In conjunction with electrolyte additives used for tuning the interfacial structures of electrodes, functional materials that eliminate or deactivate reactive substances generated by the degradation of LiPF6‐containing electrolytes in lithium‐ion batteries offer a wide range of electrolyte formulation opportunities. Herein, the recent advancements in the development of: (i) scavengers with high selectivity and affinity toward unwanted species and (ii) promoters of ion‐paired LiPF6 dissociation are highlighted, showing that the utilization of the above additives can effectively mitigate the problem of electrolyte instability that commonly results in battery performance degradation and lifetime shortening. A deep mechanistic understanding of LiPF6‐containing electrolyte failure and the action of currently developed additives is demonstrated to enable the rational design of effective scavenging materials and thus allow the fabrication of highly reliable batteries.