锂氧电池钴基三元梯度催化行为及电化学性能分析

发布时间：2018-02-28 06:39

本文关键词： 锂氧电池氧化钴三元梯度催化剂电化学性能　出处：《渤海大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着环境污染与能源短缺问题的日益加剧,开发清洁无污染且高能量效率的能源体系势在必行,因此拥有高理论比能量的锂氧电池受到了广泛关注。然而目前锂氧电池的研究仍存在很多的问题,如阴极材料、电解液的分解和阳极的保护,其中阴极材料的性能对锂氧电池的影响较大。本文主要研究了阴极材料及其在锂氧电池中的应用。首先通过直流电弧放电等离子体法制备了Co O催化剂材料,该催化剂粒径分布均匀无明显团聚现象,具有较大的比表面积和孔隙率。以Co-Pt催化剂为二元催化剂与传统的Mn-Pt进行对比,Co-Pt催化剂具有较低的电荷传递电阻且在0.025 mA cm-2的电流密度下,得到最大比容量为2285.81 mAh g-1和最高的能量密度为5582.80 mWh g-1。而后,以Co O、La2O3和Pt催化剂(Co-La-Pt催化剂)为三元催化剂应用于锂氧电池中,电化学分析表明Co-La-Pt催化剂具有较低的电池内阻,在电流密度为0.01 mA cm-2时,Co-La-Pt三元催化剂的最大放电比容量为2484.35mAh g-1和最大能量密度6072.49 mWh g-1。最后,以CoO催化剂、La2O3、Pt制备出Co-La-Pt三元梯度催化剂。通过电化学分析表明,其电荷传递阻力较小且在0.025 mA cm-2电流密度时,Co-La-Pt三元梯度催化剂的最大比容量为3250.21 mAh g-1和最大能量密度8574.23 mWh g-1,可稳定充放电循环62次。该催化剂的锂氧电池电化学性能高于Co-Pt二元催化剂和Co-La-Pt三元催化剂,表现出非常优异的电化学性能。
[Abstract]:With the increasing problems of environmental pollution and energy shortage, it is imperative to develop a clean, non-polluting and energy-efficient energy system. Therefore, lithium-oxygen batteries with high theoretical specific energy have attracted wide attention. However, there are still many problems in the research of lithium-oxygen batteries, such as cathode materials, electrolyte decomposition and anode protection. The performance of cathode material has a great influence on the performance of lithium oxide battery. This paper mainly studies the cathode material and its application in lithium oxide battery. Firstly, the Co O catalyst material was prepared by DC arc discharge plasma method. The particle size distribution of the catalyst was uniform and there was no obvious agglomeration. Compared with the traditional Mn-Pt, the Co-Pt catalyst has a lower charge transfer resistance and a current density of 0.025 Ma cm-2. The maximum specific capacity was 2285.81 mAh g ~ (-1) and the maximum energy density was 5582.80 mWh g ~ (-1). Then, Co _ 2O _ 3 and Pt catalyst Co-La-Pt were used as ternary catalysts in lithium-oxygen batteries. Electrochemical analysis showed that the Co-La-Pt catalyst had lower internal resistance. The maximum discharge specific capacity of Co-La-Pt ternary catalyst was 2484.35 mAh g-1 and the maximum energy density was 6072.49 mWh g -1 at the current density of 0.01mA cm-2. Finally, the Co-La-Pt ternary gradient catalyst was prepared from CoO catalyst La2O3Pt. The maximum specific capacity of Co-La-Pt ternary gradient catalyst is 3250.21 mAh g ~ (-1) and maximum energy density of 8574.23 mWh g ~ (-1) at 0.025 Ma cm-2 current density, which can stabilize charge and discharge cycles for 62 times. Its performance is higher than that of Co-Pt binary catalyst and Co-La-Pt ternary catalyst. It shows excellent electrochemical performance.
【学位授予单位】：渤海大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TM911.41

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