Supercritical mechano-exfoliation process

Hao Zhang; Qixuan Xiang; Zhiyuan Liu; Xianglong Zhang; Yaping Zhao; Huijun Tan

doi:10.1038/s41467-024-53810-4

Supercritical mechano-exfoliation process

Nat Commun. 2024 Oct 29;15(1):9329. doi: 10.1038/s41467-024-53810-4.

Authors

Hao Zhang¹, Qixuan Xiang¹, Zhiyuan Liu¹, Xianglong Zhang¹, Yaping Zhao², Huijun Tan³

Affiliations

¹ School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai, 200240, PR China.
² School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai, 200240, PR China. ypzhao@sjtu.edu.cn.
³ School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai, 200240, PR China. sophie93@sjtu.edu.cn.

Abstract

The intricate balance among cost, output, and quality has substantially hindered the practical application of graphene within the downstream industry chain. Here we present a scalable and green supercritical CO₂-assisted mechano-exfoliation (SCME) process that omits the use of organic solvents and oxidants throughout the production lifecycle, including exfoliation, separation, and purification. The SCME process achieves graphene powder space-time yields exceeding 40 kg/(m³·day) at laboratory (0.06-0.2 kg) and pilot scales ( > 4 kg), with resultant free-standing films showing conductivities up to 5.26 × 10⁵ S/m. Further kinetic investigations propose general guidelines for grinding-assisted exfoliation: (1) the macroscopic optimizing ability of mechanotechnics for mass transfer frequency and stress distribution and (2) the microscopic multiplication ability of exfoliation medium for shear-delamination. The comprehensive techno-economic analysis also underscores the economic viability of the SCME process for large-scale production.