Deep understanding of lithium deposition mechanisms in lithium metal anode porous hosts by combining phase-field simulations with experimental verification

Abstract

The introduction of three-dimensional (3D) porous hosts for lithium (Li) stripping/plating has been proven to be one of the most promising strategies for suppressing Li dendrite growth and alleviating volume change on Li metal anodes, but the underlying mechanisms for Li deposition in 3D porous hosts still remain unclear. Herein, we illustrate the influential mechanisms of the pore structure and lithiophilicity on the Li deposition behavior within the 3D porous host through a combination of phase-field simulations and experimental investigation. The optimal pore structure and size are predicted by simulating the Li nucleation and growth processes, which are further experimentally verified. Furthermore, the effect of lithiophilicity on the electrochemical performance of the 3D porous host is clarified by constructing a lithiophilic structure model, and a Cu-Zn alloy host with better lithiophilicity is prepared to confirm the superior comprehensive properties. Thus, the porous Cu-Zn alloy host with prestored Li (Cu-Zn@Li) presents excellent cycling stability up to 1600 hours at the current density of 1 mA cm−2 for 1 mAh cm−2. In practical occasions, Cu-Zn@Li|LFP full cell demonstrates excellent capacity retention with over 71% after 850 cycles at 0.5 C. The phase-field simulation has been demonstrated to provide deep understanding and valuable guidance for design and preparation of high-performance 3D porous current collectors for Li metal anodes.