论文标题
移动小极地解释氧化锂电池电极中的电导率
Mobile Small Polarons Explain Conductivity in Lithium Titanium Oxide Battery Electrodes
论文作者
论文摘要
氧化锂氧化锂li $ _4 $ ti $ _5 $ o $ _ {12} $（lto）是一种有趣的阳极材料，有望尤其是长期使用的电池，这是由于其在电池（DIS）充电期间的显着阶段稳定性。但是，其用法受到其固有电子电导率低的限制。引入氧气空位可以是一种克服这一缺点的方法，可能是通过改变电荷载体传输机制。我们使用Hubbard校正的密度功能理论（DFT+U）表明，偏极状态与可能的跳跃机制结合使用可以在实验观察到的电子电导率的增加中起着至关重要的作用。为了衡量二极管电荷迁移率，我们计算了不同定位模式的相对稳定性，并估算了极化子跳势垒高度。有了这一点，我们最终展示了缺陷工程如何确实可以将LTO的电子电导率提高到其离子电导率的水平，从而解释了LTO降低的首次实验结果。
Lithium titanium oxide Li$_4$Ti$_5$O$_{12}$ (LTO) is an intriguing anode material promising particularly long lived batteries, due to its remarkable phase stability during (dis)charging of the cell. However, its usage is limited by its low intrinsic electronic conductivity. Introducing oxygen vacancies can be one method to overcome this drawback, possibly by altering the charge carrier transport mechanism. We use Hubbard corrected density-functional theory (DFT+U) to show that polaronic states in combination with a possible hopping mechanism can play a crucial role in the experimentally observed increase of electronic conductivity. To gauge polaronic charge mobility, we compute relative stabilities of different localization patterns and estimate polaron hopping barrier heights. With this we finally show how defect engineering can indeed raise the electronic conductivity of LTO up to the level of its ionic conductivity, thereby explaining first experimental results for reduced LTO.
