V_(3)O_(7)·H_(2)O(VO)is a high capacity cathode material in the field of aqueous zinc ion batteries(AZIBs),but it is limited by slow ion migration and low electrical conductivity.In this paper,polypyridine(PPyd)i...V_(3)O_(7)·H_(2)O(VO)is a high capacity cathode material in the field of aqueous zinc ion batteries(AZIBs),but it is limited by slow ion migration and low electrical conductivity.In this paper,polypyridine(PPyd)intercalated VO with nanoribbon structure was prepared by a simple in-situ pre-intercalation,which is noted VO-PPyd.The total density of states(TDOS)shows that after the pre-intercalation of PPyd,an intermediate energy level appears between the valence band and conduction band,which provides a step that can effectively reduce the band gap and enhance the electron conductivity.Furthermore,the density functional theory(DFT)results found that Zn^(2+)is more easily de-intercalated from the V-O skeleton,which proves that the embeddedness of PPyd improves the diffusion kinetics of Zn^(2+).Electrochemical studies have shown that VO-PPyd cathode materials exhibit excellent rate performance(high specific capacity of 465 and 192 mA h g^(-1)at 0.2 and 10 A g^(-1),respectively)and long-term cycling performance(92.7%capacity retention rate after 5300 cycles),due to their advantages in structure and composition.More importantly,the energy density of VO-PPyd//Zn at 581 and 5806 W kg^(-1)is 375 and 247 W h kg^(-1),respectively.VO-PPyd exhibits excellent electrochemical properties compared to previously reported vanadium based cathodes,which makes it highly competitive in the field of high-performance cathode materials of AZIBs.展开更多
采用改进的碳酸盐共沉淀与高温固相法相结合的方法制备出了高倍率性能的锂离子电池正极材料Li[Ni1/3Co1/3Mn1/3]O2,通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安扫描(CV)、电化学阻抗谱(EIS)和电化学性能测试等手段对材料进行表征.结...采用改进的碳酸盐共沉淀与高温固相法相结合的方法制备出了高倍率性能的锂离子电池正极材料Li[Ni1/3Co1/3Mn1/3]O2,通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安扫描(CV)、电化学阻抗谱(EIS)和电化学性能测试等手段对材料进行表征.结果表明,该方法制备的材料具有良好的α-Na Fe O2型层状结构(R3m(166)),一次粒径平均大小为157 nm,二次颗粒成球形.同传统碳酸盐制备得到的材料相比,该材料具备良好的倍率性能和循环性能,在2.7-4.3 V电压范围内,0.1C(1.0C=180 m A?g-1)倍率下,首次放电比容量为156.4m Ah?g-1,库仑效率为81.9%.在较高倍率下,即0.5C、5.0C和20C时,其放电比容量分别为136.9、111.3、81.3m Ah?g-1.在1C倍率下100次循环容量保持率为92.9%,高于传统共沉淀法得到的材料(87.0%).展开更多
基金supported by the National Natural Science Foundation of China (21676036)the Natural Science Foundation of Chongqing (CSTB2023NSCQ-MSX0580)the Graduate Research and Innovation Foundation of Chongqing (CYB22043 and CYS22073)。
文摘V_(3)O_(7)·H_(2)O(VO)is a high capacity cathode material in the field of aqueous zinc ion batteries(AZIBs),but it is limited by slow ion migration and low electrical conductivity.In this paper,polypyridine(PPyd)intercalated VO with nanoribbon structure was prepared by a simple in-situ pre-intercalation,which is noted VO-PPyd.The total density of states(TDOS)shows that after the pre-intercalation of PPyd,an intermediate energy level appears between the valence band and conduction band,which provides a step that can effectively reduce the band gap and enhance the electron conductivity.Furthermore,the density functional theory(DFT)results found that Zn^(2+)is more easily de-intercalated from the V-O skeleton,which proves that the embeddedness of PPyd improves the diffusion kinetics of Zn^(2+).Electrochemical studies have shown that VO-PPyd cathode materials exhibit excellent rate performance(high specific capacity of 465 and 192 mA h g^(-1)at 0.2 and 10 A g^(-1),respectively)and long-term cycling performance(92.7%capacity retention rate after 5300 cycles),due to their advantages in structure and composition.More importantly,the energy density of VO-PPyd//Zn at 581 and 5806 W kg^(-1)is 375 and 247 W h kg^(-1),respectively.VO-PPyd exhibits excellent electrochemical properties compared to previously reported vanadium based cathodes,which makes it highly competitive in the field of high-performance cathode materials of AZIBs.
文摘采用改进的碳酸盐共沉淀与高温固相法相结合的方法制备出了高倍率性能的锂离子电池正极材料Li[Ni1/3Co1/3Mn1/3]O2,通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安扫描(CV)、电化学阻抗谱(EIS)和电化学性能测试等手段对材料进行表征.结果表明,该方法制备的材料具有良好的α-Na Fe O2型层状结构(R3m(166)),一次粒径平均大小为157 nm,二次颗粒成球形.同传统碳酸盐制备得到的材料相比,该材料具备良好的倍率性能和循环性能,在2.7-4.3 V电压范围内,0.1C(1.0C=180 m A?g-1)倍率下,首次放电比容量为156.4m Ah?g-1,库仑效率为81.9%.在较高倍率下,即0.5C、5.0C和20C时,其放电比容量分别为136.9、111.3、81.3m Ah?g-1.在1C倍率下100次循环容量保持率为92.9%,高于传统共沉淀法得到的材料(87.0%).
基金supported by the Guangxi Natural Science Foundation,China(Nos.2020GXNSFBA297062,2018GXNSFDA050008,2020GXNSFAA159093)the National Natural Science Foundation of China(No.51761002)the Training Plan of High-level Talents of Guangxi University,China(No.XMPZ160714)。
