Innovative lithium-sulfur cathode technology from Berlin-based Theion promises to triple battery range and usage time compared to conventional lithium-ion cells.

Company engineers have focused on sulfur to replace more commonly used and higher cost cathode materials such as nickel and cobalt. Sulfur is 99% cheaper to source than cathode materials used in state-of-the-art lithium-ion batteries, and the new battery cells also require 90% less energy to produce from raw material to finished cell.

The production process combines the crystal material properties of sulfur with carbon nanotubes and aSulfur replaces cathode materials with high processing costs, such as nickel and cobalt. Source: Theion proprietary solid electrolyte. Pure sulfur wafers are synthesized by a direct crystal imprinting method directly from molten sulfur in a few seconds. The flexible process requires no slurry coating, solvents, water or drying to produce any geometrical shape of wafer adapted to a specific product shape.

The resulting cathode operates at low porosity and use of the active material to achieve high energy density is maximized by the inclusion of conductive paths. A proprietary solid-state polymer electrolyte operates in the voids of the sulfur wafer. Current cell iterations use lithium metal foil as anodes.

The battery technology is compatible with a bipolar cell arrangement to maximize energy and power content. Targeted performances are:

• Gravimetric energy density ≥ 1,000 Wh/kg
• Volumetric energy density ≥ 1,500 Wh/l
• Power capability ≈ 12.000 W/kg
• Cycle life ≥ 1,000 at 1° C
• Operational temperature -20° C to 60° C

The first batteries will be shipped to aerospace customers later in 2022 as part of the qualification stage.