Water Harvesting MOF Enables Stable Cycling of Nickel‐Rich Batteries

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. Nickel (Ni)‐rich cathode is the representative material for developing high‐energy‐density batteries; however, Ni‐rich batteries are prone to Ni leaching and performance deterioration due to trace H2O/HF impurities in the electrolyte. Here, using one emerging metal–organic framework material with striking water‐capturing features at low humidity, stable cycling of lithium batteries under high water content electrolyte is realized.