This paper report the synthesis and properties of a series of composite polymer electrolytes formed by dispersion of a non-ionic organic plastic material SN （succinonitrile） into poly（vinyl alcohol） complexed with...This paper report the synthesis and properties of a series of composite polymer electrolytes formed by dispersion of a non-ionic organic plastic material SN （succinonitrile） into poly（vinyl alcohol） complexed with magnesium acid salt. SEM （scanning electron microscope） images of different SN concentrations of films revealed that large open pore structure were also frequently present, when SN content increase up to 7.5 wt%. The addition of SN greatly enhances ionic conductivities of the electrolytes which is due to the high polarity and diffusivity of SN. The Mg2~ （magnesium ion） ion conduction is confirmed from impedance spectroscopy and transport number measurements. The highest conducting sample in the plasticized system was used to fabricate Mg （magnesium） battery with configuration Mg/SPE/TiO2. The discharge capacity of the fabricated battery was 17.5 mAh/gm.展开更多
Orthorhombic iron-based fluorosulfate KFeSO_(4)F represents one of the most promising cathode materials due to its high theoretical capacity,high voltage plateau,unique three-dimensional conduction pathway for potassi...Orthorhombic iron-based fluorosulfate KFeSO_(4)F represents one of the most promising cathode materials due to its high theoretical capacity,high voltage plateau,unique three-dimensional conduction pathway for potassium ions,and low cost.Yet,the poor thermostability and intrinsic low electronic conductivity of KFeSO_(4)F challenge its synthesis and electrochemical performance in potassium-ion batteries(PIBs).Herein,we report,for the first time,judicious crafting of carbon nanotubes(CNTs)-interwoven KFeSO_(4)F microspheres in diethylene glycol(DEG)(denoted KFSF@CNTs/DEG)as the cathode to render high-performance PIBs,manifesting an outstanding reversible capacity of 110.9 m Ah g^(-1) at 0.2 C,a high working voltage of 3.73 V,and a long-term capacity retention of 93.9%after 2000 cycles at 3 C.Specifically,KFSF@CNTs/DEG microspheres are created via introducing CNTs into the precursors DEG solution at relatively low temperature.Notably,the strong binding of the ether groups in DEG retards the nucleation and growth of KFSF,leading to in situ formation of microspheres with CNTs interwoven within KFSF crystals,thereby greatly enhancing electronic conductivity of KFSF.Intriguingly,the remarkable electrochemical performance of KFSF@CNTs/DEG cathode is found to stem from the massively exposed(100)plane and uniform interpenetration of CNTs inside KFSF microsphere.More importantly,in situ X-ray diffraction and electrochemical kinetics study unveil outstanding structural stability and high K+diffusion rate of KFSF@CNTs/DEG.Finally,the KFSF@CNTs/DEG//graphite full cell displays a large energy density of~243 Wh kg^(-1).Such simple route to KFSF@CNTs/DEG highlights the robustness of creating inexpensive CNTs-interwoven polyanionic cathodes for high-performance PIBs.展开更多
文摘This paper report the synthesis and properties of a series of composite polymer electrolytes formed by dispersion of a non-ionic organic plastic material SN （succinonitrile） into poly（vinyl alcohol） complexed with magnesium acid salt. SEM （scanning electron microscope） images of different SN concentrations of films revealed that large open pore structure were also frequently present, when SN content increase up to 7.5 wt%. The addition of SN greatly enhances ionic conductivities of the electrolytes which is due to the high polarity and diffusivity of SN. The Mg2~ （magnesium ion） ion conduction is confirmed from impedance spectroscopy and transport number measurements. The highest conducting sample in the plasticized system was used to fabricate Mg （magnesium） battery with configuration Mg/SPE/TiO2. The discharge capacity of the fabricated battery was 17.5 mAh/gm.
基金supported by the National Natural Science Foundation of China(22179063 and 22075147)。
文摘Orthorhombic iron-based fluorosulfate KFeSO_(4)F represents one of the most promising cathode materials due to its high theoretical capacity,high voltage plateau,unique three-dimensional conduction pathway for potassium ions,and low cost.Yet,the poor thermostability and intrinsic low electronic conductivity of KFeSO_(4)F challenge its synthesis and electrochemical performance in potassium-ion batteries(PIBs).Herein,we report,for the first time,judicious crafting of carbon nanotubes(CNTs)-interwoven KFeSO_(4)F microspheres in diethylene glycol(DEG)(denoted KFSF@CNTs/DEG)as the cathode to render high-performance PIBs,manifesting an outstanding reversible capacity of 110.9 m Ah g^(-1) at 0.2 C,a high working voltage of 3.73 V,and a long-term capacity retention of 93.9%after 2000 cycles at 3 C.Specifically,KFSF@CNTs/DEG microspheres are created via introducing CNTs into the precursors DEG solution at relatively low temperature.Notably,the strong binding of the ether groups in DEG retards the nucleation and growth of KFSF,leading to in situ formation of microspheres with CNTs interwoven within KFSF crystals,thereby greatly enhancing electronic conductivity of KFSF.Intriguingly,the remarkable electrochemical performance of KFSF@CNTs/DEG cathode is found to stem from the massively exposed(100)plane and uniform interpenetration of CNTs inside KFSF microsphere.More importantly,in situ X-ray diffraction and electrochemical kinetics study unveil outstanding structural stability and high K+diffusion rate of KFSF@CNTs/DEG.Finally,the KFSF@CNTs/DEG//graphite full cell displays a large energy density of~243 Wh kg^(-1).Such simple route to KFSF@CNTs/DEG highlights the robustness of creating inexpensive CNTs-interwoven polyanionic cathodes for high-performance PIBs.
