Transportation properties in nanosized LiFePO4 positive electrodes and their effects on the cell performance
Transportation properties in nanosized LiFePO4 positive electrodes and their effects on the cell performance
复制标题
DOI：
10.1007/s10800-012-0512-3
复制
发表时间：
2013-03
影响因子：
2.9
通讯作者：
Seungho Yu;Soonkyu Kim;Tae Y. Kim;J. Nam;W. Cho
中科院分区：
文献类型：
--
作者：
Seungho Yu;Soonkyu Kim;Tae Y. Kim;J. Nam;W. Cho
为了实现锂离子电池的高能量密度，电极厚度和电极密度的优化是非常重要的。为了获得高能量密度，通常将电极设计得又厚又密。然而，厚密电极中高度曲折的传输路径会导致严重的传输损耗，从而对电池性能产生不利影响。在这项工作中，我们通过实验和模拟研究了不同电极厚度和密度对锂离子在电解液中传输的影响。这两个结果都表明，由于电解液相的有效扩散系数降低，低孔隙率的电极发生了额外的容量损失。本工作还提出了可用于设计高功率LiFePO4/石墨电池的电极厚度和密度(孔隙率)的最佳范围。
To achieve a high energy density for Li-ion batteries, it is important to optimize the electrode thickness and electrode density. It is common to design the electrodes to be thick and dense to achieve a high energy density. However, highly tortuous transport paths in thick and dense electrodes can lead to severe transport losses, which negatively affect the cell performance. In this work, we investigated the effects of varying the electrode thickness and density on lithium ion transport in the electrolytes by means of both experiments and simulations. Both results indicated that an additional capacity loss occurs from the electrode with low porosity because the effective diffusivity decreased in the electrolyte phase. Optimal ranges of the electrode thickness and density (porosity) that can be used to help design high-power LiFePO4/graphite batteries were also suggested in this work.