Highly reversible lithium metal batteries enabled by spontaneous alloying anode

Emerging lithium metal batteries are one of the candidates for increasing energy density beyond that of traditional lithium-ion batteries. Whereas, intrinsic dendrites growth is a chronic disease severely hampered the application of lithium metal batteries. Hence, partial alloying electrode (LiAl and LiC alloy) with lithiophilic sites and interconnected ion-electron conductive skeleton is presented through repeated folding-rolling strategy. Electrochemical measurement and in situ optical microscopy demonstrate the effectiveness of alloying anode for inhibiting dendrites growth by uniform Li + flux distribution. The LixMy composite electrode can delivers ultra-long cycle life for more than 800 h with negligible overpotential of ∼10 mV (1 mA cm−2, 1 mAh cm−2). Moreover, the full cell assembled with LiFePO4 cathode exhibited superior rate performance and cycle stability, even at high current density of 2 A g−1. The availability and scalable method for modifying lithium metal anode provide an essential pace to promoting lithium metal batteries application.