Rethinking EV Battery Materials

Maryland-based AquaLith Advanced Materials is developing a combination of technologies to tackle ongoing raw material supply shortages and other bottlenecks affecting three core components of lithium-ion batteries for electric vehicles. The company is introducing a water-based electrolyte, a high-energy cathode with a hybrid material, and a silicon microparticle anode, all made with inexpensive and widely available materials.

 

A General Motors scientist operates a battery pressure test at the company’s Estes Engineering Center in Michigan. Image used courtesy of GM

 

AquaLith’s technology contains no transition metals and stores more energy than incumbent products on the market. Furthermore, replacing nickel and cobalt in cathodes is advantageous for production, as the pair of metals are scarce and costly. 

The technology comes as EV manufacturers in North America and Europe are looking to shore up domestic or regional supply chains for critical components, reducing their reliance on Chinese suppliers. China leads the world’s supply of EV battery materials downstream of mining. According to the International Energy Agency, the country oversees 70% of cathode and 85% of anode material production capacity. It also dominates 80% of global graphite mining and over half of lithium, cobalt, and graphite processing. 

 

AquaLith’s Silicon Anode, Hybrid Cathode, Aqueous Electrolyte

AquaLith’s anodes are based on silicon microparticles, unlike conventional anodes containing graphite. They last longer than silicon nanoparticles, an alternative chemistry that minimizes silicon’s characteristic degradation when charging and discharging. AquaLith CEO Gregory Cooper stated this type of anode could reduce the battery’s weight by up to 20% and cut nearly 10% of the total cost of a 100 kWh battery. 

Cooper added that swapping out nanosilicon with silicon microparticles can slash anode costs by over 75% while boosting energy density by 40%. 

AquaLith’s cathode uses a hybrid material comprising lithium bromide, lithium chloride, and graphite. The former pair enables high energy density, while the graphite adds up to 10 times the charging cycles. The cobalt-free solution can unlock a 50% reduction in cathode costs. 

The aqueous electrolyte is based on water – as its name implies – rather than lithium salts, which may be flammable when overheated. While aqueous electrolytes are safer, they have a technical disadvantage since they can't efficiently operate at high voltages. However, adding salt to the water-based electrolyte creates a film that boosts the electrodes’ voltage capacity by 150%. 

 

This chart shows the main components of lithium-ion batteries and their functional roles. Image used courtesy of Samsung SDI

 

AquaLith claims its battery can work efficiently below -50°C. Cooper plans to submit anode materials for testing in 2023, though the technology is likely several years away from combining the three materials into one product and selling to automakers. The company aims to raise $5 million in the coming months. 

The company raised its first $750,000 in outside funding from private investors and the Maryland Momentum Fund in 2021. At the time, its water-based electrolyte had been demonstrated at temperatures under -50°C, supporting outdoor applications at the North and South Poles. Its aqueous electrolyte showed promise for minimizing fire risks in short circuits. The other materials could replace transition metals like cobalt and nickel with chloride and bromide salts, unlocking a more stable supply chain. 

 

The Lithium-Ion Supply Chain

Other companies are pursuing alternative battery chemistries targeting low-cost materials. For example, Lyten is developing a commercial lithium-sulfur battery with superior energy storage density at a lower cost than lithium-ion batteries. 

EV manufacturers are facing an increasingly strained battery cell supply chain mired in shortages of equipment, labor, and construction materials. According to a recent analysis by McKinsey & Company, lithium-ion battery demand is projected to grow 27% annually to about 4.7 terawatt-hours by 2030, up from 700 gigawatt-hours in 2022. Mobility applications such as EVs are the largest end sector for this increased demand. 

 

How battery advancements impact different types of cell components. Image used courtesy of McKinsey & Company 

 

While the metals and mining industry will likely provide raw materials for batteries in the foreseeable future, more manufacturers are working on sustainable products with flexible battery chemistries and lower raw material requirements. Nearly 60% of lithium is mined for battery applications, a share that could reach 95% by 2030. Still, that trajectory may shift as companies explore other technology choices, such as replacing lithium metal with silicon anodes.