Revisiting the Role of Physical Confinement and Chemical Regulation of 3D Hosts for Dendrite-Free Li Metal Anode

Abstract

Lithium metal anode has been demonstrated as the most promising anode for lithium batteries because of its high theoretical capacity, but infinite volume change and dendritic growth during Li electrodeposition have prevented its practical applications. Both physical morphology confinement and chemical adsorption/diffusion regulation are two crucial approaches to designing lithiophilic materials to alleviate dendrite of Li metal anode. However, their roles in suppressing dendrite growth for long-life Li anode are not fully understood yet. Herein, three different Ni-based nanosheet arrays (NiO-NS, Ni3N-NS, and Ni5P4-NS) on carbon cloth as proof-of-concept lithiophilic frameworks are proposed for Li metal anodes. The two-dimensional nanoarray is more promising to facilitate uniform Li+ flow and electric field. Compared with the NiO-NS and the Ni5P4-NS, the Ni3N-NS on carbon cloth after reacting with molten Li (Li-Ni/Li3N-NS@CC) can afford the strongest adsorption to Li+ and the most rapid Li+ diffusion path. Therefore, the Li-Ni/Li3N-NS@CC electrode realizes the lowest overpotential and the most excellent electrochemical performance (60 mA cm−2 and 60 mAh cm−2 for 1000 h). Furthermore, a remarkable full battery (LiFePO4||Li-Ni/Li3N-NS@CC) reaches 300 cycles at 2C. This research provides valuable insight into designing dendrite-free alkali metal batteries.[Figure not available: see fulltext.]