Synergistic enhancement of capacity and cycle life via an activated bifunctional prelithiation strategy for advanced lithium-ion batteries

During the initial charging process, lithium-ion batteries suffer from active lithium loss, which leads to a reduction in both the initial Coulombic efficiency and reversible capacity. Prelithiation emerges as an effective strategy to address this issue and enhance the energy density of these batteries. Nevertheless, conventional prelithiation agents, particularly lithium metal foil and highly reactive lithium compounds, are often limited by poor environmental stability and potential safety concerns, which significantly impede their practical application. This work reports the development and investigation of novel cathode prelithiation materials, Li₆Zn_0.8M_0.2O₄ (M = Fe, Ni, Co and Mn). The delithiation capacity of Li₆ZnO₄ was successfully activated by the introduction of Co and Mn ions. Notably, Li₆Zn_0.8Co_0.2O₄ delivers an initial charging capacity of 722.7 mAh g^–1 and a lithium-supplement capacity of 714.2 mAh g^–1, while Li₆Zn_0.8Mn_0.2O₄ achieves 725.2 and 717.9 mAh g^–1, respectively, demonstrating excellent electrochemical performance and application potential. Further systematic evaluation within coin full-cell configurations, utilizing both Si/C and graphite anodes, confirms that the incorporation of Li₆Zn_0.8Co_0.2O₄ and Li₆Zn_0.8Mn_0.2O₄ leads to a marked improvement in both initial discharge capacity and capacity retention. This study not only provides a new direction for designing and optimizing prelithiation agents but also offers valuable insights for developing high-performance lithium-ion batteries.