Activating Organic Electrode via Trace Dissolved Organic Molecules

Xin Huang; Xuan Qiu; Wei Wang; Junjie Li; Zhi Li; Xiaomeng Yu; Jing Ma; Yonggang Wang

doi:10.1021/jacs.3c06668

Activating Organic Electrode via Trace Dissolved Organic Molecules

J Am Chem Soc. 2023 Nov 29;145(47):25604-25613. doi: 10.1021/jacs.3c06668. Epub 2023 Nov 15.

Authors

Xin Huang¹, Xuan Qiu¹, Wei Wang², Junjie Li², Zhi Li¹, Xiaomeng Yu¹, Jing Ma², Yonggang Wang¹

Affiliations

¹ Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, iChEM (Collaborative Innovation Centre of Chemistry for Energy Materials), Fudan University, Shanghai 200433, China.
² Key Laboratory of Mesoscopic Chemistry of MOE School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China.

PMID: 37968563
DOI: 10.1021/jacs.3c06668

Abstract

Organic electrode materials have gained attention for their tunable structures and sustainability, but their low electronic conductivity requires the use of large amounts of carbon additives (30 wt %) and low mass loadings (<2 mg cm^-2) in electrodes. Here, we synthesize dibenzo[b,i]phenazine-5,7,12,14-tetrone (DPT) as a cathode active material for an aqueous Zn battery and find that Zn²⁺ storage dominates the cathode reaction. This battery demonstrates high capacity (367 mAh g^-1), high-rate performance, and superlong life (12000 cycles). Remarkably, despite DPT's insulative nature, even with a high mass loading (10 mg cm^-2) and only 10 wt % carbon additives, the DPT-based cathode exhibits promising performance due to trace dissolved discharge product (DPT^x-). During discharge, the DPT is reduced to trace amounts of dissolved DPT^x- at the cathode surface, which in turn reduces the remaining solid DPT as a redox mediator. Furthermore, dissolution-redeposition results in the reduction of DPT size and the formation of pores, further activating the electrode.