(Invited) Millimeter-Thick All Organic Based Electrodes for Low Cost Aqueous Batteries

Aqueous ionic batteries are a promising technology for environmentally friendly grid storage systems as they reduce cost, risk and environmental impact, although this is at the expense of energy density.[1] Designing such batteries from inexpensive, abundant, recyclable and non-toxic organic active materials provides a way towards improving both the environmental and economic impact of these systems. Herein, the first battery materials that work with simultaneous uptake and release of both cations (Na, Mg) and anions are proposed by designing mixed p-type and n-type “di-block” oligomers[2,3]. It demonstrates optimal potential, extremely fast kinetics and highly competitive capacity and cyclability in both neutral Na and Mg electrolytes, including ocean water. Through a combination of UV-Vis spectroelectrochemistry, EQCM, and operando synchrotron-XRD a simultaneous cation/anion insertion mechanism was proven and rationalized. The surprisingly fast kinetics of this di-block oligomer allow to attain an unmatched specific capacity of near to 60mAh/g per gram of electrode while entirely devoid of conducting additives, and more than 80mAh/g per gram of electrode with 10% carbon additive. Based on these findings, full organic cells with millimeter-thick electrodes were assessed [4]. These findings may well provide a viable option, thereby promoting the design of cutting-edge, low-cost, rocking-chair dual-ion aqueous batteries. [1] Wu Li, J. R. Dahn, D. S. Wainwright, Science . 1994, 264, 1115-1118 [2] S. Perticarari, Y. Sayed-Ahmad-Baraza, C. Ewels, P. Moreau, D. Guyomard, P. Poizot, F. Odobel and J. Gaubicher, Adv. Energy Materials , 2018, 8 (8), 1701988 [3] S. Perticarari, T. Doizy, P. Soudan, C. Ewels, C. Latouche, D. Guyomard,F. Odobel, P. Poizot, J. Gaubicher, Adv. Energy Materials , 2019, in press [4] S. Perticarari, E. Grange, T. Doizy, Y. Pellegrin, A.-J Fernandez-Ropero, D. Guyomard, P. Poizot, F. Odobel and J. Gaubicher, Chem . Mater . 2019, (10.1021/acs.chemmater.8b03282