26 E c o s 9 7 O c t o b e r - D e c e m b e r 1 9 9 8

Plant and animal breeders have longrecognised a phenomenon calledhybrid vigour: interbreed two related

species, and their offspring will outperformeither parent. The mule, for example,combines the hardiness and endurance ofan ass with the strength of a horse. In apast age, these traits saw mules serve thedual role of beast of burden and occasionalpower source for the farmer’s buggy.

The day of the mule has passed. In the20th century, farmers drive tractors, andmany of us enjoy personalised transport.But near century’s end, the unbridledsuccess of the internal combustion enginehas caused serious health problems in manycities: clogged arteries, breathing diffi-culties, and vistas clouded by the brownhaze of photochemical smog.

While stringent anti-pollution legislationhas greatly reduced vehicle exhaustemissions, the sheer number of vehicles inmajor cities has thwarted the quest forcleaner air. So researchers in the UnitedStates, Japan and Europe and, now, inAustralia, have sought a novel solution: a

latter-day mule, the hybrid offspring of twodifferent technologies – the internalcombustion engine and the battery-powered electric motor.

In Japan, where high fuel pricesincreased the incentive to develop analternative to the internal combustionengine (ICE) vehicle, the Toyota MotorCompany has launched a compact hybridpetrol-electric vehicle, the Prius, and isselling about 2000 vehicles a month. In theUS and Europe, governments are investingtens of millions of dollars in taxpayer-funded grants, boosting the major carcompanies’ own research and developmentprograms, which collectively are worthhundreds of millions of dollars.

In such company, Australia is a minnowamong whales, but is mounting its ownambitious research to capitalise on advan-ced technologies developed by CSIRO.These technologies are ‘highly relevant’ tothe concept of a hybrid petrol-electric vehi-cle, according to chairman of AustralianConcept Car Ltd and director of CSIRO’sAustralian Automotive Technology Centre,David Lamb.

Batter iesincluded

On the smell of an oilyrag, Australian scientistsare marrying batteryand petrol power with aview to lifting energyefficiency, cuttingemissions and injectingthe motor vehicleindustry withhomegrown expertise.Graeme O'Neillreports.

The hybrid vehicle will feature new-generation

super-capacitors that rapidly accumulate and

discharge large currents.

E c o s 9 7 O c t o b e r - D e c e m b e r 1 9 9 8 27

CSIRO and the Australian automotiveparts industry have already completed onesuccessful partnership, a project to developa one-off Australian concept car, theaXcess, as a mobile showcase for theindustry’s manufacturing and servicecapabilities. Designed by Millard DesignAustralia, the aXcess car represents a blendof existing technologies and those that willbe commercially available in three to fiveyears. It is being exhibited at automotivetrade shows in the US, Asia and Europe.

CSIRO is investing $6.5 million inresearch and development for the newhybrid ICE-electric vehicle. In the next fiveyears, CSIRO’s contribution will becomplemented by Australia’s automotiveparts industry, so that the prototype vehiclewill eventually represent an investmentapproaching $30 million.

The ICE-electric vehicle will itself be astepping stone to an even more radicalvehicle, powered by the compact ceramicfuel cell being developed by Melbourne-based high-technology company CeramicFuel Cells Ltd. Ceramic fuel cells willconvert chemical energy, in the form ofnatural gas or hydrogen, directly intoelectrical energy to power an electricvehicle (see Ecos 93).

According to Lamb, the imperative forthe project is the undertaking by in-dustrialised nations to reduce greenhousegas emissions, particularly carbon dioxideand nitrous oxides. But the project alsorepresents an opportunity for Australia todevelop the technological and manu-facturing skills required to be a significantplayer in the emerging international marketfor hybrid ICE-electric vehicles.

‘In 1963 Australia exported more ve-hicles and automotive products than Japan,but then pulled out of the race,’ Lamb says.‘We only woke up again a decade ago, butsince then we have been growing nicely.

‘Under the Button Plan, the Australianautomotive products and componentsexport industry has grown from virtuallynothing to $2.7 billion a year since 1985.

‘The industry now offsets some of thecost of the vehicles we import, but ratherthan sit on our hands and wait to importhybrid vehicles such as the Prius, we wantto show the Australian public and govern-ment that we can play a useful role.’

The technologies and services thatCSIRO brings to the project include:• High-efficiency electric motors based on

rare-earth permanent magnets that havebeen proven in the Australian-builtAurora solar car in the 1997 Darwin-Adelaide international solar car race.

• Lead-acid batteries that provide greaterspecific energies than conventional types.

• New-generation super-capacitors that canrapidly accumulate and discharge large

currents and will provide similar perform-ance characteristics to existing ICE-powered cars.

• Expertise in electronic control systems,and in system integration.

• Expertise in systems engineering and inanalysis of the total energy inputs andoutputs involved in manufacturing andoperating a hybrid vehicle.

• Expertise in design and casting of low-mass metal components, for weightreduction.

• Expertise in developing high-strength,low-mass polymer composites for racingvehicles, which is also applicable tolightweight vehicle design.The final mix of technologies has yet to

be decided; the project is still in theplanning phase, and it is no easy matter tochoose an optimal configuration. But someparameters virtually set themselves. Forexample, Lamb says the vehicle will becompact, and weigh less than a tonne, andits primary power source will be a petrolmotor of no more than one-litre capacity.

The final package is constrained by theneed to minimise weight and maximiseenergy efficiency and refuelling range. Thelaw of diminishing returns means that theheavier the vehicle, the larger the batteriesand super-capacitors required, and themore energy will be squandered just onlugging these heavy components around.

But at the same time, says Lamb, thevehicle must reproduce the familiarperformance characteristics of conven-tional-engined vehicles. It must provideenough power, at least in brief bursts, forbrisk acceleration in stop-start commuterdriving or emergencies, as well as adequateeconomy for long-haul inter-city trips athighway speeds.

‘It’s a balancing act, but we’ll probablyneed to draw about 40% of the vehicle’spower from storage,’ he says.

Lamb says that in conventional vehiclesengine capacity is determined not by therequirements of cruising, when an engine isoperating with peak efficiency, economyand minimal emissions, but by the need forrepeated cycles of acceleration from rest,when emissions are highest. Drivers rarelyuse all the engine power available to them.

‘If you run an internal combustionengine at a constant, optimal speed,

Right: The hybrid car will incorporate CSIRO

expertise in design and casting of low-mass

metal components, such as this die-cast

magnesium seat.

Below: The aXcess car is a mobile showcase

for the Australian car industry's

manufacturing and service capabilities.

Hend

erso

n In

dust

ries

emissions can be cut by up to 90%,’ he says.So the idea is to use a small-capacity engineas a constant-output generator, which incruise mode will rapidly recharge the lead-acid batteries and super-capacitor.

Rapid acceleration or hill climbing willquickly drain conventional batteries. Thekey to a viable hybrid system is the super-capacitor, which will provide bursts ofpower – up to 50 kilowatts – for about 10seconds, then recharge within 10 seconds,in readiness for the next hill or traffic lights.

Ideally, the hybrid vehicle will drawprimarily on stored electrical energy duringurban driving, reducing exhaust emissions,and rely more heavily on its small internalcombustion engine during suburban orcountry driving. The driver will not knowwhich power source is being used. Therewill be no telltale change in the pitch of thepetrol engine, only a seamless switchingbetween the storage batteries and thecapacitor.

Dr Howard Lovatt, of CSIRO Tele-communications and Industrial Physics,says the Aurora solar car employed a small,super-efficient rare-earth magnet motors todirectly drive the front wheel. But theprototype hybrid is likely to have a singlemotor and conventional drive train,complete with differential.

Indeed, there has been no decision yet touse a rare-earth magnet motor, whichwould be expensive. ‘Cost is no objectwhen building a solar racing car, but wehave to look for something that is cost-effective in a commercial vehicle,’ he says.

The Aurora’s neodymium-iron-boronmagnet motors were designed to minimisetwo phenomena that compromise effi-

ciency: so-called iron loss, due largely toeddy currents in changing magnetic fields,and copper loss, caused by resistance in themotor’s copper windings. These losses re-sult in heat. For a hybrid car, a compromisebetween efficiency and cost is necessary. Aswitched-reluctance motor, which exploitsiron’s attraction to an electromagnet,would probably serve the purpose.

Putting a small motor on the front wheelof the Aurora car eliminated friction lossesnormally associated with a chain or driveshaft, but such marginal gains would not becost-effective in a commercial vehicle.

Lamb says the choice of a petrol engineis determined mainly by the need to engagea major Australian vehicle manufacturer inthe project. ‘We need to use componentsthat Australian industry can supply,’ hesays. ‘No manufacturer is going to invest ina new plant to build a special engine.’

A burst of powerThe super-capacitor is being jointlydeveloped by the CSIRO in partnershipwith cap-XX Pty Ltd, a high-technologyAustralian start-up company which isdeveloping, manufacturing and commer-cialising the technology.

Dr Tony Vassallo, of CSIRO EnergyTechnology at Sydney, says super-capacitors provide low energy densitycompared with batteries, but their powercapacity – their ability to deliver largeamounts of power in transient bursts – is atleast an order of magnitude greater thanthat of any battery.

The CSIRO-capXX research team hasdeveloped a world-leading super-capacitorthat can deliver 50 kilowatts of power for10 seconds. It uses an advanced proprietarydesign which incorporates activated carbonand an organic electrolyte that providesvery high power capability.

The super-capacitor exploits a phen-omenon called charge separation, in whichthe positive and negative ions in theelectrolyte migrate to opposite electrodes;the capacitor discharges the accumulatedcurrent when a load is applied across theelectrodes.

‘Very high current loadings are involved,’Vassallo says. ‘The wiring and switchinghave to be designed to cope with currentsof many hundreds of amps.

‘Also, unlike a battery, whose voltageremains constant as its current is drained, acapacitor’s voltage drops as current is takenout, so the power management electronicshave to compensate. But, unlike a battery,it means that the system instantly knowsthe state of charge of the capacitor.’

Vassallo says a 50 kW capacitor wouldprobably be about the size of a smallsuitcase, weighing about 50 kilograms.

The hybrid vehicle will use advanceddesign lead-acid batteries, simply becauseno other high-technology battery can yetmatch this proven storage medium’s com-bination of low cost, high power andspecific energy.

Dr Russell Newnham of CSIRO EnergyTechnology* heads the battery develop-ment project. He is a member of Dr DavidRand’s Novel Battery Technologies Group,which is acknowledged as a world leader inlead-acid battery technology.

But the lead-acid batteries beingdeveloped for the hybrid vehicle will bevery different from those used to power thestarter motors in today’s vehicles.

Newnham says the aim is to improve thepower capability, specific energy and cycle-life of existing lead-acid batteries by usingan innovative plate design, combined witha combination gel/AGM (absorptive glassmat) separator. The separator, whose mainfunction is to avoid short-circuits betweenthe plates, comprises glass-fibres sur-rounded with gelled-electrolyte. ‘Theelectrolyte in such a separator is effectivelyimmobilised,’ Newnham says. ‘Therewould be no spillage of sulfuric acid if thevehicle was involved in an accident.’

The new battery will also be capable ofrapid recharging. The CSIRO team hasalready developed, in conjunction with theUS-based Advanced Lead-Acid BatteryConsortium, the technology to recharge alead-acid battery from dead flat to fullycharged within an hour, or from zero to80% charged in under 10 minutes.

28 E c o s 9 7 O c t o b e r - D e c e m b e r 1 9 9 8

The super-capacitor developed by the

CSIRO-capXX team incorporates activated

carbon and an organic electrolyte in a

process called charge separation. When the

electrode is uncharged, positive and negative

ions in the electrolyte are randomly

distributed. When a voltage is applied, the

positive and negative ions migrate to

opposite electrodes, discharging the

accumulated current. The super-capacitor

acts somewhat like a turbo-charger for a

conventional engine, providing surges of

power in short bursts. It is able to deliver 50

kilowatts of power for 10 seconds.

Each battery – the hybrid vehicle woulduse about five – would be about the size ofa small conventional car starter battery.Ideally, the entire battery pack will weighno more than 50 kg, maximising thevehicle’s power-weight ratio.

The hybrid power system would requiresophisticated electronics, combined withintelligent software, to ensure it operated atmaximum efficiency, while deliveringsimilar performance characteristics to aconventional ICE-powered vehicle. Again,motorists are unlikely to welcome anymajor change to established driving habits.

Researchers at CSIRO’s Division ofTelecommunications and Industrial Physicswill help design the electronic controlsystems and write the power-managementsoftware. They will be guided by mathem-atical models being developed by theDivision of Mathematical and InformationSciences at Sydney. Their task is to findways of delivering energy in the requiredamounts, and at the right time, foreveryday driving.

The modelling team is also developingmodels to simulate changes in urbanairsheds when hybrid vehicles take to theroads. There is little point in developing ahybrid vehicle if its manufacture was togenerate similar levels of air pollution tothose saved in exhaust emissions.

A Melbourne-based research team led byDr Warren Thorpe of CSIRO Manufac-turing Science and Technology’s Castingand Alloys Research Program will developlightweight components for the hybrid

vehicle. The program involves some 50scientists and engineers working in the fieldof light alloys casting.

Thorpe says the work is aimed at theefficient use of Australia’s light metals andalloys, particularly in the automotiveindustry, where they play an important rolein making vehicles lighter and fuel efficient.

The program’s Design and PrototypingService is run by CSIRO within the CASTCooperative Research Centre. The serviceis led by metallurgist Brad Cowley whosestaff use computer-aided design tools andsoftware to optimise light metal com-ponent designs.

Recent projects by the Design andPrototyping Service include the uppersuspension arms and X-frame roof structurefor the aXcess Australia concept car and thedie-cast magnesium seat for HendersonIndustries in collaboration with ADCForgecast, a local die casting company.

Cowley is positive about the potential oflight metals to impact on Australia’s urbanenvironment, particularly air quality. Andaccording to David Lamb, the focus onmetals also makes good economic sense.

‘Australia sits on enormous resources ofaluminium and magnesium ores,’ Lambsays. ‘The Federal Government recognisesthe need to ensure that these resources arefully developed. That means supplyingcomplex high-tech components such as carcomponents to the world’s auto industry.’

The budget for the entire hybrid vehicleproject is tiny, compared with the hundredsof millions of dollars being invested inJapanese, European and US hybrid electriccar development. But Lamb says Australianresearchers have a history of deliveringoutstanding technology on small budgets.

‘We represent good value,’ he says. ‘Ourprices are right, we have the range of skillsrequired to support a hybrid vehicleindustry, and we have the technology. Andit’s a matter of national pride.

‘With this project, we will end up with aprototype vehicle that will show the worldwhat we can do. It’s not an end goal initself, but a means to foster the take-up ofthese technologies by our industry, so thatwe can hope to become self-sufficient, andnot rely on imported technology.

‘And if we can achieve that, there’s agood chance we can get into the exportbusiness ourselves.’

* The Novel Battery Technologies Group trans-ferred from CSIRO Minerals to CSIRO EnergyTechnology in September, 1998.

E c o s 9 7 O c t o b e r - D e c e m b e r 1 9 9 8 29

Green paintallianceA NEW range of automotive paintsdestined to be cleaner, ‘greener’ andmore durable than today’s products isbeing developed by CSIRO MolecularScience and Du Pont Australia.

The new-generation tailored resins willbe made using techniques that giveprecision control over the size and shapeof polymers. As a result, fewer wastematerials are generated and the need forsolvents is significantly reduced. Otherpotential applications for the newpolymers include adhesives and inks.

Du Pont is a major provider ofautomotive paints, a global industryworth an estimated US$5 billion a year.The paints are expected to becomeavailable early next decade.

A B S T R A C TAustralian scientists, backed by the automotive

parts industry, are developing a hybrid internal

combustion engine-electric vehicle. The

imperative for the project is the undertaking by

industrialised nations to reduce greenhouse gas

emissions, particularly carbon dioxide and

nitrous oxides. It will also promote Australia’s

technological and manufacturing skills on the

world market. CSIRO is contributing expertise

in rare-earth motors, lead-acid batteries and

new-generation super-capacitors which provide

bursts of power for rapid acceleration, plus

electronic control systems, energy analysis, and

design of low-mass metals and polymer

composites to enable weight reduction.

Keywords: hybrid internal combustion engine-

electric vehicle; vehicle components;

automotive research; capacitors; batteries;

alloys; paints.

Russell Newnham and Warren

Baldsing with lead-acid batteries

developed for a hybrid bus. The team

at CSIRO Energy Technology is

developing for the hybrid car another

lead-acid battery that will be capable

of rapid recharging.