Lithicone‐Protected Lithium Metal Anodes for Lithium Metal Batteries with Nickel‐Rich Cathode Materials

The high energy density advantage of lithium (Li) metal batteries (LMBs) makes them increasingly desirable; however, problems such as strong reactivity and dendrite growth of Li metal anode limit their practical uses. In this work, a novel Li‐containing glycerol (LiGL) or lithicone protection layer on a 50 μm thick Li metal anode is employed for improving the performance of LMBs. This LiGL layer was accurately deposited via a molecular layer deposition (MLD) process at 150 °C, using lithium tert‐butoxide and glycerol as precursors. The as‐formed LiGL coating layer is highly tunable in its thickness by simply adjusting MLD cycles and shows a good stability and outstanding ionic transport properties. The LiGL layer is found to effectively mitigate side reactions and enhance cycling stability in both symmetric cells and full cells. Specifically, the LMBs with LiGL@Li anode of 400 MLD cycles and LiNi0.6Mn0.2Co0.2O2 cathode enable a capacity retention of ≈87%, much higher than ≈35% of the cells with bare Li after 200 cycles at a charge/discharge current density of 2.1 mA cm−2. This work paves a feasible way for practical LMBs with improved capacity and stability through applying an innovative protection layer on Li metal anodes. A uniform and stable lithium (Li)‐ion conductive lithicone layer is coated on Li metal surface via molecular layer deposition process as an artificial solid‐electrolyte‐interphase layer. This layer enables more uniform and denser Li deposition morphology and effectively suppresses parasitic side reactions between Li metal and electrolyte, thus improves the cycling stability and rate capability of the Li metal batteries.