A Facile and Efficient Chemical Prelithiation of Graphite for Full Capacity Utilization of Li-Ion Batteries

Chemical prelithiation is considered to be a facile and efficient strategy to compensate the initial irreversible capacity loss of anode materials for achieving full capacity utilization of Li-ion batteries (LIBs). However, most of the prelithiation reagents reported so far are difficult to apply for commercially used graphite (Gr) anode due to their higher redox potentials than the formation potential of graphite–lithium compounds and the co-intercalation behavior in the interlayers of Gr anode, causing the exfoliation and destruction of Gr structure during prelithiation process. Herein, a new prelithiation solution for Gr anode by using lithium naphthalenide as a lithiation reagent and 2-methyl tetrahydrofuran as a reduction-tolerant solvent is demonstrated. This prelithiation solution has a very low redox potential of 0.19 V and can controllably and efficiently prelithiate Gr anode to a required degree in a few minutes without the solvent co-intercalation. Benefiting from these advantages, the Gr anode prelithiated for 3 min exhibits a high initial Coulombic efficiency of 100%, a better rate capability, and higher cycling capacity retention than conventional pristine Gr anode. Particularly, this prelithiation solution is low cost, easily synthesized, and recycled for industrial production, thus offering a practical convenience for LIBs manufacture.