New Mercedes EV solid state battery to deliver 1,000km range

A prototype Mercedes EQS sedan is being tested with a solid-state battery that could deliver a range of more than 1,000km on a single charge. The first production car to use this new battery is scheduled to hit roads before the end of the decade. Preliminary trials are being conducted in the UK to evaluate the efficiency, durability and performance of the solid state pack, which Mercedes-Benz has co-developed with US-based Factorial Energy.

1. Mercedes EQS prototype has been lightly modified
2. New solid-state tech claimed to 25 percent increase in range

Mercedes EQS sedan prototype with solid state battery details

The battery housing has been reworked

The EQS sedan being used since early February to test the battery has been lightly modified to accommodate the new pack. Mercedes says work was mainly focused on reworking the battery housing. The solid state battery pack uses a floating cell carrier, which has pneumatic actuators developed by Mercedes-Benz’s Formula 1 engineers in Brixworth. This system manages the expansion and contraction of materials inside the battery cells during charging and discharging for improved stability and longevity.

Range claimed to increase by 25 percent compared to Li-ion battery

While the company has yet to reveal the full specifications, it confirms that the EQS’s current 12-module battery compartment allows for flexible configurations and capacities. The brand also claims that the solid state tech offers around a 25 percent increase in range compared with a lithium-ion battery of equivalent size and weight. In fact, Mercedes-Benz expects its new solid-state unit to push the EQS prototype’s real-world range beyond 1,000km. For reference, the EQS 580 sedan on sale in India comes with a 107.8kWh lithium ion battery that has a WLTP range of 588km (857km on the Indian MIDC cycle).

Factorial Energy had confirmed in June last year that the battery cells it had supplied Mercedes with battery cells featuring an energy density of up to 391Wh/kg and a charging capacity exceeding 106Ah. The pack also holds a patented lithium-metal anode and polymer separator.

Mercedes solid state battery future

The technology being trialled in the EQS prototype marks an initial step towards a more advanced solid-state battery. Codenamed Solstice by Mercedes and Factorial, this next-generation unit replaces the polymer separator with a sulphide-based solid electrolyte. The target energy density is 450Wh/kg and an estimated 80 percent range increase over today’s lithium ion batteries.

Together with the new battery technology, Mercedes is also developing a new-generation of silicon carbide inverters and power electronics. The AMG High Performance Powertrain division in Brixworth is developing them to bring higher power efficiency and improved performance to Mercedes’ future models.