新型锂硫电池硫正极水基粘结剂的制备研究

发布时间：2018-03-02 11:03

  本文关键词： 硫电极 水溶性粘结剂 嵌段共聚物 聚(苯乙烯-b-丙烯酸正丁酯-b-苯乙烯)　出处：《高校化学工程学报》2017年03期 　论文类型：期刊论文

【摘要】：硫正极材料因具有较高的能量密度而广受关注,但由于其在充放电过程中体积变化大、硫穿梭效应使其容量衰退快等原因,大大限制了其实际使用。本文通过RAFT乳液聚合首次设计合成了聚(苯乙烯-b-丙烯酸正丁酯-b-苯乙烯)(Sn BAS)三嵌段共聚物作为硫电极粘结剂。通过制备粘结剂薄膜测试其在醚类电解液的溶胀性,并进行多倍率充放电、电池寿命测试,与聚苯乙烯(PS)、聚丙烯酸正丁酯(Pn BA)及商用SBR对比,发现通过调配苯乙烯/丙烯酸正丁酯(St/n BA)质量比率可获得兼具高力学强度及高电解液溶胀率的电极粘结剂。将粘结剂Sn BAS100用于制备硫电极,所得硫正极分别在0.1C、0.2C、0.5C、1C、2C、0.1C倍率充放电后,再次以0.2C倍率充放电所得放电比容量为781 m Ah×g-1,与首次充放电时的放电比容量1061 m Ah×g~(-1)相比,容量保留率为73.6%。电极继续100次循环后放电比容量为740m Ah×g~(-1),容量保留率为94.7%,每次充放电的平均容量衰退率为0.05%。结果表明,水溶性嵌段结构的SnBAS粘结剂是一种极具应用潜力的水基硫正极粘结剂。
[Abstract]:Sulfur cathode materials have attracted much attention because of their high energy density. However, due to the large volume change in charge and discharge process, the sulfur shuttle effect causes its capacity to decline rapidly. In this paper, the triblock copolymers of n-butyl styrene-bacrylate (n-butyl acrylate) as binder for sulfur electrode were designed and synthesized for the first time by RAFT emulsion polymerization. The binder film was prepared by the preparation of binder film. To test its swelling in ether electrolyte, Multirate charge-discharge, battery life test, and comparison with polystyrene (PS), poly (butyl acrylate) (PN), and commercial SBR were carried out. It was found that an electrode binder with high mechanical strength and high swelling rate of electrolyte could be obtained by blending styrene / n-butyl acrylate (St / n-BA) mass ratio. The binder Sn BAS100 was used to prepare sulfur electrode. The specific discharge capacity obtained by charging and discharging at 0.2C rate was 781mAh 脳 g-1, which was compared with 1061mAh 脳 gc-1 at the first charge-discharge. The specific discharge capacity of the electrode is 740mAh 脳 gu ~ (-1), the capacity retention is 94.77.The average capacity decline rate of each charge and discharge is 0.05. the results show that, after 100 cycles, the specific discharge capacity of the electrode is 740mAh 脳 GG ~ (-1), and the capacity retention ratio is 94.70.The results show that, SnBAS binder with water soluble block structure is a potential water-based sulfur positive binder.
【作者单位】： 化学工程联合国家重点实验室(浙江大学);浙江大学化学工程与生物工程学院;浙江省能源与核技术应用研究所;Department
【基金】：国家自然科学基金(21574115) 浙江省科技计划项目(2015F50022)
【分类号】：TM912;TQ437
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