High　electrochemical　reversibility　is　required　for　the　application　of　high-energy-　density　lithium　(Li)　metal　batteries;　however,　inactive　Li　formation　and　SEI　(solid　electrolyte　interface)-instability-　induced　electrolyte　consumption　cause　low　Coulombic　efficiency　(CE).　The　prior　interfacial　chemical　designs　in　terms　of　alloying　kinetics　have　been　used　to　enhance　the　CE　of　Li　metal　anode;　however,　the　role　of　its　redox　chemistry　at　heterointerfaces　remains　a　mystery.　Herein,　the　relationship　between　heterointerfacial　redox　chemistry　and　electrochemical　transformation　reversibility　is　investigated.　It　is　demonstrated　that　the　lower　redox　potential　at　heterointerface　contributes　to　higher　CE,　and　this　enhancement　in　CE　is　primarily　due　to　the　regulation　of　redox　chemistry　to　Li　deposition　behavior　rather　than　the　formation　of　SEI　films.　Low　oxidation　potential　facilitates　the　formation　of　the　surface　with　the　highly　electrochemical　binding　feature　after　Li　stripping,　and　low　reduction　potential　can　maintain　binding　ability　well　during　subsequent　Li　plating,　both　of　which　homogenize　Li　deposition　and　thus　optimize　CE.　In　particular,　Mg　hetero-metal　with　ultra-low　redox　potential　enables　Li　metal　anode　with　significantly　improved　CE　(99.6%)　and　stable　cycle　life　for　700　cycles　at　3.0　mA　cm-2.　This　work　provides　insight　into　the　heterointerfacial　design　principle　of　next-generation　negative　electrodes　for　highly　reversible　metal　batteries.　©　2024　National　Academy　of　Sciences.　All　rights　reserved.