EMBATT Technology Could Double the Driving Range of EVs

Chassis-embedded energy technology provides higher energy density versus conventional battery systems.

May 6, 2019

Kami Buchholz

An in-development chassis-integrated sandwich structure of solid electrolytes is projected to deliver all-electric driving ranges that far out-distance today’s typical 200-mile (320 km) EV real-world driving range. IAV, Thyssenkrupp AG and Fraunhofer Institute for Ceramic Technologies and Systems (IKTS) are the core project partners working to develop EMBATT, a chassis-embedded energy technology.

The next-generation battery system’s sandwich structure makes it possible to break up the conventional cell and module boundaries and integrate the energy storage system as a component into the vehicle chassis. (IAV)

“Driving ranges depend on the application, but it’s possible to achieve up to 1000 km [621 mi] with EMBATT technology and that’s a significant increase from what is possible today,” said Michael Clauss, development engineer at IAV GmbH, an automotive engineering services company headquartered in Germany. Current EV applications generally package lithium-ion batteries as wound or stacked structures that are inserted into cylindrical or prismatic cell housings or sealed within a pouch bag.

Miniature model of the EMBATT battery concept as shown at SAE WCX 2019. (IAV)

With several patents relating to the technology and its fabrication, EMBATT removes the need for complex module and battery housing due to its platform integration. “From the storage side, the system is similar to fuel cells with regard to the single cell connectors being integrated with the bipolar plates. It’s a design that reduces the internal resistance, and it also reduces the amount of connections,” noted Clauss.

The EMBATT system’s sandwich structure is comprised of bipolar electrodes that span approximately two square meters. Initial R&D projects used lithium-titanium-oxide (LTO) on the anode side, and lithium-iron-phosphate (LFP) or lithium-nickel-manganese-oxide (LNMO) on the cathode side. The current project switches the bipolar electrodes on the anode side to a graphite coating, while the cathode-side coating will be nickel-manganese-cobalt (NMC). An anticipated 3.7 volts per cell is likely with the latest coating choices.

Today’s battery systems typically provide between 140 and 300 Wh/l of volumetric energy density. In contrast, the EMBATT system can provide volumetric energy densities of 500 Wh/l with fluid electrolyte, or greater than 800 Wh/l with solid electrolyte on a system level. “We are working with polymer electrolytes in current development projects, but we are still looking for other companies to provide solid electrolytes for large-scale application,” Clauss said.

IAV’s EMBATT responsibilities include concept development and system integration. IKTS is tasked with material and cell development. Thyssenkrupp is developing the manufacturing equipment. Clauss expects that EMBATT’s functional prototype phase will begin in 2022, but that timetable could be affected by the availability of solid electrolytes. “Serial production is possible in 2026,” noted Clauss. “We are still looking for technology partners and investors and hope to switch as fast as possible from funding projects to industrial development,” he added.