Share This Article
21700 and 4680 are the two dominant cylindrical lithium cell formats — but they serve different masters. This guide compares dimensions, energy density, manufacturing, and applications to help you choose.
Dimensions at a Glance
| Format | Diameter × Height | Volume |
|---|---|---|
| 21700 | 21mm × 70mm | ~24 mL |
| 4680 | 46mm × 80mm | ~133 mL |
The 4680 holds ~5.5x the volume of a 21700 — fewer cells per pack, simpler BMS wiring, but less granular thermal management.
Energy Density Comparison
- 21700 (NMC): 250–270 Wh/kg cell-level (mature)
- 21700 (LFP): 160–180 Wh/kg
- 4680 (NMC): 270–300 Wh/kg claimed (Tesla)
- 4680 (LFP): In development
Manufacturing: Tabless vs Traditional
The 4680’s tabless design (shingled current path) reduces internal resistance and heat generation vs the 21700’s single-tab design. However, 4680 manufacturing yield remains challenging — dry electrode coating at scale is still being perfected.
Best Uses
| Application | Recommended | Why |
|---|---|---|
| EV (high volume) | 4680 | Fewer cells, structural pack |
| Power tools / e-bikes | 21700 | Mature supply, proven |
| Energy storage | Neither* | *Prismatic LFP dominates ESS |
| Custom packs | 21700 | Available from multiple suppliers |
Supply Chain Reality (2026)
21700: Commodity. Available from Samsung, LG, Panasonic, EVE, Lishen, and dozens more. Spot market exists.
4680: Tesla-centric. Limited merchant supply. If you’re not Tesla or a qualified partner, 4680 is effectively unavailable.
Frequently Asked Questions
Can I buy 4680 cells for my project?
Unlikely unless you’re a Tesla partner. Stick with 21700 for available supply.
Which is better for DIY powerwalls?
Neither — use prismatic LFP (280Ah+) for stationary storage. See our cell selection guide.
Does bigger always mean better?
No. Larger cells mean fewer interconnects but harder thermal management and single-point-of-failure risk.
Contact LJY Energy for 21700 and prismatic LFP cell sourcing.
Share This Article