Increasing performance and stability of mass-manufacturable biobatteries by ink modification

In this work, biobatteries assembled using roll-to-roll screen printed enzymatic electrodes were characterised in terms of their electrical performance and storage stability. The enzymes and mediators used on the anode and cathode were glucose oxidase with ferrocenemethanol and laccase with ABTS, respectively. This study shows that besides rheological properties of enzyme inks used for the printing of the biobattery electrodes also adhesion of these electrodes to the printing substrate can be adjusted by varying the amount and composition of the binder in the ink. Another important observation is that the mediator has a strong impact on both the performance and the stability of the anode electrode. Consequently, electrochemical performance of biobatteries can be enhanced by adding fresh mediator into the battery during activation or by some other method preserving the activity of the mediator. Hence, this study discusses and sheds light on important practical aspects for up-scaling production process of biobatteries and also other printed bioelectronics.