Lithium-sulfur batteries(LSBs)are promising as the next generation energy storage options.However,their wide applications have been technically challenged by the diffusion losses of polysulfides and polysulfide shuttl...Lithium-sulfur batteries(LSBs)are promising as the next generation energy storage options.However,their wide applications have been technically challenged by the diffusion losses of polysulfides and polysulfide shuttle effect.In this work,the small organic molecules of 2,5-dichloropyrazine(2,5-DCP)were combined with Co-doped carbon(CoA NAC)flakes to achieve the synergic effect of the covalent and chemical sulfur fixation,so as that the immobilization-conversion of polysulfides in LSBs was greatly enhanced.More specifically,the nucleophilic substitution of the 2,5-DCP additive in the electrolyte with polysulfides formed the CAS bonds.Through the further covalent N-Li bonds between the N atoms in 2,5-DCP and polysulfides,sulfur fixation was achieved in the form of solid organosulfur.Meanwhile,the CoA NAC flakes served as the sulfur cathode to chemically anchor the polysulfides.The interaction mechanism between CoA NAC/2,5-DCP and polysulfides was explored by the density functional theory(DFT)calculations and in-situ infrared spectroscopy.The results showed that the optimal“with 2,5-DCP”sample-assembled LSB exhibited an initial discharge specific capacity of 1244 mA h g^(-1)at 0.2C,and a capacity decay rate of 0.053%per cycle was displayed after 800 cycles at 1C.The good cycling stability with a high sulfur-loaded electrode sample suggested that the synergic effect of covalent/chemical sulfur fixation enabled the enhancement of polysulfides immobilization-conversion in LSBs.展开更多
To satisfy the requirement on the separation of solid and liquid in waste drilling mud, prepare a high effective floccu-lant for high density waste drilling mud used starch, 2-Trimethylammonium ethyl methacrylate chlo...To satisfy the requirement on the separation of solid and liquid in waste drilling mud, prepare a high effective floccu-lant for high density waste drilling mud used starch, 2-Trimethylammonium ethyl methacrylate chloride (DMC) and acrylamide (AM). The result showed that when the ratio of starch, DMC and AM was 2:1:3, the weight of initiator (po-tassium persulfate) was 0.2% of the AM, reaction temperature was 65℃ and reaction time was 5h, the performance of product was the best. The water content in filter cake was 27.6% after the waste drilling mud disposed by the optimization flocculant. The flocculent effect of optimization flocculant was superior to that of other flocculant in market.展开更多
To satisfy the requirement on solid-liquid separation in high-density waste drilling mud, prepare the nano-modified polyacrylamide(PAM) flocculant for high density waste drilling mud by in-situ dispersion method, dire...To satisfy the requirement on solid-liquid separation in high-density waste drilling mud, prepare the nano-modified polyacrylamide(PAM) flocculant for high density waste drilling mud by in-situ dispersion method, direct dispersion method and simultaneous formation method. The result showed the flocculent effect of nano-modified polyacrylamide prepared by simultaneous formation method was the best. When the content of water glass and acrylamide(AM) were respectively 3% and 15% , reaction temperature was 60?C and reaction time was 3h, the performance of product was the best. The water content in filter cake was 24.32% after the waste drilling mud disposed by the optimization flocculant. The flocculent effect of optimization flocculant was superior to that of other flocculant in market.展开更多
基金the financially supports from the National Natural Science Foundation of China(51963004)the Natural Science Foundation of Shandong Province of China(ZR2020MB024)。
文摘Lithium-sulfur batteries(LSBs)are promising as the next generation energy storage options.However,their wide applications have been technically challenged by the diffusion losses of polysulfides and polysulfide shuttle effect.In this work,the small organic molecules of 2,5-dichloropyrazine(2,5-DCP)were combined with Co-doped carbon(CoA NAC)flakes to achieve the synergic effect of the covalent and chemical sulfur fixation,so as that the immobilization-conversion of polysulfides in LSBs was greatly enhanced.More specifically,the nucleophilic substitution of the 2,5-DCP additive in the electrolyte with polysulfides formed the CAS bonds.Through the further covalent N-Li bonds between the N atoms in 2,5-DCP and polysulfides,sulfur fixation was achieved in the form of solid organosulfur.Meanwhile,the CoA NAC flakes served as the sulfur cathode to chemically anchor the polysulfides.The interaction mechanism between CoA NAC/2,5-DCP and polysulfides was explored by the density functional theory(DFT)calculations and in-situ infrared spectroscopy.The results showed that the optimal“with 2,5-DCP”sample-assembled LSB exhibited an initial discharge specific capacity of 1244 mA h g^(-1)at 0.2C,and a capacity decay rate of 0.053%per cycle was displayed after 800 cycles at 1C.The good cycling stability with a high sulfur-loaded electrode sample suggested that the synergic effect of covalent/chemical sulfur fixation enabled the enhancement of polysulfides immobilization-conversion in LSBs.
文摘To satisfy the requirement on the separation of solid and liquid in waste drilling mud, prepare a high effective floccu-lant for high density waste drilling mud used starch, 2-Trimethylammonium ethyl methacrylate chloride (DMC) and acrylamide (AM). The result showed that when the ratio of starch, DMC and AM was 2:1:3, the weight of initiator (po-tassium persulfate) was 0.2% of the AM, reaction temperature was 65℃ and reaction time was 5h, the performance of product was the best. The water content in filter cake was 27.6% after the waste drilling mud disposed by the optimization flocculant. The flocculent effect of optimization flocculant was superior to that of other flocculant in market.
文摘To satisfy the requirement on solid-liquid separation in high-density waste drilling mud, prepare the nano-modified polyacrylamide(PAM) flocculant for high density waste drilling mud by in-situ dispersion method, direct dispersion method and simultaneous formation method. The result showed the flocculent effect of nano-modified polyacrylamide prepared by simultaneous formation method was the best. When the content of water glass and acrylamide(AM) were respectively 3% and 15% , reaction temperature was 60?C and reaction time was 3h, the performance of product was the best. The water content in filter cake was 24.32% after the waste drilling mud disposed by the optimization flocculant. The flocculent effect of optimization flocculant was superior to that of other flocculant in market.