木质纳米纤维素载银纳米线复合协同作用机制及其银锌电池性能研究

Wood cellulose nanocomposites have gained more attentions for flexible and portable energy storage, because of their intrinsic network structures as well as advantageous mechanical property and surface chemistry. However, too many study works were focused on nanocellulose-derived supercapacitors and lithium batteries, the research related to silver-zinc battery was limited. In the present project, we will integration cellulose nanofibers and silver nanowires to fabricate flexible and conductive composite nanopapers. We will systematically research the structure-performance relationship of the nanopapers. Then, we will assemble silver-zinc battery using the composite nanopapers as positive electrode. The effect of cellulose nanofibers and silver nanowires on the mechanical property, flexibility, and electrochemistry property of the composite nanopapers will be studied. Next, the structures and electrochemistry performance of the composite nanopaper-, cellulose nanofiber nanopaper-, and silver nanowire nanopaper-derived silver-zinc battery and commercial silver-zinc battery will be compared. The structures and electrochemistry performance of these batteries during the cycling process will further be compared. Considering the entangled network structures within the composite nanopapers, the effect of cellulose nanofibers on avoiding the structure corrosion of silver nanowires and the effect of silver nanowires on the energy storage capability of the battery, will be examined. The synergy mechanism of cellulose nanofibers and silver nanowires within the composite nanopapers for the performance of the silver-zinc battery will be illustrated, to guide the assemble and structural designing strategy of the silver-zinc battery.

木质纤维素复合材料因其独特的网络结构、力学以及表面化学特点，在柔性、便携式能量储存领域得到广泛关注。但是，多数研究聚焦于纳米纤维素基超级电容器和锂电池，对银锌电池等能量储存器件的关注较少。本项目拟利用木质纳米纤维素与银纳米线复合构筑柔韧、导电复合纳米纸，在深入研究复合纳米纸构效关系的基础上，利用复合纳米纸作为正极组装银锌电池。研究纳米纤维素与银纳米线对银锌电池力学性能、柔韧性以及电化学性能的影响规律。通过对比研究复合纳米纸基银锌电池与复合纳米纸中各单一构筑单元衍生的银锌电池以及商用银锌电池的结构和电化学性能以及它们在电池循环使用过程中的变化规律，结合纳米纤维素与银纳米线间的缠结网络结构，阐明在银锌电池循环使用过程中，纳米纤维素对银纳米线结构“腐蚀”的抑制作用以及银纳米线对银锌电池能量储存能力的重要作用，进而揭示纳米纤维素和银纳米线的协同作用机制，以指导优化银锌电池的组装与结构设计策略。

利用木质纳米纤维素与银纳米线等导电材料复合构筑柔韧、导电复合纳米纸，在深入研究复合纳米纸构效关系的基础上，解析纳米纤维素与导电材料对纸电池力学性能、柔韧性以及电化学性能的影响规律。.1、明确均质/高效木质纳米纤维素制备的最佳条件，从植物细胞多层次结构入手，分析原材料、细胞壁结构、开纤方法、处理时间、聚集体形貌、纳米纤维化效率等对纤维素的结构与性能的影响，确定木质纳米纤维素的构建机制。.2、通过冷冻干燥-煅烧过程，合成了CNF/MnOx复合气凝胶。复合材料表现出准矩形CV曲线、赝电容行为和小阻抗等特性。在充放电1000次后，比电容保持率为80%，表现出良好的循环稳定性。本项目还阐述了CNF-GR珍珠仿生层状复合纸的制备方法。当石墨烯质量浓度比例为10%时复合纸的力学性能最好。但随着GR比例浓度的增加，复合纸的导电性能和电化学性能也随之更加稳定。.3、完成Zn-Ag电池的组装，并通过对比不同载银量的CNF-AgNWs银锌电池的循环稳定性，指导优化银锌电池的组装与结构设计策略。明确纳米纤维素和银纳米线在Zn-Ag电池循环使用过程中的结构、性能特点及其协同作用机制，开发出具有柔性、高强、导电以及高比电容的复合纳米纸电极。