Water Harvesting MOF Enables Stable Cycling of Nickel‐Rich Batteries

Abstract Nickel (Ni)‐rich cathode materials use a high abundance of Ni instead of Cobalt (Co) while increasing battery voltage, making them the representative materials for developing high‐energy‐density batteries. However, Ni‐rich batteries are prone to Ni leaching and performance deterioration; stable cycling thus requires strict control of the H₂O/HF content in the electrolyte. Here, the use of an emerging H₂O capture metal–organic framework (MOF) is reported to realize stable cycling of Ni‐rich batteries with H₂O‐containing electrolytes. The MOF‐801 separator enables NCM622 and even NCM811 batteries containing electrolyte solutions with a 300 ppm H₂O content to maintain 91.4% and 81% of the initial capacities after 200 cycles at 0.2 C. Moreover, MOF‐801 is found to significantly suppress fragmentation of the cathode, Li–Ni intermixing, and Ni dissolution. Additionally, the MOF‐801@PP based separator can largely inhibit the lithium dendrite. The results reveal the pivotal role of MOF‐801 in high‐energy‐density batteries, inspiring in‐depth exploration of MOF's indispensable application in lithium batteries.