Lithium carbonate(Li_(2)CO_(3))stands as a pivotal raw material within the lithium-ion battery industry.Hereby,we propose a solid-liquid reaction crystallization method,employing powdered sodium carbonate instead of i...Lithium carbonate(Li_(2)CO_(3))stands as a pivotal raw material within the lithium-ion battery industry.Hereby,we propose a solid-liquid reaction crystallization method,employing powdered sodium carbonate instead of its solution,which minimizes the water introduction and markedly elevates one-step lithium recovery rate.Through kinetic calculations,the Li_(2)CO_(3)solid-liquid reaction crystallization process conforms by the Avrami equation rather than shrinking core model,which means the dissolution rate of Na_(2)CO_(3)is the most important factor affecting the reaction process.The effects of reaction conditions such as temperature and stirring speed on the Li_(2)CO_(3)precipitation behavior were evaluated.The results indicated that temperature is a most essential parameter than other reaction conditions or stirring speed.The exceptional 93%recovery of Li_(2)CO_(3)at 90℃with a remarkable purity of 99.5%was achieved by using 1.2 M ratio of Na_(2)CO_(3)/Li_(2)SO_(4).This method provides a new idea for the efficient preparation of battery-grade Li_(2)CO_(3).展开更多
A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution,and then a hydrothermal process for the precursor was conducted to ...A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution,and then a hydrothermal process for the precursor was conducted to obtain the spherical cobalt carbonate with low sulfur content.The experimental results show that the feeding method,final p H value of the precipitation reaction slurry and the concentration of the cobalt sulfate solution have obvious effects on the sulfur content,morphology and particle size distribution of the precursor.The sulfur content of the precursor is 0.0115 wt.%under the optimized conditions.The hydrothermal treatment with temperatures of 125-150℃can transform the precursor of cobaltous dihydroxycarbonate into spherical cobalt carbonate and decrease the sulfur content to 0.0030 wt.%in the obtained product.展开更多
SP-C was applied for the removal of Cu^2＋ from simulated cobalt sulfate electrolyte containing Co2＋ 50 g/L and Cu2＋ 0.5-2.0 g/L. Experimental conditions included pH of 2-4, temperature of 20-60℃ and contact time o...SP-C was applied for the removal of Cu^2＋ from simulated cobalt sulfate electrolyte containing Co2＋ 50 g/L and Cu2＋ 0.5-2.0 g/L. Experimental conditions included pH of 2-4, temperature of 20-60℃ and contact time of 10-40 min. The investigation demonstrated that SP-C had recommendable efficiency in adsorbing Cu2＋ from the electrolyte with 25- to 100-fold of Co2＋ The optimal adsorption conditions of SP-C were pH of 4, contact time of 30 min and ambient temperature. The study also showed that the loaded resin could be effectively eluted with 2.0 mol/L H2SO4 solution at a contact time of 40 min; the peak concentration of Cu2＋ in the eluate was about 35 g/L. The sorption characteristics of Cu2＋ by SP-C could be described by Langrnuir isotherm and the pseudo second-order kinetic equation. Infrared spectra showed that nitrogen atoms in the functional group coordinated with Cu2＋ to form coordination bands.展开更多
A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yiel...A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yield,at room temperature,without solvent.The catalyst could be recycled six times without a distinct loss of activity.展开更多
Switching the reaction routes in peroxymonosulfate(PMS)-based advanced oxidation processes have attracted much attention but remain challenging.Herein,a series of Co-N/C catalysts with different compositions and struc...Switching the reaction routes in peroxymonosulfate(PMS)-based advanced oxidation processes have attracted much attention but remain challenging.Herein,a series of Co-N/C catalysts with different compositions and structures were prepared by using bimetallic zeolitic imidazolate frameworks based on ZIF-8 and ZIF-67(x Zn/Co-ZIFs).Results show that Co doping amount could mediate the transformation of the activation pathway of PMS over CoN/C.When Co doping amount was less than 10%,the constructed x Co-N/C/PMS system(x≤10%)was singlet oxygen-dominated reaction;however further increasing Co doping amount would lead to the generation and coexistence of sulfate radicals and high-valent cobalt,besides singlet oxygen.Furthermore,the nitrogen-coordinated Co(Co-NX)sites could serve as main catalytically active sites to generate singlet oxygen.While excess Co doping amount caused the formation of Co nanoparticles from which leached Co ions were responsible for the generation of sulfate radicals and high-valent cobalt.Compared to undoped N/C,Co doping could significantly enhance the catalytic performance.The 0.5%Co-N/C could achieve the optimum degradation(0.488 min^(-1))and mineralization abilities(78.4%)of sulfamethoxazole among the investigated Co-N/C catalysts,which was superior to most of previously reported catalysts.In addition,the application prospects of the two systems in different environmental scenarios(pH,inorganic anions and natural organic matter)were assessed and showed different degradation behaviors.This study provides a strategy to regulate the reactive species in PMS-based advanced oxidation process.展开更多
Generally,the metal sulfide itself has poor conductivity,and the volume expansion occurs when it is converted with sodium,which will destroy the integrity of the electrode structure,resulting in poor cycle performance...Generally,the metal sulfide itself has poor conductivity,and the volume expansion occurs when it is converted with sodium,which will destroy the integrity of the electrode structure,resulting in poor cycle performance and rate performance.To solve the problems of low initial coulombic efficiency(ICE)and volume expansion of metal compounds used as anodes in sodium-ion batteries(SIBs).Inspired by nature,the CoSO_(4)/hard carbon/graphene(CHG)fractal structure electrode was designed.Self-fractal structures with electron/ion transport channels and high strain tolerance proved to be an effective strategy to overcome these challenges.The fractal dimension(D)is measured by synchronous Small Angle X-ray scattering,and the D remains stable during charging and discharging.The fractal CHG also showed excellent electrochemical performance,especially 97.4%ICE.Theoretical calculation shows that self-fractal CHG can promote the formation of a thin solid electrolyte interface(SEI).Synchrotron radiation absorption spectrum proved the reaction mechanism of CHG.This study not only proves that cobalt sulfate is a feasible strategy for developing high-performance SIBs anodes but also provides an advanced method for measuring the fractal dimension of energy storage electrode materials.展开更多
Nanocrystalline cobalt coatings were produced from cobalt sulfate based electrolytes by using pulse current electrodeposition technique.The effects of bath composition and electrodeposition condition on current effici...Nanocrystalline cobalt coatings were produced from cobalt sulfate based electrolytes by using pulse current electrodeposition technique.The effects of bath composition and electrodeposition condition on current efficiency,morphology,structure and hardness of the coatings were investigated and the optimum deposition condition was determined.It was found that increment of cobalt sulfate concentration and sodium dodecyl sulfate(SDS)concentration in the bath had a negligible effect on microhardness of the coatings,while they were effective on electrodeposition current efficiency.Adding saccharin to electrodeposition bath decreased crystallite size of hexagonal close-packed(hcp)cobalt films and increased their microhardness without significant effect on current efficiency.Smoother and less defective coatings were also obtained from baths containing SDS and saccharin.The results revealed that both the current efficiency and microhardness were changed by variation of peak current density and duty cycle.Besides change of smooth morphology of the coatings to needle-shaped one,crystallite sizes and preferred orientation also varied with increasing the current density and duty cycle.展开更多
基金Science and Technology Key Project of Anhui Province,China(grant No.2022e03020004).
文摘Lithium carbonate(Li_(2)CO_(3))stands as a pivotal raw material within the lithium-ion battery industry.Hereby,we propose a solid-liquid reaction crystallization method,employing powdered sodium carbonate instead of its solution,which minimizes the water introduction and markedly elevates one-step lithium recovery rate.Through kinetic calculations,the Li_(2)CO_(3)solid-liquid reaction crystallization process conforms by the Avrami equation rather than shrinking core model,which means the dissolution rate of Na_(2)CO_(3)is the most important factor affecting the reaction process.The effects of reaction conditions such as temperature and stirring speed on the Li_(2)CO_(3)precipitation behavior were evaluated.The results indicated that temperature is a most essential parameter than other reaction conditions or stirring speed.The exceptional 93%recovery of Li_(2)CO_(3)at 90℃with a remarkable purity of 99.5%was achieved by using 1.2 M ratio of Na_(2)CO_(3)/Li_(2)SO_(4).This method provides a new idea for the efficient preparation of battery-grade Li_(2)CO_(3).
基金Project(51874372)supported by the National Natural Science Foundation of China
文摘A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution,and then a hydrothermal process for the precursor was conducted to obtain the spherical cobalt carbonate with low sulfur content.The experimental results show that the feeding method,final p H value of the precipitation reaction slurry and the concentration of the cobalt sulfate solution have obvious effects on the sulfur content,morphology and particle size distribution of the precursor.The sulfur content of the precursor is 0.0115 wt.%under the optimized conditions.The hydrothermal treatment with temperatures of 125-150℃can transform the precursor of cobaltous dihydroxycarbonate into spherical cobalt carbonate and decrease the sulfur content to 0.0030 wt.%in the obtained product.
文摘SP-C was applied for the removal of Cu^2＋ from simulated cobalt sulfate electrolyte containing Co2＋ 50 g/L and Cu2＋ 0.5-2.0 g/L. Experimental conditions included pH of 2-4, temperature of 20-60℃ and contact time of 10-40 min. The investigation demonstrated that SP-C had recommendable efficiency in adsorbing Cu2＋ from the electrolyte with 25- to 100-fold of Co2＋ The optimal adsorption conditions of SP-C were pH of 4, contact time of 30 min and ambient temperature. The study also showed that the loaded resin could be effectively eluted with 2.0 mol/L H2SO4 solution at a contact time of 40 min; the peak concentration of Cu2＋ in the eluate was about 35 g/L. The sorption characteristics of Cu2＋ by SP-C could be described by Langrnuir isotherm and the pseudo second-order kinetic equation. Infrared spectra showed that nitrogen atoms in the functional group coordinated with Cu2＋ to form coordination bands.
文摘A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yield,at room temperature,without solvent.The catalyst could be recycled six times without a distinct loss of activity.
基金supported by the National Natural Science Foundation of China(Nos.52100081,51978178,and 51521006)the Department of Science and Technology of Guangdong Province of China(Nos.2021A1515011797,2023A1515012062,2019A1515012044,and 2022A1515010226)+4 种基金the Department of Education of Guangdong Province of China(No.2021KTSCX078)the Program for Innovative Research Teams of Guangdong Higher Education Institutes of China(No.2021KCXTD043)Maoming Municipal Department of Science and Technology of Guangdong Province of China(No.2018S0013)the Key Laboratory of Petrochemical Pollution Control of Guangdong Higher Education Institutes(No.2017KSYS004)the Startup Fund of GDUPT(Nos.2018rc63 and 2020rc041)。
文摘Switching the reaction routes in peroxymonosulfate(PMS)-based advanced oxidation processes have attracted much attention but remain challenging.Herein,a series of Co-N/C catalysts with different compositions and structures were prepared by using bimetallic zeolitic imidazolate frameworks based on ZIF-8 and ZIF-67(x Zn/Co-ZIFs).Results show that Co doping amount could mediate the transformation of the activation pathway of PMS over CoN/C.When Co doping amount was less than 10%,the constructed x Co-N/C/PMS system(x≤10%)was singlet oxygen-dominated reaction;however further increasing Co doping amount would lead to the generation and coexistence of sulfate radicals and high-valent cobalt,besides singlet oxygen.Furthermore,the nitrogen-coordinated Co(Co-NX)sites could serve as main catalytically active sites to generate singlet oxygen.While excess Co doping amount caused the formation of Co nanoparticles from which leached Co ions were responsible for the generation of sulfate radicals and high-valent cobalt.Compared to undoped N/C,Co doping could significantly enhance the catalytic performance.The 0.5%Co-N/C could achieve the optimum degradation(0.488 min^(-1))and mineralization abilities(78.4%)of sulfamethoxazole among the investigated Co-N/C catalysts,which was superior to most of previously reported catalysts.In addition,the application prospects of the two systems in different environmental scenarios(pH,inorganic anions and natural organic matter)were assessed and showed different degradation behaviors.This study provides a strategy to regulate the reactive species in PMS-based advanced oxidation process.
基金supported by Beijing Synchrotron Radiation 1W2A Work Station and 4B9A Work Station in China and was financially supported by National Natural Science Foundation of China(No.52250710161).
文摘Generally,the metal sulfide itself has poor conductivity,and the volume expansion occurs when it is converted with sodium,which will destroy the integrity of the electrode structure,resulting in poor cycle performance and rate performance.To solve the problems of low initial coulombic efficiency(ICE)and volume expansion of metal compounds used as anodes in sodium-ion batteries(SIBs).Inspired by nature,the CoSO_(4)/hard carbon/graphene(CHG)fractal structure electrode was designed.Self-fractal structures with electron/ion transport channels and high strain tolerance proved to be an effective strategy to overcome these challenges.The fractal dimension(D)is measured by synchronous Small Angle X-ray scattering,and the D remains stable during charging and discharging.The fractal CHG also showed excellent electrochemical performance,especially 97.4%ICE.Theoretical calculation shows that self-fractal CHG can promote the formation of a thin solid electrolyte interface(SEI).Synchrotron radiation absorption spectrum proved the reaction mechanism of CHG.This study not only proves that cobalt sulfate is a feasible strategy for developing high-performance SIBs anodes but also provides an advanced method for measuring the fractal dimension of energy storage electrode materials.
文摘Nanocrystalline cobalt coatings were produced from cobalt sulfate based electrolytes by using pulse current electrodeposition technique.The effects of bath composition and electrodeposition condition on current efficiency,morphology,structure and hardness of the coatings were investigated and the optimum deposition condition was determined.It was found that increment of cobalt sulfate concentration and sodium dodecyl sulfate(SDS)concentration in the bath had a negligible effect on microhardness of the coatings,while they were effective on electrodeposition current efficiency.Adding saccharin to electrodeposition bath decreased crystallite size of hexagonal close-packed(hcp)cobalt films and increased their microhardness without significant effect on current efficiency.Smoother and less defective coatings were also obtained from baths containing SDS and saccharin.The results revealed that both the current efficiency and microhardness were changed by variation of peak current density and duty cycle.Besides change of smooth morphology of the coatings to needle-shaped one,crystallite sizes and preferred orientation also varied with increasing the current density and duty cycle.
