摘要
锂离子电池尽管已成为便携式电子设备的主流电源,也是电动汽车、混合动力汽车等电源的主要选择之一,但依然存在使用过程中因形成锂枝晶而发生内短路的安全隐患。本文设计了一个宏微观实验研究商业用锂离子电池电极材料的充放电循环性能。在常温小电流充放电条件下,实时原位地观测锂枝晶的产生、生长、消融以及死锂残留等过程。实验结果揭示了锂枝晶不仅仅只是大电流过充或低温充电状态下的产物,常温常态小电流充电条件下依然能够生成锂枝晶。实验发现:锂枝晶出现在充电后期,随后直线伸长,尖端区域形貌保持不变;放电时,锂枝晶逐渐消融,尖端区域形貌依然不变,放电结束后电极上有死锂残留。
Lithium-ion batteries （LIBs） are the state-of-the-art power sources for portable electronic devices. Furthermore, LIBs have now emerged as the most promising power source for electric vehicles, hybrid vehicles and plug-in hybrid vehicles. LIBs have some safety problems, such as the formation of lithium dendrite which can cause internal short-circuiting. In this paper, the cyclic performance of electrode in commercial lithium-ion battery is studied with a macro-micro experiment. Electrochemical experiment is carried at room temperature with small current G and the generation, growth, dissolution and residue of lithium dendrite are observed. It reveals that lithium dendrite can be formed not only under large-current overcharge or low-temperature charge but also under small current and at room temperaatre. It has been found that lithium dendrite appears in the late charge, stretching straightly, and its tip topography remains unchanged. Lithium dendrite begins dissolving when discharge, whose tip morphology still unchanged, and dead lithium residues on the electrode after fully discharge.
出处
《储能科学与技术》
CAS
2015年第1期66-71,共6页
Energy Storage Science and Technology
基金
国家自然科学基金(11472165
11332005)
上海市自然科学基金(12ZR1410200)项目
关键词
锂离子电池
原位实时观测
锂枝晶
死锂
lithium-ion battery： in situ observation： lithium dendrite： dead lithium
