Batteries are the heart of an electric vehicle (EV). Nestled in a large shell beneath the floorboard, you’ll find dozens of modules that house hundreds of battery cells, all of which release and store energy – no fossil fuels required.
Batteries of the lithium-ion (Li-ion) variety are ubiquitous not only in EVs, but in all manner of portable electronic devices. Drivers are always looking to go further on a single charge and reduce the amount of time it takes to replenish depleted batteries. But the mass market is also very price conscious – most will only purchase an EV if it is cost competitive compared to an internal combustion engine car. Scientists are taking all this into account and continuously improving battery chemistry through R&D, resulting in new formulations that perform better, cost less, and are easier to recycle.
Li-ion batteries are well-suited to EVs for many reasons. Besides being rechargeable, they exhibit great energy density (which is energy measured per unit volume) and specific energy (or energy-to-weight ratio). This allows for smaller and lighter batteries, characteristics which are ideal in the automotive world. They also have a wide operating range, making them suitable to charge and use in most parts of the world. Performance issues will only become apparent in the most extreme temperatures (lower than 50 and above 104 degrees Fahrenheit).
It’s estimated that for EVs to be competitive with gas-powered equivalents, the cost of the massive batteries that power them must fall below $100 per kWh. Some analysts have set this target as low as $60. The industry has made great strides in this regard; a decade ago, battery prices of over $1,100 per kWh were common. In 2020 the average price for Li-ion batteries was $137 per kWh, and the $100 mark is expected to be attained in just a few years.
Li-ion technology is here to stay, at least in the short term. Most EV manufacturers currently opt for lithium nickel manganese cobalt oxide (NMC) batteries, while Tesla uses lithium nickel cobalt aluminum (NCA) formulations.
Researchers are focusing on tweaking the chemical makeup of these batteries, specifically concerned with reducing the amount of cobalt. This metal is toxic and expensive, having exhibited major price fluctuations in recent years. Even at its one-year low of $32,000 per ton in 2020, cobalt is still far more expensive and less abundant than manganese, which trades at around $2,000 per ton.
Expect the next generation of LG batteries, which will be found in GM’s upcoming EV chassis, to bring levels of cobalt down to 10% while increasing manganese levels. We can expect similar developments from VW and Tesla.
In order to completely replace cobalt in batteries with manganese, kinks like energy density issues will need to be ironed out, but researchers are confident that challenges can be overcome.
This formulation is interesting for several reasons. Replacing nickel, manganese, and/or aluminum with iron (represented by the word ferro) makes the batteries less expensive. Iron as a resource is plentiful and has low toxicity. LFP batteries are remarkably resistant to impact and don’t ignite, allowing carmakers to shed some weight from the typically dense shell used to protect batteries that contain other Li-ion formulations. On the performance side, they exhibit excellent energy output and longer lifespans.
The only major downside to LFP batteries lies in their lower energy density, which translates into reduced range on a single charge. The aforementioned weight savings only partly compensate for this. There are also concerns about performance in cold weather. While LFP is largely absent from the US market, these batteries are thriving in China, where they own a 47% market share.
Recent comments by Volkswagen, Tesla, and Ford executives provide hints as to how LFP technology will be deployed in other territories: these batteries will soon power entry-level vehicles. Consider that batteries with high nickel concentrations have the greatest energy density. While iron-based LFP batteries suffer in this regard, they have other attributes that make them ideal for mass market commuter vehicles, and carmakers are intent on exploiting this. LFP batteries will play a starring role in Tesla’s upcoming $25,000 EV, as well as in Ford’s future commercial vehicles. Conversely, expensive cars designed to be more high-performing will likely have high-nickel battery formulations powering them.
It’s worth noting that LFP batteries may be easier to recycle than their counterparts. Disassembling the Li-ion batteries that currently dominate the US market is a laborious process because of their nested, glue-intensive design. Recycling plants are forced to melt them down, either by shredding and burning them, or by immersing them in pools of acid, before they can extract the valuable minerals inside. These processes, known respectively as pyrometallurgy and hydrometallurgy, produce waste and emit greenhouse gasses.
Chinese LFP manufacturer BYD produces a battery named Blade which simplifies the design of the pack. Battery cells are not glued inside modules – they are installed directly inside the main battery shell instead and are easily removed. Designing all batteries with easy recycling in mind is imperative to keep EVs environmentally friendly after their useful lives are over.
As carmakers and battery manufacturers tinker with their battery formulas, drivers will have more options than ever.
Lithium ferro phosphate batteries are poised to make more affordable EVs a reality, while midrange cars stand to benefit from batteries with less cobalt. Electric sports cars and SUVs that require uncompromised energy can be outfitted with high-nickel batteries.
Several new battery formulations are being demonstrated in lab settings every year, making this an exciting space to follow in the long-term.