We report the lithium ionic conductivities of closo –type complex hydrides synthesized from various molar ratios of lithium borohydride(LiBH4) and decaborane(B10H14) as starting materials. The prepared closo –type c...We report the lithium ionic conductivities of closo –type complex hydrides synthesized from various molar ratios of lithium borohydride(LiBH4) and decaborane(B10H14) as starting materials. The prepared closo –type complex hydrides comprised [B12H12]^2-, [B11H11]^2-, and [B10H10]^2- complex anions. In addition, increasing the LiBH4 content in the starting materials increased the amounts of [B11H11]^2- and [B10H10]^2-, leading to an improved ion conductivity of the prepared sample. The present study offers useful insights into strategies for controlling the complex anion composition in emerging solid electrolytes of closo-type complex hydrides at the molecular level, and improving their ionic conductivities.展开更多
Herein, we developed novel silicon-carbon-nitrogen （SiCN） composites synthesized by pyrolyzing silsesquiazane polymer as an anode material for rechargeable lithium-ion batteries. Among variable pyrolysis temperature...Herein, we developed novel silicon-carbon-nitrogen （SiCN） composites synthesized by pyrolyzing silsesquiazane polymer as an anode material for rechargeable lithium-ion batteries. Among variable pyrolysis temperatures of 700 ℃, 1000 ℃ and 1300 ℃, the SiCN composites prepared at 1000 ℃ showed the highest capacity with outstanding battery cycle life by cyclic voltammetry and electrochemical impedance spectroscopy. Such good battery and electrochemical performances should be attributed to a proper ratio of carbon and nitrogen or oxygen in the SiCN composites. Furthermore, our SiCN electrode possessed better lithium ion conductivity than pure silicon nanoparticles. This work demonstrates that polymer-derived composites are among the promising strategies to achieve highly stable silicon anodes for rechargeable batteries.展开更多
We have prepared a high-density polyaniline（PANI） paste（50 mg/m L）, with similar physical properties to those of paints or pigments. The synthesis of PANI is confirmed by Fourier transform infrared（FT-IR） spectr...We have prepared a high-density polyaniline（PANI） paste（50 mg/m L）, with similar physical properties to those of paints or pigments. The synthesis of PANI is confirmed by Fourier transform infrared（FT-IR） spectroscopy. The morphologies of PANI, doped PANI, and doped PANI paste are confirmed by scanning electron microscopy（SEM）. Particles of doped PANI paste are approximately 40–50 nm in diameter, with a uniform and cubic shape. The electrochemical performances of doped PANI paste using both liquid and solid polymer electrolytes have been measured by galvanostatic charge and discharge process. The cell fabricated with doped PANI paste and the solid polymer electrolyte exhibits a discharge capacity of ～87 μAh/cm2（64.0 m Ah/g） at the second cycle and～67 μAh/cm2（50.1 m Ah/g） at the 100 th cycle.展开更多
基金supported by METX,JSPS KAKENHI (Grant numbers, 16K0 676 6, 17H0 6519, 17K18972, 18H01727, and JP18H05513)Collaborative Research Center on Energy Materials in IMR (E-IMR)Target Project 4 of WPI-AIMR, Tohoku University
文摘We report the lithium ionic conductivities of closo –type complex hydrides synthesized from various molar ratios of lithium borohydride(LiBH4) and decaborane(B10H14) as starting materials. The prepared closo –type complex hydrides comprised [B12H12]^2-, [B11H11]^2-, and [B10H10]^2- complex anions. In addition, increasing the LiBH4 content in the starting materials increased the amounts of [B11H11]^2- and [B10H10]^2-, leading to an improved ion conductivity of the prepared sample. The present study offers useful insights into strategies for controlling the complex anion composition in emerging solid electrolytes of closo-type complex hydrides at the molecular level, and improving their ionic conductivities.
基金supported by the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Ministry of Knowledge Economy (No. 20124030200070), Republic of Korea
文摘Herein, we developed novel silicon-carbon-nitrogen （SiCN） composites synthesized by pyrolyzing silsesquiazane polymer as an anode material for rechargeable lithium-ion batteries. Among variable pyrolysis temperatures of 700 ℃, 1000 ℃ and 1300 ℃, the SiCN composites prepared at 1000 ℃ showed the highest capacity with outstanding battery cycle life by cyclic voltammetry and electrochemical impedance spectroscopy. Such good battery and electrochemical performances should be attributed to a proper ratio of carbon and nitrogen or oxygen in the SiCN composites. Furthermore, our SiCN electrode possessed better lithium ion conductivity than pure silicon nanoparticles. This work demonstrates that polymer-derived composites are among the promising strategies to achieve highly stable silicon anodes for rechargeable batteries.
基金supported by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Korean Ministry of Knowledge Economy and by the Priority Research Centers Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(2009-0093818)
文摘We have prepared a high-density polyaniline（PANI） paste（50 mg/m L）, with similar physical properties to those of paints or pigments. The synthesis of PANI is confirmed by Fourier transform infrared（FT-IR） spectroscopy. The morphologies of PANI, doped PANI, and doped PANI paste are confirmed by scanning electron microscopy（SEM）. Particles of doped PANI paste are approximately 40–50 nm in diameter, with a uniform and cubic shape. The electrochemical performances of doped PANI paste using both liquid and solid polymer electrolytes have been measured by galvanostatic charge and discharge process. The cell fabricated with doped PANI paste and the solid polymer electrolyte exhibits a discharge capacity of ～87 μAh/cm2（64.0 m Ah/g） at the second cycle and～67 μAh/cm2（50.1 m Ah/g） at the 100 th cycle.
