In situ monitoring the evolution of electrode materials in micro/nano scale is crucial to understand the intrinsic mechanism of rechargeable batteries. Here a novel on-chip Langmuir-Blodgett nanowire (LBNW) microdevice is designed based on aligned and assembled MnO2 nanowire quasimonolayer films for directly probing Zn-ion batteries (ZIBs) in real-time. With an interdigital device configuration, a splendid Ohmic contact between MnO2 LBNWs and pyrolytic carbon current collector is demonstrated here, enabling a small polarization voltage. In addition, this work reveals, for the first time, that the conductance of MnO2 LBNWs monotonically increases/decreases when the ZIBs are charged/discharged. Multistep phase transition is mainly responsible for the mechanism of the ZIBs, as evidenced by combined high-resolution transmission electron microscopy and in situ Raman spectroscopy. This work provides a new and adaptable platform for microchip-based in situ simultaneous electrochemical and physical detection of batteries, which would promote the fundamental and practical research of nanowire electrode materials in energy storage applications.
Keywords: Zn-ion batteries; electrical transport; manganese dioxide; nanowire assembly.
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