二氧化钒同质异构多晶的可控制备，性能评价与应用探索

The reserves and the production of vanadium resource in China account for the first in the world, while their application is mostly limited mainly in traditional iron and steel industries. Recently, vanadium compounds, particularly compounds in the vanadium-oxygen system, most of which are with sharp semiconductor-to-metal phase transition properties accompanied by sharp changes in optical and electromagnetic properties, continue to discover new properties and update its application fields, which cover energy saving in buildings, uncooled infrared camera, optical storage and optical switching devices, lithium ion batteries, energy storage and thermal storage of such many high-tech fields. Keeping up closely with the world trend, making full use of our precious resources, and using our advanced materials technology with good research platform, to catch up with the world advanced level in the field of high-tech use of vanadium resources, are the responsibilities and tasks of our researchers. This project takes the most famous compound of the vanadium dioxide as the research object for its phase transition behavior and diversity of crystalline polymorphs, and focusing on the polymorphs of phase A, B and C which are still in the early stage of research and applications. First, we carry out the controllable preparation of the various crystalline polymorphs in the nanopowder form by a soft chemical method, and to study their phase transition behavior, the crystalline phase formation and transformation processes in solution,. Second, we prepare thin films of polymorphs by both the chemical and the physical methods and their combinations. Third, we make a detailed study of the structure and physical properties of the nanopowder and thin films, expecting for new findings on optical, electromagnetic properties. Finally, the applications of the new properties will be considered, and it is expected in such a way to enhance significantly the high-tech use of our vanadium resources.

我国钒资源储产量均占世界第一，主要用在钢铁等传统产业。最近钒的化合物，特别是钒氧体系中丰富的化合物种类及其优异的光电磁学性能被不断发现和更新，其应用涵盖了节能，红外摄像，光储存光开关，锂离子电池，储能储热等诸多高新科技领域。把握世界研究趋势，利用我国资源，人才优势和优良研究平台，在钒资源高科技利用领域赶超世界先进水平，符合我国科技发展战略的需要。本项目以钒氧体系重要组成之二氧化钒为研究对象，针对其丰富的同质异构多晶特点，重点对目前尚处于萌芽阶段的A，B，C相等多晶进行深入研究，以期及早发现新性能和新应用。拟首先以软化学法实现各种纳米多晶结构的可控制备，研究反应过程中多晶结构的形成与转换机制，以及各自的相变特性等基础科学问题；其次结合化学制备与物理制备实现多晶的薄膜化，并详细表征其光电性能，发现新性能，探索新用途，为促进我国钒资源的高科技利用做出贡献。

钒的化合物特别是钒氧体系中丰富的化合物种类及其优异的光电磁学性能被不断发现和更新，其应用涵盖了节能，红外摄像，光储存光开关，锂离子电池，储能储热等诸多高新科技领域。本课题首先以软化学法实现了二氧化钒同质异构纳米粉体的可控制备。通过设计和优化反应体系，精密调控溶液组分、浓度、添加剂以及合成温度、压力和时间等多种工艺参数，成功获得二氧化钒同质异构单一晶相（A、B、M/R）纳米粉体。通过对晶体形貌的调控，获得了线、片、带、球、空心球及花状等不同形貌。详细研究了上述化学反应过程中纳米多晶的形成与相互转换机制。其次，结合化学和物理两种制备方式获得一系列二氧化钒纳米薄膜，并对其相变特性和光电性能进行了深入研究，获得如下主要成果：1）通过对不同结构与形貌VO2(A)和VO2(B)的电学性能测试，分析了其充放电过程中的损耗机制，并通过与石墨烯复合提高了电学性能；2）新开发出一种新型微乳液方法制备M相二氧化钒纳米粉体，该方法制备出的纳米粉体除具有优良的分散性、稳定性外，太阳能调节率可以达到12%以上，该方法可实现连续化和规模化生产，具有潜在的应用前景；3）研发出超细M/R相纳米粒子及其复合薄膜的制备方法，其太阳能调节率最高可达21%；4）对磁控溅射法制备的M/R二氧化钒薄膜的光电性能进行研究，其具有合适的室温电阻率、较高的TCR，可满足非制冷红外焦平面要求。.在本项目的资助下，已发表SCI收录论文14篇，申请国家发明专利13项，参加学术会议10人次，培养博士、硕士研究生共6名。项目按计划圆满完成。