Perfl uorosulfonic acid/ceramic nanocomposite membranes were investigated as electrolytes for polymer electrolyte membrane fuel cell applications under low relative humidity. Different nanosized ceramics（SiO2, ZrO2, ...Perfl uorosulfonic acid/ceramic nanocomposite membranes were investigated as electrolytes for polymer electrolyte membrane fuel cell applications under low relative humidity. Different nanosized ceramics（SiO2, ZrO2, TiO2） with diameters in the range of 2-6 nm were synthesized in situ in Nafion solution through a sol-gel process and the formed nanosized ceramics were well-dispersed in the solution.The nanocomposite membranes were formed through a casting process. The nanocomposite membrane showes enhanced water retention ability and improved proton conductivity compared to those of pure Nafi on membrane. The mechanical strength of the formed nanocomposite membranes is slightly less than that of pure Nafi on membrane. The experimental results demonstrate that the polymer ceramic nanocompsite membranes are potential electrolyte for fuel cells operating at elevated temperature.展开更多
An iron film percolation system is fabricated by vapour-phase deposition on fracture surfaces of α-Al2O3 ceramics. The zero-field-cooled （ZFC） and field-cooled （FC） magnetization measurement reveals that the magn...An iron film percolation system is fabricated by vapour-phase deposition on fracture surfaces of α-Al2O3 ceramics. The zero-field-cooled （ZFC） and field-cooled （FC） magnetization measurement reveals that the magnetic phase of the film samples evolve from a high-temperature ferromagnetic state to a low-temperature spin-glass-like state, which is also demonstrated by the temperature-dependent ac susceptibility of the iron films. The temperature dependence of the exchange bias field He of the iron film exhibits a minimum peak around the temperature T=5 K, which is independent of the magnitude of the cooling field Hcf. However, for T 〉 10K, （1） He is always negative when Hcf=2kOe and （2） for Hcf= 20 kOe （1Oe≈80 A/m）, He changes from negative to positive values as T increases. Our experimental results show that the anomalous hysteresis properties mainly result from the oxide surfaces of the films with spin-glass-like phase.展开更多
Ceramic electrolytes are important in ceramic-liquid hybrid electrolytes(CLHEs),which can effectively solve the interfacial issues between the electrolyte and electrodes in solid-state batteries and provide a highly e...Ceramic electrolytes are important in ceramic-liquid hybrid electrolytes(CLHEs),which can effectively solve the interfacial issues between the electrolyte and electrodes in solid-state batteries and provide a highly efficient Li-ion transfer for solid–liquid Li metal batteries.Understanding the ionic transport mechanisms in CLHEs and the corresponding role of ceramic electrolytes is crucial for a rational design strategy.Herein,the Li-ion transfer in the ceramic electrolytes of CLHEs was confirmed by tracking the 6Li and 7Li substitution behavior through solid-state nuclear magnetic resonance spectroscopy.The ceramic and liquid electrolytes simultaneously participate in Li-ion transport to achieve highly efficient Li-ion transfer in CLHEs.A spontaneous Li-ion exchange was also observed between ceramic and liquid electrolytes,which serves as a bridge that connects the ceramic and liquid electrolytes,thereby greatly strengthening the continuity of Li-ion pathways in CLHEs and improving the kinetics of Li-ion transfer.The importance of an abundant solid–liquid interface for CLHEs was further verified by the enhanced electrochemical performance in LiFePO4/Li and LiNi0.8Co0.1Mn0.1O2/Li batteries from the generated interface.This work provides a clear understanding of the Li-ion transport pathway in CLHEs that serves as a basis to build a universal Li-ion transport model of CLHEs.展开更多
基金Funded by the Postdoctoral Science Foundation of China(2013M540610)the Hubei Province Scientific Research Projects(D20131601)
文摘Perfl uorosulfonic acid/ceramic nanocomposite membranes were investigated as electrolytes for polymer electrolyte membrane fuel cell applications under low relative humidity. Different nanosized ceramics（SiO2, ZrO2, TiO2） with diameters in the range of 2-6 nm were synthesized in situ in Nafion solution through a sol-gel process and the formed nanosized ceramics were well-dispersed in the solution.The nanocomposite membranes were formed through a casting process. The nanocomposite membrane showes enhanced water retention ability and improved proton conductivity compared to those of pure Nafi on membrane. The mechanical strength of the formed nanocomposite membranes is slightly less than that of pure Nafi on membrane. The experimental results demonstrate that the polymer ceramic nanocompsite membranes are potential electrolyte for fuel cells operating at elevated temperature.
基金supported by the National Natural Science Foundation of China (Grant Nos 10574109 and 50701037)the Zhejiang Provincial Science and Technology Department of China (Grant No 2005C24008)
文摘An iron film percolation system is fabricated by vapour-phase deposition on fracture surfaces of α-Al2O3 ceramics. The zero-field-cooled （ZFC） and field-cooled （FC） magnetization measurement reveals that the magnetic phase of the film samples evolve from a high-temperature ferromagnetic state to a low-temperature spin-glass-like state, which is also demonstrated by the temperature-dependent ac susceptibility of the iron films. The temperature dependence of the exchange bias field He of the iron film exhibits a minimum peak around the temperature T=5 K, which is independent of the magnitude of the cooling field Hcf. However, for T 〉 10K, （1） He is always negative when Hcf=2kOe and （2） for Hcf= 20 kOe （1Oe≈80 A/m）, He changes from negative to positive values as T increases. Our experimental results show that the anomalous hysteresis properties mainly result from the oxide surfaces of the films with spin-glass-like phase.
基金supported by the National Natural Science Foundation of China(U2001220)Key-Area Research and Development Program of Guangdong Province(2020B090919001)+2 种基金Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center(XMHT20200203006)Shenzhen Technical Plan Project(RCJC20200714114436091,JCYJ20180508152210821JCYJ20180508152135822)。
文摘Ceramic electrolytes are important in ceramic-liquid hybrid electrolytes(CLHEs),which can effectively solve the interfacial issues between the electrolyte and electrodes in solid-state batteries and provide a highly efficient Li-ion transfer for solid–liquid Li metal batteries.Understanding the ionic transport mechanisms in CLHEs and the corresponding role of ceramic electrolytes is crucial for a rational design strategy.Herein,the Li-ion transfer in the ceramic electrolytes of CLHEs was confirmed by tracking the 6Li and 7Li substitution behavior through solid-state nuclear magnetic resonance spectroscopy.The ceramic and liquid electrolytes simultaneously participate in Li-ion transport to achieve highly efficient Li-ion transfer in CLHEs.A spontaneous Li-ion exchange was also observed between ceramic and liquid electrolytes,which serves as a bridge that connects the ceramic and liquid electrolytes,thereby greatly strengthening the continuity of Li-ion pathways in CLHEs and improving the kinetics of Li-ion transfer.The importance of an abundant solid–liquid interface for CLHEs was further verified by the enhanced electrochemical performance in LiFePO4/Li and LiNi0.8Co0.1Mn0.1O2/Li batteries from the generated interface.This work provides a clear understanding of the Li-ion transport pathway in CLHEs that serves as a basis to build a universal Li-ion transport model of CLHEs.
