Diminished availability of these much-needed raw materials, combined with growing concern about the geopolitical and sometimes reputational risks attached to sourcing them from mines in countries that face socio-economic and environmental challenges, is driving the search for alternative battery chemistries.
While lithium is widely available in the earth’s crust, the recent global push to mainstream battery electric vehicle (BEV) production has caused demand for this raw material to soar, and prices have increased exponentially. In 2015, only 30% of lithium demand was for batteries, but by 2030, this is expected to have increased to 95%.
A report published recently by the Advanced Propulsion Centre UK has concluded that a modest global lithium deficit is likely in 2025, significantly widening by 2030. If current mines are unable to meet global demand, then battery makers won’t be able to source the lithium they need, potentially halting BEV production and preventing net-zero emissions targets from being met. Creating new mines is an option, but this would take years.
Sourcing lithium isn’t the only problem, nickel and cobalt are also in short supply. Issues surrounding the practices used to extract these particular minerals are also an important consideration for car makers. Tesla has recently set out its strategy for sourcing minerals directly from mines in a bid to secure supplies and keep a close eye on quality and ethical standards.
In a race to avert a supply crisis on route to electrification, car makers are exploring the potential of alternative battery chemistries. Tesla is using lithium iron phosphate (LFP) batteries for its Model 3 and other standard ranges. While LFP batteries have lower energy density, the charging and safety characteristics are better than their nickel-based counterparts and benefit from a longer lifespan.
Other battery chemistries currently under development include graphene batteries, which could replace the need for lithium-ion batteries in the future. For battery manufacturers, graphene has several advantages over existing lithium-ion chemistries, including faster recharging times, more resistance to wear, improved safety and a longer lifespan. The main disadvantage currently is cost, although this could reduce in the future. The Chinese car maker, GAC, was first to market with a graphene battery in its all-electric SUV, the Aion V, which went into production last year.
All-solid-state batteries (ASSBs) are also the focus of a great deal of innovation activity and patent filing activity is intense. This area of R&D has been described as the ‘holy grail’ for EV battery manufacturers, at least in the short term, due to its potential to double the energy density of a standard lithium-ion battery. The technology involves replacing liquid electrolyte with solid electrolyte, which while heavier could increase battery performance and, importantly for the motorist, increase driving range.
The lithium-ion patent filing giants such as Samsung, Panasonic, LG and Toyota are active in this field and can be expected to continue to driving solid state innovation forward. Toyota in particular appears to be embracing solid state technology and was responsible for filing approximately 15% of all patent applications relating to solid state technology at the European Patent Office (EPO) in the period 2014 – 2018. Mainstream production of ASSBs is thought to be just a few years away, and most auto makers are already working with tech partners to develop this technology.
Although it’s yet to be commercialised, another runner in the race to avert an EV battery supply crisis is sodium-ion technology. Despite being similar in construction to lithium-ion batteries, sodium-ion batteries are potentially more eco-friendly as they mainly use sodium-chloride, which is abundant in the ocean, and is relatively easy to access. Unlike lithium-ion batteries, they are not reliant on nickel, cobalt and manganese, and instead use widely-available materials such as Prussian blue, a ferrocyanide salt more commonly used as a pigment in paint. Tech company, Natron, has developed a number of industry-leading sodium-ion battery technologies and is set to commence mass production of its commercial product in 2023.
The race to EVs is the biggest and most rapid change the automotive industry has ever seen and the level of innovation activity targeted at finding new battery chemistries is unprecedented.
Data published by the EPO confirms that patent filings for non-lithium-ion chemistry inventions are steadily increasing. It remains unclear which technology will become dominant in the future, but the winner is likely to be one that is able to avert a supply crisis whilst delivering a more sustainable solution that gives motorists the performance they expect.
Ben Palmer is a partner and patent attorney at European intellectual property firm, Withers & Rogers. He has specialist knowledge of battery technologies and the EV industry.
