Highly Crystalline Graphene Fibers with Superior Strength and Conductivities by Plasticization Spinning

Abstract Graphene fiber (GF), a macroscopic one‐dimensional assembly of individual graphene sheets, promises both extraordinary mechanical performance and superior multifunctionality. However, the properties of graphene fiber are still limited due to the unfavorable crystalline structures, especially induced by wrinkled conformations of graphene. A plasticization spinning strategy is presented to achieve GF with both high mechanical strength and electrical/thermal conductivity. Adjusting the interlayer space from 1.2 to 1.8 nm by intercalating proper plasticizers to adjacent graphene oxide sheets enables graphene oxide fibers to achieve a 580% enhanced deformable plasticity. Such a plasticization spinning flattens random graphene wrinkles, and regulates sheets with high order and stacking density, thereby forming large crystallite domains. The GF exhibits all around record performance including mechanical strength (3.4 GPa), electrical conductivity (1.19 × 10 6 S m −1 ), and thermal conductivity (1480 W m −1 K −1 ). The optimally crystalline GF with the integration of benchmark overall properties and scalable fabrication is likely to be attractive and competitive in future industrial applications.