Eliminating anion depletion region and promoting Li+ solvation via anionphilic metal organic framework for dendrite-free lithium deposition

Lithium metal batteries (LMBs) have great potential for next-generation rechargeable batteries due to the high theoretical capacity and ideal compatibility coupled with diverse cathode materials . However, the random Li deposition associated with the large local space charge caused by the anion depletion near the surface of anode, as well as the insufficient reduction of Li + related to the suppressed Li + solvation process induced by the electrostatic force between anion and cation hinder the development of high-energy-density LMBs. Herein, as evidenced theoretically and experimentally, we simultaneously eliminate the anion depletion region and promote the lithium salt dissociation by employing ZIF-67 with unsaturated metal sites as anionphilic additive to regulate anion distribution and weaken its bond with Li + . As a result, the short-circuit hazard is remitted in symmetrical cell with modified electrolyte at 3 mA cm −2 under capacity of 3 mAh cm −2 for more than 2000 h. As employed for the lithium-sulfur battery with high sulfur loading of 4.5 mg cm −2 , the modulated electrolyte enables the battery delivering an initial capacity of 713 mAh g −1 with decay rate of 0.05% per cycle over 100 cycles at 3 mA cm −2 . This work demonstrates an efficient and scalable strategy for constructing dendrite-free LMBs via eliminating the anion depletion region and facilitating the Li + solvation process.