Increased Conductivity in the Metastable Intermediate in LixFePO4 Electrode
Increased Conductivity in the Metastable Intermediate in LixFePO4 Electrode
复制标题
DOI：
10.1021/acs.chemmater.5b04508
复制
发表时间：
2016-02
影响因子：
8.6
通讯作者：
Jiechen Lu;Gosuke Oyama;S. Nishimura;A. Yamada
中科院分区：
文献类型：
--
作者：
Jiechen Lu;Gosuke Oyama;S. Nishimura;A. Yamada
随着人们对能源和环境问题的日益关注，锂离子电池正在向电动汽车等大规模应用领域渗透。作为电极反应过程，通常认为具有结构重排和大的晶格失配的两相反应阻碍了高速率能力。然而，LixFePO4，其LiFePO4和FePO4之间的两相反应，表现出优异的高倍率性能。在这篇文章中，在确认了即使在中等速率下也存在单相反应后，我们证明了淬火中间体Li0.6FePO4的电导率增加了约2个数量级。除了广泛接受的应变弛豫效应在两相界面，显着增加的导电性，由于极化子/锂载流子密度的增加，在中间相应强调作为一个重要因素，以加速橄榄石LixFePO4的电极反应。
With increasing concerns about energy and environmental issues, lithium ion batteries are now penetrating into large-scale applications such as electric vehicles. As an electrode reaction process, it is generally believed that two-phase reaction with structural rearrangement and large lattice mismatch impedes high-rate capability. However, LixFePO4, with its two-phase reaction between LiFePO4 and FePO4, exhibits an exceptional high-rate performance. In this article, after confirming the existence of a single-phase reaction even under moderate rates, we demonstrate an approximately 2 orders of magnitude increase of the conductivity for the quenched intermediate Li0.6FePO4. In addition to the widely accepted strain relaxation effect at the two-phase interface, the dramatically increased conductivity due to polaron/lithium carrier density increase in the intermediate phase should be highlighted as an important factor to accelerate the electrode reaction of olivine LixFePO4.