New Insights into the Structure Changes and Interface Properties of Li3VO4 Anode for Lithium-Ion Batteries during the Initial Cycle by in Situ Techniques
New Insights into the Structure Changes and Interface Properties of Li3VO4 Anode for Lithium-Ion Batteries during the Initial Cycle by in Situ Techniques
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原位技术对锂离子电池 Li3VO4 负极在初始循环过程中结构变化和界面特性的新见解
DOI：
10.1021/acsami.6b07811
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发表时间：
2016
影响因子：
9.5
通讯作者：
Sun Shi-Gang
中科院分区：
文献类型：
--
作者：
Zhou Li-Li;Shen Shou-Yu;Peng Xin-Xing;Wu Li-Na;Wang Qi;Shen Chong-Heng;Tu Ting-Ting;Huang Ling;Li Jun-Tao;Sun Shi-Gang
Li3VO4是近年来被认为是一种新型的锂离子电池负极材料，具有394mAHg-1的理论比容量、合适的Li+插入/脱出电位(∼1V)和良好的倍率容量。但其初始库仑效率低、导电性差、循环性能差等问题制约了其发展。为了找出Li3VO4材料初始库仑效率低的原因，采用柠檬酸辅助的溶胶-凝胶法合成了纳米Li3VO4材料。用原位X射线衍射仪和原位交流阻抗谱技术研究了所制备的Li3VO4材料的储锂行为。原位X射线衍射结果表明，Li3VO4在初始充放电过程中发生了不可逆的相变。在恒电位间歇滴定(PITT)过程中进行了现场交流阻抗谱(EIS)实验，讨论了Li3VO4上固体电解质界面(SEI)的形成和锂离子扩散动力学。值得指出的是，这是首次通过现场EIS实验证明Li3VO4在初始充放电过程中存在SEI。结果表明，Li3VO4上的不可逆相变和SEI的形成是导致Li3VO4材料初始库仑效率低的两个重要原因。
Li3VO4has been regarded as a new-type anode of lithium-ion batteries in recent years, which has a high theoretical specific capacity of 394 mAh g–1, a proper potential for Li+insertion/deinsertion (∼1 V), and a good rate capacity. However, its low initial Coulombic efficiency, poor conductivity, and poor cycle performance restricts its development. In order to figure out the cause of the low initial Coulombic efficiency of Li3VO4material, the nanosized Li3VO4material was synthesized by citric acid-assisted sol–gel method. The lithium storage behaviors of the prepared Li3VO4material were studied by in-situ XRD and in-situ EIS techniques. In-situ XRD results indicated that there was irreversible phase transformation of Li3VO4during the initial charging/discharging process. In-situ EIS experiment was performed during the potentiostatic intermittent titration technique (PITT) process to discuss the formation of the solid electrolyte interface (SEI) on the Li3VO4and the kinetics of lithium-ion diffusion. It is worth pointing out that this is the first time to prove the existence of SEI on Li3VO4during the initial charging/discharging process by in-situ EIS experiment. It turned out that the irreversible phase transformation and the formation of SEI on Li3VO4were the two important reasons causing the low initial Coulombic efficiency of Li3VO4material.