Battery recycling study finds airborne SWCNTs below limit, MWCNTs exceed limit

OCSiAl Europe, a Luxembourg-based manufacturer of TUBALL single wall carbon nanotubes (SWCNTs), has released findings from a study on airborne nanotube release during lithium-ion battery recycling. Conducted by BOKU University in Vienna and Swiss measurement specialist Stat Peel, the study was published in Communications Materials on 29 September 2026. The research focused on the release of ultrafine particles and airborne carbon nanotubes in the recycling process of nanomaterial-containing lithium-ion batteries.

The study simulated mechanical recycling at a laboratory scale, shredding lithium iron phosphate (LFP) battery cells to particles below 1 mm, followed by milling to below 0.5 mm. Two cell types were tested: one containing TUBALL SWCNTs and another with multi wall carbon nanotubes (MWCNTs). The particle size distributions were monitored using an optical particle sizer and a scanning mobility particle sizer. Airborne nanotubes were collected using Stat Peel Identifier C2 samplers and quantified via Raman spectroscopy, which distinguishes between single wall and multi wall tubes and other carbon forms. The limits of quantification were 0.013 ng for SWCNTs and 0.27 ng for MWCNTs.

Results showed that airborne SWCNT concentrations ranged from 0.097 to 0.875 micrograms per cubic meter, below the NIOSH recommended exposure limit of 1 microgram per cubic meter. In contrast, MWCNT concentrations ranged from 1.21 to 1.37 micrograms per cubic meter, exceeding the limit. The study also noted the release of fine and ultrafine particles during mechanical recycling.

The authors suggest that their methodology provides a robust and selective approach for monitoring nanomaterial exposure in battery manufacturing and recycling facilities. This is particularly relevant as the industry expands its gigafactory and recycling capacities. OCSiAl emphasized the importance of understanding the differences between nanotube types as recycling processes scale up.

Commissioned by OCSiAl Europe, the study includes contributions from OCSiAl's Gunther Van Kerckhove. It is important to note that the results pertain to the specific cells and conditions tested, rather than offering a general comparison of nanotube types.