The prototype battery, integrated into a modified EQS at the close of 2024, replaces traditional liquid electrolytes with a solid medium. This advancement not only bolsters cell safety but also facilitates the use of lithium-metal anodes, potentially elevating energy density to 450 watt-hours per kilogram. Such a boost could enable the test vehicle to surpass 620 miles on a single charge.
Markus Schäfer, Chief Technology Officer of Mercedes-Benz Group AG, emphasized the company’s dedication to innovation, stating, “Developing an automotive-scale solid-state battery underlines our commitment to innovation and sustainability.”
The development process involved rigorous bench testing before the battery’s integration into the EQS. Engineers devised a unique floating cell carrier, now patented, to manage the expansion and contraction of materials during charging cycles. This design incorporates pneumatic actuators to accommodate these volume changes, enhancing both performance and longevity.
Siyu Huang, CEO and Co-Founder of Factorial Energy, highlighted the project’s significance, noting that it “marks a historic achievement in electric mobility.”
Mercedes-Benz plans to continue extensive laboratory and road evaluations in the coming months to assess the solid-state battery’s performance and its potential for mass production. This development signifies a pivotal step toward integrating advanced battery technology into consumer electric vehicles, potentially setting new standards for the automotive industry.
Solid-state batteries are emerging as a transformative technology in electric mobility, offering significant advancements over traditional lithium-ion cells. By replacing the liquid electrolyte with a solid medium, these batteries enhance safety and enable the use of high-capacity anodes, such as lithium metal, which substantially increase energy density.
This shift not only reduces the overall weight of the battery but also has the potential to elevate the gravimetric energy density to approximately 450 watt-hours per kilogram at the cell level, thereby extending the driving range of electric vehicles.
Gravimetric energy density, defined as the amount of energy stored per unit mass, is a critical parameter in assessing battery efficiency and performance, particularly in applications like electric vehicles where minimizing weight is essential. The adoption of solid-state technology addresses safety concerns associated with liquid electrolytes and paves the way for more efficient and longer-lasting energy storage solutions.
Mercedes-Benz is conducting extensive laboratory and road tests over the next few months to evaluate the performance of its new solid-state battery in electric vehicles. These tests aim to assess the battery’s durability and potential for mass production.