Li-rich layered oxide cathodes have received considerable attention because of the high operating potential and specific capacity. However, the structural instability and parasitic reactions at high potential cause se...Li-rich layered oxide cathodes have received considerable attention because of the high operating potential and specific capacity. However, the structural instability and parasitic reactions at high potential cause severe degradation of the electrochemical performance. In our studies, the cycling stability of Li_(1.14)Ni_(0.133)Co_(0.133)Mn_(0.544)O_(2) cathode is improved with LiPO_(2)F_(2) electrolyte additive. After 500 cycles, the capacity retention is increased from 53.6% to 85% at 3 C by LiPO_(2)F_(2) modification. This performance is mainly attributed to the enhanced interfacial stability of the Li-rich cathode. Based on systematic characterization, LiPO_(2)F_(2) additive was found to promote a stable interface film on the cathode surface during the cycling and mitigates the interfacial side reactions. This study provides new insights for improving high-potential Li-rich layered oxide batteries.展开更多
Constructing a reliable and favorable electrode-electrolyte interface is crucial to utilize the exceptional energy storage capability in commercial lithium-ion batteries.Here,we report a facile synthesis approach for ...Constructing a reliable and favorable electrode-electrolyte interface is crucial to utilize the exceptional energy storage capability in commercial lithium-ion batteries.Here,we report a facile synthesis approach for the lithium difluorophosphate(LiPO_(2)F_(2))solution as an effective film-forming additive via direct adding the Li_(2)CO_(3) into LiPF6 solution at 45℃.Benefiting from the significantly reduced interface resistance(RSEI)and charge transfer impedance(Rct)of both the cathode and anode by adding the prepared LiPO_(2)F_(2)solution into a baseline electrolyte,the cycling performance of the graphite||LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2) pouch cell is remarkably improved under all-climate condition.展开更多
基金supported partially by the Natural Science Foundation of Beijing Municipality (L172036)the Joint Funds of the Equipment Pre-Research and Ministry of Education (6141A020225)+2 种基金the National Natural Science Foundation of China (Grants Nos. 52072323 and 51872098)the Science and Technology Beijing 100 Leading Talent Training Projectthe NCEPU ‘‘Double First-Class” Program. We thank Dr. Rui Liu for suggestions on the crystal structure analysis。
文摘Li-rich layered oxide cathodes have received considerable attention because of the high operating potential and specific capacity. However, the structural instability and parasitic reactions at high potential cause severe degradation of the electrochemical performance. In our studies, the cycling stability of Li_(1.14)Ni_(0.133)Co_(0.133)Mn_(0.544)O_(2) cathode is improved with LiPO_(2)F_(2) electrolyte additive. After 500 cycles, the capacity retention is increased from 53.6% to 85% at 3 C by LiPO_(2)F_(2) modification. This performance is mainly attributed to the enhanced interfacial stability of the Li-rich cathode. Based on systematic characterization, LiPO_(2)F_(2) additive was found to promote a stable interface film on the cathode surface during the cycling and mitigates the interfacial side reactions. This study provides new insights for improving high-potential Li-rich layered oxide batteries.
基金National Natural Science Foundation of China(Nos.21935009,21761132030 and 21621091)National Key Research and Development Program of China(No.2018YFB0905400)the Doctoral Research Foundation of Binzhou University(No.2016Y06)。
文摘Constructing a reliable and favorable electrode-electrolyte interface is crucial to utilize the exceptional energy storage capability in commercial lithium-ion batteries.Here,we report a facile synthesis approach for the lithium difluorophosphate(LiPO_(2)F_(2))solution as an effective film-forming additive via direct adding the Li_(2)CO_(3) into LiPF6 solution at 45℃.Benefiting from the significantly reduced interface resistance(RSEI)and charge transfer impedance(Rct)of both the cathode and anode by adding the prepared LiPO_(2)F_(2)solution into a baseline electrolyte,the cycling performance of the graphite||LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2) pouch cell is remarkably improved under all-climate condition.
