High-Output-Voltage and -Energy-Density All-Organic Dual-Ion Battery Using Molecular Thianthrene

Dual-ion organic batteries are attracting much more attention because of the need to replace critical materials (Ni, Co, and V). Because of its particular mechanism, this battery technology has several advantages but is still limited in terms of output voltage and energy density. Here we present the evaluation of p-type positive molecular materials based on thianthrene and their use to build a high-performance, all-organic battery. Thanks to a substitution in the 2,7-position with a donating or withdrawing group, electrochemical properties and material stability were tuned to maximize storage performances. In addition, through a series of post-mortem analyses coupled with electrolyte engineering, the electrochemical properties of thianthrene-based electrodes in half-cells were optimized. The best electrodes were then coupled to a negative electrode material (dilithium naphthalene dicarboxylate, Li-2-NDC), to build the first all-organic dual-ion battery with an output voltage of 3.4 V and an outstanding energy density of 78-105 Wh kg(-1) based on the electrode mass (49-66.5 Wh kg(-1) by also considering the anion counterpart) after 100 cycles, one of the highest values reported in the literature.

Automated summary

Dual-ion organic batteries have gained much attention as a replacement for critical materials. By using p-type positive molecular materials based on thianthrene, the electrochemical properties and material stability can be tuned for better storage performances. Coupled with a negative electrode material, the all-organic dual-ion battery achieved an outstanding output voltage and energy density.