In-situ Electro-polymerization Enables Ultrafast, Long Cycle Life and High Voltage Organic Cathodes for Lithium Batteries.

Organic cathode materials have attracted extensive attention owing to diverse structures, facile synthesis, and environmental friendliness. However, they often suffer from insufficient cycling stability caused by the dissolution problem, poor rate performance, and low voltages. Here, in-situ electro-polymerization method is developed to stabilize and enhance organic cathodes for lithium batteries. 4,4',4''-tris(carbazol-9-yl)-triphenylamine (TCTA) was adopted because carbazole groups not only can be polymerized under the electric field but also served as high voltage redox-active centers. The electro-polymerized TCTA electrodes demonstrated excellent electrochemical performance with a high discharge voltage of 3.95 V, ultrafast rate capability of 20 A g-1, and long cycle life of 5000 cycles. Our findings not only provide a new strategy to address the dissolution issue but also shed light on a molecular design of organic electrode materials for rechargeable batteries.