Molybdenum host and interphase induced decentralized lithium deposition for dendrite-free lithium metal anodes

Abstract

Lithium metal anode confronts great challenge of dendrite growth and safety hazard to reform present lithium ion batteries. Constructing advanced Li/host composite anode is an effective approach to settle these issues. However, the intrinsic characteristics of host substrates have not been carefully investigated, which can extremely affect the interactions of Li atoms and thereby alter Li deposition morphology. Herein, we propose metallic Mo as a specific host to fabricate Li/Mo anode to promote dendrite-free Li deposition. Density functional theory results reveal that the deposited Li atoms tend to mutually repulse on Mo substrate, while present interattraction on Li substrate. Benefiting from the positive effects of 3D Mo host and interphase, Li/Mo anode exhibits decentralized deposition with granular morphology, differs from severe dendrite growth on bare Li. Besides, the anode delivers stable cycling lifespan and low voltage hysteresis with only 25 mV after 800 h at 2 mA cm−2 with capacity of 1 mAh cm−2 in symmetric batteries. Matching with LiFePO4 cathode, the full cells exhibit superior electrochemical performance in both ether- and more corrosive carbonate-based electrolytes. This exploration offers a new research orientation for developing more appropriate hosts for metallic anodes.