Effects of low-temperature annealing on capacitance performances of NiCo-based bimetal-organic framework materials synthesized in various solvents

摘要

As electrode materials, MOFs have large specific capacitance but poor stability. Here, a low-temperature annealing strategy is reported to optimize structures and capacitance performances of bimetallic MOFs (NiCo-BPDC) synthesized in various solvents. Annealing at 350 degrees C or 400 degrees C hardly changes crystalline and chemical structure of NiCo-BPDC, but expels trapped or coordinated solvent molecules and homogenizes MOFs, which can benefit electrolyte-ion transport and storage. Annealing does enhance significantly rate capability and cycling stability of NiCo-BPDC. Capacitance retention of annealed NiCo-BPDC is above 59% as current density increases to 10 A g(-1) from 0.5 A g(-1), and exceeds 70% after 3000 GCD cycles at 1 A g(-1). (C) 2020 Elsevier B.V. All rights reserved.