Development of 1-Wh-class stacked lithium-air cells

A joint research team from NIMS and Toyo Tanso has developed a carbon electrode that enables stable operation of a 1-Wh-class stacked lithium-air battery, achieving higher output, longer life and scalability simultaneously.
The team created this electrode by combining manufacturing technology that Toyo Tanso developed for its “CNovel™” porous carbon product with proprietary technology NIMS developed to fabricate self-standing carbon membranes.
This combination made it possible to scale up the battery cell size—a significant step toward practical, industrial-scale lithium-air batteries. The research was published online in Cell Reports Physical Science on September 18, 2025.

Background

Lithium-air batteries are attracting attention as the “ultimate rechargeable batteries” because their theoretical gravimetric energy density is several times higher than that of conventional lithium-ion batteries.
In 2021, a NIMS research group developed a lithium-air battery with a gravimetric energy density of approximately 500 Wh/kg—more than twice that of typical lithium-ion batteries.
However, several technical challenges remain before practical implementation is possible, including the need for higher output performance and longer cycle life.
Furthermore, most lithium-air batteries reported to date have had energy capacities of 0.01 Wh or less, making it essential to scale up cell size to advance research and development toward practical use.

Key Findings

The joint research team successfully developed a carbon electrode that simultaneously achieves higher output, longer life and scalability—key requirements for practical lithium-air batteries.
In this study, proprietary technology developed by NIMS to fabricate self-standing carbon membranes was applied to Toyo Tanso’s CNovel™ porous carbon material, which features a controlled mesoporous structure.
This approach enabled the fabrication of carbon electrodes with a hierarchically controlled porous structure, resulting in high-output operation of lithium-air batteries.
In addition, by enhancing the crystallinity of the carbon electrode, the team improved its durability, thereby significantly extending the battery’s lifespan.
The researchers also established a manufacturing process capable of producing large-area electrodes measuring 10 cm × 10 cm or more, laying a solid technical foundation for scaling up to larger battery cells.
By integrating these advances, the team prototyped a 1-Wh-class stacked lithium-air battery using a 4 cm × 4 cm electrode and confirmed its stable operation.

Future Outlook

The high-performance carbon electrode developed in this study represents a major achievement in simultaneously overcoming the three key challenges to the practical implementation of lithium-air batteries: higher output, longer cycle life and scalability.
Lithium-air batteries, known for their light weight and high energy capacity, are expected to play a vital role in advancing the electrification of critical sectors, such as electric aircraft and electric vehicles.
However, their practical use has long been constrained by technical challenges.
This study has made it possible to scale up the electrode area, paving the way for industrial-scale applications and representing a significant step toward the real-world deployment of lithium-air batteries.

Other Information

• This project was carried out by a joint research team led by Shoichi Matsuda (Leader, Automated Electrochemical Experiments Team (AEET), Research Center for Energy and Environmental Materials (GREEN), NIMS), Arghya Dutta (Special Researcher, AEET, GREEN, NIMS), Takashi Kameda (Engineer, AEET, GREEN, NIMS) and Takahiro Morishita (Executive Fellow, Kondo Teruhisa Memorial Advanced Carbon Technology Center, Toyo Tanso Co., Ltd.).
• This research was published online in Cell Reports Physical Science on September 18, 2025.