The 4680 battery cell

At "Battery Day" in September 2020, Tesla unveiled the 4680 — a larger, tabless cylindrical cell (46 mm by 80 mm) designed to store more energy, charge faster, and cost far less per kilowatt-hour than previous cells. Paired with a structural battery pack that uses the cells as part of the car's body, it promised lower cost and weight.

The harder prize was manufacturing. Tesla pursued a "dry electrode" process — coating battery electrodes without the energy-intensive solvents and drying ovens the industry relies on — a technique long sought and long considered impractical at scale. Tesla reported industrializing a full dry-electrode process, projecting major additional cost reductions.

Battery cost is the central constraint on electric vehicles and grid storage. By attacking it at the cell-chemistry, pack-design and manufacturing levels simultaneously, the 4680 program is part of Tesla's long campaign to make clean energy cheaper than fossil fuels.