Cutting-Edge Electric Vehicle Battery Query: The Unresolved Issues Remain

The next generation of electric vehicle (EV) batteries is on the horizon, and it's shaping up to be a game-changer. Lithium metal, solid-state technology is emerging as the front-runner, offering the potential for significantly longer ranges and reduced fire risks.

University of Michigan (U-M) associate professors of mechanical engineering, Jeff Sakamoto and Neil Dasgupta, have been at the forefront of lithium metal, solid-state battery research over the past decade. They have worked closely with leaders in the auto industry to develop this promising technology.

In a perspective piece published in the journal Joule, Sakamoto and Dasgupta outline the main questions facing lithium metal, solid-state batteries as they move towards commercialization. Sakamoto warns against letting the enthusiasm for this technology get ahead of the challenges that need to be addressed before it can be widely adopted.

One of the key questions is how the added hardware in lithium metal, solid-state batteries may impact battery pack performance. The use of lithium metal for the battery anode along with a ceramic for the electrolyte could potentially double the EV range for the same size battery while dramatically reducing the potential for onboard fires. However, the reduction in mass and volume of the battery management system, or its removal altogether, may affect the performance and durability of the batteries.

Additional hardware is needed to apply pressure and maintain contact between lithium metal and the ceramic electrolyte in lithium metal, solid-state batteries. The production of ceramics, which are brittle and require high temperatures for manufacturing, presents a challenge for lithium metal batteries used in electric vehicles. The energy required to heat ceramics for lithium metal batteries may offset their environmental benefits in electric vehicles.

Adapting the manufacturing process of ceramics and the process itself to account for defects, such as cracking, is necessary but may require significant changes in battery manufacturing operations. Sakamoto and his collaborators have written a paper titled "Transitioning solid-state batteries from lab to market: linking electro-chemical mechanics with practical considerations" to address these issues.

Despite the challenges, the progress made in advancing lithium metal, solid-state batteries over the last decade is considerable. Major automakers are going all-in on electric vehicles this year, with many announcing plans to phase out internal combustion engine cars in the coming years. Currently, QuantumScape Corporation is a leading company developing and manufacturing lithium-metal-based solid-state batteries for electric vehicles, in partnership with PowerCo SE, the battery division of the Volkswagen Group. They recently demonstrated a Ducati motorcycle powered by QuantumScape’s solid-state lithium-metal batteries at the IAA Mobility conference in Munich.

However, lithium-ion batteries remain the most common power supply for the latest electric vehicle models coming off assembly lines. While lithium-ion batteries have served the industry well, they are approaching their peak performance in terms of the EV range on a single charge. The development of lithium metal, solid-state batteries could help push the boundaries of what is possible in electric vehicle technology and bring EVs to a larger part of the population. The questions facing this technology need answering quickly to make that a reality.