A composite polymer electrolyte of Polyethylene oxide (PEO) LiClO 4 containing fine Al 2O 3 particles was studied by using differential scanning calorimetry, infrared spectroscopy and electrochemical impedance spectro...A composite polymer electrolyte of Polyethylene oxide (PEO) LiClO 4 containing fine Al 2O 3 particles was studied by using differential scanning calorimetry, infrared spectroscopy and electrochemical impedance spectroscopy. Compared with the polymer electrolyte without Al 2O 3 particles, the glass transition temperature and the degree of crystallinity were decreased, and the room temperature conductivity of PEO LiClO 4 Al 2O 3 composite polymer electrolyte was considerably enhanced. Moreover, the equivalent circuits and the effect of dc potential on impedance spectroscopy were discussed.展开更多
凝胶聚合物电解质(GPE)因其优良的热稳定性和卓越的电化学性能而具备增强锂离子电池性能的潜力,从而受到越来越多的认可.尽管其具有上述优点,但传统GPE的实际应用通常因其溶胀性和有限的机械强度而受到阻碍.为了解决这些问题,本项研究...凝胶聚合物电解质(GPE)因其优良的热稳定性和卓越的电化学性能而具备增强锂离子电池性能的潜力,从而受到越来越多的认可.尽管其具有上述优点,但传统GPE的实际应用通常因其溶胀性和有限的机械强度而受到阻碍.为了解决这些问题,本项研究工作提出了一种通过简单方法构建的刚柔并济的仿生GPE,由聚环氧乙烷(PEO)和聚偏二氟乙烯-六氟丙烯(PVDF-HFP)组成并通过Kevlar纤维织物进行增强.所得的PEO/PVDF-HFP/Kevlar(PPK)GPE表现出2.815 mS cm^(−1)的优异离子电导率和0.571的锂离子迁移数,以及32.59 MPa的超高机械强度.这些特性有助于防止锂枝晶生长并增强LiFePO4电池的电化学性能,从而实现稳定的循环性能.PPK GPE可以为高性能锂离子电池的各种实际应用提供理论基础.展开更多
The polyethylene oxide/succinonitrile/lithium perchlorate(PEO/SN/LiClO4) composite electrolytes with different PEO/SN molar ratios were prepared and their room temperature(RT) ionic conductivities were detected. The i...The polyethylene oxide/succinonitrile/lithium perchlorate(PEO/SN/LiClO4) composite electrolytes with different PEO/SN molar ratios were prepared and their room temperature(RT) ionic conductivities were detected. The influences of phase structure and morphology on ionic conductivity of composite electrolytes were characterized via wide-angle X-ray diffraction and polarized optical microscopy. The results show that with addition of PEO,the spherulitic morphology for plastic crystal phase of SN gradually disappears and the liquid phase of SN as a plasticizer role to PEO starts to appear,which is beneficial to the enhancement of RT ionic conductivity,thus the PEO/SN/LiClO4(molar ratio 50/45/5) sample shows the highest RT ionic conductivity of 1.5×10-3 S/cm. With PEO molar fraction above 50%,the RT ionic conductivity of composite electrolytes decreases due to increasing crystallinity of PEO.展开更多
文摘A composite polymer electrolyte of Polyethylene oxide (PEO) LiClO 4 containing fine Al 2O 3 particles was studied by using differential scanning calorimetry, infrared spectroscopy and electrochemical impedance spectroscopy. Compared with the polymer electrolyte without Al 2O 3 particles, the glass transition temperature and the degree of crystallinity were decreased, and the room temperature conductivity of PEO LiClO 4 Al 2O 3 composite polymer electrolyte was considerably enhanced. Moreover, the equivalent circuits and the effect of dc potential on impedance spectroscopy were discussed.
基金supported by the Huaneng Clean Energy Research Institute Found Project(CERI/TU-23-CERI01).
文摘凝胶聚合物电解质(GPE)因其优良的热稳定性和卓越的电化学性能而具备增强锂离子电池性能的潜力,从而受到越来越多的认可.尽管其具有上述优点,但传统GPE的实际应用通常因其溶胀性和有限的机械强度而受到阻碍.为了解决这些问题,本项研究工作提出了一种通过简单方法构建的刚柔并济的仿生GPE,由聚环氧乙烷(PEO)和聚偏二氟乙烯-六氟丙烯(PVDF-HFP)组成并通过Kevlar纤维织物进行增强.所得的PEO/PVDF-HFP/Kevlar(PPK)GPE表现出2.815 mS cm^(−1)的优异离子电导率和0.571的锂离子迁移数,以及32.59 MPa的超高机械强度.这些特性有助于防止锂枝晶生长并增强LiFePO4电池的电化学性能,从而实现稳定的循环性能.PPK GPE可以为高性能锂离子电池的各种实际应用提供理论基础.
文摘The polyethylene oxide/succinonitrile/lithium perchlorate(PEO/SN/LiClO4) composite electrolytes with different PEO/SN molar ratios were prepared and their room temperature(RT) ionic conductivities were detected. The influences of phase structure and morphology on ionic conductivity of composite electrolytes were characterized via wide-angle X-ray diffraction and polarized optical microscopy. The results show that with addition of PEO,the spherulitic morphology for plastic crystal phase of SN gradually disappears and the liquid phase of SN as a plasticizer role to PEO starts to appear,which is beneficial to the enhancement of RT ionic conductivity,thus the PEO/SN/LiClO4(molar ratio 50/45/5) sample shows the highest RT ionic conductivity of 1.5×10-3 S/cm. With PEO molar fraction above 50%,the RT ionic conductivity of composite electrolytes decreases due to increasing crystallinity of PEO.
