LiBSB及其衍生物的合成与性质研究

发布时间：2018-05-14 23:21

本文选题：LiBSB + LiBOB　；参考：《辽宁大学》2017年硕士论文

【摘要】：电解质是电池的重要组成部分之一,电解质对电池性能有直接的影响,其中,电导率大小及稳定性是制约电池性能的重要因素。在寻找新型电解质材料的同时,对已有的电解质材料优化和改善也具有非常重要的意义。目前,获得高品质二次电池的电解质也是当前化学研究的热点课题之一。本论文目标在于通过混合盐组合的方式,改进双水杨酸硼酸锂(LiBSB)电解质的相关性能。首先,以水杨酸、硼酸、一水合氢氧化锂和一水合草酸为原料,通过固相烧结法合成6种不同比例锂硼盐LiBSB、LiBSB-LiBOB-1、LiBSB-LiBOB-2、LiBSB-LiBOB-3、LiBSB-LiBOB-4和LiBOB。对所合成的6种化合物进行了IR、XRD、SEM及TG等方法的表征。电导率测试结果可以看出,其他5种锂硼盐的电导率高于LiBSB,但热稳定性却低于LiBSB。当草酸和水杨酸的比例为一定值时,化合物的电导率值达到最大。另外,对所合成的锂硼盐0天和15天的热重进行分析,发现6种锂硼盐都有一定的吸湿性。其次,以水杨酸、硼酸、一水合氢氧化锂和羧基碳球(HTC)为原料,通过固相烧结法合成了LiBSB/C包覆物。对所合成的LiBSB/C包覆物,采用IR、XRD、TG及SEM等方法进行了表征。通过SEM和TG分析发现,当采用LiBSB化合物对HTC进行包覆时,可以一定程度改善它的吸湿性。对所合成的包覆物溶液电导率进行测试,结果表明LiBSB/C包覆物的离子电导率要低于LiBSB盐自身电导率值。为解决电导率和吸湿性的问题,以水杨酸、二水合草酸、硼酸、一水合氢氧化锂和羧基碳球(HTC)为原料,合成了LiBSB-LiBOB/C的系列化合物,同样采用IR、XRD、SEM及TG等方法对该系列化合物进行了表征。结果发现,LiBSB-LiBOB/C与LiBSB-LiBOB相比,不仅吸湿性有所改善,热稳定性也一定程度得到了提高。LiBSB-LiBOB/C在PC、AN和DMF等三种溶剂中的电导率进行测试,其在AN中的电导率最高,而在PC中的电导率最低。结合热重分析及电导率测试结果发现,当HTC达到一定量时,化合物具有较高的电导率,且热稳定性高。
[Abstract]:Electrolyte is one of the important components of the battery. The electrolyte has a direct impact on the performance of the battery, among which, the conductivity and stability are important factors that restrict the performance of the battery. At the same time, it is of great significance to optimize and improve the existing electrolyte materials. At present, obtaining high-quality electrolytes for secondary batteries is also one of the hot topics in chemical research. The aim of this thesis is to improve the properties of LiBSBs electrolyte by mixing salt. Firstly, six kinds of LiBSB-LiBSB-LiBOB-1 LiBSB-LiBOB-2 + LiBSB-LiBOB-3 (LiBSB-LiBOB-3) and LiBSB-LiBOB-4 (LiBSB-LiBOB-4) were synthesized by solid-state sintering from salicylic acid, boric acid, lithium hydroxide monohydrate and oxalic acid monohydrate. The synthesized six compounds were characterized by IR XRD SEM and TG. The conductivity test results show that the conductivity of the other five lithium borates is higher than that of LiBSBs, but the thermal stability is lower than that of LiBSBs. When the ratio of oxalic acid and salicylic acid is a certain value, the conductivity of the compound reaches the maximum. In addition, the thermogravimetric analysis of the synthesized lithium-borate at 0 and 15 days showed that all of the six lithium-boron salts had certain moisture absorption. Secondly, the LiBSB/C coating was synthesized by solid phase sintering from salicylic acid, boric acid, lithium hydroxide monohydrate and carboxyl carbon ball HTC. The synthesized LiBSB/C coating was characterized by IR XRD TG and SEM. By SEM and TG analysis, it was found that the hygroscopicity of HTC could be improved to some extent when LiBSB compound was coated. The results show that the ionic conductivity of LiBSB/C coating is lower than that of LiBSB salt. A series of LiBSB-LiBOB/C compounds were synthesized from salicylic acid, oxalic acid dihydrate, boric acid, lithium hydroxide monohydrate and carboxyl carbon ball HTC. The compounds were also characterized by IR XRD SEM and TG. The results show that compared with LiBSB-LiBOB, LiBSB-LiBOB / C not only improves the hygroscopicity, but also improves the thermal stability of LiBSB-LiBOB / C in some extent. The conductivity of LiBSB-LiBOB / C in PC and DMF is the highest in an and the lowest in PC. Combined with thermogravimetric analysis and conductivity test, it was found that when HTC reached a certain amount, the compound had high conductivity and high thermal stability.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O614.111;O646

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