Battery technology company 24M said new testing data on its battery separator Impervio showed a full hour of cells overcharging without shorting or overheating.
The testing was conducted at 24M laboratories and compared performance and safety between two different battery pouch cells – a 10Ah high nickel NMC/graphite pouch cell with an Impervio separator and another off-the-shelf nickel NMC graphite pouch cell with a conventional separator.
It said both cells were brought to a fully charged state and then advanced to 100% overcapacity – twice the manufacturers’ specified maximum voltage. It claimed the cells with Impervio demonstrated robust performance without shorting or overheating with a full hour of overcharge.
The off-the-shelf cells overheated consistently with dendrite-caused micro shorts occurring after 15 minutes’ overcharging and the cell exploding into flames after 38 minutes. See its video of the side-by-side comparison.
The company said Impervio, which was introduced in January, obstructs dendrite propagation by controlling the cell at the individual electrode level. This stops dendrites propagating and enables early fault detection. It can prevent thermal runaway by monitoring the cell’s electrochemistry and enabling the implementation of a failsafe in the event of a potential short, it claimed.
“Battery safety is a major roadblock to the widespread adoption of EVs. Recent EV fires around the globe have highlighted why new battery safety innovations are required,” said Naoki Ota, 24M president and CEO.
24M plans to introduce Impervio to the market in 2025 or 2026. It is working with volume production partners and license partners.
