Lithium Intensity of Solid-State Batteries

In the ever-evolving world of lithium-ion batteries, solid-state batteries (SSB) are seen as the next generation of lithium-ion batteries. In an SSB, the liquid electrolyte used in conventional lithium-ion cells is replaced by a solid electrolyte capable of conducting lithium. There are three main families of solid electrolytes: oxides, sulphides, and polymers.

SSBs promise to bring increases in energy and power density, in addition to improved safety over conventional cells. A number of companies are working on SSBs, including Prologium and Samsung, who are targeting SSB production in 2026 and 2027 respectively. As SSBs are set to become more widespread by 2030, its important to investigate how the lithium-intensity of solid-state batteries compares to conventional lithium-ion cells.

Using the CAMS tool, five different cell chemistries were modelled to estimate the amount of lithium in each cell. These cell chemistries were:

  • NMC 811 cathode vs Graphite anode with an LP30 liquid electrolyte (baseline)
  • NMC 811 cathode vs Lithium metal anode with an LP30 liquid electrolyte
  • NMC 811 cathode vs Lithium metal anode with a PEO polymer solid electrolyte
  • NMC 811 cathode vs Lithium metal anode an LLZO oxide solid electrolyte
  • NMC 811 cathode vs Lithium metal anode an LPSCl sulphide solid electrolyte

The table below presents the corresponding cell energy densities and the resulting lithium intensity for each cell chemistry. The sulphide electrolyte SSB has the highest lithium intensity, 78% more than the conventional baseline liquid electrolyte cell. This is driven by the solid electrolyte, which has much higher concentrations of lithium than liquid electrolytes. While SSBs will (in the short term) be more expensive to produce than conventional lithium-ion cells, it will be interesting to see how the price of SSBs will vary based on the price of lithium, given their increased lithium intensity.

Below are the details of the cells which were modelled:

  1. All cells were modelled to be as close to 100 Wh as possible.
  2. Liquid electrolyte cells used a cathode loading of 20 mg/cm2. Solid-state cells used a cathode loading of 30 mg/cm2 (similar to previously published values).
  3. Solid-electrolyte separator layers were all modelled at 40 microns.
  4. Liquid electrolyte cells used a cathode electrode composition of 96% active material, 2% carbon and 2% binder. Solid electrolyte cells used a cathode electrode composition of 85% active material, 5% carbon, 3% binder and 7% solid-electrolyte.
  5. A5 cell dimensions were used, with the number of layers being varied to get the correct cell energy.

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