Flashlight-induced Ultrafast, Scalable Surface Activation of Highly Loaded Graphite Composite Anode.

Abstract

Herein, a straightforward route for fabricating highly loaded graphite composite anodes with enhanced electrochemical performance via ultrafast, scalable flashlight irradiation is presented. When a flashlight irradiates the surface of a thick graphite anode, instantaneous and non-equilibrium photo-thermochemical interactions occur between the flashlight and the constituent materials of the anode. As a result, a porous structure (through which the electrolyte easily penetrates), a large reaction site, improved conductivity, as well as phase transformation of active graphite material can be developed on the anode surface, which can facilitate ion and electron transport at the interface with the electrolyte. By fabricating a half-cell using this flash-activated, highly loaded graphite anode, it is found that the electrochemical performance, such as increases in the charge density, rate capability, and stability can be improved. Finally, the roll-to-roll (R2R)compatibility of the high-performance thick-film electrode fabrication process consisting of coating-drying-flashlight surface activation (FLSA) is successfully demonstrated using a self-built R2R system integrated with a flashlight irradiation module.