A composite electrode of stabilized lithium metal powder and lithiophilic Ag-coated Cu powder for lithium metal batteries

In this study, we fabricate a composite electrode of lithium metal powder (LMP) and Ag-coated Cu powder (Li/Cu@Ag) for lithium metal battery simply by Ag-coating on Cu powder through galvanic replacement and pelletizing their mixture. Due to the structure of the composite electrode and high surface area of LMP, local current density can be reduced. The lithiophilic Ag particles on the Cu powder lower lithium nucleation overpotential and enable uniform lithium plating. The Li/Cu@Ag electrode shows superior electrochemical performance with this synergetic effect and the reason for the improvement has been investigated. Specifically, a long lifespan of 400 h at a current density of 1 mA/cm2 is achieved with a Li||Li symmetric cell when using the Li/Cu@Ag electrode in a corrosive carbonate electrolyte. In addition, LiFePO4||Li/Cu@Ag cell shows excellent cycling stability and high-capacity retention (over 74 % after 400 cycles at 3C).