Zhang Xiaoxiao, Qu Huainan, Ji Weixiao, Zheng Dong, Ding Tianyao, Abegglen Caleb, Qiu Dantong, Qu Deyang
Department of Mechanical Engineering, College of Engineering and Applied Science, University of Wisconsin Milwaukee, Milwaukee, Wisconsin 53211, United States.
ACS Appl Mater Interfaces. 2020 Mar 11;12(10):11589-11599. doi: 10.1021/acsami.9b21417. Epub 2020 Feb 26.
Hard carbon has been extensively investigated as anode materials for high-energy lithium-ion batteries owing to its high capacity, long cycle life, good rate capability, and low cost of production. However, it suffers from a large irreversible capacity and thus low initial coulombic efficiency (ICE), which hinders its commercial use. Here, we developed a fast and controllable prelithiation method based on a chemical reaction using a lithium-containing reagent (1 M lithium biphenylide dissolved in tetrahydrofuran). The prelithiation extent can be easily controlled by tuning the reaction time. An SEI layer is formed during chemical prelithiation, and the ICE of prelithiated hard carbon in half-cell format can be increased to ∼106% in 30 s. When matched with a LiNiCoMnO cathode, the full cell with the prelithiated hard carbon anode exhibits a much improved ICE (90.2 vs 75%) and cycling performance than those of the pristine full cell. This facile prelithiation method is proved to be a practical solution for the commercial application of hard carbon materials.
由于具有高容量、长循环寿命、良好的倍率性能和低成本等优点，硬碳作为高能锂离子电池的负极材料已得到广泛研究。然而，它存在较大的不可逆容量，因此初始库仑效率（ICE）较低，这阻碍了其商业应用。在此，我们基于使用含锂试剂（1 M联苯锂溶解在四氢呋喃中）的化学反应开发了一种快速且可控的预锂化方法。通过调整反应时间可以轻松控制预锂化程度。在化学预锂化过程中会形成一个固体电解质界面（SEI）层，预锂化硬碳半电池形式的ICE在30秒内可提高到约106%。当与LiNiCoMnO正极匹配时，具有预锂化硬碳负极的全电池相比原始全电池展现出显著提高的ICE（90.2%对75%）和循环性能。这种简便的预锂化方法被证明是硬碳材料商业应用的一种实用解决方案。
