多糖水凝胶聚合物电解质的制备及其在锌二次电池中的应用研究

With the widespread application of renewable energy, it is an urgent requirement to develop novel types of secondary battery systems with high safety, high energy density, high power density, low cost and eco-friendliness. Aqueous rechargeable zinc batteries (ARZBs) have drawn great attentions of researchers with the characteristics of low cost, eco-friendliness, high safety and good electrochemical performance. However, the risk of leakage will always exist in traditional ARZBs. For solving the problem, it is necessary to intensify the research of hydrogel polymer electrolyte and to develop quasi-solid-state ARZBs. In this project, polysaccharide, one kind of biocompatible, abundant, nontoxic and pollution-free natural macromolecules, will be applied as raw material to prepare hydrogel polymer electrolytes (HGPEs) for ARZBs with the process of casting, phase inversion or electrospinning. Then ionic conductivity and mechanical strength of HGPEs will be improved by the methods of chemical and physical modification. Furthermore, the inhibiting capacity to zinc dendrites and their compatibility with cathode materials and zinc anode of the prepared polysaccharide-based HGPEs will also be explored. The electrochemical performance of the prepared HGPEs will be evaluated by assembled quasi-solid-state ARZBs. More than one target HGPEs which can satisfy the application requirements of the ARZBs will be find out in the research. The research will also expand the application of quasi-solid-state energy storage devices.

可再生能源的广泛应用迫切需要开发高安全、高能量密度、高功率密度、低价格、环境友好的新型二次电池体系。水溶液作为电解质的锌二次电池（水锌二次电池）相对其它二次电池具有成本低廉、环境友好、安全性高、电化学性能优良等特点，引起各国研究人员的高度关注。但传统水锌二次电池存在电解液泄露风险，易造成事故。为解决这一困扰锌二次电池发展的难题，加大水凝胶聚合物电解质的研发,发展准固态水锌二次电池成为必须。本研究以生物相容性好、来源丰富、无毒、无污染的天然多糖为原料，通过浇铸、相反转或静电纺丝等方法制备水凝胶聚合物电解质，将所得准固态电解质进行物理和化学改性，进一步提高其电导率和力学性能，对制得的聚合物电解质对锌枝晶的抑制能力及与正极材料和锌负极相容性进行研究，同时构筑准固态水锌二次电池对其电化学性质进行评价，以期寻找到一种或几种可应用于水锌二次电池的多糖水凝胶聚合物电解质，拓展准固态储能器件的应用。

水溶液作为电解质的锌二次电池（水锌二次电池）具有成本低廉、环境友好、安全性高、电化学性能优良等特点，引起各国研究人员的高度关注。但传统水锌二次电池存在电解液泄露风险，易造成事故。为解决这一难题，开发水凝胶聚合物电解质，发展准固态水锌二次电池成为必须。本项目以生物相容性好、保水性好、来源丰富、无毒、无污染的天然多糖（琼脂、海藻酸锌、海藻酸钠、纤维素等）为原料，通过浇铸、相反转或冷冻干燥等方法制备水凝胶聚合物电解质，借助复合改性和成膜工艺优化等方法提高了水凝胶聚合物电解质对锌枝晶的抑制能力及与电极材料的界面相容性，获得了多种可用于水锌二次电池的多糖水凝胶聚合物电解质。制备的锌离子水凝胶聚合物电解质机械应力：92 MPa，室温锌离子电导率：2.8×10-3 S cm-1，锌离子迁移系数：0.46，电化学稳定窗口：2.3 V（vs. Zn2+/Zn）；通过准固态锌离子电池评价显示，制备的锌离子水凝胶聚合物电解质在2 A g-1电流密度下放电容量为151.9 mAh g-1，2000次循环后库伦效率和容量保持率均接近100%，显示了优异的锌枝晶抑制能力和循环稳定性。该项目的开展为绿色、低成本、高性能固态电化学储能器件的研发提供了新方向。通过项目支持，发表SCI论文12篇；申请中国专利8项，含发明专利7项，实用新型专利1项；参加国内/国际学术会议9人次，并做邀请报告4次；培养硕士研究生5名。