Zeolitic imidazolate framework-derived ZnO polyhedrons wrapped by Co nanoparticle embedded in N-doped carbon for high-performance lithium and potassium storage

Metal oxides are considered as promising anodes for alkali-ion batteries due to their high theoretical ca-pacity and moderate volume expansion. However, they still suffer from the low electrical conductivity and capacity decay, resulting poor rate capability and cyclic stability. In this work, core-shell ZnO polyhedrons coated by Co nanoparticle embedded in N-doped carbon (ZnO@Co/NC) were prepared via a convenient route using zeolitic imidazolate frameworks as precursors. The unique structural design not only sy-nergistically forms a three-dimensional conductive network to promote the transfer and storage of Li+/K+ ions, but also restrains the volume changes of ZnO polyhedron during repeated lithiation/potassiation processes, contributing to enhanced lithium and potassium storage performances. The ZnO@Co/NC anode delivers 458.3 mAh g-1 after 1000 cycles at an ultrahigh current density of 10 A g-1 with a capacity retention of 95% for LIBs, and remains 181.5 mAh g-1 after 1000 cycles at 200 mA g-1 with 84% retention for KIBs. When coupled with commercial LiFePO4 cathode, the full cell delivers a capacity of 140.6 mAh g-1 after 250 cycles at 1 A g-1. This work not only shows the promising potential ZnO-based materials for long-term and high-rate lithium-ion batteries, but also gives an insight into the design of ZnO-based anodes for potassium storage.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

In this work, core-shell ZnO polyhedrons coated by Co nanoparticle embedded in N-doped carbon (ZnO@Co/NC) were prepared using zeolitic imidazolate frameworks as precursors. The unique structural design not only forms a conductive network to promote ion transfer, but also restrains the volume changes of ZnO polyhedron, enhancing the storage performance of lithium and potassium.