▎ 摘　　要

The free-standing electrodes are important for high-performance supercapacitors. Polyaniline/graphene (PANI/rGO) composites are extensively researched. However, the structural design of free-standing PANI/rGO electrodes needs further discussion. Herein, free-standing PANI/rGO with 3D double-crosslinked network structures is prepared by rGO modification, freeze drying, in situ polymerization, and gel die-casting technology. The uniform precipitation of the ammonium persulfate on the surface of modified graphene (P-rGO) sheets is profit to build a 3D double-crosslinked network structure with PANI. Besides, the synergistic effect of aniline and p-phenylenediamine helps to construct crosslinked PANI on the surface and deep in the pores of P-rGO. The PANI/P-rGO aerogels with a 3D porous double-crosslinked structure are pressed into free-standing electrodes by gel die casting and assembled into symmetrical supercapacitors. The electrodes show good cycling stability, which is much higher than that of P-rGO or pure PANI.