Lithium　cobalt　oxide　(LiCoO2)　delivers　enticing　specific　capacities　when　operating　above　4.45　V　(vs　Li+/Li),　yet　experiences　concurrent　degradation　mechanisms:　bulk　structural　collapse　caused　by　detrimental　phase　transitions　and　surface　deterioration　induced　by　parasitic　reactions,　which　synergistically　accelerate　capacity　fading.　Existing　modifications　inadequately　address　the　dual　challenges:　bulk　doping　neglects　surface　instability,　while　coatings　impede　ionic　transport.　Herein,　we　develop　a　gradient　high-valent　Zr4+　doping　strategy　that　synergistically　stabilizes　bulk　crystallinity　and　interfaces　of　LiCoO2.　Density　functional　theory　calculations　predict　preferential　Zr4+　substitution　at　Co3+　sites,　inducing　lattice　expansion　that　alleviates　Li+　diffusion　barriers.　The　experimental　results　confirmed　the　predicted　crystallographic　modification.　The　surface　gradient　Zr4+　layer　effectively　optimized　the　interfacial　charge　transfer　kinetics　by　enhancing　the　surface　electronic　conductivity.　Meanwhile,　the　large-sized　Zr4+　ions　broadened　the　Li+　diffusion　channels,　thereby　significantly　increasing　the　lithium-ion　transport　rate.　It　also　demonstrated　that　the　O3　→　H1–3　phase　transitions　and　surface　parasitic　reactions　were　concurrent　suppressed　via　surface-gradient　Zr-enriched　protective　layer,　thereby　verifying　the　dual　stabilizing　effect.　This　dual　optimization　enables　stable　cycling　and　superior　rate　capability　for　4.6　V　LiCoO2　cathodes.　This　work　demonstrates　valence-engineered　dopant　gradient　engineering　that　integrates　bulk　structural　reinforcement　with　surface　optimization,　providing　a　unified　strategy　for　high-voltage　oxide　cathodes　requiring　concurrent　bulk-surface　stabilization.　©　2025　Elsevier　B.V.