A nickel coordination supramolecular network synergized with nitrogen-doped graphene as an advanced cathode to significantly boost the rate capability and durability of supercapacitors

作者：Zhang, Gaowei; Zhang, Feng; Yao, Hua; Liu, Zhixian; Yang, Yangyi^*

来源：Journal of Materials Chemistry A, 2017, 5(36): 19036-19045.

DOI：10.1039/c7ta05667b

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.

• 出版日期2017-9-28
• 单位中山大学