Lithium-ion batteries reign supreme in the green energy transition. Over the years, producers have doubled down on one key advantage — the fact that they store a lot of energy for their weight — to power the vast majority of electric vehicles on our roads. But there could be trouble ahead.
Supply chains for the raw materials at the heart of lithium-ion batteries might struggle to satisfy growing EV adoption targets. Global demand for lithium alone is forecast to increase almost fourfold by 2030.
Mining the raw materials needed — whether it’s lithium, nickel or cobalt — is also contentious, and has spawned legal battles over indigenous rights, water pollution and child labour accusations.
There are also rising costs — this year battery pack prices are set to increase for the first time in a decade as raw materials get more expensive. That threatens to push back the timeline for price parity between electric and fossil fuel vehicles by several years.
Fighting to topple the lithium-ion battery and develop a power source for vehicles that doesn’t harbour any dirty secrets under the hood are a number of startups in Europe using naturally abundant materials as their starting point.
“There will be another battery technology that is less raw material intensive. Now what that is, that's the battle right now,” says David Brown, founder and CEO of BroadBit, which is working on batteries made primarily from table salt.
So could alternative tech prevail?
The startups worth their salt
In one corner, you have sodium-harnessing companies like BroadBit, alongside UK-based Faradion, which has already started small-scale manufacturing of sodium-ion batteries, and Sweden-based Altris, which focuses on sodium-based materials for battery cathodes.
Also looking for a slice of the market are Finland-based Geyser Batteries and Norway-based Beyonder, which are working on batteries based on activated carbon derived from wood. Germany-based VoltStorage, meanwhile, has developed a battery from the metals vanadium and iron.
Lithium-ion producers won’t be able to keep up with demand on their own, says Brown. “The main thing is scalability — lithium-ion just can't be scaled to the needs of these coming markets. It's just an impossibility.”
Pontus Stråhlman, partner at deeptech-focused VC Voima Ventures and investor in Geyser Batteries, thinks it’s not so much a question of one winning technology as of several. That’s because batteries’ charge and discharge powers and storage capacity tend to be optimised for distinct use cases.
“Quite often, if you have an innovation, you will have strengths in some of these factors, but not necessarily in all of them, which makes them more suited to one particular application,” he explains. “Since the use cases [of batteries] are so different, can there actually be one solution superior to all others?”
Developing an alternative to lithium-ion batteries
Developing a battery to take on lithium-ion is a long-winded process for startups.
The process starts with running a proof-of-concept project centred around a first customer. Then startups need to generate enough buzz to raise investment to help pay for a production facility.
“I guess one of the reasons why we see lithium-ion batteries continuing to be developed is that quite often startups [working on alternatives] can only demonstrate incremental improvements, whereas what’s needed is real groundbreaking innovation,” explains Stråhlman.
Brown believes that BroadBit’s batteries will be around 40% the cost of lithium-ion batteries at scale. But in the beginning, they will be marketed on their safety, ability to handle a wide range of temperatures and general robustness.
That marketing strategy is based on Lithium-ion batteries' one big disadvantage, which other challengers are seizing upon too: they’re highly flammable, risking incidents like the two electric buses that caught fire in Paris this April. “That won’t happen with our batteries,” insists Brown. “Those are advantages that niche markets will pay a lot for.”
What’s clear, though, is that in passenger electric vehicles lithium-ion batteries will continue to dominate the industry for at least this decade.
“When you’re looking at a range of 300 to 400 miles, it’s very difficult to achieve that in an electric vehicle with alternative ions to lithium, because it'll be a lot bulkier, and you don't want a big battery in the car,” says Pooja Vadhva, consultant at battery-focused research company Intercalation. “That’s because from an elemental standpoint, lithium is just really, really hard to overthrow as a light metal with very high energy for its mass — or energy density — compared to other alternative materials.”
Though she thinks there is potential for new battery types in situations where battery weight doesn’t play an outsized role, like in stationary storage, or electric vehicles with lower mileage requirements such as those used for last-mile delivery.
Pluses and minuses
When it comes to scaling up, Brown’s plan is to assemble BroadBit batteries using existing lithium-ion plants. In his view, prior investment in lithium-ion manufacturing will benefit his startup “because there's not enough raw materials to serve those factories”.
Vadhva, however, cautions against startups underestimating the challenges of taking over existing assembly lines. Like any battery, there’s a plus and a minus involved.
“From the outside a lot of processes might look the same, but changing even one composition takes a lot of downtime and a lot of engineers redoing all kinds of checks — and that's for the same line changing just one parameter.”
It will be crucial for challenger startups to demonstrate that their tech can be mass manufactured to compete with lithium-ion, Vadhva says.
The increased awareness around lithium’s patchy environmental credentials is an opportunity. When BroadBit was founded, Brown recalls that “we were whistling in the wind — people didn't understand that this would be a problem in the future”.
And despite the ongoing difficulty of raising money from “hardware-averse” investors, conversations with potential customers leave Brown optimistic for the future. “There is high interest — everybody wants us to be ready.”