Читать книгу Biofuel Cells - Группа авторов - Страница 23

The last section of supports for biofuel cells is devoted to the recent advances in flexible electrodes for the development of flexible BFCs. The most recent works have been focused on enzymatic biofuel cells rather than in microbial biofuel cells, where most of these works operate with glucose and oxygen as fuel and oxidant, respectively. Hui et al. [126] used nickel foam coated with gold as electrodes to decrease ohmic resistances, while the flexibility is achieved using agarose as gel electrolyte, a cellulose acetate membrane, and silicone rubber as cases. This flexible BFC constructed using glucose oxidase and laccase achieved a maximum power density of 2.32 mW cm⁻² with an OCV close to 0.6 V. Niiyama et al. [127] constructed a flexible BFC using a carbon cloth modified with MgO. The reported BFC employed a flavine adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) as bioanode, and bilirubin oxidase (BOD) as biocathode. The OCV displayed by this flexible device was 0.75 V, while the maximum power density was 2.0 mW cm⁻². Another strategy to gain flexibility is through the development of graphene paper as reported by Shen et al. [128]. They used pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH) as bioanode and bilirubin oxidase as biocathode. With this configuration, an OCV of 0.66 V and a maximum current density of 4.03 μW cm⁻² were obtained.

It is worth mentioning that in all of these works, bending tests were not presented, nor in other revised works [129]. Thus, the development of fully functional bendable and flexible biofuel cells is still a hot topic area.