As a cathode material for potassium-ion batteries (PIBs), manganese-based layered oxides have attracted widespread attention due to their low cost, ease of synthesis, and high performance. However, the Jahn–Teller effect caused by Mn³⁺ and the irreversible phase transformation of the structure leads to poor cycle stability, limiting the development of layered oxides in PIBs. Herein, we demonstrate the use of phase-transition-free CaTiO₃ as rivets in K_0.5Mn_0.9Ti_0.1O₂ by a simple solid-state method. As verified by the in situ X-ray diffraction, the CaTiO₃ rivets effectively prevent the slippage of the transition metal layer during charge and discharge, inhibiting structural degradation. As a result, the obtained K_0.5Mn_0.9Ti_0.1O₂-0.02CaTiO₃ shows excellent cycling stability and rate performance, with high capacities of 119.3 and 70.1 mAh·g⁻¹ at 20 and 1000 mA·g⁻¹, respectively. At 200 mA·g⁻¹, the capacity retention remains 94.7% after more than 300 cycles. This work represents a new avenue for designing and optimizing layered cathode materials for PIBs and other batteries.

The urgent need for highly safe and sustainable large-scale energy storage systems for residential buildings has led to research into aqueous zinc ion batteries. However, when zinc is used in aqueous zinc ion batteries, it suffers from severe irreversibility due to its low Coulombic efficiency, dendrite growth, and side reactions. To address these challenges, we take advantage of organic cation to induce trifluoromethanesulfonate decomposition to build zinc fluoride/zinc sulfide-rich solid electrolyte interphase (SEI) that not only can adapt to a high areal capacity of deposition/stripping disturbance but also adjust zinc ion deposition path to eliminate dendrite. As a result, the unique interface can promote the Zn battery to achieve excellent electrochemical performance: high levels of plating/stripping Coulombic efficiency (99.8%), stability life (6,600 h), and cumulative capacity (66,000 mAh·cm⁻²) at 68% zinc utilization (20 mAh·cm⁻²). More importantly, the SEI significantly enhances the cyclability of full battery under limited Zn, lean electrolyte, and high areal capacity cathode conditions.