Multifunctional ultrafine vacancy-rich ZnO particles incorporated with carbon nanofibers for Li/Na metal batteries and microwave absorption

Lithium and sodium metal as the anodes are preferable choices for next-generation energy storage devices due to high energy density and low redox potential. Unfortunately, the unstable interface, cycling instability and safety issues can arise from dendrite formation, severely hindering its practical application. Here, a multifunctional artificial protective layer of ultrafine vacancy-rich ZnO particles incorporated with carbon nanofibers (vacancy-rich ZnO@CNFs) is constructed on the separator by facile separator modification method. First-principles calculations results clarify stronger adsorption of ultrafine vacancy-rich ZnO particles is helpful for anchoring the Li and Na atoms, which can serve as the highly cohesive nucleation seeds in order to homogenize Li/Na deposition. The modified Li/Na symmetric and full cells exhibit superior electrochemical performance than blank one. In addition, depending on the defect engineering of oxygen vacancy and heterogeneous interfaces, the vacancy-rich ZnO@CNFs also has good electromagnetic wave absorption performance with minimum reflection loss (RL min ) of -41.24 dB and effective absorption bandwidth of 4.48 GHz. This work exhibits significant insights into exploring the multifunctional applications of materials. In this paper, the 3D carbon nanofibers decorated with ultrafine vacancy-rich ZnO particles is developed as lightweight and multifunctional material by calcining, electrospinning, and carbonization for the Li/Na metal batteries and microwave absorption. This vacancy-rich ZnO@CNFs multifunctional material is beneficial for modifying surface properties, such as the atomic arrangement and adsorption energy, guiding uniform deposition of Li + /Na + and generating the interfacial polarization. Accordingly, the vacancy-rich ZnO@CNFs is not only modified interface of anode, but also can be considered as the electromagnetic wave absorption material. It has demonstrated that the vacancy-rich ZnO@CNFs is a promising multifunctional material, which is able to address the problem of alkali metal dendrite formation and have the effective the microwave absorption.