EV battery technology must become more sustainable if we are to transition to net-zero.
While future technologies like graphene are exciting, the next step is to move away from materials that come at a significant human and environmental cost.
The big material in question is cobalt.
Cobalt is the least abundant and most expensive component in EV battery cathodes, yet it is crucial for traditional lithium-ion chemistry.
Cobalt acts as a stabiliser in the cathode, enabling high energy density while preventing corrosion. In other words, it gives lithium-ion batteries stability. It keeps the layered pack stable as ions in the cathode move around during battery operation.
Cobalt has played a huge role in our lives ever since Sony commercialised the first rechargeable lithium-ion battery in 1991 for its range of small digital cameras.
Today, cobalt is used in every lithium-ion battery, but supply chain risks and ethical concerns are at odds with the EV industry, which needs a stable supply of raw materials that don’t come at a human cost.
Cobalt-free EV batteries are the future
Many automakers and battery producers are moving away from cobalt quickly. Tesla is the most notable example. They are moving away from lithium-ion chemistry to lithium-iron chemistry known as LFP for lithium ferrophosphate, for standard range batteries. Tesla LFP batteries are based on nickel and manganese with zero cobalt.
Nickel is more abundant than cobalt, and iron is basically everywhere, making LFP a leading chemistry for future EV batteries.
The downside to LFP batteries is their lower energy density, which is why Tesla only install them in Standard Range vehicles. Thankfully, the chemistry is configurable, and Tesla will undoubtedly improve the technology over time.
Tesla is transitioning from cobalt chemistry for its LFP batteries in Model 3 standard range models, sticking with cobalt chemistry for long-range models (for now). But, this could mark a shift away from long-range cobalt chemistries in the future.
Tesla’s cut of cobalt has been significant so far, so big that it contributed to making Volkswagen a bigger consumer of cobalt earlier this year.
Zero cobalt batteries
The dream is to create a 100% nickel battery, which would enable high energy density without compromising safety, longevity and charging speed. The highest nickel chemistry achieved so far is 89%, produced by the University of Texas at Austin.
Although the University’s battery has a slightly lower energy density than comparable lithium-ion batteries, it operates at higher voltages and offers similar charge rates.
Another alternative is the sodium-ion battery. In July, Chinese battery company CATL announced its first sodium-ion battery. It will have an energy density of 160Wh/kg and take 15 minutes to reach 80% of its charge. Sodium-ion batteries do not contain lithium, cobalt or nickel.
Aside from sodium, aluminium-ion batteries also show huge potential. General Motors has committed to a battery called Ultium, a modular battery cell architecture that uses 70 per cent less cobalt by swapping the element with aluminium. These batteries swap out cobalt for more aluminium.
Another future battery is the solid-state battery. Factorial Energy’s solid-state battery uses more nickel to reduce reliance on cobalt.
With Tesla moving to cobalt-free chemistry in standard range batteries, moving to cobalt-free chemistry in long-range batteries seems like a logical next step.
The problem with cobalt
Demand for cobalt will only grow as battery production multiplies with EV adoption, however, cobalt threatens mass EV adoption for several reasons that are well known.
Cobalt is fraught with political issues. It is mined in conflict areas like the Congo, and cobalt mining is associated with enormous emissions, higher than most other metals used in EV batteries.
Cobalt has also been heralded as the biggest supply chain risk to EV batteries.
In this landmark report, the risks associated with cobalt are concisely explained, “Firstly, the cobalt market is highly concentrated, with more than half of the cobalt mined in the Democratic Republic of the Congo, and almost half of the cobalt refined in China. Secondly, almost all cobalt is mined as a by-product of copper and nickel. Finally, political stability in production countries is considered to be medium to very weak.”
As a byproduct of nickel and copper mining, the price of cobalt is extremely volatile, with it at the mercy of nickel and copper production. Today, the average cost of cobalt is more than the combined cost of all the other battery metals. Because of this, cobalt is a barrier to falling EV battery prices.
As society embraces electric vehicles and the world becomes greener, cobalt is at odds with the transition. Tesla moving away from cobalt for standard range batteries is their best decision yet, and one that the rest of the industry must follow.
Battery recycling is also crucial
Additionally, EV battery recycling has to ramp up to reduce demand on primary mining measures. Metals are fully recyclable, but recycling batteries is time-intensive and difficult. UK EV battery recycling company Technology Minerals is addressing this with the country’s first circular economy in the battery metals sector.