Ordered lithiophilic sites to regulate Li plating/stripping behavior for superior lithium metal anodes†
Uncontrollable dendrite growth and large volume expansion severely impede the practical application of lithium metal anodes. To address these issues, in this work, we report novel MgO nanosheets on carbon cloth (CC) forming highly ordered lithiophilic sites to regulate the plating/stripping behavior of Li. Interestingly, MgO nanosheets composed of crosslinked nanoparticles show excellent lithiophilicity and successfully tune the electric-field distribution to decrease the current density, thereby suppressing the dendrite growth, supported by COMSOL Multiphysics simulation. Notably, the as-prepared MgO/CC can store Li with an ultrahigh areal capacity of ∼12 mA h cm−2 without an obvious dendrite morphology and volume change. Furthermore, the lithiophilic nature of MgO as a nucleation site for Li deposition is demonstrated by DFT calculation. Consequently, the MgO/CC@Li anode exhibits prominent electrochemical performance with a stable voltage hysteresis of ∼30 mV (0.5 mA cm−2) over 2000 h (500 cycles), making it superior to its CC@Li and Cu@Li counterparts. When coupled with a Li4Ti5O12 (LTO) cathode, the MgO/CC@Li anode also exhibits excellent compatibility both in terms of enhanced capacity retention and boosted rate performance. Our work demonstrates the effectiveness of the synergetic design of lithiophilic sites plus hierarchical architecture for Li metal anodes.