The demand for high safety and high reliability lithium-ion batteries(LIBs)is strongly considered for practical applications.However,due to their inherent self-discharge properties or abuse,LIBs face the threat of ove...The demand for high safety and high reliability lithium-ion batteries(LIBs)is strongly considered for practical applications.However,due to their inherent self-discharge properties or abuse,LIBs face the threat of over-discharge,which induces premature end of life and increased risk of thermal runaway.In addition,a strong demand for batteries with zero-volt storage is strongly considered for aerospace and implantable medical devices.In this review,we firstly introduce the necessity and the importance of over-discharge and zero-volt protection for LIBs.The mechanism of damage to the Cu current collectors and SEI induced by potential changes during over-discharge is presented.The current over-discharge protection strategies based on whether the zero-crossing potential of the electrodes is summarized.Finally,the fresh insights into the material design of cathode prelithiation additives are presented from the perspective of over-discharge protection.展开更多
The understanding of reaction mechanisms of electrode materials is of significant importance for the development of advanced batteries.The LiMn2O4 cathode has a voltage plateau around 2.8 V(vs.Li^+/Li),which can provi...The understanding of reaction mechanisms of electrode materials is of significant importance for the development of advanced batteries.The LiMn2O4 cathode has a voltage plateau around 2.8 V(vs.Li^+/Li),which can provide an additional capacity for Li storage,but it suffers from a severe capacity degradation.In this study,operando X-ray diffraction is carried out to investigate the structural evolutions and degradation mechanisms of LiMn2O4 in different voltage ranges.In the range of 3.0-4.3 V(vs.Li^+/Li),the LiMn2O4 cathode exhibits a low capacity but good cycling stability with cycles up to 100 cycles and the charge/discharge processes are associated with the reversible extraction/insertion of Li^+from/into LixMn2O4(0≤x≤1).In the range of 1.4-4.4 V(vs.Li^+/Li),a capacity higher than 200 mAh/g is achieved,but it rapidly decays during the cycling.The voltage plateau around 2.8 V(vs.Li^+/Li)is related to the transformation of the cubic LiMn2O4 phase to the tetragonal Li2Mn2O4 phase,which leads to the formation of cracks as well as the performance degradation.展开更多
基金supported by the Beijing Natural Science Foundation(L233004)National Natural Science Foundation of China(62071274 and 22393900)+2 种基金National Key Research and Development Program of China(2021YFB2400300)Shuimu Tsinghua Scholar ProgramTsinghua University Initiative Scientific Research Program.
文摘The demand for high safety and high reliability lithium-ion batteries(LIBs)is strongly considered for practical applications.However,due to their inherent self-discharge properties or abuse,LIBs face the threat of over-discharge,which induces premature end of life and increased risk of thermal runaway.In addition,a strong demand for batteries with zero-volt storage is strongly considered for aerospace and implantable medical devices.In this review,we firstly introduce the necessity and the importance of over-discharge and zero-volt protection for LIBs.The mechanism of damage to the Cu current collectors and SEI induced by potential changes during over-discharge is presented.The current over-discharge protection strategies based on whether the zero-crossing potential of the electrodes is summarized.Finally,the fresh insights into the material design of cathode prelithiation additives are presented from the perspective of over-discharge protection.
基金the financial support by the National Natural Science Foundation of China (51871133, 51671115)support by the Department of Science and Technology of the Shandong Province for the Young Tip-Top Talent Support Project.
文摘The understanding of reaction mechanisms of electrode materials is of significant importance for the development of advanced batteries.The LiMn2O4 cathode has a voltage plateau around 2.8 V(vs.Li^+/Li),which can provide an additional capacity for Li storage,but it suffers from a severe capacity degradation.In this study,operando X-ray diffraction is carried out to investigate the structural evolutions and degradation mechanisms of LiMn2O4 in different voltage ranges.In the range of 3.0-4.3 V(vs.Li^+/Li),the LiMn2O4 cathode exhibits a low capacity but good cycling stability with cycles up to 100 cycles and the charge/discharge processes are associated with the reversible extraction/insertion of Li^+from/into LixMn2O4(0≤x≤1).In the range of 1.4-4.4 V(vs.Li^+/Li),a capacity higher than 200 mAh/g is achieved,but it rapidly decays during the cycling.The voltage plateau around 2.8 V(vs.Li^+/Li)is related to the transformation of the cubic LiMn2O4 phase to the tetragonal Li2Mn2O4 phase,which leads to the formation of cracks as well as the performance degradation.
