A dynamic capacity fading model with thermal evolution considering variable electrode thickness for lithium-ion batteries
A dynamic capacity fading model with thermal evolution considering variable electrode thickness for lithium-ion batteries
复制标题
考虑可变电极厚度的锂离子电池热演化动态容量衰减模型
DOI：
10.1007/s11581-018-2476-8
复制
发表时间：
2018
期刊：
影响因子：
2.8
通讯作者：
Liu Yongzhong
中科院分区：
文献类型：
--
作者：
Huang Xiankun;Ke Shaoyong;Lv Haichao;Liu Yongzhong
容量是表征锂离子电池性能的关键参数之一。发热分析对于评估电池的安全性至关重要。为了研究电极厚度对电容衰减和热行为的影响，提出了一个考虑反应动力学和固体电解质界面（SEI）层传质过程以及热演化的电容衰减模型。对7个不同电极厚度的LiFePO4电池进行了模拟。结果表明，随着电极厚度的增加，电池的容量损失恶化，总发热量增加。对于厚电极的电池，极化过电位和活性物质颗粒表面锂离子浓度梯度在边缘处增大，然后垂直于阴极方向减小。在绝热条件下，电池（阳极68 μm，阴极140 μm）的温度在第六次循环时升高到130 °C以上。电池的温度在放电开始时下降，然后上升，这对于具有薄电极的电池是明显的。所提出的模型和仿真结果将为电池的设计和运行提供深入的见解。
Capacity is one of the key parameters to characterize the performances of lithium-ion batteries. Heat generation analysis is essential to evaluate the safety of batteries. To figure out the effects of electrode thickness on capacity fade and thermal behaviors, a capacity fading model is proposed considering reaction kinetics and mass transfer processes on solid electrolyte interface (SEI) layers coupled with thermal evolution. Simulations are conducted on seven LiFePO4batteries with variable electrode thicknesses. Results show that, with the increase of electrode thickness, the capacity losses of batteries deteriorate, and the total heat generation aggravates. For the battery with thick electrode, both the polarization overpotential and the gradient of lithium ion concentrations on particle surfaces of active materials increase on the edges, and then decrease perpendicularly to the cathodes. Under the adiabatic conditions, the temperature of battery (with anode 68 μm and cathode 140 μm) is increased to over 130 °C at the sixth cycle. The temperature of batteries declines when discharging in the beginning and then rises, which is noticeable for the batteries with thin electrodes. The proposed model and the simulation results would provide deep insights into both design and operation of batteries.