A high-voltage solid-state organic lithium battery based on 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane cathode

Organic electrode material has advantages of renewable, low cost, and environmentally friendly, which are promising for application in lithium-ion batteries (LIBs). However, most organic cathode materials demonstrate low redox potentials and are easy to dissolve in conventional liquid electrolytes that retard the development of organic lithium batteries (OLBs). In this paper, 2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F(4)TCNQ), a novel organic electrode with a high-voltage of 3.4 V is reported as cathode material for OLBs. To suppress the flow out of active materials and improve cycling performance, solid-state PEO-LLZTO is used as an electrolyte. Through adjusting the molecular weight of PEO, optimizing electrochemical windows, and using electrolyte additive, we finally fabricated an organic solid-state lithium battery which delivered a capacity of 80 mAh g(-1) at a current density of 10 mA g(-1), and maintained 77% capacity after 50 cycles. Our work provides a new material option for high-voltage OLBs, and gives instructions for fabrication of solid-state OLBs with high-stability.

Automated summary

Organic electrode materials have advantages such as renewability, low cost, and environmental friendliness, but they often have low redox potentials and can dissolve in conventional liquid electrolytes. This paper introduces a novel organic electrode material, F(4)TCNQ, with a high voltage and uses a solid-state electrolyte to improve cycling performance. The researchers successfully fabricated an organic solid-state lithium battery with high stability.