LAUSR

ABSTRACT The commercial application of Li metal anodes is hindered by the dendrite growth and short cycling lifespan under high current density that are caused in part by the imbalance in the charge transport capability in the anode. Here, we present a design principle of a three-dimensional (3D) skeleton to introduce highly efficient ion- and electron-conducting channels in the Li anode. A process of thermal infusion followed by cooling is used to synthesize a dual-phase Li-rich Li-Zn alloy that consists of an LiZn intermetallic compound phase as the 3D framework and the uniformly distributed Li metal phase as the active material. The phase-segregated Li-Zn phase endows the Li10Zn alloy with built-in fast ion transport channels, in addition to the ionic conducting pathway of the liquid electrolyte, leading to better charge balance and conformal deposition of Li on the scaffold. Consequently, the Li10Zn alloy anode can be operated for more than 10000 cycles at a high current density of 5 mA cm−2 and areal capacity of 1 mAh cm−2. Remarkably, even for the high current density of 10 mA cm−2 and areal capacity as large as 10 mAh cm−2, the cycling lifetime is still greater than 500 cycles. Thus, the scaffold with high ion/electron mixed conductivity is highly effective for inhibiting Li dendrite growth and prolonging the cycling lifespan, highlighting the great promise of the fast ion conducting alloy framework for use in Li secondary batteries at high current densities.