Dry-processed composite cathode design with fast electron transfer network for high energy density lithium-ion...

The process of solvent-free binder fibrillation is a promising technology in the field of increasing electrode density and green economy. However, the electron conduction and homogeneity of thick electrodes are limited, resulting in poor battery performance and mechanical properties. Herein, we compare the effect of three different forms of conductive materials on the cathode, and design a "point-line" combined conductive carbon-binder network with polytetrafluoroethylene fiber embedded in carbon nanotubes and super P by air mill. We illustrate that the performance enhancement of the optimized cathode originates from the combined factors of excellent electronic conductivity, low surface energy and special nested structure. Furthermore, the embedded binder has the ability to protect the cathode and maintain structural stability. These characteristics result in superior cycling stability for the optimized cathode, with a capacity retention rate of 91.4 % after 150 cycles at 1C and a better rate capability (158.6 and 142.2mAhg^-1 at 1 and 2C, respectively). Consequently, it provides a valuable strategy to combine the functions of different materials to develop high energy density lithium-ion batteries.