External view of the 1-Wh-class stacked lithium-air battery fabricated in this study.NIMS
The goal of electric planes and better electric cars just moved a lot closer.
A joint research team from Japan’s National Institute for Materials Science (NIMS) and the carbon specialist company Toyo Tanso has announced the development of a novel carbon electrode that could enhance the performance of lithium-air batteries.
Interestingly, the team built a prototype 1-Wh-class stacked lithium-air battery with a 4 cm x 4 cm electrode and confirmed it runs stably. It proves that the technology can be scaled up for industry.
Since these batteries are lightweight and high-energy, they are important for sectors such as electric aircraft and EVs.
This development addresses the three fatal flaws — low output, short life, and poor scalability — that have kept these “ultimate rechargeable batteries” grounded.
(A) Schematic illustration of the synthesis process for a carbon material with controlled mesoscale porosity. (B) External view of the 1-Wh-class stacked lithium-air battery fabricated in this study.
The scaling challenge
For a long time, the lithium-air battery has been an exciting idea. It stores much more energy than current lithium-ion batteries and promises long driving or flight distances.
But the previous small batteries the researchers built, usually 0.01 Wh (watt-hour) or less, were too weak for anything bigger than a microchip.
In 2021, NIMS developed a lithium-air battery that delivered about 500 Wh/kg, more than twice the energy density of standard lithium-ion batteries. However, this battery still needs to be improved with higher power output and a longer lifespan before it can be used practically.
The core challenge has been designing a carbon-based positive electrode with the right porosity and stability.
In this new work, the NIMS-Toyo Tanso collaboration developed a carbon electrode to advance the development of larger lithium-air batteries.
For the electrode production, Toyo Tanso’s “CNovel” porous carbon, known for its controlled mesoporous structure, was combined with NIMS’s unique technology for fabricating self-standing carbon membranes.
This combination created a carbon electrode with a layered porous structure. The design improves how ions move and how the battery reacts chemically.
Electric flight and the EV range race
The development showcased that a 4 cm x 4 cm carbon electrode successfully powered a stable 1-Wh-class stacked lithium-air battery.
According to the study, the lithium-oxygen battery made with these new hierarchically porous carbon membranes and a lean electrolyte demonstrated stable cycling for over 150 cycles at a high current density of 1.5 mA cm−2.
Notably, this unique electrode design could enable the battery to deliver higher output, which is essential for instant acceleration in electric vehicles or vertical lift in air taxis.
In addition, the enhanced crystallinity of the carbon simultaneously improves the electrode’s durability and extends the battery’s lifespan.
The team has also developed a method for manufacturing large electrodes (10 cm x 10 cm or larger), providing a strong foundation for future large battery cells.
While today’s top-tier lithium-ion batteries struggle to break past 300 Wh/kg, lithium-air batteries promise a theoretical density that could eventually match that of gasoline, potentially advancing transportation.
This development suggests the end of short-range EVs and grounded flying cars may be near.
The Blueprint
