▎ 摘　　要

The strategy of developing new electrode materials, which integrate well with carbon materials or conducting polymers to form a robust synergistic composite, can distinctly boost the electrochemical performance of supercapacitors (SCs). In this study, a novel Ni coordination supramolecular network (CSN) of [Ni-2(3,5- PDC)(2)center dot(H2O)(8)center dot(H2O)(2)](n) (denoted as Ni-PDC, 3,5-PDC = 3,5-pyridinedicarboxylic acid) was successfully integrated with nitrogen-doped graphene (NG) via a one-step hydrothermal method, forming a superior composite electrode material of Ni-PDC@NG. The Ni-PDC@NG electrode showed a high specific capacitance of 735 F g(-1) at a current density of 1 A g(-1) and an outstanding cycling stability (85.3% capacitance retention after 14 000 cycles); furthermore, it also maintained a good rate capability by exhibiting a capacitance retention of 53% even at a high current density of 40 A g(-1). Significantly, a SC device was assembled with the Ni-PDC@NG electrode as the cathode and an activated carbon electrode as the anode, which not only exhibited a high energy density of 21.7 W h kg(-1) at a power density of 801 W kg(-1), but also retained 45.2% of its initial energy density even at a high power density of 16 036 W kg(-1). Besides, this as-fabricated device exhibited excellent long-term durability with 97.9% capacitance retention after 6000 cycles.