Flexible glucose/oxygen enzymatic biofuel cells based on three-dimensional gold-coated nickel foam

A high-efficiency, stable, and flexible glucose/oxygen enzymatic biofuel cell is fabricated based on three-dimensional gold-coated nickel foam. The gold-coated layer makes the skeleton of nickel foam rougher, enhancing the relative apparent surface area of nickel foam and decreasing the electron transfer resistance. With the gold-coated nickel foam as substrate, the bioanode and biocathode exhibit good electrocatalysis activity and stability. By assembling the bioanode and biocathode with agarose gel electrolyte, cellulose acetate membrane, and silicone rubber layer-by-layer, the flexible biofuel cell is obtained. As per the results, the three-dimensional gold-coated nickel foam enlarges the enzymatic loading density to 5.68 × 10 ⁻⁷  mol cm ⁻² , increasing the short circuit current density to 9.04 mA cm ⁻² . The maximum power density of this flexible biofuel cell reaches 2.32 ± 0.07 mW cm ⁻² with excellent stability for retaining 84.6% of its performance after 60 days. Additionally, the flexible biofuel cell can be very stable in and after 1000 times of bending.