HPQ Silicon has reported a major performance breakthrough, with 21700 cells using Novacium’s GEN4 silicon‑based anode material surpassing 6,600 mAh on average — a result that places the technology among the highest‑performing industrial cells in this format.
One cell achieved a peak result of 6,696 mAh, with gravimetric energy density of 319.9 Wh/kg and volumetric density of 906.2 Wh/L. These figures form part of HPQ Silicon’s ongoing programme to validate and commercialise silicon‑based battery materials.
For comparison, commercially available 21700 graphite cells generally fall between 4,800 and 5,000 mAh. Only a handful of global developers — including Molicel, EVE Energy and Amprius — have reported capacities above 6,500 mAh in this format.
The latest results continue a clear generational progression. Starting from a 2,778 mAh graphite reference in 18650 format, performance has advanced through GEN1 (~3,153 mAh), GEN2 (~3,808 mAh), GEN3 (~4,030 mAh in 18650 / ~6,050 mAh in 21700), and now GEN4, surpassing 6,600 mAh on average. This marks a 45% uplift over the graphite baseline and a 9% improvement on GEN3 in the same cell size. HPQ expects further gains, with future versions targeting the 7,000 mAh range.
The company holds exclusive North American rights to commercialise Novacium’s GEN3 and GEN4 materials under the HPQ ENDURA+ brand.
“Reaching an average above 6,500 mAh, with a peak of 6,696 mAh… confirms we have an industrially viable, high‑performance solution,” said Bernard Tourillon, President and CEO of HPQ Silicon.
“These results validate the strategic direction we have pursued since GEN1,” added Dr Jed Kraiem, COO of Novacium.
