Introducing Ionic Transport Islands in Graphite Anode towards Fast-Charging Lithium-Ion Batteries

Abstract

The development of lithium-ion batteries (LIBs) possessing excellent fast charging performance is particularly important for expanding the worldwide application market of LIBs. However, the grievous growth of lithium dendrites during high rate charging and discharging process occurring on the surface of the anode material still restricts the development of commercial fast charging LIBs, which raises capacity deterioration and even enormous safety risks. Herein, we developed simple physical mixing of active carbon (AC) powder into graphite negative slurry to generate the hybrid fast charging anode (called AS anode), which can realize unprecedented fast charging capability whether at room temperature or low temperature, along with greatly improved capacity retention cycling at high 2 C rate. Importantly, the density functional theory calculation and combined characterizations including in situ electrochemical confocal system spectroscopy and lithium ion (Li+) diffusion coefficient analysis can decipher that AC particles with rapid Li+ diffusion and adsorption can act as ion transport islands in graphite electrode to accelerate the transport process of lithium ion inside the whole negative electrode, leading to the faster charging performance. This work not only promotes the development of anode construction with fast charging capability for LIBs, but also deciphers the ion transport mechanism inside the electrode.