TiNb_(2)O_(7)represents an up-and-coming anode material for fast-charging lithium-ion batteries,but its practicalities are severely impeded by slow transfer rates of ionic and electronic especially at the low-temperat...TiNb_(2)O_(7)represents an up-and-coming anode material for fast-charging lithium-ion batteries,but its practicalities are severely impeded by slow transfer rates of ionic and electronic especially at the low-temperature conditions.Herein,we introduce crystallographic engineering to enhance structure stability and promote Li+diffusion kinetics of TiNb_(2)O_(7)(TNO).The density functional theory computation reveals that Ti^(4+)is replaced by Sb^(5+)and Nb^(5+)in crystal lattices,which can reduce the Li+diffusion impediment and improve electronic conductivity.Synchrotron radiation X-ray 3D nano-computed tomography and in situ X-ray diffraction measurement confirm the introduction of Sb/Nb alleviates volume expansion during lithiation and delithiation processes,contributing to enhancing structure stability.Extended X-ray absorption fine structure spectra results verify that crystallographic engineering also increases short Nb-O bond length in TNO-Sb/Nb.Accordingly,the TNO-Sb/Nb anode delivers an outstanding capacity retention rate of 89.8%at 10 C after 700 cycles and excellent rate performance(140.4 mAh g^(−1) at 20 C).Even at−30℃,TNO-Sb/Nb anode delivers a capacity of 102.6 mAh g^(−1) with little capacity degeneration for 500 cycles.This work provides guidance for the design of fast-charging batteries at low-temperature condition.展开更多
基金supported by the National Natural Science Foundation of China(22279026,2247090373)the Natural Science Foundation of Chongqing(CSTB2022NSCQ-MSX1401)+2 种基金the China Postdoctoral Science Foundation(2024M764198)the National Natural Science Foundation of China(22509044)the Fundamental Research Funds for the Central Universities(grant no.HIT.OCEF.2022017).
文摘TiNb_(2)O_(7)represents an up-and-coming anode material for fast-charging lithium-ion batteries,but its practicalities are severely impeded by slow transfer rates of ionic and electronic especially at the low-temperature conditions.Herein,we introduce crystallographic engineering to enhance structure stability and promote Li+diffusion kinetics of TiNb_(2)O_(7)(TNO).The density functional theory computation reveals that Ti^(4+)is replaced by Sb^(5+)and Nb^(5+)in crystal lattices,which can reduce the Li+diffusion impediment and improve electronic conductivity.Synchrotron radiation X-ray 3D nano-computed tomography and in situ X-ray diffraction measurement confirm the introduction of Sb/Nb alleviates volume expansion during lithiation and delithiation processes,contributing to enhancing structure stability.Extended X-ray absorption fine structure spectra results verify that crystallographic engineering also increases short Nb-O bond length in TNO-Sb/Nb.Accordingly,the TNO-Sb/Nb anode delivers an outstanding capacity retention rate of 89.8%at 10 C after 700 cycles and excellent rate performance(140.4 mAh g^(−1) at 20 C).Even at−30℃,TNO-Sb/Nb anode delivers a capacity of 102.6 mAh g^(−1) with little capacity degeneration for 500 cycles.This work provides guidance for the design of fast-charging batteries at low-temperature condition.
