Electrochemical Lithium Deposition on Li x Ti 5 O 12 .

Lithium metal batteries (LMBs) have been regarded as one of the most promising next-generation high-energy-density storage devices. However, uncontrolled lithium dendrite growth leads to low Coulombic efficiencies and severe safety issues, hindering the commercialization of LMBs. Reducing the diffusion barrier of lithium is beneficial for uniform lithium deposition. Herein, a composite is constructed with Li 4 Ti 5 O 12 as the skeleton of metallic lithium (Li@Li x Ti 5 O 12 ) because Li 4 Ti 5 O 12 is a "zero-strain" material and exhibits a low lithium diffusion barrier. It was found that the symmetric cells of Li@Li x Ti 5 O 12 can stably cycle for over 400 h at 1 mA cm -2 in the carbonate electrolyte, significantly exceeding the usual lifespan (∼170 h) of the symmetric cell using a lithium metal electrode. In a full cell with Li@Li x Ti 5 O 12 as the anode, the cathode LiFePO 4 delivers a capacity retention of 78.2% after 550 cycles at 3.6C rate and an N/P ratio = 8.0. This study provides new insights for designing a practical lithium anode.