Evaluating the Polymer Backbone – Vinylene versus Styrene – of Anisyl‐substituted Phenothiazines as Battery Electrode Materials

Desmaizieres, Gauthier; Perner, Verena; Wassy, Daniel; Kolek, Martin; Bieker, Peter; Winter, Martin; Esser, Birgit

Abstract

Organic electrode materials are capable candidates for next-generation greener energy storage solutions. One advantage is that their electrochemical performance can be tuned by structural modification. We herein investigate anisyl-substituted poly(vinyl-) and poly(styrylphenothiazines) as positive electrode materials for dual-ion batteries. π-Interactions – characteristic to phenothiazine redox polymers – are facilitated in the poly(styrene) derivatives PSAPT and PSAPT-X-DVB due to the longer spacing between phenothiazine units and polymer backbone and lead to high cycling stabilities, but reduce their specific capacities. In the poly(vinylenes), the linear PVAPT shows high cycling stability but a dissolution/redeposition mechanism, diminishing its capacity, while the cross-linked X-PVAPT demonstrates high cycling stabilities at specific capacities up to 81 mAh g−1 paired with an excellent rate performance, where 10,000 cycles at 100 C rate proceed with 86 % capacity retention.