为解决MnO2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MnO2纳米粒子,获得椰壳碳@MnO2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@MnO2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MnO2材料(64.3 mA h g-1);椰壳碳@MnO2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.
Application of coconut shell@MnO2 nanomaterials in aqueous zinc-ion batteries
In order to solve the problems of poor electrical conductivity and low material utilisation of MnO2 ma-terials in water-based zinc-ion batteries(ZIBs),this paper took agricultural waste coconut shells as raw materi-als,introduces low-cost,abundant,and green renewable biomass resources into electrode materials,and ob-tained coconut shell carbon with excellent conductivity through high-temperature carbonization.MnO2 nanopar-ticles were grown on the surface of coconut shell carbon by hydrothermal method to obtain coconut shell carbon@MnO2 composite nanomaterials.By using scanning electron microscopy(SEM),X-ray diffraction(XRD),electrochemical techniques and other characterization testing methods,the morphology,structure,and electro-chemical performance of the composite material were analyzed.The results showed that the specific capacity of coconut shell carbon@MnO2 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 MnO2 materials(64.3 mA h/g).The excellent electrical conductivity of coco carbon@MnO2,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.
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