SoftBank Corp teamed with the local subsidiary of US battery maker Enpower Greentech to develop an all-solid-state battery cell with lithium metal anode the companies stated boosts capacity and improves safety.

In a statement, SoftBank cited potential applications in powering IoT devices and mobile base stations.

The companies developed a technology which reduces interface resistance between the cathode active material and solid electrolyte, resulting in a lower weight ratio of the latter in the cathode mixture and increasing the specific energy to 300Wh/kg, matching the maximum value of lithium-ion battery cells.

SoftBank cited the use of organic liquid electrolyte as an ion conductor in lithium-ion batteries as a safety hazard, noting the solid-state option removes the risk of the liquid leaking or igniting.

It stated use of a solid electrolyte is expected to improve battery lifetime and temperature characteristics, and expand the operation voltage range.

Enpower Greentech was founded in 2012 and develops ultra-high energy density solid-state batteries for the drone and electric vehicle markets. It raised $35 million in a pair of funding rounds in 2022 from investors including Sequoia China and Dayone Capital.

It also collaborates with SoftBank Group and automotive OEMs.