Zeolitic imidazolate framework-8 modified LiNi1/3Co1/3Mn1/3O2: A durable cathode showing excellent electrochemical performances in Li-ion batteries

摘要

Surface coating is a useful strategy to enhance the cycling stability of cathode materials. Achieving superior rate capability at the same time, however, is still a challenge. In this work, the zeolitic imidazolate framework-8 (ZIF-8), one of metal-organic framework material, is initially coated on the surface of LiNi1/3Co1/3Mn1/3O2 (NCM333). After ZIF-8 coating, the cycling stability and rate capability of NCM333@ZIF-8 are simultaneously improved in comparison with that of NCM333. A high capacity retention ratio of 81.4% is achieved after 300 cycles at 800 mA g(-1), which is much larger than that of NCM333 (41.2%). Even at an elevated temperature (55 degrees C), the cycling stability of NCM333@ZIF-8 is still excellent. In addition, a high capacity of 122 mA h g(-1) is obtained at a high current density of 1200 mA g(-1). The enhanced performances are highly related with the unique properties of permanent porosity, exceptional thermal and chemical stability and the high ionic conductivity (3.16 x 10(-4) S cm(-1)) of ZIF-8 that not only acts as a shield for NCM333 against the electrolyte corrosion, but also enables faster lithium-ion transfer at the interfacial regions. The current work offers guidance for improving the overall electrochemical performance of electrode materials in lithium-ion batteries. (C) 2020 Elsevier Ltd. All rights reserved.