固态锂离子电池以其高的理论比容量与宽的电化学窗口成为替代传统液态锂离子电池的主要研究方向。NASICON型的LATP作为固态电解质中研究较为广泛的种类,其与锂金属电极间的副反应问题制约着LATP未来的发展。本文通过掺杂LiTFSI的环氧树...固态锂离子电池以其高的理论比容量与宽的电化学窗口成为替代传统液态锂离子电池的主要研究方向。NASICON型的LATP作为固态电解质中研究较为广泛的种类,其与锂金属电极间的副反应问题制约着LATP未来的发展。本文通过掺杂LiTFSI的环氧树脂粘结剂表面渗透修复LATP固态电解质表面孔隙,环氧树脂的填充有效减少了Li|LATP界面间的接触面积,延缓了Li|LATP界面间的副反应,LiTFSI的掺杂使环氧树脂粘结剂具有一定的离子导电性,增强了电池的长循环性能。改性后的对称电池在0.1 mA cm−2电流密度下循环超过130 h。在Li|LATP界面间加入PEO凝胶缓冲层后,在0.1 mA cm−2电流密度下稳定循环超过1800 h,全电池稳定循环200次,容量保持率为89%,库伦效率约为100%。展开更多
Organic soft linear actuators were fabricated using galvanostatic electropolymerization of the polypyrrole (PPy) thin film using a methyl benzoate electrolyte solution of N,N-Diethyl-N-methyl-N-(2-methoxyethyl) ammoni...Organic soft linear actuators were fabricated using galvanostatic electropolymerization of the polypyrrole (PPy) thin film using a methyl benzoate electrolyte solution of N,N-Diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide. The electrochemical deformation behaviors of the PPy actuators were investigated in aqueous solutions of an electrolyte, lithium bis (trifluoromethanesulphonyl) imide (LiTFSI) or sodium chloride (NaCl), containing different concentrations of methanol. The actuating strain of approximately 9% was achieved when the actuator was driven by a potential between –1 and 1 V with the potential sweep rate of 10 mV/s corresponding to 0.0025 Hz in the LiTFSI electrolyte containing 40% to 50% of methanol under a load stress of 0.3 MPa. However, the PPy actuator could not catch up with the higher frequency. On the other hand, the PPy actuator caught up with the potential sweep up to 0.1 Hz in the NaCl solutions with a methanol concentration between 40% and 60% with the expense of the actuating strain to approximately 1%.展开更多
To achieve high power conversion efficiency(PCE) and long-term stability of perovskite solar cells(PSCs), a hole transport layer(HTL) with persistently high conductivity, good moisture/oxygen barrier ability, and adeq...To achieve high power conversion efficiency(PCE) and long-term stability of perovskite solar cells(PSCs), a hole transport layer(HTL) with persistently high conductivity, good moisture/oxygen barrier ability, and adequate passivation capability is important. To achieve enough conductivity and effective hole extraction, spiro-OMe TAD, one of the most frequently used HTL in optoelectronic devices, often needs chemical doping with a lithium compound(LiTFSI). However, the lithium salt dopant induces crystallization and has a negative impact on the performance and lifetime of the device due to its hygroscopic nature. Here, we provide an easy method for creating a gel by mixing a natural small molecule additive(thioctic acid, TA) with spiro-OMe TAD. We discover that gelation effectively improves the compactness of resultant HTL and prevents moisture and oxygen infiltration. Moreover, the gelation of HTL improves not only the conductivity of spiro-OMe TAD, but also the operational robustness of the devices in the atmospheric environment. In addition, TA passivates the perovskite defects and facilitates the charge transfer from the perovskite layer to HTL. As a consequence, the optimized PSCs based on the gelated HTL exhibit an improved PCE(22.52%) with excellent device stability.展开更多
The new room-temperature molten salt was prepared based on LiTFSI[LiNC(SO 2CF 3) 2] with OZO(C 3H 5NO 2) which were not reported in literature. Its thermal and electrochemical properties were studied by differential s...The new room-temperature molten salt was prepared based on LiTFSI[LiNC(SO 2CF 3) 2] with OZO(C 3H 5NO 2) which were not reported in literature. Its thermal and electrochemical properties were studied by differential scanning calorimetry, ac impedance spectroscopy and cyclic voltammertry respectively. The results indicated that the structure symmetry of the molecule was depressed and the extent of charges delocalization was expanded, because of introducing oxygen atom of differential electronegativity in OZO molecule. DSC analysis showed that the LiTFSI-OZO molten salt has the excellent thermal stability and its eutectic temperature is below about 223.15 K. Meanwhile, the conductivity of LiTFSI-OZO molten salt at a molar ratio of 1∶4.5 is 0.75×10 -3 S/cm at 298.15 K and 3.50×10 -3 S/cm at 333.15 K. CV analysis showed that the electrochemical window of the sample is about 4 V.展开更多
文摘固态锂离子电池以其高的理论比容量与宽的电化学窗口成为替代传统液态锂离子电池的主要研究方向。NASICON型的LATP作为固态电解质中研究较为广泛的种类,其与锂金属电极间的副反应问题制约着LATP未来的发展。本文通过掺杂LiTFSI的环氧树脂粘结剂表面渗透修复LATP固态电解质表面孔隙,环氧树脂的填充有效减少了Li|LATP界面间的接触面积,延缓了Li|LATP界面间的副反应,LiTFSI的掺杂使环氧树脂粘结剂具有一定的离子导电性,增强了电池的长循环性能。改性后的对称电池在0.1 mA cm−2电流密度下循环超过130 h。在Li|LATP界面间加入PEO凝胶缓冲层后,在0.1 mA cm−2电流密度下稳定循环超过1800 h,全电池稳定循环200次,容量保持率为89%,库伦效率约为100%。
文摘Organic soft linear actuators were fabricated using galvanostatic electropolymerization of the polypyrrole (PPy) thin film using a methyl benzoate electrolyte solution of N,N-Diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide. The electrochemical deformation behaviors of the PPy actuators were investigated in aqueous solutions of an electrolyte, lithium bis (trifluoromethanesulphonyl) imide (LiTFSI) or sodium chloride (NaCl), containing different concentrations of methanol. The actuating strain of approximately 9% was achieved when the actuator was driven by a potential between –1 and 1 V with the potential sweep rate of 10 mV/s corresponding to 0.0025 Hz in the LiTFSI electrolyte containing 40% to 50% of methanol under a load stress of 0.3 MPa. However, the PPy actuator could not catch up with the higher frequency. On the other hand, the PPy actuator caught up with the potential sweep up to 0.1 Hz in the NaCl solutions with a methanol concentration between 40% and 60% with the expense of the actuating strain to approximately 1%.
基金supported by the National Natural Science Foundation of China (21975028, U21A20172 and 22011540377)the Special Key Projects (2022-JCJQ-ZD-224-12)。
文摘To achieve high power conversion efficiency(PCE) and long-term stability of perovskite solar cells(PSCs), a hole transport layer(HTL) with persistently high conductivity, good moisture/oxygen barrier ability, and adequate passivation capability is important. To achieve enough conductivity and effective hole extraction, spiro-OMe TAD, one of the most frequently used HTL in optoelectronic devices, often needs chemical doping with a lithium compound(LiTFSI). However, the lithium salt dopant induces crystallization and has a negative impact on the performance and lifetime of the device due to its hygroscopic nature. Here, we provide an easy method for creating a gel by mixing a natural small molecule additive(thioctic acid, TA) with spiro-OMe TAD. We discover that gelation effectively improves the compactness of resultant HTL and prevents moisture and oxygen infiltration. Moreover, the gelation of HTL improves not only the conductivity of spiro-OMe TAD, but also the operational robustness of the devices in the atmospheric environment. In addition, TA passivates the perovskite defects and facilitates the charge transfer from the perovskite layer to HTL. As a consequence, the optimized PSCs based on the gelated HTL exhibit an improved PCE(22.52%) with excellent device stability.
文摘The new room-temperature molten salt was prepared based on LiTFSI[LiNC(SO 2CF 3) 2] with OZO(C 3H 5NO 2) which were not reported in literature. Its thermal and electrochemical properties were studied by differential scanning calorimetry, ac impedance spectroscopy and cyclic voltammertry respectively. The results indicated that the structure symmetry of the molecule was depressed and the extent of charges delocalization was expanded, because of introducing oxygen atom of differential electronegativity in OZO molecule. DSC analysis showed that the LiTFSI-OZO molten salt has the excellent thermal stability and its eutectic temperature is below about 223.15 K. Meanwhile, the conductivity of LiTFSI-OZO molten salt at a molar ratio of 1∶4.5 is 0.75×10 -3 S/cm at 298.15 K and 3.50×10 -3 S/cm at 333.15 K. CV analysis showed that the electrochemical window of the sample is about 4 V.
