리튬이온전지의 고성능화를 위한 반응성 화합물 제거형 전해액 첨가제

Abstract

Enhancing the performance of lithium-ion batteries (LIBs) is of paramount importance to widely leverage LIBs in a variety of industries from electronic mobile devices to grid/utility energy storage systems and electric vehicles.1,2 However, conventional LIBs exhibit rather limited long-term cycling lifetimes, which can be increased by structural and compositional tuning of the corresponding electrode materials and electrolytes. In conjunction with electrolyte additives used for tuning the interfacial structures of electrodes, functional materials that eliminate or de-activate reactive substances generated by the degradation of LiPF6-containing electrolytes in lithium-ion batteries offer a wide range of electrolyte formulation opportunities. Herein, we highlight 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, 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.