生物质基碳材料用作钠离子电池负极材料研究

Hard carbons have been intensively investigated as anode materials for sodium-ion batteries due to their large interlayer distance, which facilitates sodium insertion and extraction. However, the high cost and complicate synthesis process of the currently reported hard carbons limit their practical application. This project aims to synthesize several biomass-based hard carbons through a two-step strategy including carbonization of low-cost, renewable biomass and subsequent doping or activation. The as-prepared hard carbons are expected to have large interlayer spacing and surface area. The electrochemical properties of the hard carbons as anode materials for sodium-ion batteries will be investigated in detail. We hope to overcome the problems of carbon-based sodium-ion battery anodes, such as low capacity, poor rate capability, and bad cycling stability. This project will explore the effect of biomass species, carbonization temperature, doping type, and activation atmosphere on sodium storage properties. The desirable carbon-based sodium-ion battery anode materials will be developed with high capacity, excellent rate performance and long cycle life, which can provide theoretical and experimental basis for development and application of sodium-ion batteries.

由于具有较大的层间距，硬碳在作为钠离子电池负极材料时受到广泛关注。但是，目前报道的硬碳成本高、制备程序复杂，限制了其在实际生产中的应用。本项目首先通过碳化低成本、可再生的生物质原料，再通过掺杂、活化等后处理制备出几种生物质基硬碳。这类碳材料有望具有较大的层间距和比表面积。系统研究这类碳材料在作为钠离子电池负极材料时的电化学性能，期望可以解决目前碳基钠离子电池负极材料容量低、倍率性能差以及循环寿命短等不足。探讨生物质原料种类、碳化温度、掺杂类型、活化气氛对储钠性能的影响。开发出具有高容量、高倍率、长循环寿命的碳基钠离子电池负极材料，为钠离子电池的应用提供理论和实验依据。

钠离子电池由于钠资源丰富、分布广泛，在大规模储能领域受到越来越多的关注。 然而，对于钠离子电池的实际应用而言，开发可行的负极材料仍然是一个巨大的挑战。为了解决这个难题，我们以低成本、可再生的荷叶杆、海带、稻壳和棉花为原料，通过简单酸处理再热解的方法制备出多种生物质衍生硬碳，并将所得硬碳用作钠离子电池负极材料。通过改变热解温度等调节了生物质衍生硬碳中乱层纳米晶的石墨烯层间距和微观结构，改善了生物质衍生硬碳作为钠离子电池负极时存在的可逆容量低、循环稳定性和倍率性能差的问题，所制备的硬碳均表现出较好的储钠性能和商业化应用前景。其中，稻壳衍生硬碳在25 mA g−1电流密度下循环100圈后可逆容量为346 mAh g−1，与Na3V2(PO4)2F3/C正极组装的全电池（Na3V2(PO4)2F3/C//RHHC-1300）在25 mA g−1电密度下流循环100圈后可逆容量为228 mAh g−1。项目负责人以第一/通讯作者发表SCI论文19篇、中文核心期刊3篇，其中影响因子10以上的6篇，授权专利1项，申请专利2项。研究工作受到国内外同行的广泛关注、引用和好评，截止目前，共被他引715次。