Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Accelerated aging and degradation mechanism of LiFePO4/graphite batteries cycled at high discharge rates†
RSC Advances ( IF 3.9 ) Pub Date : 2018-07-18 00:00:00 , DOI: 10.1039/c8ra04074e Shun Sun 1 , Ting Guan 1 , Xinqun Cheng 1 , Pengjian Zuo 1 , Yunzhi Gao 1 , Chunyu Du 1 , Geping Yin 1
RSC Advances ( IF 3.9 ) Pub Date : 2018-07-18 00:00:00 , DOI: 10.1039/c8ra04074e Shun Sun 1 , Ting Guan 1 , Xinqun Cheng 1 , Pengjian Zuo 1 , Yunzhi Gao 1 , Chunyu Du 1 , Geping Yin 1
Affiliation
|
The effects of discharge rates (0.5C, 1.0C, 2.0C, 3.0C, 4.0C and 5.0C) on the aging of LiFePO4/graphite full cells are researched by disassembling the fresh and aged full cells. The capacity degradation mechanism is analyzed via electrochemical performance, surface morphologies and compositions, and the structure of the anode and cathode electrodes. The capacity fade is accelerated with increasing discharge rates. The irreversible loss of active lithium due to the generation of an SEI film is the primary aging factor for the full cells cycled at low discharge rates. However, when the discharge rate is greater than or equal to 4.0C, the performance degradation of the LiFePO4 electrode is distinct due to structure decay, which is caused by quick and repeated intercalation of lithium ions and elevated temperature during discharging. In addition, the SEI film on the anode tends to be unstable after the rapid extraction of lithium ions at high discharge rates, and this enhances the loss of active lithium. Therefore, it is indicated that the degradation mechanism is changed for the full cells aged at 4.0C and 5.0C. Besides, the high discharge rate also increases the internal resistance of the full cell, which is detrimental to high rate discharge performance.
中文翻译：
高放电率循环的 LiFePO4/石墨电池的加速老化和降解机制†
通过拆解新鲜和老化全电池，研究了放电倍率（0.5C、1.0C、2.0C、3.0C、4.0C和5.0C）对LiFePO 4 /石墨全电池老化的影响。通过电化学性能、表面形貌和成分以及阳极和阴极电极的结构来分析容量退化机制。随着放电率的增加，容量衰减加速。由于SEI膜的生成而导致的活性锂的不可逆损失是低放电率循环的全电池的主要老化因素。然而，当放电倍率大于或等于4.0C时，LiFePO 4电极由于结构衰减而性能下降明显，这是由锂离子快速反复嵌入和放电过程中温度升高引起的。此外，在高放电倍率下快速脱嵌锂离子后，阳极上的SEI膜往往不稳定，这会增加活性锂的损失。因此，表明在4.0C和5.0C老化的全电池的降解机制发生了变化。此外，高倍率放电还会增加全电池的内阻，不利于高倍率放电性能。
更新日期：2018-07-18
中文翻译：
高放电率循环的 LiFePO4/石墨电池的加速老化和降解机制†
通过拆解新鲜和老化全电池，研究了放电倍率（0.5C、1.0C、2.0C、3.0C、4.0C和5.0C）对LiFePO 4 /石墨全电池老化的影响。通过电化学性能、表面形貌和成分以及阳极和阴极电极的结构来分析容量退化机制。随着放电率的增加，容量衰减加速。由于SEI膜的生成而导致的活性锂的不可逆损失是低放电率循环的全电池的主要老化因素。然而，当放电倍率大于或等于4.0C时，LiFePO 4电极由于结构衰减而性能下降明显，这是由锂离子快速反复嵌入和放电过程中温度升高引起的。此外，在高放电倍率下快速脱嵌锂离子后，阳极上的SEI膜往往不稳定，这会增加活性锂的损失。因此，表明在4.0C和5.0C老化的全电池的降解机制发生了变化。此外，高倍率放电还会增加全电池的内阻，不利于高倍率放电性能。
京公网安备 11010802027423号