High-performance quasi-solid-state flexible supercapacitors based on a flower-like NiCo metal-organic framework

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Metal-organic frameworks (MOFs) are promising for energy storage due to their tunable structures.
• Developing efficient and stable electrode materials is crucial for advanced supercapacitors.

Purpose of the Study:

• To synthesize flower-like NiCo MOF electrodes using a simple hydrothermal method.
• To evaluate the electrochemical performance of NiCo MOF electrodes and their application in asymmetric quasi-solid-state flexible supercapacitors (AFSCs).

Main Methods:

• Hydrothermal synthesis of flower-like NiCo MOF.
• Fabrication of NiCo MOF//activated carbon (AC) asymmetric supercapacitor devices.
• Testing electrochemical performance including specific capacitance, energy density, power density, and cycle stability.
• Assessing the performance of AFSCs under bending conditions.

Main Results:

• The flower-like NiCo MOF electrode achieved a specific capacitance of 927.1 F g^-1 at 1 A g^-1 with a 1.2 V potential window.
• The NiCo MOF//AC device exhibited an energy density of 28.5 W h kg^-1 at 400.5 W kg^-1 and 95.4% capacitance retention after 5000 cycles.
• The AFSC demonstrated good capacitance retention after bending (79% after 100 bends, 64.4% after 200 bends).

Conclusions:

• The flower-like NiCo MOF is a highly effective electrode material for supercapacitors.
• The developed asymmetric quasi-solid-state flexible supercapacitors show significant potential for flexible and wearable energy storage.
• The successful powering of LED lights highlights the practical applicability of these devices.