ZnMn2O4/ZnMnO3/ZnO composite with novel bilayer heterojunction structure for enhanced lithium storage performance

Abstract

Innovative anode materials with high capacity and good cyclic stability play a vital role on pursuing the high-performance lithium-ion batteries (LIBs). Herein, ZnMn2O4/ZnMnO3/ZnO composite with a unique bilayer heterojunction structure is successfully synthesized by sintering of ZIF-8 coated Zn1/3Mn2/3CO3. The crystal phase, microstructure and chemical composition of ZnMn2O4/ZnMnO3/ZnO composite are characterized to analyze the heterostructure in detail. When used as anode materials for LIBs, the rich heterostructure interface of the composite can adsorb more e- and Li+, improving the lithium storage behavior of material. Meanwhile, the build-in electric field generated by the heterojunction is conducive to accelerating the migration speed of e- and Li+, thus improving the conductivity of the material. As a result, after long-term cycles of 320 times, the specific capacity of ZnMn2O4/ZnMnO3/ZnO composite is up to 857.5 mAh g−1, and it still keeps a high specific capacity of 201.4 mAh g−1 at the high current of 5 C. These results indicate that ZnMn2O4/ZnMnO3/ZnO composite has great potential in the field of LIBs.