The invention discloses a composite
fiber and a preparation method and application thereof. The composite
fiber comprises a
polymer fiber, a
sulfur layer attached to the surface of the
polymer fiber and a first conductive agent layer attached to the surface of the
sulfur layer; wherein the
polymer fiber is treated by air
plasma. In the composite fiber, the polymer fiber provides
ion conduction performance, the first conductive agent layer provides
electron conduction performance, rapid transmission of electrons and ions can be promoted through the synergistic effect of the polymer fiber and the first conductive agent layer, and oxidation-reduction reaction
kinetics of
sulfur can be accelerated as a battery positive
electrode material. The composite fiber disclosed by the invention is subjected to shearing treatment, is mixed with a conductive agent dispersion liquid, and is subjected to vacuum
filtration, so that a continuous conductive network is formed, and finally, the flexible self-supporting sulfur positive
electrode is constructed. The flexible self-supporting
sulfur electrode has excellent
electron and
ion transmission capability, can effectively inhibit the shuttle effect of LiPSs, can improve the wettability with an
electrolyte, and has excellent
mechanical stability.