Integrating Multiredox Centers into One Framework for High-Performance Organic Li-Ion Battery Cathodes

Abstract

Organic cathode materials are promising for developing high-energy and high-power Li-ion batteries (LIBs). However, the energy storage of most organic cathodes relies on the electron transfer of a single type of functional group, leading to either a low redox potential or a low capacity. Here we propose a new strategy for the structure design and performance optimization of organic materials. A new organic cathode, dithianon (DTN), containing three functional groups (−S–, C═O, C≡N) in one framework, is reported. The −S– group increases the redox potential to 3.0 V, while C═O and C≡N groups enable a three Li-ions-involved redox reaction. As a cathode, DTN delivers 270.2 mAh g–1 at 0.5C for 300 cycles. Even at 5C, it still retains 161.5 mAh g–1 after 1000 cycles. The high-capacity, high-power, and stable DTN cathode offers great promise for high-performance and sustainable LIBs.