Ceramics International | 2021
Ultrathin carbon layer enhanced Cu2Nb34O87 nanowires as high-performance lithium host
Abstract
Abstract Cu2Nb37O87 exhibits excellent electrochemical properties, high theoretical capacity (401 mAh g−1), safe working voltage (~1.7\xa0V) and outstanding rate performance for lithium-ion batteries. However, poor electrical conductivity inhibits its further development. In this study, Cu2Nb37O87@C nano-wires are prepared by combining electrospinning and carbon-coating techniques to mitigate this issue, which breaks through the barrier of low conductivity, improves the ion diffusion rate and relieves the change of crystal volume. Besides, the sample is tested by scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy and most importantly, the mechanism of lithium-ion storage is explored by an in-situ X-ray diffraction analysis. Moreover, according to a sequence of electrochemical tests, it is clarified that the electronic conductivity and electrochemical activity of Cu2Nb37O87 are enhanced significantly. All these are inseparable from the synergistic effect of the nano-crystallisation and carbon coating. Therefore, nano-structures and surface cladding provide effective tactics to construct effective ion-migration interfaces and enhance conductivity for the further study of Cu2Nb37O87 and other electrode materials.