{3-[2-(2-methoxyethoxy) ethoxy]-propyl} triethoxysilane (TESM2) was synthesized and used as an electrolyte additive to improve the performances of lithium-ion batteries (LIBs). The electrochemical properties of the el...{3-[2-(2-methoxyethoxy) ethoxy]-propyl} triethoxysilane (TESM2) was synthesized and used as an electrolyte additive to improve the performances of lithium-ion batteries (LIBs). The electrochemical properties of the electrolyte (1 mol/L lithium hexafluorophosphate (LiPF 6 )/ethylene carbonate (EC):diethylene carbonate (DEC):dimethyl carbonate (DMC), 1:1:1) with different contents of TESM2 were characterized by ionic conductivity measurement, galvanostatic charge/discharge test of graphite/Li half cells, and electrochemical impedance spectroscopy. Both the cycling performances and C-rate capabilities of graphite/Li half cells were significantly improved with an optimized content of 15% TESM2 in the electrolyte. The graphite/Li half cell delivered a very high specific capacity of 370 mAh/g at 0.2C rate without any capacity loss for 60 cycles, and retained a capacity of 292 mAh/g at 2C rate. The solid electrolyte interphase (SEI) film on the surface of the graphite anode was investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), indicating that TESM2 was effectively involved in the formation of SEI film on the surface of graphite.展开更多
The conversion of perhydropolysilazane(PHPS)to silica at low temperature is beneficial for its application on thermally vulnerable substrates.In this work,it is demonstrated that(3-aminopropyl)triethoxysilane(APTES)ha...The conversion of perhydropolysilazane(PHPS)to silica at low temperature is beneficial for its application on thermally vulnerable substrates.In this work,it is demonstrated that(3-aminopropyl)triethoxysilane(APTES)has high catalytic efficiency for the low temperature conversion of PHPS and the catalytic mechanism of APTES was suggested.The influence of temperatu re and humidity on the catalytic conversion process was investigated,and it was found that PHPS can be rapidly converted to silica in 10 min at 80℃with relative humidity of 90%.The achieved silica is mainly composed of SiNO_(3)/SiO_(3)OH and SiO_(4)structure with O/Si of 1.74 and N content of 1%.As an approach to prepare inorganic coating,the low-temperature conversion method achieves a silica coating with low volume shrinkage of 0.86%,low roughness of R_(a)=0.293 nm,high nanoindentation hardness of 3.62 GPa and modulus of 30.06 GPa,which exhibits high potentials as protective coating for va rious materials even those vulnerable to high temperature.展开更多
基金supported by the National Natural Science Foundation of China (No. 50973112)the Hundred Talents Program of the Chinese Academy of Sciences (CAS), the CAS-Guangdong Collaboration Program (No. 20108)+1 种基金the Science & Technology Project of Guangzhou (No. 11A44061500)the Amperex Technology Ltd. (China)
文摘{3-[2-(2-methoxyethoxy) ethoxy]-propyl} triethoxysilane (TESM2) was synthesized and used as an electrolyte additive to improve the performances of lithium-ion batteries (LIBs). The electrochemical properties of the electrolyte (1 mol/L lithium hexafluorophosphate (LiPF 6 )/ethylene carbonate (EC):diethylene carbonate (DEC):dimethyl carbonate (DMC), 1:1:1) with different contents of TESM2 were characterized by ionic conductivity measurement, galvanostatic charge/discharge test of graphite/Li half cells, and electrochemical impedance spectroscopy. Both the cycling performances and C-rate capabilities of graphite/Li half cells were significantly improved with an optimized content of 15% TESM2 in the electrolyte. The graphite/Li half cell delivered a very high specific capacity of 370 mAh/g at 0.2C rate without any capacity loss for 60 cycles, and retained a capacity of 292 mAh/g at 2C rate. The solid electrolyte interphase (SEI) film on the surface of the graphite anode was investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), indicating that TESM2 was effectively involved in the formation of SEI film on the surface of graphite.
基金financially supported by the National Natural Science Foundation of China(No.21872152)Guangdong Natural Science Foundation(No.2019A1515111028)Xiejialin Foundation in the Institute of High Energy Physics(No.E15466U210)。
文摘The conversion of perhydropolysilazane(PHPS)to silica at low temperature is beneficial for its application on thermally vulnerable substrates.In this work,it is demonstrated that(3-aminopropyl)triethoxysilane(APTES)has high catalytic efficiency for the low temperature conversion of PHPS and the catalytic mechanism of APTES was suggested.The influence of temperatu re and humidity on the catalytic conversion process was investigated,and it was found that PHPS can be rapidly converted to silica in 10 min at 80℃with relative humidity of 90%.The achieved silica is mainly composed of SiNO_(3)/SiO_(3)OH and SiO_(4)structure with O/Si of 1.74 and N content of 1%.As an approach to prepare inorganic coating,the low-temperature conversion method achieves a silica coating with low volume shrinkage of 0.86%,low roughness of R_(a)=0.293 nm,high nanoindentation hardness of 3.62 GPa and modulus of 30.06 GPa,which exhibits high potentials as protective coating for va rious materials even those vulnerable to high temperature.
