In search of 'sustainable' EV battery metals

A NEW study out of Canada has revealed some key environmental and economic benefits of mining deep-sea polymetallic nodules for use in the batteries of electric vehicles compared to more traditional land-sourced metals.

The study, ‘Where Should Metals for the Green Transition Come From?’, was commissioned by deep-sea metal mining company DeepGreen as “calls for a transition to renewable energy and electric transport grow louder”.

This is critical as global demand for EVs increases in the years ahead and the world’s major motor vehicle manufacturers continue to transition from combustion engines to electrified powertrains, despite the current slowdown due to the coronavirus pandemic and world oil price shock.

An estimated 2.2 million full-electric and plug-in hybrid light vehicles were sold globally last year, up 10 per cent on 2018.

Six key improvement areas for EV battery metal mining were identified by the team of researchers and scientists who used a lifecycle sustainability analysis framework and standard lifecycle analysis methodology to compare the two methods.

The first of these findings relates to sheer amount of land needed to extract and process the relevant materials, with nodule collection said to use 94 per cent less land than traditional mining and refining.

The study claims that to make one billion EV batteries, 156,000 square kilometres of land – roughly the size of England and Wales combined – would need to be mined as opposed to the 9360sq-km needed to process nodules on-shore.

That said, however, the study did acknowledge that “a larger area of seabed” would be impacted due to “the two-dimensional nature of the nodule resource”, specifically, as much as 508,000sq-km.

Polymetallic nodules are comprised of magnesium, nickel, cobalt and copper and are said to be 100 per cent reusable with absolutely zero solid waste.

Citing data from the World Bank, DeepGreen says demand for certain EV battery metals is projected to increase by 11 times the current level by 2050 while shortages in nickel, cobalt and copper – three of the four key elements – could emerge as soon as 2025.

“We believe that polymetallic nodules are an important part of the solution … they’re effectively an EV battery in a rock,” said DeepGreen chairman and CEO Gerard Barron.

“The purpose of this in-depth research effort is to provide a substantive look into the impacts of different sources of the critical battery metals that make up the bedrock of the clean energy economy.

“The scale of the green transition is monumental, and the timeline is daunting.”

Following on from the vastly reduced land required for processing and refining, ocean nodule mining also brings with it a claimed 92 per cent lower need for deforestation and land clearing.

According to figures in the study, just 5200sq-km of forest would need to be flattened in order to produce one billion EV batteries from ocean nodules compared to the 66,000sq-km that would need to go to cater for a mine site and processing plant.

The less need for land and subsequent deforestation also reduces the amount of wildlife put at risk.

According to the study, as many as 44 trillion fewer ‘megafauna’ are affected for every billion EV batteries that are produced using ocean-sourced elements, equating to a 94 per cent reduction.

Another key finding was the drastically reduced carbon footprint of the nodule collecting and refining processes, which are claimed to emit 70 per cent less CO2 than land mining with a “94 per cent reduction in stored carbon at risk”.

On the topic of emissions, nitrogen oxide (NOx) and sulphur oxide (SOx) pollution levels were also found to be 90 per cent lower than that of a traditional mine.

Away from the environmental benefits, job safety was also identified as an area of significant improvement with a 97 per cent lower expected mortality rate associated with collecting ocean nodules compared to land mining, with zero child labour.

For every billion batteries produced, there are an anticipated 1800 deaths associated with land mining compared to just 47 relating to nodule collection – a difference of 1753 lives.

According to marine biologist and ecologist Dr Steven Katona – one of the lead researchers behind the study – there has been a heightened awareness of the environmental, social and economic impacts of producing metals from land ores over the past five years.

“We essentially built on existing lifecycle assessment indicators work for land-based mining and created an apples-to-apples comparison for battery material production from ocean nodules,” he said.

“This unique comparative LCSA enables auto manufacturers, technology companies and policy-makers to understand how these different sources of key base metals measure up against each other with regards to their impacts.”

One glaring acknowledgement of the paper under the wildlife impacts was that “more research is needed on the role of important species in deep seabed ecosystems”.

In a recent statement, DeepGreen said: “While the deep seabed is a food-poor environment with limited biomass, uncertainties remain over the nature as well as temporal and spatial scales of impacts from nodule collection on deep-sea wildlife”.

As a result, preparation work on a multi-year environmental and social impact assessment – the biggest ever of its kind – has started with over 100 individual studies set to be undertaken.