The unstable interfaces between a SnO_(2)anode and an electrolyte in a Li-ion battery dramatically impair the reversibility and cycling stability of lithiation and delithiation,resulting in low roundtrip Coulombic eff...The unstable interfaces between a SnO_(2)anode and an electrolyte in a Li-ion battery dramatically impair the reversibility and cycling stability of lithiation and delithiation,resulting in low roundtrip Coulombic efficiency(CE)and fast capacity decay of SnO_(2)-based anode materials.Herein,a simple strategy of modifying the solid electrolyte interphase(SEI)is developed to enhance the interfacial stability and lithium storage reversibility of SnO_(2)by compositing it with graphite(G)and an inorganic component of the SEI,such as Li_(2)CO_(3)or LiF,which results in the SnO_(2)-Li_(2)CO_(3)/G and SnO_(2)-LiF/G composite anodes with high CEs,large capacities and long cycle lives.Specifically,the SnO_(2)-Li_(2)CO_(3)/G composite anode exhibits an average initial CE of 79.6%,a stable reversible capacity of 927.5 mA hg^(-1)at a current rate of 0.2 A g^(-1),and a charge capacity over 1200 mA hg^(-1)with a CE>99%after 900 cycles at a higher current rate of 1 A g^(-1).It is revealed that Li_(2)CO_(3)induces the formation of a dense and stable SEI on SnO_(2)grains and inhibits the coarsening of nanosized Sn particles generated from the dealloying reaction in the SnO_(2)-Li_(2)CO_(3)/G electrode.Moreover,the CE and cycling stability of other alloying-type(Si)and conversion reaction(MnO_(2)and Fe_(3)O_(4))anodes can also be greatly promoted by simply milling with Li_(2)CO_(3).Thus,a universal and simple strategy is developed to achieve highly reversible and stable electrodes for large-capacity lithium storage.展开更多
基金the National Natural Science Foundation of China(52071144,51621001,51822104 and 51831009)。
文摘The unstable interfaces between a SnO_(2)anode and an electrolyte in a Li-ion battery dramatically impair the reversibility and cycling stability of lithiation and delithiation,resulting in low roundtrip Coulombic efficiency(CE)and fast capacity decay of SnO_(2)-based anode materials.Herein,a simple strategy of modifying the solid electrolyte interphase(SEI)is developed to enhance the interfacial stability and lithium storage reversibility of SnO_(2)by compositing it with graphite(G)and an inorganic component of the SEI,such as Li_(2)CO_(3)or LiF,which results in the SnO_(2)-Li_(2)CO_(3)/G and SnO_(2)-LiF/G composite anodes with high CEs,large capacities and long cycle lives.Specifically,the SnO_(2)-Li_(2)CO_(3)/G composite anode exhibits an average initial CE of 79.6%,a stable reversible capacity of 927.5 mA hg^(-1)at a current rate of 0.2 A g^(-1),and a charge capacity over 1200 mA hg^(-1)with a CE>99%after 900 cycles at a higher current rate of 1 A g^(-1).It is revealed that Li_(2)CO_(3)induces the formation of a dense and stable SEI on SnO_(2)grains and inhibits the coarsening of nanosized Sn particles generated from the dealloying reaction in the SnO_(2)-Li_(2)CO_(3)/G electrode.Moreover,the CE and cycling stability of other alloying-type(Si)and conversion reaction(MnO_(2)and Fe_(3)O_(4))anodes can also be greatly promoted by simply milling with Li_(2)CO_(3).Thus,a universal and simple strategy is developed to achieve highly reversible and stable electrodes for large-capacity lithium storage.
