Li Chengfeng, Deng Yingkang, Wang Kang, Li Shuli, Meng Xiangyu, Chen Min, Liao Youhao, Xing Lidan, Xu M Q, Li Weishan
School of Chemistry, National and Local Joint Engineering Research Center of MPTES in High Energy and Safety LIBs, Engineering Research Center of MTEES (Ministry of Education), and Key Laboratory of ETESPG (GHEI), South China Normal University, Guangzhou, Guangdong 510006, People's Republic of China.
Guangzhou Great Power Energy & Technology Company, Limited, Guangzhou, Guangdong 511483, People's Republic of China.
J Phys Chem Lett. 2024 Sep 5;15(35):9105-9112. doi: 10.1021/acs.jpclett.4c01891. Epub 2024 Aug 28.
Prelithiation in a graphite anode is widely considered as an effective strategy to compensate for the lithium loss due to the formation of the solid electrolyte interphase (SEI), thus improving the cycle life of lithium-ion batteries (LIBs). However, less attention has been paid to the difference of the SEI established by prelithiation from that resulting from the charging process. To address this issue, a prelithiated graphite anode is prepared by thermal contact and its performances are investigated by electrochemical measurements and spectral characterizations. It is found that the significantly improved initial coulombic efficiency (ICE) and cyclic stability of the graphite anode by prelitiation are attributed to the formation of LiF-rich SEI. Different from the charging process that favors decomposition of solvents and results in a SEI mainly consisting of organic and inorganic carbonates, prelithiation is beneficial for the reduction of LiPF and results in a LiF-rich SEI that presents high stability and robustness, enabling the graphite anode with significantly improved cyclic stability.
石墨负极中的预锂化被广泛认为是一种有效的策略，可补偿由于固体电解质界面（SEI）形成而导致的锂损失，从而提高锂离子电池（LIB）的循环寿命。然而，人们较少关注预锂化形成的SEI与充电过程形成的SEI之间的差异。为了解决这个问题，通过热接触制备了预锂化石墨负极，并通过电化学测量和光谱表征对其性能进行了研究。研究发现，预锂化显著提高石墨负极的初始库仑效率（ICE）和循环稳定性，这归因于富含LiF的SEI的形成。与有利于溶剂分解并导致主要由有机和无机碳酸盐组成的SEI的充电过程不同，预锂化有利于LiPF的还原，并导致形成具有高稳定性和坚固性的富含LiF的SEI，使石墨负极的循环稳定性得到显著提高。
