The Fast and the Capacious: A [Ni(Salen)]‐TEMPO Redox‐Conducting Polymer for Organic Batteries

Redox‐active nitroxyl‐containing polymers are promising candidates as possible replacements for inorganic based energy‐storage materials, due to their high energy density and fast redox kinetics. One challenge towards the implementation of such a system is the insufficient electrical conductivity, impeding the charge collection even with highly conductive additives. Herein, the first implementation of a polymeric bis(salicylideniminato) nickel (NiSalen) conductive backbone as an active charge‐collecting wire is reported. NiSalen simultaneously serves as a charge collector for nitroxyl pendants and supports the redox capacity of the material. This novel polymer exhibits a specific capacity of up to 91.5 mAh g−1, retaining 87 % of its theoretical capacity at 800 C and more than 30 % at as high as 3000 C (66 % capacity retention after 2000 cycles). The properties of the new material upon operation was studied by means of operando electrochemical methods, UV‐Vis, and electron paramagnetic resonance spectroscopy. Going organic: A synthetic approach was developed to combine capacious nitroxyl‐groups (TEMPO) with a conductive NiSalen type backbone. Simultaneous operation of the backbone and the pendant groups in the charge‐discharge process was demonstrated by means of electrochemical and operando spectroscopic methods. The electrochemical properties of the novel polymer hold promise for the further development of energy‐storage devices based on redox‐conducting polymers promising.