Elevating the charging voltage to 4.6 V presents a promising avenue for enhancing the energy density of LiCoO2 cathodes in Li-ion batteries. However, significant surface degradations at high voltage often leads to rapid capacity decay during long-term cycling of LiCoO2 cathodes. In this study, a novel surface reconstruction strategy is applied to LiCoO2 through successive ion-exchange reaction and subsequent sintering, successfully introducing polyanionic PO43− species in the Li layer at the particle surface, and significantly enhancing its battery performance at high voltage. The successful outcome provides novel sights into the design of layered cathode materials for high-performance Li-ion batteries.