Lithium Oxalate as a Cathode Prelithiation Additive for Lithium-Ion Batteries

Lithium-ion batteries (LIBs), as the most representative energy storage devices, have become deeply integrated into our daily lives. However, the formation of solid electrolyte interphase during the initial cycle consumes a substantial amount of lithium ions (Li⁺). Moreover, the continuous consumption of Li⁺ in subsequent cycles further shortens the lifespan of LIBs. To compensate for this irreversible lithium loss, prelithiation technology has attracted substantial attention in recent years and is now recognized as an effective strategy to boost battery performance. Among various prelithiation additives, lithium oxalate (Li₂C₂O₄) stands out as a particularly attractive cathode prelithiation additive, owing to its low cost, excellent air stability, and the absence of solid residual by-products. To date, no systematic review has focused exclusively on Li₂C₂O₄ as a prelithiation additive. In this review, we present a comprehensive overview of the research progress on Li₂C₂O₄, focusing on three critical aspects: delithiation mechanism, modification strategies, and application methods. Furthermore, we discuss future directions and prospects for Li₂C₂O₄, aiming to offer guidance for subsequent research in this field.