Deep-sea mining seemed a far-off, futuristic endeavor not too long ago. Now that it’s getting closer to reality, electric vehicle fans will have to consider how deep-sea mining impacts the sustainability profile of EV batteries. In the latest development, Japanese researchers have found a huge new cache of manganese nodules on the ocean floor, and the race is on to vacuum them up to the surface.
The Most Sustainable EV Batteries In The World
Before we get to that new mother lode of manganese, I’ll just put this thought out there: All else being equal in terms of battery materials, the most sustainable EV batteries are the ones that go into electric commuter buses, group transit vans, and passenger trains.
New wireless, in-road EV charging technology can also help contribute to EV battery sustainability by reducing the size of a battery needed for a particular vehicle. Also falling into that category are electric bikes and scooters, which require far less material to move a person from one point to another, compared to a car.
Here in the US, an uptick in the market for smaller cars could also make a broader impact on battery size and demand for materials, if the trend catches on.
Then there’s the emerging battery-swapping field, which has the potential to extend battery lifespan by ensuring that EV batteries are recharged efficiently.
The EV battery recycling and repurposing market is another sustainability factor that helps recirculate materials through the economy. The “15-minute city” concept is yet another solution, but that’s a whole ‘nother can of worms.
The World Needs More Manganese
Alternative EV battery formulas, flow batteries, and fuel cells could also help ratchet down the speed at which demand for critical materials grows. However, in the case of manganese these same factors can also act as accelerators.
Either way, the International Energy Agency has concluded that EV sales are pushing demand, and the market research firm Benchmark is on record with the anticipation of an eight-fold increase in demand for magnesium in batteries alone over the coming years, driven by the killer combo of EV sales and new manganese-dependent battery formulas.
Into this picture steps deep-sea mining. On June 21, Japanese researchers from the University of Tokyo and the Nippon Foundation held a press conference to announce the confirmation of a new deep-sea cache of manganese nodules located within Japan’s Exclusive Economic Zone, off the coast of Minamitorishima Island at a depth of 5,500 meters.
As reported by the Japanese public media organization NHK, the nodules also contain cobalt and nickel among other materials, for a total of 230 million tons. The nodules are “present in a condition easy to extract as resources,” NHK added.
Not wasting any time, the researchers have already recruited a firm to test a large-scale nodule harvesting operation beginning as early as 2025, with an initial goal of 2,500 tons daily.
Deep-Sea Manganese For EV Batteries: Not As Easy As It Sounds
The “easy to extract” thing depends on your definition of “easy.” The nodules really are lying around loose on the ocean floor like so many potatoes, and they could be scooped up with equipment that resembles a potato harvester.
However, that is where the trouble begins. Back in 2014, World Ocean Review took a deep dive into undersea manganese mining and raised the obvious concern: This will suck for marine life.
Surface disruption in the mined area is just one concern, and it is a big one. “Directly in the ploughed area all organisms are killed that cannot escape the plough quickly enough, including snails, sea cucumbers and worms, WOR notes. The recovery process involves vacuuming the nodules up to a waiting ship for processing, which would kill off any surviving organisms.
Stirring up sediment is another issue, as ocean currents can move the sediment cloud outside of the mined area. “When the sediments finally settle down to the sea floor again, sensitive organisms, particularly the sessile, immobile ones are covered and die,” WOR explains. Adding to the potential for catastrophe is waste sediment pitched from processing ships, which could impact algae, plankton, and other near-surface aquatic life.
WOR further notes that the mining, pumping, and cleaning operations are noisy, vibration-inducing operations that can drive dolphins and other marine life from their familiar habitats.
Mitigation solutions are possible. For example, cowling the harvester has been studies as a way to help contain sediment in its original area. However, WOR cites a seven-year study of a ploughed sea-floor site conducted through the on-again, off-again German research project Disturbance and Recolonization (DISCOL), showing that some, but not all, marine life returns to ploughed areas. “This means that after 7 years the disturbed area was significantly species-depleted,” WOR concludes.
The Search For Sustainable EV Batteries Continues
The news organization Deep Sea Mining Observer revisited the DISCOL project and other studies in 2019. Their conclusion was much more harrowing.
“Twenty-six years after DISCOL*, deep-sea ecologists returned to the site of disturbance to assess the recovery of the seabed in the preceding two-and-a-half decades,” DSMO reported. “What they discovered was a sea floor still largely altered, with little evidence of recovery following such severe disturbance.”
The asterisk refers to the 3+ years that passed between data collection and publication. DMSO notes that the stretched-out timeline underscores “the slow and steady pace of formal scientific research, which may ultimately serve as an unavoidable bottleneck for the expansion of deep-sea mining development in the Area.”
That call for temperance seems to be falling by the wayside. Last fall, Scientific American was among those noting that deep-sea mining is coming soon, ready or not, with Japan being just one among many stakeholders on the move.
Meanwhile, signs are emerging that a long term solutions for sustainable EV batteries are emerging. Keep an eye on Lamborghini, which has been working with MIT to develop an EV battery based on an organic material called TAQ, which resembles the structure of graphene.
Interesting! Graphene is a new superstar material, discovered in 2004. It has been a frequent guest at the CleanTechnica table for many years, mainly on account of its potential for application in solar cells. More recently, EV battery stakeholders have begun sniffing around for new opportunities.
“The California firm Lyten, for example, has just begun shipping samples of its new graphene-enhanced lithium-sulfur EV battery to automakers for testing,” CleanTechnica reported just last March. “The new battery formula eliminates cobalt, manganese, and nickel in favor of local supply chains, attracting the eye of Stellantis among others.”
Electric vehicle fans, keep pressing your favorite car maker for better EV batteries. Short of preventing catastrophic mining on the ocean floor, at least you can help motivate the next-generation wave of sustainable mobility.
