ProLogium announced on 2 September 2026 that its Gen 3.5 all-solid-state cell, rated at 185.4 Ah, has entered mass production in Taiwan, with a third-party TÜV test showing 381 Wh/kg gravimetric and 903 Wh/L volumetric energy density.
What a solid-state battery is
A solid-state battery replaces the liquid electrolyte found in conventional lithium-ion cells with a solid material that conducts lithium ions. This change can enable lithium-metal anodes and reduce reliance on flammable solvents, potentially improving safety and energy storage.
Turning a solid electrolyte into a reliable, large-format cell is technically demanding. The solid must stay in intimate contact with electrode surfaces while the cell expands, contracts, heats and cools over thousands of cycles. Issues such as interface resistance, cracking and pressure control have historically limited scale-up.
ProLogium’s claim matters because it moves the technology from a laboratory prototype to an industrial line, even if current output is modest compared with mainstream EV battery factories. Demonstrating repeatable production is a prerequisite for any future automotive adoption.
Energy-density claims in context
The International Energy Agency lists typical 2026 benchmarks of about 175 Wh/kg for sodium-ion, up to 205 Wh/kg for LFP and roughly 265 Wh/kg for the latest NMC chemistries. At 381 Wh/kg, ProLogium’s cell sits roughly 44% above the NMC reference.
Those figures are cell-level numbers measured under different test conditions, so they do not directly translate into vehicle range. For an 80 kWh pack, the higher density would reduce cell weight from about 302 kg (NMC) to roughly 210 kg, a saving of 90 kg before adding pack hardware.
While the arithmetic is clear, real-world range depends on many factors: vehicle aerodynamics, motor efficiency, tire rolling resistance and thermal-management systems all influence how much of the stored energy is usable.
In practice, solid-state designs may simplify some pack components, but a complete automotive module still requires casings, wiring, battery-management electronics and crash-structure provisions. Until a full pack is engineered and homologated, the net advantage remains uncertain.
Production capacity and market timing
ProLogium’s May 2026 investor presentation lists an annual capacity of 0.5 GWh for its Taiwan facility. Competitors such as Toyota aim to introduce all-solid-state cells between 2027 and 2028, Nissan targets fiscal 2028, and BYD has spoken of a 2027 rollout.
These timelines suggest the technology will first appear in premium or low-volume models rather than mass-market vehicles. The International Energy Agency expects solid-state batteries to stay concentrated in higher-end segments through the early 2030s.
In the United Kingdom, MG has announced a semi-solid-state “SolidCore” battery slated for European cars at the end of 2026. Though it uses a partly solid electrolyte, it is not equivalent to ProLogium’s fully solid-state Gen 3.5 cell or the all-solid-state programmes of Toyota and Nissan.
To date, no mass-market passenger EV has been confirmed to use ProLogium’s Gen 3.5 traction cell, and the company has not identified a specific model that will be equipped with the battery.
All-solid-state versus semi-solid technologies
Differentiating the battery families is essential for understanding market signals. The industry separates designs into three groups: semi-solid, almost-solid and all-solid-state. Semi-solid cells retain a liquid component in the electrolyte system, allowing them to reach commercial vehicles already in some markets. Almost-solid designs replace most of the liquid with a rigid solid electrolyte but keep a small amount of liquid near the cathode to aid ion transport. Only the all-solid-state category eliminates the conventional liquid entirely, relying on a fully solid electrolyte matrix.
Qualification testing and classification
Testing procedures provide the basis for classifying a cell as all-solid-state. An independent safety lab subjected the large-format cell to an extended vacuum-heat cycle, observing weight loss far below the maximum allowed for the relevant Chinese battery methodology. The outcome satisfied the criteria for an all-solid-state designation, confirming that the cell’s solid electrolyte remains stable under harsh conditions.