their charging and discharging is based on ionic diffusion, which is more instantaneous than chemical reactions. Therefore, super-capacitors would permit much more rapid charging and discharging. Nevertheless, the limitations of super-capacitors are apparent in prototypes.

One limitation involves the use of expensive component materials, which makes the technology uneconomic at present. An urgent search is underway for natural alternatives to these more expensive high technology components.

Meanwhile, the anticipated shift to driverless trucks, buses and cars is getting closer.

Driverless buses have already appeared in China, the Netherlands, Italy and Switzerland.

Also, Norway, Singapore and London are now testing driverless buses. The case for driverless buses is simple. There were 32,000 road deaths in 2014 in the United States alone and 94 per cent of these involved human driver errors.

Following the emergence of electric cars is the impressive appearance of electric boats and ships, including developments here in New Zealand. Also, electric planes seem certain to appear soon. Norway promises that all its short-haul flights will be on electric aircraft by 2040.

Professor Ralph Cooney
r.cooney@auckland.ac.nz