▎ 摘　　要

Graphene fibers have gained tremendous attention because of their wide application in wearable energy storage and conversion device. However, it is still a great challenge to achieve a highly conductive graphene-based fiber with acceptable fracture elongation due to the brittle interaction between graphene. Herein, we prepared a graphene and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hybrid fiber with simultaneous enhancement of electrical conductivity and fracture elongation via a hydrothermal process. The optimal electrical conductivity of the hybrid fiber was 96.3 S cm-1, which was about 2 times higher than that of previous reports. Moreover, the fracture elongation doubled to be 10.1% after the introduction of PEDOT:PSS. Furthermore, the dominant charge carriers in the hybrid fibers was altered from the hole to the electron after polyethyleneimine ethoxylated (PEIE) treatment. Finally, a fiber thermoelectric device consisting of three pairs of the as-prepared p- and n-type hybrid fiber was assembled and the output properties were quantified under a serious temperature gradient. This work may provide a good reference to achieve a highly conductive graphene fiber with enhanced fracture elongation for versatile applications.