Tailoring K ⁺ /Vacancy Disordered Layered Oxide via Charge Engineering for Stabilizing High‐Performance Potassium‐Ion Batteries

ABSTRACT Layered transition metal oxides represent attractive cathode candidates for potassium‐ion batteries (PIBs), due to their high theoretical specific capacity. However, sluggish K + diffusion and structural instability, stemming from the inherent K + /vacancy ordered structure, lead to poor rate performance and cycling stability. Herein, a charge‐ion coupling engineering strategy, wherein transition‐metal electronic structure is tuned to modulate interlayer K + /vacancy configurations, is initially pioneered. Specifically, a K + /vacancy‐disordered P3‐type structure is constructed via targeted transition metal (TM) doping in Mn/Co‐based layered oxides. Exploiting the identical valence of Ti 4+ and Mn 4+ coupled with their divergent redox potential, the doping sites suppress charge ordering within TM slabs through modulating charge delocalization, thereby inducing interlayer K + /vacancy disordering. The K + /vacancy disordered K 0.5 Mn 0.8 Co 0.1 Ti 0.1 O 2 delivers long‐term stability with 58.6 mAh g −1 over 800 cycles at 1 A g −1 and remarkable rate capability of 61.7 mAh g −1 at 2 A g −1 , facilitating a highly reversible single‐phase solid‐solution reaction in K 0.5 Mn 0.8 Co 0.1 Ti 0.1 O 2 and enhancing the structural stability during K + extraction/insertion. Meanwhile, molecular dynamics simulations demonstrate that the K + /vacancy disordered structure contains interconnected channels enabling continuous and rapid K + diffusion. This work establishes a cation substitution strategy for manipulating K + /vacancy order‐disorder to develop high‐performance, kinetically robust cathode materials for next‐generation PIBs.