The practical application of lithium (Li) metal anodes is critical for the next generation high energy density batteries. However, the mainstream challenge of Li dendrites formation that affects the cycle performance and safety of the battery still needs to be addressed. Here, Li/LixC/LiySn (Li/C/Sn) composites with uniform distribution of Li metal alloys are fabricated and applied to a Li metal anode. Electrochemical measurements and post-mortem analysis reveals the effectiveness of the Li alloy phases for promoting uniform Li deposition and inhibiting Li dendrite growth. The Li/C/Sn composite electrode delivers enhanced cycle stability over 1800 and 1200 h at the current densities of 1 and 2 mA cm−2, respectively. Moreover, the full cells of the Li/C/Sn electrode paired with LiFePO4 exhibited significantly enhanced rate performance and cycle stability. The effective and scalable method for modifying Li metal anodes represents an essential step to promote the commercial application of Li metal batteries.