Metal organic framework derived CoNiOOH nanorods anchored on carbon cloth as electrodes for asymmetric supercapacitors

Metal-organic frameworks (MOFs) with high porosity, large specific surface area, and versatile structures are an outstanding electrode material for supercapacitors, but the electrochemical energy storage performance of MOFs is limited due to their low electrical conductivity and the difficulty of growing uniformly on carbon cloth conductive substrate. Herein, the CoNi-MOF nanorods successfully anchor on carbon cloth by growing the Ni (OH)(2) nanosheets on carbon cloth as precursors, and by the electrochemical induction strategy, the solid CoNi-MOF intermediates convert into porous hollow CoNiOOH nanorods. The CoNiOOH-2 electrode shows an ul-trahigh area specific capacitance of 11.6F/cm(2) at 2 mA/cm(2). For assembling an asymmetric supercapacitor (ASC), the nitrogen doped activated carbon cloth (NAC) is prepared as the negative electrode. The CoNiOOH-2// NAC ASC device delivers a high energy density of 0.732 mWh/cm(2) at 1.6 mW/cm(2), and exhibits excellent cycling stability with 98.59% capacitance retention after 10,000 cycles. This work provides a novel way to grow MOF materials on carbon cloth and prepare self-supported electrodes with excellent performance, which has a broad application prospect.

Automated summary

Metal-organic frameworks (MOFs) are excellent electrode materials for supercapacitors due to their high porosity, large surface area, and versatile structures. However, their electrochemical energy storage performance is limited by low electrical conductivity and difficulties in growing uniformly on carbon cloth conductive substrates. This study presents a novel approach to anchor CoNi-MOF nanorods on carbon cloth by growing Ni (OH) (2) nanosheets as precursors and converting them into porous hollow CoNiOOH nanorods. The resulting CoNiOOH-2 electrode exhibits an ultrahigh area specific capacitance of 11.6F/cm (2) at 2 mA/cm (2). In addition, the CoNiOOH-2// NAC ASC device, assembled with nitrogen-doped activated carbon cloth (NAC) as the negative electrode, demonstrates a high energy density of 0.732 mWh/cm (2) at 1.6 mW/cm (2) and excellent cycling stability with 98.59% capacitance retention after 10,000 cycles.