Amprius Unveils 500 Wh/kg Battery Cell for Long-Endurance Aviation

Amprius Tech­nolo­gies has intro­duced a sil­i­con-anode bat­tery cell capa­ble of reach­ing 500 Wh/kg at a 1C con­tin­u­ous dis­charge rate, with the com­pa­ny tar­get­ing long-endurance avi­a­tion appli­ca­tions includ­ing high-alti­tude plat­form sta­tions (HAPS) and fixed-wing drones.

The com­pa­ny says the sec­ond-gen­er­a­tion SiCore cell dif­fers from ear­li­er Amprius bat­ter­ies that exceed­ed 500 Wh/kg by being designed for pro­duc­tion using con­ven­tion­al lithi­um-ion man­u­fac­tur­ing equip­ment. Pre­vi­ous cells at this ener­gy den­si­ty relied on spe­cialised process­es and cell con­struc­tion and were not pro­duced at com­mer­cial vol­ume.

The man­u­fac­tur­ing approach is sig­nif­i­cant because increas­ing bat­tery ener­gy den­si­ty is only one part of mak­ing high­er-per­for­mance cells com­mer­cial­ly viable. Using exist­ing equip­ment and stan­dard process­es could reduce the need for addi­tion­al man­u­fac­tur­ing infra­struc­ture and make it eas­i­er to move from cus­tomer qual­i­fi­ca­tion to larg­er-scale pro­duc­tion.

Amprius expects the new cells to become com­mer­cial­ly avail­able in the fourth quar­ter of 2026. Ini­tial pro­duc­tion is planned at the company’s Fre­mont, Cal­i­for­nia facil­i­ty, with vol­ume pro­duc­tion expect­ed to be expand­ed through its exist­ing net­work of con­tract man­u­fac­tur­ers.

The com­pa­ny is ini­tial­ly tar­get­ing avi­a­tion appli­ca­tions where bat­tery weight has a direct impact on endurance, range and pay­load. HAPS air­craft, for exam­ple, need to store enough ener­gy dur­ing day­light hours to sup­port oper­a­tions after sun­set. High­er spe­cif­ic ener­gy can allow air­craft to car­ry more ener­gy with­out a cor­re­spond­ing increase in bat­tery weight.

Amprius has sup­plied bat­ter­ies to AALTO HAPS since 2018 for its Zephyr plat­form. AALTO, an Air­bus sub­sidiary, is devel­op­ing solar-elec­tric HAPS air­craft for appli­ca­tions includ­ing con­nec­tiv­i­ty and Earth obser­va­tion. A 2025 Zephyr flight was report­ed to have remained air­borne for 67 days.

The new cell will be offered in cus­tomer-spe­cif­ic for­mats as well as a stan­dard small uncrewed air­craft sys­tems pouch for­mat defined by SAE JA1016.

Thomas Sleightholm

Thomas is a con­tent writer for eVTOL Insights, cov­er­ing all aspects of the glob­al Advanced Air Mobil­i­ty ecosys­tem. Got a sto­ry for him? Please send an email to editorial@evtolinsights.com

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