Uniform titanium nitride decorated Cu foams by electrophoretic deposition for stable lithium metal anodes

Abstract

Metallic Li, with ultrahigh theoretical capacity (3860 mA h g−1) and the lowest electrochemical potential (−3.04 V vs. the standard hydrogen electrode), is perfectly meet the needs of high energy density lithium batteries. However, the direct use of metallic lithium as anode would cause serious dendrite and huge volume expansion, which will bring safety hazards and restrict the practical commercialization of Li metal anodes. Herein, a facile electrophoretic deposition (EPD) method was employed for the first time to fabricate uniform TiN modified commercial Cu foam (TiN@Cu foam) as the lithiophilic 3D conductive skeleton. The lithiophilic TiN acts as the well-distributed seeds to promote the uniform lithium deposition, attributing to the lowed nucleation overpotential. The porous and conductive Cu foams can further mitigate the formation of Li dendrites, on account of its high specific surface area reduce the effective current density. The TiN@Cu foam based half cells and symmetric cells both exhibit improved reversibility and reduced polarization voltage in lithium plating/stripping process. Furthermore, better rate performance and cycling stability were also achieved in the full-cell configurations of TiN@Cu foam-Li/Li4Ti5O12 (LTO) and TiN@Cu foam-Li/LiFePO4 (LFP). This work demonstrates a facile strategy to modify the commercial current collectors with pre-synthesized lithiophilic nanoparticles for achieving uniform Li deposition.