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
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
Poly(ethylene oxide)-based polymer all-solid-state lithium metal batteries(ASSLBs)have received widespread attention due to their low cost,good process ability,and high energy density.Nevertheless,the growth of Li den...Poly(ethylene oxide)-based polymer all-solid-state lithium metal batteries(ASSLBs)have received widespread attention due to their low cost,good process ability,and high energy density.Nevertheless,the growth of Li dendrites within polymer solid-state electrolytes damages the reversibility of Li anodes and still impedes their widespread application.One efficient strategy is to construct a superior solid electrolyte interface.Herein,a stable interface enriched with Li3N and LiF is in-situ formed between Li anode and a terna ry salt electrolyte.This terna ry salt electrolyte is innovatively designed by introducing lithium bis(trifluoromethane sulfonyl)imide(LiTFSI),lithium bis(fluorosulfonyl)imide(LiFSI),and LiNO_(3)to poly(ethylene oxide)matrix.Surface characterization indicates that LiNO3and LiFSI contribute to forming a Li3N-LiF-enriched interface and meanwhile LiTFSI ensures excellent conductivity.Theoretically,among various Li compound components,Li3N has high ionic conductivity,which is beneficial for reducing overpotential,while LiF has high interfacial energy which can enhance nucleation energy and suppress the formation of Li dendrites.The experimental results show that ASSLBs coupled with LiFePO4cathode display extremely excellent cycle stability approximately 2200 cycles at 2 C,with a final and corresponding discharge specific capacity of 96.7 mA h g^(-1).Additionally,a schematic illustration of the working mechanism for the Li_(3)N-LiF interface is proposed.展开更多
To achieve good performance for LiFePO4-based batteries operated at a wide temperature range,mixed salts of LiBF4 LiBOB（lithium bis（oxalato）borate） and LiTFSI（lithium bis（trifluoromethanesulfonyl）imide）-LiBOB ...To achieve good performance for LiFePO4-based batteries operated at a wide temperature range,mixed salts of LiBF4 LiBOB（lithium bis（oxalato）borate） and LiTFSI（lithium bis（trifluoromethanesulfonyl）imide）-LiBOB were investigated as alternative lithium salts to LiPF6 in non-aqueous electrolytes.LiFePO4/Li half cells using LiPF6,LiBF4-LiBOB and LiTFSI-LiBOB slats as lithium salts were investigated by galvanostatic cycling,cyclic voltammetry,thermogravimetric analysis.The results show that LiBF4-LiBOB and LiTFSI-LiBOB mixed salts are much more thermally stable than LiPF6.Corrosion of Al foil in the LiTFSI-based electrolytes can be suppressed successfully by the addition of LiBOB as a co-salt.The electrochemical performance of LiBF4-LiBOB and LiTFSI-LiBOB mixed salts based cells are both better than that of LiPF6-based cell.LiTFSI-LiBOB mixed salt based electrolyte is considered to be a very promising electrolyte candidate for Li-ion batteries that will be used in wide-temperature applications.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
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
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%.
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%。
基金supported by the National Natural Science Foundation of China(nos.22309027 and 52374301)the Natural Science Foundation of Hebei Province(no.E2022501014)+3 种基金the Shijiazhuang Basic Research Project(nos.241790667A and 241790907A)the Fundamental Research Funds for the Central Universities(no.N2423054)the 2023 Hebei Provincial Doctoral Candidate Innovation Ability Training Funding Project(no.CXZZBS2023159)the Performance Subsidy Fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province(no.22567627H).
文摘Poly(ethylene oxide)-based polymer all-solid-state lithium metal batteries(ASSLBs)have received widespread attention due to their low cost,good process ability,and high energy density.Nevertheless,the growth of Li dendrites within polymer solid-state electrolytes damages the reversibility of Li anodes and still impedes their widespread application.One efficient strategy is to construct a superior solid electrolyte interface.Herein,a stable interface enriched with Li3N and LiF is in-situ formed between Li anode and a terna ry salt electrolyte.This terna ry salt electrolyte is innovatively designed by introducing lithium bis(trifluoromethane sulfonyl)imide(LiTFSI),lithium bis(fluorosulfonyl)imide(LiFSI),and LiNO_(3)to poly(ethylene oxide)matrix.Surface characterization indicates that LiNO3and LiFSI contribute to forming a Li3N-LiF-enriched interface and meanwhile LiTFSI ensures excellent conductivity.Theoretically,among various Li compound components,Li3N has high ionic conductivity,which is beneficial for reducing overpotential,while LiF has high interfacial energy which can enhance nucleation energy and suppress the formation of Li dendrites.The experimental results show that ASSLBs coupled with LiFePO4cathode display extremely excellent cycle stability approximately 2200 cycles at 2 C,with a final and corresponding discharge specific capacity of 96.7 mA h g^(-1).Additionally,a schematic illustration of the working mechanism for the Li_(3)N-LiF interface is proposed.
基金Project(2013JSJJ027)supported by the Teacher Research Fund of Central South University,China
文摘To achieve good performance for LiFePO4-based batteries operated at a wide temperature range,mixed salts of LiBF4 LiBOB（lithium bis（oxalato）borate） and LiTFSI（lithium bis（trifluoromethanesulfonyl）imide）-LiBOB were investigated as alternative lithium salts to LiPF6 in non-aqueous electrolytes.LiFePO4/Li half cells using LiPF6,LiBF4-LiBOB and LiTFSI-LiBOB slats as lithium salts were investigated by galvanostatic cycling,cyclic voltammetry,thermogravimetric analysis.The results show that LiBF4-LiBOB and LiTFSI-LiBOB mixed salts are much more thermally stable than LiPF6.Corrosion of Al foil in the LiTFSI-based electrolytes can be suppressed successfully by the addition of LiBOB as a co-salt.The electrochemical performance of LiBF4-LiBOB and LiTFSI-LiBOB mixed salts based cells are both better than that of LiPF6-based cell.LiTFSI-LiBOB mixed salt based electrolyte is considered to be a very promising electrolyte candidate for Li-ion batteries that will be used in wide-temperature applications.
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.
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.
