富锂层状正极材料电化学体系优化与应用研究

发布时间：2018-05-15 04:13

  本文选题：锂离子电池 + 富锂层状正极材料　； 参考：《吉林大学》2017年硕士论文

【摘要】：富锂层状正极材料由于具有高工作电压和高放电比容量而受到广泛关注,被认为是最有前景的新型锂离子电池正极材料。然而,其在现有电化学体系下的循环性能较差,严重阻碍了富锂层状正极材料的实际应用。因此,为解决上述问题,我们对富锂层状正极材料Li_(1.18)Co_(0.15)Ni_(0.15)Mn_(0.52)O_2的电解质体系进行优化,首先使用Li ODFB与Li PF_6作为锂盐,制备了Li ODFB/Li PF_6双盐电解液。双盐电解液提高了材料的界面稳定性,使材料在常温及高温下都具有良好的循环性能。进一步,我们使用PVDF-HFP作为聚合物基质,将传统的1 M Li PF_6液态电解液制成凝胶聚合物电解质,凝胶聚合物电解质在提高材料的循环稳定性的同时,也将材料的适用温度提高至70℃。本文不仅为改善富锂层状正极材料的电化学性能提供了新的研究思路,并且通过分析其作用机理,为富锂层状正极材料的实际应用提供了一定的实验与理论依据。
[Abstract]:Lithium-rich layered cathode materials have attracted wide attention due to their high working voltage and high discharge specific capacity, and are considered to be the most promising cathode materials for lithium ion batteries. However, its poor cycling performance in the existing electrochemical systems seriously hinders the practical application of lithium-rich layered cathode materials. Therefore, in order to solve the above problems, we optimized the electrolyte system of lithium rich layered cathode material Li_(1.18)Co_(0.15)Ni_(0.15)Mn_(0.52)O_2. Firstly, Li ODFB and Li PF_6 were used as lithium salts to prepare Li ODFB/Li PF_6 double salt electrolyte. The double salt electrolyte improves the interfacial stability of the material and makes the material have good cycling performance at room temperature and high temperature. Furthermore, we use PVDF-HFP as the polymer matrix to prepare the gel polymer electrolyte from the traditional liquid electrolyte of 1 M Li PF_6. The gel polymer electrolyte not only improves the cycle stability of the material, but also improves the cycle stability of the material. The suitable temperature of the material was raised to 70 鈩，

本文编号：1890909