A Lithium Ion Highway by Surface Coordination Polymerization: In Situ Growth of Metal–Organic Framework Thin Layers on Metal Oxides for Exceptional Rate and Cycling Performance

A thin layer of a highly porous metal–organic framework material, ZIF‐8, is fabricated uniformly on the surface of nanostructured transition metal oxides (ZnO nanoflakes and MnO 2 nanorods) to boost the transfer of lithium ions. The novel design and uniform microstructure of the MOF‐coated TMOs (ZIF‐8@TMOs) exhibit dramatically enhanced rate and cycling performance comparing to their pristine counterparts. The capacities of ZIF‐8@ZnO (nanoflakes) and ZIF‐8@MnO 2 (nanorods) are 28 % and 31 % higher that of the pristine ones at the same current density. The nanorods of ZIF‐8@MnO 2 show a capacity of 1067 mAh g −1 after 500 cycles at 1 Ag −1 and without any fading. To further improve the conductivity and capacity, the ZIF‐8‐coated materials are pyrolyzed at 700 °C in an N 2 atmosphere (ZIF‐8@TMO‐700 N). After pyrolysis, a much higher capacity improvement is achieved: ZIF‐8@ZnO‐700 N and ZIF‐8@MnO 2 ‐700 N have 54 % and 69 % capacity increases compared with the pristine TMOs, and at 1 Ag −1 , the capacity of ZIF‐8@MnO 2 ‐700 N is 1060 mAh g −1 after cycling for 300 cycles.