期刊
JOURNAL OF ENERGY STORAGE
卷 28, 期 -, 页码 -出版社
ELSEVIER
DOI: 10.1016/j.est.2020.101268
关键词
Full-cell lithium-ion batteries; Porous silicon/carbon composite anode; Lithium-iron phosphate cathode; Prelithiation; Precycling
资金
- Ford Motor Company University Research Program (URP)
Silicon-based composites are considered a promising anode for lithium-ion batteries (LIBs) due to their high theoretical capacity of 3579 mAh/g at room temperature. However, when paired with conventional cathode materials, silicon-based full-cells perform poorly due to an unbalanced capacity ratio (N/P ratio) between the anode and the cathode. Their performance is further diminished by the irreversible Li+ losses in the siliconbased anode associated with the continuous volume expansion during cycling. To address these issues, we implement various N/P ratios and cycling strategies in a silicon-based anode and track the occurrence of lithium plating. A porous silicon-carbon (PSi-C) based composite anode is paired with a lithium-iron phosphate (LFP) cathode to investigate the effects of different N/P ratios in full-cell batteries. Based on these results, the optimal N/P ratio is tested using a three-electrode cell to monitor the anode and cathode voltages (versus reference electrode, Li) simultaneously in full-cell cycling and to detect lithium plating. Contrary to expectation, no lithium plating is observed at the optimized N/P ratio of 0.8. Finally, prelithiation strategies, such as contact treatment on the PSi-C anode with Li metal and precycling of the PSi-C anode against a lithium foil counter electrode, are performed to compensate for the initial lithium losses. When the PSi-C anode is cycled 5.5 times (5 full cycles and follow by 1 lithiation process) against lithium metal and then assembled with an oversized LFP cathode, the full-cell battery achieves 1000 mAh/(g-anode) for over 500 cycles. These results further validate the use of silicon-based anodes in full-cell LIBs by providing new assembly strategies and techniques to significantly improve stability and cycling performance.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据