Anion‐Rocking Chair Batteries with Tuneable Voltage using Viologen‐ and Phenothiazine Polymer‐based Electrodes**
Manik Bhosale, Caroline Schmidt, Philipp Penert, Gauthier Studer, Birgit Esser
Abstract
Abstract Organic battery electrode materials offer the unique opportunity for full cells to operate in an anion‐rocking chair mode. For this configuration a pair of p‐type redox‐active electrode materials is required with a substantial potential gap between their redox processes. We herein investigate viologen‐functionalized polystyrenes as negative electrode paired with a phenothiazine polymer as positive electrode in all‐organic full cells. The 10 % crosslinked viologen polymer X 10 ‐PVBV gave better performance than the linear PVBV and was employed in a full cell as negative electrode with cross‐linked poly(3‐vinyl‐ N ‐methylphenothiazine) (X‐PVMPT) as positive electrode. Three cell configurations regarding the voltage range were investigated, of which one with an operating potential of 0.9 V gave the highest performance. The full cell delivered a specific discharge capacity of 64 mA h g −1 (of X‐PVMPT) in the first cycle and a capacity retention of 79 % after 100 cycles. This is one of only few reported anion rocking chair all‐organic cells and the first employing a phenothiazine‐based positive electrode material.