Unlock the full potential of carbon cloth-based scaffolds towards magnesium metal storage via regulation on magnesiophilicity and surface geometric structure

Abstract

The development of rechargeable magnesium (Mg) batteries is of practical significance to upgrade the electric energy storage devices due to exceptional capacity and abundant resources of Mg-metal anode. However, the reversible Mg electrochemistry suffers from unsatisfied rate capability and lifespan, mainly caused by non-uniform distribution of electrodeposits. In this work, a fresh design concept of three-dimensional carbon cloths scaffolds is proposed to overcome the uncontrollable Mg growth via homogenizing electric field and improving magnesiophilicity. A microscopic smooth and nitrogen-containing defective carbonaceous layer is constructed through a facile pyrolysis of ZIF8 on carbon cloths. As revealed by finite element simulation and DFT calculation results, the smooth surface endows with uniform electric field distribution and simultaneously the nitrogen-doping species enable good magnesiophilicity of scaffolds. The fine and uniform Mg nucleus as well as the inner electrodeposit behavior are also disclosed. As a result, an exceptional cycle life of 500 cycles at 4.0 mA cm−2 and 4.0 mA h cm−2 is firstly realized to our best knowledge. Besides, the functional scaffolds can be cycled for over 2200 h at 2.0 mA cm−2 under a normalized capacity of 5.0 mA h cm−2, far exceeding previous results. This work offers an effective approach to enable the full potential of carbon cloths-based scaffolds towards metal storage for next generation battery applications.