Hydrogel electrolytes based on bio-derived polymers for solar cells

(1)

Hydrogel electrolytes based on bio-derived polymers

for solar cells

Simone Galliano,

a

_{Federico Bella,}

b

_{Marisa Falco,}

b

_{Claudia Barolo,}

a

Fabrizio Giordano,

c

_{Gerrit Boschloo,}

d

_{Michael Grätzel,}

c

_Anders

Hagfeldt,

c

_{Claudio Gerbaldi,}

b

_{and Guido Viscardi}

a

a_{Dipartimento di Chimica, Università degli Studi di Torino, Via P. Giuria 7,}

10125-Torino, Italy

b_{Dipartimento di Scienze Applicate e Tecnologia, Politecnico di Torino, Corso Duca}

degli Abruzzi 24, 10129-Torino, Italy

c_{Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de}

Lausanne, Station 3, CH1015-Lausanne, Switzerland

d_{Department of Chemistry, Uppsala University, Box 523, 75120-Uppsala, Sweden}

E-mail simone.galliano@unito.it

In recent years, with the idea of creating efficient, safe, stable and low-cost dye-sensitized solar cells (DSSCs), the research moved the attention towards alternative solvent-based electrolytes. In particular, DSSCs with water-based electrolytes have been proposed as one of the possible solution providing reduced costs, non-flammability and environmental compatibility. Recently we demonstrated that stability issues can be properly addressed by choosing the appropriate dye [1]. Moreover, the possibility of gelling the liquid solvent into a polymeric matrix can reduce the electrolyte leakage outside the device, thus increasing the long-term stability. Above all, bio-derived polymers appear promising being renewable and easy available with low cost.

In this work, the study on a series of iodine and cobalt-based 100% aqueous electrolytes is presented. Thanks to our previous experience [2] and to a multivariate approach (Design of Experiment), the effects of the photoanode preparation and the electrolyte compositions have been evaluated on DSSCs performances. Finally, the gelation of aqueous electrolytes with bio-derived polymers has been performed and evaluated [3]. Photovoltaic performances and stabilities will be discussed by comparing liquid and gel electrolytes. In lab-scale solar cells interesting photovoltaic performances superior to 4% were achieved.

[1] S. Galliano, F. Bella, C. Gerbaldi, M. Falco, G. Viscardi, M. Grätzel, and C. Barolo, Energy Technol. 5 (2016) 300-311.

[2] F. Bella, S. Galliano, M. Falco, G. Viscardi, C. Barolo, M. Grätzel, and C. Gerbaldi, Chem. Sci. 7 (2016) 4880-4890.

[3] F. Bella, S. Galliano, M. Falco, G. Viscardi, C. Barolo, M. Grätzel, and C. Gerbaldi, Green Chem. 19 (2017) 1043-1051.