《Lifecycle Synergistic Prelithiation Strategy of Both Anode and Cathode for High-Performance Lithium-Ion Batteries》

Lithium-ion batteries (LIBs) encounter significant challenges due to considerable consumption of active lithium during solid electrolyte interphase (SEI) formation and following cycling, which lower their specific energy density and lifespan. Prelithiation is recognized as an effective technology for addressing the depletion of active lithium, but conventional methods are constrained by their reliance on singular lithium replenishment mechanisms and limited functionality. Herein, we introduce a synergistic and comprehensive lifecycle prelithiation technology applicable to both anode and cathode. For anode prelithiation, highly reactive biphenyl lithium (Bp-Li) is leveraged as a lithium replenishing agent, supplemented by functional additives, ethoxy(pentafluoro)cyclotriphosphazene (PFPN) and fluoroethylene carbonate (FEC), to generate a robust SEI enriched with Li₃N, LiF, Li₃P and Li₂O. This approach not only compensates for the initial loss of active lithium but also fortifies the structural integrity of the SEI. For cathode prelithiation, the high-capacity lithium replenisher Li₂C₂O₄ and Li₂C₄O₄ comprising B, N double-doped carbon loaded Mo₂C-W₂C (Mo-W@BNC) heterogeneous catalysts is employed, which exhibits superior catalytic performance in facilitating the release of lithium from Li₂C₂O₄ and Li₂C₄O₄. The exceptional efficient liberations of lithium are achieved at discharge voltages of 3.78 V and 4.14 V for Li₂C₄O₄ and Li₂C₂O₄, respectively. The prelithiation for both anode and cathode mitigates the initial active lithium loss by 22.6% and enhances the initial coulombic efficiency to 97.3%. Moreover, a singular activation during subsequent usage contributes an additional 0.8 mAh cm⁻² of active lithium, achieving a remarkable capacity retention of 99.3% after 250 cycles at 0.5C. This synergistic prelithiation strategy enhances batteries’ specific energy and cycling, laying a substantial foundation for further enhancing performance of LIBs.