椰壳碳@MnO_(2)纳米材料在水系锌离子电池中的应用

Application of coconut shell@MnO_(2) nanomaterials inaqueous zinc-ion batteries

为解决MnO_(2)材料在水系锌离子电池(ZIBs)中存在的导电性差、材料利用率低等问题,以农业废弃物椰壳为原料,将低成本、来源丰富、绿色可再生的生物质资源引入到电极材料中,通过高温碳化得到导电性优异的椰壳碳,用水热法在椰壳碳表面生长MnO_(2)纳米粒子,获得椰壳碳@MnO_(2)复合纳米材料。借助扫描电子显微镜(SEM)、X射线衍射仪(XRD)、电化学技术等表征测试手段,分析该复合材料的形貌结构以及电化学性能。结果表明椰壳碳@MnO_(2)在100 mA g^(-1)的电流密度下,经过300次循环,比容量仍高达到344.6 mA h g^(-1),性能远高于商用MnO_(2)材料(64.3 mA h g^(-1));椰壳碳@MnO_(2)优异的导电性,纳米化的结构设计提高了材料利用率,减少了离子扩散路径,带来更快的离子扩散速率,提高了材料的倍率性能,具有良好的应用前景。

In order to solve the problems of poor electrical conductivity and low material utilisation of MnO_(2) materials in water-based zinc-ion batteries(ZIBs),this paper took agricultural waste coconut shells as raw materials,introduces low-cost,abundant,and green renewable biomass resources into electrode materials,and obtained coconut shell carbon with excellent conductivity through high-temperature carbonization.MnO_(2) nanoparticles were grown on the surface of coconut shell carbon by hydrothermal method to obtain coconut shell carbon@MnO_(2) composite nanomaterials.By using scanning electron microscopy(SEM),X-ray diffraction(XRD),electrochemical techniques and other characterization testing methods,the morphology,structure,and electrochemical performance of the composite material were analyzed.The results showed that the specific capacity of coconut shell carbon@MnO_(2) was still as high as 344.6 mA h/g after 300 cycles at a current density of 100 mA/g,and its performance was much higher than that of commercial MnO_(2) materials(64.3 mA h/g).The excellent electrical conductivity of coco carbon@MnO_(2),the nanosized structural design improved the material utilisation,reduced the ionic diffusion path,brought faster ionic diffusion rate and improved the multiplicity performance of the material,which had a good application prospect.