| The rapid development of flexible electronics and other applications makes it imperative to develop flexible energy storage devices and gas sensors.At present,flexible electronic devices are faced with many problems,which are not only limited by the complex preparation process of materials,the poor electrochemical performance of battery anode materials and the insufficient gas-sensitive performance of gas sensors,but also easy to damage the structure of devices under deformation conditions.In order to solve these problems,the nanofiber base flexible battery material and the gas sensor are constructed by electrospinning technology.The main research contents are as follows:（1）Sodium titanium-phosphate（Na Ti2（PO4）3,NTP）anode material has a suitable potential platform and stable crystal structure.As the anode material of sodium ion energy storage devices,it has high research value and future.However,the low electronic conductivity of NTP is not conducive to electronic transmission,resulting in its small specific capacity and poor multiplier performance.Na Ti2（PO4）3@C nanofibers（NTP/C-NFs）film with three-dimensional（3D）network structure were prepared by electrospinning combined with high-temperature calcination.Through characterization analysis and performance test,the uniform carbon coating improves the electronic conductivity of the electrode,so that the specific capacity of NTP/C-NFs is 124.7 m Ah g-1 under the current density of 2 m A cm-2,and the specific capacity can still maintain91.7%of the initial capacity after 1000 cycles.Therefore,this work provides a new strategy for the design of flexible sodium ion anode materials with high performance and opens a new design approach.（2）Flexible gas sensor has been paid much attention because of its wide application prospect.However,the interface binding force between the gas-sensitive material and the flexible substrate is poor,and the structure is easy to be damaged under deformation conditions.By growing cobalt-doped tin disulfide（Co-Sn S2）ultra-thin nanosheets directly on polyacrylonitrile（PAN）nanofibers,PAN/Co-Sn S2 composite nanomaterials with bionic"branches-leaves"structure were constructed.The interfacial bonding between PAN nanofibers and Sn S2 nanosheets was used to enhance the stress distribution/transfer and energy dissipation characteristics.In addition,Co doping regulates the electronic structure and S vacancy of Sn S2,thereby improving gas transport/diffusion,gas-sensitive reactivity and carrier transfer/transport performance.The integrated NO2 gas sensor has excellent flexibility（minimum theoretical radius of curvature 3.9μm）,high response and fast response/recovery speed（6.2 and 27.5/60 s）.At the same time,it has low detection limit and long-term stability.This integrated strategy of mechanical and gas-sensitive characteristics has solved the inherent bottleneck of traditional thin-film gas-sensitive sensors and opened up a new way for the development of flexible gas sensors.（3）Due to the complex monitoring environment,easy to be affected by humidity interference,the anti-humidity interference ability of room temperature gas sensor is poor,and the room temperature stability is insufficient.In this paper,a flexible room temperature gas sensor with good room temperature gas sensitivity was prepared by using PAN nanofibers loaded with cerium doped Sn S2 nanosheets.3%Ce-doped Sn S2showed fast response/recovery time（60.4/55.4 s）and high response（12.9）.In addition,the elongation at break of PAN/Ce-Sn S2-3 composite nanofibers film reaches 5.5%,which exceeds the previously reported flexible room temperature gas sensor of metal oxide composites.Moreover,thanks to the polyvalent catalytic properties of Ce,the material has a higher response value at room temperature.This work provides a new idea for enhancing the room temperature gas sensitivity of the flexible room temperature gas sensor. |
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