HPQ Silicon has unveiled a fourth-generation version of its Endura+ battery platform, achieving 23.4 watt-hours in the widely used 21700 cylindrical cell format. The new cell is rated at 6,500 mAh with a nominal voltage of 3.6 V.
Incremental gains within a standard form factor
To reach the higher capacity, HPQ slightly reduced the voltage, meaning the total energy in watt-hours does not scale directly with the milliamp-hour rating. Still, the 23.4 Wh figure sits above typical 6,000 mAh cells operating at 3.7 V and also exceeds the 22.4 Wh rating of Acebeam’s recently introduced 6,400 mAh 21700 battery. Compared with its own preceding Gen3 platform, which offered 6,000 mAh, the Gen4 cell represents an 8.3 percent capacity increase. Energy density has risen in parallel from roughly 300 Wh/kg to 319.9 Wh/kg, all while maintaining the standard 21700 dimensions.
Safety certification nears market readiness
The silicon-anode cell is not yet commercially available, but it has cleared two important safety milestones. The Endura+ Gen4 platform has received UL 1642 certification, which applies to lithium-ion battery safety, and UN 38.3 certification—a transport-sector requirement designed to mitigate hazards during shipping. These certifications indicate the design is moving closer to market introduction, even though no launch date has been set.
Lab results signal further capacity milestones
HPQ Silicon has not named any commercial partners planning to bring the new cell to market. However, the company disclosed that it has already produced 21700 cells surpassing 7,000 mAh in laboratory settings, hinting that higher-capacity variants remain under active development. The broader industry continues to push silicon-anode technology as a route to denser energy storage, and HPQ’s progress suggests this trajectory still has room to run.
Source: hpqsilicon.com