Critical role of surface craters for improving the reversibility of Li metal storage in porous carbon frameworks

Abstract

Recently, a certain type of porous carbon framework (PCF) based on zeolitic imidazolate frameworks (ZIFs) has been proposed as a promising anode material for metallic Li storage owing to its controllable pore structure and functionality. With the purpose of improving the Li storage capability and reversibility, meso-scale surface craters (SCs) are strategically introduced on the outermost surface of the PCF via hard templating with colloidal SiO2 nanoparticles. Combined structural and electrochemical investigations demonstrate the critical role of SCs in improving the reversibility of PCF in repeated Li plating and stripping. The SCs on the PCF surface provide facile pathways for the transport of Li ions through the electrode, promote Li plating in the internal pores, and serve as meso-scale sites for metallic Li storage. Furthermore, an SC-integrated PCF anode has shown improved rate capability and cycling performance in a full-cell configured with a commercial cathode, when compared to the conventional PCF anode. This work could offer practical guidelines for the development of robust Li storage materials for advanced Li-metal batteries. © 2021 Elsevier Ltd