Cost‐Effective Vat Orange 3‐Derived Organic Cathodes for Electrochemical Energy Storage

Organic compounds are desirable alternatives for sustainable lithium‐ion battery electrodes. Vat orange 3 (VO3, 4,10‐dibromoanthanthrone) is a highly cost‐effective organic dye containing two conjugated carbonyl groups, which can reversibly accept two electrons. The skeleton also contains two bromine atoms, which allows easy incorporation of the anthanthrone unit into polymers through simple reactions. In this work, we report the preparation of organic cathodes derived from the low‐cost VO3 dye for lithium‐organic batteries (LOBs). The results show that polymeric VO3‐based materials exhibit remarkably high cyclability and rate performance, because of their effective suppression of dissolution. In particular, the sulfide polymer poly(anthanthrone sulfide) (PATS) shows an initial large‐current (0.2 A g−1) discharge capacity of 133 mAh g−1 at a potential near 2.4 V. The capacity reaches a maximum capacity of 147 mAh g−1 after 24 cycles and is maintained at 132 mAh g−1 after 300 cycles. Moreover, a full battery cell with the structure: PATS cathode||graphite anode, further delivers an impressive electrochemical performance with an energy density up to 237 Wh kg−1 along with an output voltage of 2.3 V. The present study initiates the use of VO3‐based organics, which show promising potential for future application in LOBs on a large scale. Cheap and effective! A new class of anthanthrone‐based organics with excellent performance and stability in secondary batteries can easily be prepared through simple and scalable synthesis from the cheap, commercially available dye vat orange 3 (VO3). This work highlights that anthanthrone is a promising building block in conjugated polymers for energy‐storage applications.