Lithium Difluorophosphate as a Widely Applicable Additive to Boost Lithium-Ion Batteries: a Perspective

Lithium difluorophosphate (LiDFP) is among the most widely applicable additives used to construct a robust solid electrolyte interphase (SEI) on electrode, which can improve the cycling performance and rate performance of high-voltage cathodes and Li metal anodes at extreme temperatures. Regarding the working mechanism of LiDFP, reasonable but divided understandings have been proposed based on specific battery chemistry. Herein, the broad applications of LiDFP in various electrochemical systems are reviewed and a universal working mechanism based on the state-of-the-art understanding of LiDFP is offered. Then, future directions of the missing part in mechanism comprehension are highlighted. Furthermore, the approaches to effectively apply LiDFP and other similar additives according to their limits are summarized. Finally, questions regarding the missing part of the mechanism are discussed by which LiDFP forms a robust SEI and how these lead to opportunities for future understanding and promotion of interfacial passivation. This study not only provides new knowledge on the mechanism of LiDFP and other existing additives but also helps inspire more effective additive applications.

Automated summary

Lithium difluorophosphate (LiDFP) is widely used as an additive to improve the performance of high-voltage cathodes and Li metal anodes. This article reviews its applications and proposes a universal working mechanism based on the current understanding. Future directions for further comprehension and effective application strategies are discussed. This study provides new knowledge and inspires more effective additive applications.