Study backs Li-ion batteries for EVs

One of the major sources of concern for the EV industry lies in swings-and-roundabouts claims on the matter of environmental impact -- namely, that the environmental benefits of EVs on the road are diluted or scotched by the processes it takes to develop and build them, particularly their batteries.

But a team from Switzerland's Federal Laboratories for Materials Science and Technology (Empa) has found otherwise, releasing a report hailing from extensive life cycle assessment (LCA) of vehicular lithium ion batteries.

LCA is a multifaceted process for evaluating a product's environmental impact taking into account its full lifecycle, from the extraction of raw materials, through its operational life to how it ends up, for example as landfill or in recycling processes.

The study scoped out and expressed the environmental burdens according to several important criteria, both abstract and actual:

Green Car Congress reports that the EV study, published in the ACS journal Environmental Science & Technology, finds that "the environmental burdens of mobility are dominated by the operation phase regardless of whether a gasoline-fueled ICEV or a European electricity-fueled BEV is used".

In plain English, that means cars do most of their polluting on the road rather than in the factory, regardless of their power source. Since EVs do much less polluting on the road, they scrub up better than their combustion-engined counterparts overall.

The study pitted a Volkswagen Golf-sized EV with a range of about 200km per charge and an assumed lifespan of 150,000 km against what it described as "a new efficient gasoline car", Euro 5 compliant, averaging 5.2 L/100km on the New European Driving Cycle, with CO2 emissions rated at 120g/km.

Assuming an overall operating efficiency of 80 percent, the team deemed 14.1 kWh of electric energy a reasonable ask to propel the Golf-class EV 100 km, assigning 2.9 kWh/100km to HVAC, audio and other operating electronics, taking the vehicle's total consumption to 17 kWh/100 km.

Charge would come from what they calculated to be Europe's "average electricity production mix" -- important, given the single biggest influence on an EV's total burden on the environment resides in the source of electricity from which it's charged.

What they found didn't all go the EV's way. Surprisingly, while its environmental burden was lower on the four major assessment fronts, the total particulate matter, oxides of nitrogen and sulphur dioxide emissions brought about by E-mobility exceeded those of internal combustion engines.

Little of this was attributable to the Li-ion battery -- just 15 percent. The report sheeted home less than 2.3 percent of the environmental burden to the extraction of lithium for the battery. Most of the blame went towards copper and aluminium supply for anode and cathode production respectively, plus cabling and battery management system components.

The team's breakeven analysis showed that the IC engine would need to be very fuel efficient indeed to match the Li-ion EV's environmental lightness of touch -- less than 3.9 L/100km for a better CED score and less than 2.6 L/100km to outdo it on the EI99 criteria.

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