Preparing both safe and high-performance lithium-ion batteries(LIBs) based on commonly used commercial electrolytes is highly desirable,yet challenging.To overcome the poor compatibility of conventional small-molecula...Preparing both safe and high-performance lithium-ion batteries(LIBs) based on commonly used commercial electrolytes is highly desirable,yet challenging.To overcome the poor compatibility of conventional small-molecular flame-retardants as electrolyte additives for safe LIBs with graphite anodes,in this study,we propose and design a novel low-cost flame-retardant oligomer that achieves an accurate and complete reconciliation of fire safety and electrochemical performance in LIBs.Owing to the integration of phosphonate units and polyethylene glycol(PEG) chains,this oligomer,which is a phosphonatecontaining PEG-based oligomer(PPO),not only endows commercial electrolytes with excellent flame retardancy but also helps stabilize the electrodes and Li-ion migration.Specifically,adding 15 wt% of PPO can reduce 70% of the self-extinguishing time and 54% of total heat release for commercial electrolytes.Moreover,LiFePO_(4)/lithium and graphite/lithium cells as well as LiFePO_(4)/graphite pouch full cells exhibit good long-term cycling stability.展开更多
The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid elect...The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid electrolytes to severally adjust the solvation structure of lithium ions, control the components of solid electrolyte interphase, or reduce flammability. While it is highly desirable to develop low-cost multifunctional electrolyte additives integrally that address both safety and performance on LIBs, significant challenges remain. Herein, a novel phosphorus-containing organic small molecule, bis(2-methoxyethyl) methylphosphonate(BMOP), was rationally designed to serve as a fluorine-free and multifunctional additive in commercial electrolytes. This novel electrolyte additive is low-toxicity,high-efficiency, low-cost, and electrode-compatible, which shows the significant improvement to both electrochemical performance and fire safety for LIBs through regulating the electrolyte solvation structure, constructing the stable electrode-electrolyte interphase, and suppressing the electrolyte combustion. This work provides a new avenue for developing safer and high-performance LIBs.展开更多
基金supported by the National Natural Science Foundation of China (51773134, U19A2095)the Sichuan Science and Technology Program (2019YFH0112)+2 种基金the Fundamental Research Funds for the Central UniversitiesInstitutional Research Fund from Sichuan University (2021SCUNL201)the 111 Project (B20001)。
文摘Preparing both safe and high-performance lithium-ion batteries(LIBs) based on commonly used commercial electrolytes is highly desirable,yet challenging.To overcome the poor compatibility of conventional small-molecular flame-retardants as electrolyte additives for safe LIBs with graphite anodes,in this study,we propose and design a novel low-cost flame-retardant oligomer that achieves an accurate and complete reconciliation of fire safety and electrochemical performance in LIBs.Owing to the integration of phosphonate units and polyethylene glycol(PEG) chains,this oligomer,which is a phosphonatecontaining PEG-based oligomer(PPO),not only endows commercial electrolytes with excellent flame retardancy but also helps stabilize the electrodes and Li-ion migration.Specifically,adding 15 wt% of PPO can reduce 70% of the self-extinguishing time and 54% of total heat release for commercial electrolytes.Moreover,LiFePO_(4)/lithium and graphite/lithium cells as well as LiFePO_(4)/graphite pouch full cells exhibit good long-term cycling stability.
基金supported by the National Natural Science Foundation of China (51773134)the Sichuan Science and Technology Program (2019YFH0112)+2 种基金the Fundamental Research Funds for the Central UniversitiesInstitutional Research Fund from Sichuan University (2021SCUNL201)the 111 Project (B20001)。
文摘The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid electrolytes to severally adjust the solvation structure of lithium ions, control the components of solid electrolyte interphase, or reduce flammability. While it is highly desirable to develop low-cost multifunctional electrolyte additives integrally that address both safety and performance on LIBs, significant challenges remain. Herein, a novel phosphorus-containing organic small molecule, bis(2-methoxyethyl) methylphosphonate(BMOP), was rationally designed to serve as a fluorine-free and multifunctional additive in commercial electrolytes. This novel electrolyte additive is low-toxicity,high-efficiency, low-cost, and electrode-compatible, which shows the significant improvement to both electrochemical performance and fire safety for LIBs through regulating the electrolyte solvation structure, constructing the stable electrode-electrolyte interphase, and suppressing the electrolyte combustion. This work provides a new avenue for developing safer and high-performance LIBs.